SST 201 Mid-Sem Notes
SST 201 Mid-Sem Notes
SST 201 Mid-Sem Notes
SEED
SEED
... is any part (or) organ of plant which has the capability to regenerate a
new plant.
Rapid multiplication
Reasonable price
Seed is the basic input in agriculture upon which other inputs are applied.
A vigorous seed utilizes all the resources and realize a reasonable out put to
the grower.
Seed of food crops including oilseed crops, fruits, vegetables & flowers.
Seedlings, tubers, bulbs, rhizomes, roots, cuttings, all types of grafts and
other vegetatively propagated material.
Grain
Need not be
Not so
No such requirements
No such specifications
No such condition
Not considered
Goal
Rapid multiplication
Timely supply
Assured high quality seed
Reasonable price
Difference between seed and grain production
Seed production
Grain production
Need not be
Need not be
Not so
Not so
Harvestable maturity
Not so
Monsanto
Mahyco
Pioneer
Advanta India
Nath
Cargill
Syngenta
JK Seeds
EID Parry
Indo-American
Ankur
Namdhari Seeds
responsible for poor quality seeds. The contaminants can be classified as genetical
and physical contaminants.
shedders and shedding tassels. Physical contaminants are inseparable other crop
plants, objectionable weed plants and diseased plants. Above mentioned sources of
contaminants are discussed below.
a. Off-types
Off-type is a plant, which differs, in morphological characters from the rest of
the population of a crop variety. Off type does not confirm to the morphological
characters as described by the breeder. Off-type may belong to same species or
different species of a given variety. Off-types are easily identifiable as it deviates
from the given set of morphological characters such as bulb, tuber, root features,
plant, plant type, branching, pigmentation, mottling, hairiness, stem features, leaf
shape and arrangement, colour, shape and size of flower and flower parts and
colour, size and shape of fruit and seed or characteristics such as duration to flower
and maturity, tillering, male sterility, resistance to diseases etc.
Plants of a
seed parent developed from the flowers, which escaped crossing and developed by
self-fertilization and improperly emasculated flowers.
b. Pollen shedders
These are contaminant plants in the production of parental lines and hybrids.
By Exploiting male sterility, (Genetic or Cytoplasmic) male sterile line (Line A),
male fertile maintainer (Line B) and Restorer (Line R) are involved in parental
and hybrid seed production.
A line or male sterile line could not produce mature, reproductive pollen
because of its male sterility. B line or male fertile maintainer resembles A line in
all morphological character, but produces mature viable healthy pollen grains.
When A line and B line are crossed the resultant progeny is male sterile A line.
In hybrid seed production, male sterile A line and R line are allowed to be
crossed and the resulting hybrid is male fertile and produces healthy pollen. Hence,
the presence of B line in the A line (AxB) or (AxR) production is called pollen
shedder. Some times A line tends to exhibit symptoms of fertility on one or more
side tillers or one side or part of an ear head. These plants are also called as pollen
shedders.
c. Shedding Tassels
Tassel is the male or staminate inflorescence at the tip of a maize plant.
Shedding tassel means those plants which shed or shedding pollen in female parent
rows. In counting process sucker tassels, portions of tassels, and tassels on main
plants should be counted as shedding tassel, only when 5 cm or more of the entire
spike, the side branches or a combination of the two have the anthers exerted from
the glumes and are shedding pollen. Tassels, which have exerted, but not yet shed,
are not to be counted, even though these tassels are to be mentioned as Not
similar habit and growth characters, counting is to be taken up along with other
contaminants. Presence of other crop plants in the seed field must be informed to
the producer and asked to remove in time.
Crop designated as inseparable in various seed crops
Crop
Designated inseparable crop plants
Wheat
Barley, Oats, Gram and Triticale
Barley
Oats, Gram, Wheat and Triticale
Oats
Barley, Wheat, Gram and Triticale
Triticale
Wheat, Barley, Oats, Gram and Rye
b. Objectionable weed plants
Weeds whose seeds are difficult to be separated once mixed with crop seed
or which are poisonous or injurious or having smothering effect on the main crop or
are difficult to eradicate once established or are having high multiplication ratio
thus making their spread quick.
Objectionable weed species in crop plants
S.No.
Crop
1.
2.
Paddy
Wheat
3.
4.
Rape
Mustard
Sunflower
5.
6.
7.
Safflower
Berseem
Lucerne
8.
Napier grass
9.
10.
Oats
Bitter gourd
11.
12.
13.
Cucumber
Long melon &
Musk melon
Snake gourd
14.
Water melon
15.
Bhendi
16.
Amaranth
(Tender)
Fenugreek
Lettuce
17.
18.
Canada thistle
Dodder
Jhonson grass
Quack grass
Wild morning glory
Wild oats
Balsam apple
Bhat karela
Jangle karaela
-Weed melon (Takmek)
Non desert forms
--Jangli chachinda
(Rambel)
Wild watermelon
(Indrayan)
Wild okra
Wild amaranth
A. ficulneus (L)
A.manihot (L)
A.moschatus (L)
Amaranthus spinosus
Senji
Wild lettuce
Melilotus spp.
Lactuca scariola L.
Prophylactic control
measures can be applied to prevent and control disease causing pathogens in seed
lots.
In order to produce disease free seeds, some diseases are designated and
Crop
Wheat
Barley
Causal organism
Ustilago tritici
Ustilago nuda
3.
4.
5.
Oats
Triticale
Sorghum
6.
Pearl millet
7.
8.
Greengram
Cowpea
9.
Indian bean
(Lab lab
purpureus)
Cluster bean
10.
11.
Rajmash
(French beans)
12.
13.
14.
Gingelly
Sunflower
Potato
15.
16.
Musk melon
Summer squash
17.
18.
Brinjal
Capsicum
(Sweet pepper)
Tomato
19.
20.
21.
Taro (Arvi)
(Colocasia
esculenta)
Cabbage
Cauliflower
Knolkhol
Loose smut
Ergot
Kernal or Grain smut
Head smut
Ergot
Grain smut
Downy mildew
Hallow blight
Ashy stem blight
Anthracnose
Ascochyta blight
Anthracnose
Ascochyta blight
Bacterial blight
Anthracnose
Asochyta blight
Bean mosaic
Anthracnose
Bacterial blight
Ascochyta blight
Leaf spot
Downy mildew
Brown rot or Bacterial
wilt
Mosaic Virus
Mosaic Virus
Ustilago avenae
Claviceps purpurea
Sphacelotheca sorghi
Sphacelotheca reiliana
Claviceps microcephala
Tolyposporium
pencilariae
T.senegalense
Sclerospora graminicola
Pseudomonas phasiolicola
Macrophomina phaseoli
Colletotrichum lindemuthianum
Ascochyta spp.
Colletotrichum lindemuthianum
Ascochyta spp
and
Xanthamonas campestris
Colletotricum lindemuthianum
Asochyta spp.
Macrosiphum pisi
Colletotrichum lindemuthianum
Xanthamonas spp.
Asochyta phaseolorum
Cercospora sesasmi
Plasmopara halstedii
Pseudomonus solanacearum
Phomopsis blight
Leaf blight
Anthracnose
Early blight
Leaf spot
Virus
Phytophthora disease
Mosaic virus
Blackleg
Blackrot
Soft rot
Leptosphaeria maculans
Xanthomonas campestris
Erwinia carotovora
ABIOTIC FACTORS
1. Agro-climatic conditions
Regions of moderate rainfall and humidity are much more suited to seed
production than regions of high rainfall and high humidity. Too high temperatures,
very cold temperatures and excessive dew and temperatures during flowering and
pollination affect the normal pollination and pollen fertility resulting in poor seed
set. High humidity followed by high temperature result in the production of
bleached or blonded or dimpled seeds. Excessive and continuous rainfall leads to
a higher incidence of diseases and makes seed harvesting extremely difficult. It
also results in delayed maturity and harvesting, which leads to pre-germination in
standing crops, shattering loss and reduction in the seed quality.
Some adverse influence of climatic conditions on crop seeds
Symptom
Blackening of seed due to black
mould
Tip sterility (Low seed set)
Off coloured seed
Mottled seed
Crop
Cumbu, sorghum
Insitu germination
Pseudo styled flowers
Groundnut
Brinjal
Tomato
Vegetable (tomato,
chillies, brinjal)
Bhendi
Cumbu
Pulses
Peas
Climatic factor
Rainfall or high humidity
at maturation
Heavy wind at flowering
Rainfall at maturation
High humidity at
maturation
Rainfall at harvest
High temperature at
flowering
Rainfall at harvest
Rainfall at maturation
Rainfall at maturation
2. Soil condition
Poor soil is associated with salinity, water logging and poor aeration. High pH
induces seed dormancy. In low pH soils plant growth is inhibited by too high
concentrations of Al-ions in the soil solution. If Al-toxicity is more severe, lesser will
be the availability of other nutrients. High salt concentrations in the soil reduced
availability of soil water and impose osmatic stress on the plant. Symptoms of salt
injury are growth reduction and in severe cases, leaf necrosis.
High fertile soil with good aeration and drainage should be selected for seed
production purpose. Seed production in problem soil is not advisable because it
results in the production of poor quality seed. The problems arises due to seed
production in problem soil are as follows,
Infertile pollen
3. Season
Normally the season in which the seed multiplication is to be taken should
result in high quality seeds. Therefore, the seed production programme should be
planned accordingly to suit the season for the proposed crop varieties / hybrids so
as to get highest percentage of seed set and seed maturity. Keeping the duration
of the variety in mind, the crop should be raised in such a way that the peak
flowering time will coincide with clear sunlight, dry humidity and will not be during
rainy period. So optimum and correct season should be selected for seed crops to
avoid adverse climatic conditions and pests and diseases attack problems. Raising
sunflower in October-November is found to reduce the oil content of seed. March
sowing produced high quality seed. October November sowing is the best for seed
production in cereal and millets.
4. Cultural practices
a. Seed treatment
Seed treatment should be made before sowing for speedy germination and
quick establishment of seedling. Fungicides like Thiram or Captan may be used @ 2
g / kg of seed as dry dressing or slurry treatment to check seed borne diseases.
Treatment with biofertilizers like Azospirillum and Rhizobium should be given to the
seeds of all crops as per recommendation for early vigorous growth. Pre-sowing
seed treatment with chemicals, major and micronutrients and growth regulators
increased the growth, flowering, seed set, yield, germinability, vigour and storability
of seeds.
b. Nutrition
Balanced
and
timely
application
of
optimum
doses
of
major
and
which in turn increases the germinability and vigour. Similarly phosphorus and
potassium increases the germinability, vigour and storability of seeds.
Application of micronutrients is also advocated to improve the flowering, seed
setting and seed yield. For, application of zinc sulphate at 25 kg / ha to rice is
recommended for seed crops to increase the flowering and seed set. Foliar spraying
of 1% ferrous sulphate to paddy 0.1% boric acid to groundnt and 20 ppm
naphthalene acetic acid (planofix) to vegetables, are in practice for maximisign the
yield and quality of seeds. Iron deficiency in soil was found to induce female
sterility in crops. In sorghum hybrid seed production, foliar spraying of 0.2% urea
and 200 ppm GA hasten the flowering in female parent in order to achieve
synchronization.
To produce super elite seedlings in paddy, application of diammonium
phosphate @ 2 kg / cent in the nursery is advocated. Gypsum application at 500 kg
/ ha for paddy is recommended to increase the yield. For groundnut, 200 kg
gypsum / ha is recommended for uniform filling of pods which resulted in kernel
size increase.
c. Irrigation management
Moisture stress during critical or sensitive stages of crop growth has
adversely reduced the yield and quality of seeds. So, sufficient or optimum
irrigation is needed during vegetative, flowering, seed formation and development
stages to increase the yield and quality of seeds. Experiments conducted with
various irrigation levels for paddy, sorghum and chillies revealed that optimal
irrigation level recorded higher seed yield compared to sub-optimal irrigation.
d. Weed management
Weeds not only reduce the yield but also affect the quality of seeds. In seed
production, it causes mechanical mixture with crop seeds thereby it interferes in
seed processing, seed certification, seed testing etc. the following are some
examples of objectionable weeds.
Crop
Paddy
Sorghum
Objectionable weeds
Wild rice Oryza sativa L. Var. fatua prain
Johnsons grass Sorghum halepense (L) (Pers.)
Sunflower
Bhendi
Therefore, suitable care must be taken to eradicate these weed plants form
the seed plots. For paddy, application of butachlor @ 2.5 litre / ha at 3-5 th day after
transplanting control the weeds. Spraying of Atrazine at 625 g/ha on 2 nd or 3rd day
after sowing is recommended for cholam. For vegetables, spraying of Lasso or
Basalin at 2.5 litre / ha after sowing irrigation is recommended to control the weed
population.
e. Plant Protection
Successful disease and insects control is another important factor in raising
healthy seed crops. Apart from reduction in yield, the quality of seeds from
diseased and insect damaged plants is invariably poor. The marketability of seeds is
also affected by the presence of discoloured and diseased seeds. Pre-sanitation
spray is also recommended to reduce the insect and pathogen load at field level so
that the multiplication of the same at storage is prevented.
f. Roguing
Adequate and timely roguing is extremely important in seed production.
Removal of off types, rogues, pollen shedders, volunteer plants, objectionable
weeds, insect disease and virus infected plants must be done at every stage of crop
growth namely vegetative, flowering and harvesting to avoid genetic and physical
contaminations.
g. Post-harvest technology of seeds
The seed corps should be harvested at optimum stage when the seed will
have maximum germinability and vigour and minimum moisture. Then, they should
be dried safely and cleaned. Suitable sieves and methods are followed for
processing of seeds to get uniform size and physically pure seeds which fetches
high prices in the market. Before distribution of seeds, the seeds should be treated
with suitable fungicides and insecticides and packed in suitable containers of
prescribed size.
5. Seed storage environment
b. FOUR - Generation model Breeder seed - Foundation seed (I) Foundation seed
(II) Certified seed
c. FIVE - Generation model -Breeder seed - Foundation seed (I)- Foundation seed
(II) Certified seed (I) - Certified seed (II)
For most of the often cross pollinated and cross pollinated crops 3 &4
generation models is usually suggested for seed multiplication .e.g. Castor, Red
gram, Jute, Green gram ,Rape, Mustard ,Sesame , Sunflower & most of the
vegetable crops.
Classes of seed
The four generally recognized classes of seeds are: Breeder's seed,
foundation seed, registered seed and certified seed. The Association of Official Seed
Certifying Agencies (AOSCA) has defined these seed classes as follows:
a) Breeder's seed: The seed or vegetatively propagated material directly
controlled by the originating or the sponsoring breeder or institution, providing for
the initial and recurring increase of foundation seed.
b) Foundation seed: The seed stock handled to maintain specific identity and
genetic purity, which may be designated or distributed and produced under careful
supervision of an agricultural experiment station. This seed is the source of all other
certified seed classes either directly or through registered seed.
c) Certified seed: The progeny of foundation, registered or certified seed that is
handled so as to maintain satisfactorily genetic identity and purity and that has
been approved and certified by the certifying agency.
CERTIFIED SEED
11. Shall be the progeny of the foundation seed
22. Its production is so handled to maintain genetical identity and physical purity
according to standards specified for the crop being certified
33. It should have the minimum genetical purity of 99%
14. Certified seed may be the progeny of certified seed , provided this reproduction
does not exceed two generations beyond foundation seed and provided that if
certification agency determines the genetic and physical purity, if not be
significantly altered
5. In case of highly self pollinated crops certification of one further generation may
be permitted
Generation system of seed multiplication and quality control (notified
varieties and hybrids)
Class of
seed
Nucleus
seed
Breeder
seed
Foundation
seed
Agency
Concerned breeder
or sponsoring
institution breeding
Breeder himself
Concerned breeder
or sponsoring
institution
State seed National
Seeds corporation
Certification seed
Cooperative and
Private sectors
Certified
seed
Truthful
labeled
seed
Tag
colour
No tag
Golden
yellow tag
White tag
Opal green
Azhur blue
tag
3. Mutations
4. Natural crossing
5. Minor genetic variations
6. Selective influence of diseases
7. The technique of the plant breeder
Of these, mechanical mixtures, natural crossing and selective influence of
diseases are perhaps the most important reasons for genetic deterioration of
varieties during seed production, followed by raising the seed crops in areas outside
their adaptation which may cause developmental variations and genetic shifts in
varieties.
1. Developmental variations.
When the seed crops are grown in difficult environment, under different soil
and fertility conditions, or different climatic
3. Mutations.
This is not a serious factor of varietal deterioration. In the majority of the
cases it is difficult to identify or detect minor mutations. The mutants such as
fatuoids in oats, rabbit ear in peas should however, be removed by roguing from
seed plots to purify the seeds. In the case of vegetatively propagated crops,
periodic increase of true to type stock would eliminate the deteriorating effects of
mutations.
4. Natural crossing.
In sexually propagated crops, natural crossing is another most important
source of varietal deterioration due to introgression to genes from unrelated stocks
which can only be solved by prevention. The extent of varietal contamination,
however, depends upon the amount of natural cross-fertilization. The deterioration
in varieties due to natural crossing occurs due to the following three reasons:
1. Natural crossing with undesirable types.
2. Natural crossing with diseased plants.
3. Natural crossing with off-type plants.
In predominantly self-fertilised crops, natural crossing, there fore, is not a
serious source of contamination and variety. Deterioration unless the variety is male
sterile and is grown in close proximity to other varieties. On the other hand, natural
crossing is the major source of genetic contamination and variety deterioration in
cross-fertilised or often cross-fertilised crop species. According to Bateman (1947)
the extent of genetic contamination in seed fields due to natural crossing depends
upon the following factors:
(a) The breeding system of species.
(b) Isolation distance.
(c) Varietal mass.
(d) Pollinating agent.
As the isolation between varieties is increased, the contamination generally
decreases, although there may be small amounts of contamination over wide
distances. Isolation of seed crops therefore is a primary factor in the seed
production of crop plants cross-fertilised by wind or insects. The extent of
In addition to the factors discussed above, other factors, such as, break
down in male sterility, certain environmental conditions, and other heritable
variations may considerably lower the genetic Purity.
Maintenance of Genetic Purity during Seed Production
The methods suggested by Home (1953), and Hartmann and Kester (1968)
may be used wholly or in part to maintain high levels of genetic purity during seed
production.The various steps suggested by Home (1953), to maintain varietal
purity, are as follows:
1. Use of approved seed only in seed multiplications.
2. Inspection and approval of fields prior to planting.
3. Field inspection and approval of growing crops at critical stages for verification
of genetic purity, detection of mixtures, weeds, and for freedom from noxious
weeds and seed-borne diseases, etc.
4. Sampling and sealing of cleaned lots.
5. Growing of samples of potentially approved stocks for comparison with authentic
stocks.
The
by
for
(c) Isolation. The isolation of seed crops from various sources of contamination is
also a necessary requirement for raising seed crops. Contamination may be due to
natural crossing with other varieties grown alongside and off-types present in the
seed field; contamination due to mechanical mixtures at the time of sowing,
harvesting, threshing, processing and handling of seeds; and, contamination due to
seed-borne diseases from nearby fields. Protection from these sources of
contamination is necessary for maintaining genetic purity and the good quality of
the seed.
(d) Roguing of Seed Fields. The existence of off-type plants, i.e., plants differing
in their characteristics from those of the seed variety is another potent source of
genetic contamination. Al though a low percentage of such plants may not seriously
jeopardise the genetic purity of the variety, their continued presence would
certainly deteriorate the genetic purity of the variety. The removal of such plants is
referred to as roguing.
Three main sources of off-types
after harvesting to verify quality, and at the processing plants draw samples for
seed testing and sometimes for grow-out tests also. The genetic purity of seed is
thus assured if the certification agency has approved the seed.
(f) Grow-out Tests. Varieties being grown for seed production are to be
periodically tested for genetic purity by grow-out tests, to make sure that they are
being maintained in their true form.
SEED MULTIPLICATION RATIO
It is nothing but the number of seeds to be produced from a single seed
when it is sown and harvested. According to expert group on seeds (1989), the
seed multiplication ratio for different crops are as follows.
CROP
Wheat
Paddy
SMR
1:20
1:80(Variety)
1:100 (Hybrids)
Maize
1:100( Hybrids)
1:80 (Varieties)
Sorghum
1:100
Bajra
1:200
Ragi
1:80
Gram
1:10
Lack gram
1:40
Green gram
1:40
Cowpea
1:40
Horse gram
1:40
Moth bean
1:40
Red gram
1:100
Colecrops
1:433
Potato
1:4
Ground nut
1:8
Mustard & rape
1:100
Soy bean
1:16
Sunflower
1:50
Sesame
1:250
Safflower
& 1:60
castor
CROP
Cotton
Jute
Mestha
Sun hemp
Berseem
Lucerne
Oats
Bhendi
Tomato
Brinjal
Chilies
Watermelon
Pumpkin
Bitter guard
Bottle guard
Ridge guard
Cucumber
French bean
Clusterbean
Peas
Onion
Radish
Carrot
SMR
1:50
1:100
1:40
1:30
1:10
1:25
1:15
1:100
1:400
1:450
1:240
1:100
1:160
1:41
1:99
1:83
1:200
1:9
1:50
1:19
1:171
1:100
1:83
Price of seed
Availability of certified seed
Limited choice of varieties
Lack of awareness among farmers about the use of quality certified seeds
N.S
B.S
F.S
Commercial -
C.S
C.S
The
isolation of a seed crop is usually done by providing distance between seed fields
and contaminating fields.
Types of isolation
Physical or distance isolation expression is in meters.
Time isolation taking up of sowing in different dates (ie) 30 days for most of
the crops except in crops having indeterminate growth habit.
Barrier isolation if the above said isolation is not possible we can go for
barrier isolation by erecting tall shelter trees.
Physiological isolation differ in flowering due to change in altitude.
8. Pre-sowing treatment
Seeds should be appropriately treated.
Leaching
Chemical treatment
stratification
Line
sowing is advisable for seed crop adopting correct spacing then only we can
achieve required population producing equal opportunity to each plant to
develop and mature which is not possible in broadcasted crop.
10.
Time of planting
Should be in the proper time.
11.
12.
Depth of sowing
13.
14.
Rogueing spacing
B.S
F.S
C.S
Irrigation
Life irrigation and at critical stages depending upon the crop. Irrigate plot by
plot and not to plot to plot.
15.
Gap filling
Gap filling within 7-10 days beyond means the maturity will be different and
harvesting is difficult.
16.
Rogueing
It should be at vegetative, pre-flowering, flowering, pre-harvest and harvest
stages based on morphological characters.
17.
Weeding
Either manually or by using chemical means.
19.
20.
21.
22.
Seed storage
The type of container, duration of storage, type of seed, chemical
2.
Time isolation taking up of sowing in different dates (ie) 30 days for most
of the crops except in indeterminate growth crops.
3.
Time isolation
Raising the crop by staggered sowing so that synchronization of flowering
and pollination in seed crop and the contamination is prevented.
Normally one
month is the time isolation given for agricultural crops but not in crops having
indeterminate growth.
Factors influencing isolation distance
1. Pollination behaviour of crop
Wind velocity
If insect
3. Pollen characters
Viability of pollen.
Weight of pollen.
Time of anthesis.
inbreds require
more I.D.
F.S
C.S
I. MALE SERILITY
Genetic male sterility (GMS)
Also known as nuclear male sterility as it is controlled by nuclear genes.
Genetic male sterility is governed by a single recessive gene msms. Male sterile
lines may be maintained by crossing it with heterozygous (Msms) male fertile
plants. Such mating produces 1: 1 male sterile and male fertile plants.
Maintanance of male sterility
msms x Msms
ms
Ms
msms x MsMs
ms
Msms
- All fertile
Msms : msms
1
Fertile : Sterile
For hybrid seed production, progeny from msms x Msms crosses are used as
female and are interplanted with a homozygous male fertile (MsMs) pollinator. The
female line would contain both male sterile and male fertile plants, and later male
fertile plants must be removed before shedding pollen. Removal of fertile plants is
the limiting factor and laborious process.
cotton and sunflower because of this problem it could not be utilized. It is practiced
in redgram hybrid seed production.
Cytoplasmic male sterility (CMS)
This type of male sterility is determined by the
cytoplasm and progeny of such male sterile lines
would always be male sterile. CMS may be utilized
for producing hybrid seeds in certain ornamental sps
or in sps where vegetative part is of economic
values. But, in those crop plants where seed is the
economic part, it is of no use because the hybrid
progeny would be male sterile.
The plant would be male sterile in the presence of male sterile cytoplasm if
the nuclear genotype were rr. But would be male fertile, if the nucleus were Rr or
RR. The fertility restorer gene R is dominant and this gene restores male fertility in
male sterile lines hence, it is known as restorer gene.
Environmental sensitive GMS (ESGMS)
Male sterility occurs depends on photoperiod and temperature. It is otherwise
called as two line breeding system. This system involves two lines i.e., male
sterile line and pollinator line. Seed production is easy and economical.
This type of system is utilized in rice. The first report on a photoperiod
sensitive male sterile mutant in rice Nong- ken 58s came from China in 1973
(Shi, 1981, Shi and Deng, 1985). The maintenance of purity of ESGMS line is very
important and much more critical than the 3 line breeding system.
Advantages
Classification of ESGMS
1.
length of more than 13 hours while flower transfer into male fertile when day length
is less than 10hours. The day length between the critical sterility point and critical
fertility point is the transition phase where the plants are partially fertile. Eg. of
PGMS lines are Nong-ken 58s, 7001s in rice
2.
C is critical
sterile point above which the plants will be sterile and 24 0 C or below plants will be
fertile. Eg. For TGMS lines are Annong s, Hennong s, Novin PL 12 and IR 68945
3.
2.
3.
Disadvantages:
1.
2.
3.
4.
Phytotoxicity
5.
Carcinogenic
6.
Crops
Rice, rape
2. Dalapon
Cotton, pearlmillet,
Wheat, linseed
3. Ethepon (2-chloromethyl phosphonic acid)
Sunflower
Maize
6. 1-0-methyl threonine
Cotton
Sorghum
Male Parent
Male sterility
Plant height
Lodging resistant
Fertility restoration
Somatic embryogenesis
Commercial hybrids produced in some of the crop species
1. Single cross (AxB) in case of Bajra, Brinjal, Carrot, Castor, Chillies, Cotton,
Cucurbits, Onion, Sorghum, Tobacco, tomato, Water melon, Wheat
2. Double cross (AxB) x (CxD) in case of Maize, Sugarbeet
3. Three way cross (AxB) x C in case of sweet maize
4. Double Top cross (AxB) x OPV in case of maize
5. Triple cross (AxB)xCx(DxE)xF in case of cabbage
6. All types of hybrid can be found in potato and sugarcane etc.
SEED PRODUCTION TECHNIQUES IN RICE VARIETIES AND HYBRIDS
Paddy is a self-pollinated crop with cross-pollination upto 0-4%. The flower
opening starts from the tip of the primary and secondary branches and proceeds
downwards. Normally 6-8 days are required to complete flowering in a panicle.
Under normal condition flower opening is between 7 to 10 a.m. The flower remains
open for 10 minutes and afterwards it closes. The dehiscence of anthers is
independent of spikelet opening. The dehiscence may take place before opening up
of flowers or after flower opening. The stigma is receptive for 3 days and pollen
grains viable for 10 minutes.
Methods of seed production
a. Varieties
The crop is raised in isolation and seeds are allowed to set by self pollination.
Nucleus seeds are raised in ear to row method under isolation. The rows containing
off types are removed. Very true to type earheads are marked and harvested
separately and issued for further multiplication.
b. Hybrids
In India, the first hybrid was released in 1994 at TNAU, Coimbatore CORH 1
(MGR). In Tamil Nadu, 4 hybrids have been released (CORH 1, CORH 2 and ADTRH
1 and CORH 3). The tool involved in hybrid seed production is known as cytoplasmic
genic male sterility. It is a 3 line breeding system, where three lines A, B and R
lines are involved. In hybrid seed production programme, particularly in breeder
seed and foundation seed stages, A line is multiplied with the use of B line and is
produced in isolation from R line, which is multiplied as that of a variety. In certified
seed production, A line and R line are crossed to produce actual hybrid.
Season
Kharif
Rabi
Topographic features like hills, wood lot, vegetative barrier like maize,
sesbania, sugarcane etc., to a distance over 30 m and artificial obstacles (plastic
sheets above 2 m in height) will provide better isolation.
Season and sowing (Rice seasons of Tamil Nadu)
Season
Navarai
Sornavari,
Early
kar
Kar
Kuruvai
Early samba
Samba
Late
samba
/
Thaladi
/
Pishanam
Late thaladi
Seed rate
Varieties
Hybrids
Month of sowing
December - January
April - May
May - June
June - July
July- August
August
September - October
October-November
Short duration
Medium duration
Long duration
: 60 kg /ha
: 40 kg /ha
: 30 kg /ha
A line
B and R lines
: 20 kg /ha
: 10 kg /ha
Upgrading of seeds
Upgrade the seeds before sowing by density grading using common salt
solution having a specific gravity of 1.13 (1.5 kg of salt in 10 liters of water) and
collect only the heavy seeds that sink at the bottom.
Presowing seed hardening treatment
The paddy seeds are soaked in 1% KCl solution for 10 hours in 1:1 ratio.
Then they are dried back to original moisture content (11-12%). Then the seeds
are treated with Captan/Thiram @ 4g Kg -1 and also with Azospirillum/ Azatobacter
@ 3 pockets/acre seeds.
To raise wet nursery, the rice seeds should be pregerminated as the seeds
will not germinate in the waterlogged anaerobic condition since oxygen is very
essential for germination, which is not available in the submerged condition. For
pregerminating, the seeds are soaked overnight in loosely tied moist gunny bags.
Then the gunny bags are tied tightly with thread. These bags are incubated in dark
for 24 hours. The emerged plumule can be seen as white dots on the gunny bags
after 24 hours.
Dormancy breaking treatment
Seeds may be soaked in 0.18 con. HNO 3 (240 ml in 45 liters of water) at 1:1
equal volume for 12 - 16 hours. The seeds may then be air dried to original
moisture.
Nursery management
For hybrid seed production female and male nurseries should be raised
separately. Sparse sowing in nursery beds @ 1 kg cent -1 should be practiced to get
robust seedlings.
Application of DAP @ 2 kg cent-1 as basal in the nursery will ensure robust
seedlings with 2-3 tillers at the time of planting.
Seedlings of 20 - 25 days old have to be planted (hybird). Varieties: short
duration 18-22 days medium duration 25-30 days and long duration 35-40 days.
Staggered sowing of parents for synchronization
As the seed set on CMS line depends on cross pollination it is most important
to synchronize the heading date of the male and female parents, especially for the
hybrid combinations having parents with quite different growth duration. In
addition, in order to extend the pollen supply time, the male parent is usually
seeded twice or thrice at an interval of 4-5 days.
The following 3 methods can be used to determine the differences in
seedlings date for synchronization between male and female parents.
1. Growth Duration Difference (GDD) method
2. Leaf Number Difference (LND ) method
3. Effective Accumulated Temperature (EAT) method
Among these 3 methods though the LND method is more reliable one, the
GDD method is mostly followed since it is rather simple and easy to adopt. In GDD
method by checking the previous data on the difference in duration from seedling to
heading between male and female parents, the proper seeding date of both parents
in current season can be determined. This method is suitable in seasons or regions
where the temperature fluctuation is small.
Staggered seeding of R line for synchronization.
1. Single seeding of R line
2. Two seeding of R line
3. 3 seeding of R line.(Refer class notes)
Planting ratio
8:2 or 10:2
A
x
x
x
x
x
x
x
x
A
x
x
x
x
x
x
x
x
A
x
x
x
x
x
x
x
x
A
x
x
x
x
x
x
x
x
A
x
x
x
x
x
x
x
x
A
x
x
x
x
x
x
x
x
A
x
x
x
x
x
x
x
x
A
x
x
x
x
x
x
x
x
x
x
R
R
A
30 cm
20 cm
x
x
A
x
x
x
x
A
A
15 cm
x
x
A
Wind direction
x
x
A
x
x
A
x
x
A
R
30 cm
Make a longitudinal slit from the base upto the top of the tiller
Supplementary pollination
Natural outcrossing was recorded less than 10% by Ramlingam et al. (1994).
However, this depends upon the wind direction and its velocity. Shaking the R line
panicles by rope pulling at panicle level or rod driving during anthesis can make
their anthers dehisce and spread the pollen widely and evenly thus the outcrossing
rate could be increased. It is more effective especially on calm or breezy days.
Generally, supplementary pollination is carried out at 30 minutes interval for
5 times daily both morning and evening during peak anthesis (10-12 am and 2-4
p.m.) until no pollen remains on the R line. It is not needed when the wind is
greater than moderate breeze.
Fertilizers
Short duration varieties
Hybrid
Medium duration
"
80 "
"
100 "
Roguing
Remove the undesirable plants either in A or R line rows that differ from plants
that are true to type. The pollen shedders and off types are removed.
The undesirable plants come from many sources. They may be volunteer plants
from the previous cropping.
The most important stages for roguing are at maximum tillering, at flowering
and just before harvesting.
Roguing in hybrids
In A line remove pollen shedders. In A line only 40-50% of seed set is possible.
If > 60-70% seed is noticed and the panicle is drooping it would be R line (or) other
varieties.
Harvesting, threshing & drying
Turning of 90% green seeds to straw yellow colour is the stage of physiological
maturity i.e 28 days after 50% flowering in short and 31 days in medium and 35 in
long duration. Moisture content will be 17-20%.
Grading
Size of seed
Sieve size
Long slender
Slender -
= 1/15 x 3/4"
Medium slender
Short bold
"
Seed treatment
Seeds are treated with thiram / captan @ 4 g/kg. Or with 5 gm halogen
mixture. The halogen mixture is prepared by mixing CaOCl 2 + CaCO3 for 1 week in
air tight container.
Storage
For short term storage, use gunny bag or cloth bag. For long term storage
use polythene bag of > 700 gauge and dry the seeds to 8% moisture content.
When compared with varieties, the hybrids and parental lines A & B lines are poor
in storability. The order of the storage potential is R > F1 > B > A.
1. Inbreds
2. Composite,
400
400
Spacing
Seeds are sown in ridges and furrows
Varieties
45 x 10 cm
Hybrids
60x 25 cm
Seed rate
Varieties
: 20 kg /ha
Hybrids
Planting ratio
Single cross
4:2
Double cross
6:2
3 way cross
6:2
Border rows a. Inbreds
b. Others
Seed treatment
1.Treat the seeds with carbendazim or thiram @ 2g/kg seeds
2. After 24 hours treat the seeds with azospirillum 600 gm.
Fertilizers(varieties) 150:75:75
Basal 40:75:40 NPK kg/ha
1st top 20 DAS 50:0 :0 kg/ha
2nd top 40 DAS 60:0:35 kg/ha.
Hybrids
200:100:100 kg NPK /ha.
Micronutrients
Grasp entire tassel so that all the pollen parts are fully removed.
Do not break or remove leaves as removal will reduce yields and will result in
lower quality of seed.
Roguing
FS
0.2
0.5
CS
0.5
1.0 (when receptive silk is 5% or more)
Irrigation
Once in a week. Critical period (40-65 DAS)
Pest and disease
Shoot fly and cob borer are the important insects to be controlled.
Harvesting
Harvest when the husk completely turns into straw colour.
Methods of harvesting
Male lines are harvested first followed by female lines.
Threshing
a. Dehusking
b. Cob sorting
Xenia
The direct and visible effects of the pollen on endosperm and related tissues
in the formation of a seed colour. e.g. seed colour. In maize, the gene present in
sperm cell contributes in the expression of colour of hybrid seeds.
Mataxenia
Is the effect of a pollen on the maternal tissues of fruit.
Shelling
The cobs are shelled either mechanically or manually at 15-18% moisture
content.
Drying
Seeds are dried to 12% moisture content.
Grading
Grade the seeds using 18/64" (7.28 mm) sieve.
Seed treatment
Slurry treat the seeds with 8% moisture content either with captan or thiram
75% W.P. @ 70 g/100 kg with 0.5 litre of water. Treated seeds can be stored for 1
year in cloth bag.
Modification of isolation distance
Differential blooming dates are permitted for modifying isolation distance
provided 5.0% or more of the plants in the seed parent do not have receptive silks
when more than 0.50% of plants in the adjacent field (s) within the isolation
distance are shedding pollen.
Distances less than 200 meters may be modified by planting border rows of
male parent, if the kernel colour and the texture of the contaminant are the same
as that of seed parent. The number of border rows shall be determined by the size
of the field and isolation distance from the contaminant.
Seed standard inbreds
---------------------------------------------------------------------------------------Varieties
Hybrids
Parameters
Inbreds FS
CS
FS
CS
--------------------------------------------------------------------------------------------1. Physical purity (%) (min)
98
98
98
98
98
2. Inert matter (%) (max)
2
2
2
2
2
-1
-1
-1
3. Other crop seed (max)
5 /kg 5 kg
10 kg
5 kg
10 kg-1
4. ODV seeds (max)
5/kg 5 kg-1
10 kg-1
10 kg-1
10 kg-1
5 Germination % (min)
80
80
90
90
90
6. Moisture content (%) (max)
a. Moisture pervious
12
12
12
12
12
b. Moisture vapour proof 8
8
8
8
8
---------------------------------------------------------------------------------------------
Breeder seed
---> A x B
- R
- B
- R
Certified seed
AxR
--->
Varieties
K5, K7, CO 19, CO 20 (Fodder), CO 21, K9, BSR 1, CO 26, K4, K8, CO 25,
APK 1, K 10, Paiyur 1,2.
Hybrids
CSH1
: CK 60 A x IS 84
CSH 5
: MS 20 77 A x CS 35 41
CSH 9
: MS 296 A x CS 3541
COH3
: MS 2077 A x 699 Tall
COH 4
: MS 296 A x TNS 30
CSH 13 R :
296 A x RS 29
CSH 15 (R) :104 A x R 585
The first hybrid (CSH 1) was released in 1964. In 1969, the Coordinated
Sorghum Improvement Project was established. Now there are more than 30
hybrids.
Season
a. Varieties -
b. Hybrids
October - December.
Land requirement
The field offered for seed production should not have been grown with the
same crop in the previous season. If it was grown it should be of the same variety.
In this case the field is to be irrigated 3 weeks before ploughing to destroy the
germinated seeds. Land should be fertile and should not be problematic soil viz.,
calcareous or acidic soils.
Isolation
Foundation stage (M)
Varieties
200
400
400
Hybrids
300
200
Differential blooming dates are not allowed.
Seed rate
Varieties:
Pre-sowing treatment
1. Soak the seeds in 2% KH2PO4 for 10 hrs. Seeds are soaked in equal volume and
the seeds are dried back to original moisture content (or)
2. Soak the seeds in 1% prosopis and pungam leaf extract in1:0.6% volume for 16
hours and dry back to original moisture. Then pellet the seeds with pungam leaf
powder at 500 mg/kg of seeds using 10% maida as the adhesive material, which
is pollution free and eco friendly treatment.
3. Seeds can also be treated with 5% carbofuran 3G along with rice gruel as
adhesive to protect the seed from shootfly infestation in the field.
Spacing
Varieties
: 45 x 10 cm
Hybrids
A line 45 x 10 cm R line 45 x 10 cm
Fertilizers (varieties)
NPK
:100:50:50 kg ha-1
Basal
:50:50:50 kg ha-1
Top dressing : 25 kg N (25 DAS)
:25 kg N (45 DAS)
Synchronization
1. Staggered sowing: Sowing of male parent and female parents are adjusted in
such a way that both parents come to flowering at the same time. In CSH-5, MS
2077 A must be sown 10-15 days earlier to the male CS 3541, and in CSH 6,
the female parent MS 2219 A can be sown simultaneously with CS 3541 and in
CSH 9, the female parent MS 296 A must be sown 7-10 days earlier than male
CS 3541 in November- December season.
2. Spraying growth retardent MH 500 ppm at 45 DAS, delays flowering in
advancing parent. MH wont dissolve in water and hence dissolve it in NaOH and
then mix with water.
3. Urea spraying 1% to the lagging parent.
4. Withhold one irrigation to the advancing parent.
5. Spraying CCC 300 ppm will delay flowering.
Gapfilling
It should be done within a week after sowing.
Markers
For easy identification of male line live markers are used. It is other crops
like sunflower are grown at both ends of the male line. The markers should not be
pollinator and their duration should be more than the crop age.
Roguing
Roguing should be done periodically to remove off types, pollen shedders,
volunteer plants based on leaf orientation , leaf margin, size of leaf blade,type of
earhead and seed colour.
Field Standards
Foundation
seed %
Offtypes (max) Varieties
0.05
Hybrids
0.05
Pollen shedders (max)
0.05
Designated diseased plants (max)
0.05
Certified
seed %
0.10
0.10
0.10
0.10 (Ergot and smut)
Pollen shedders
Presence of B line plants in A line are called pollen shedders.
Partials
In certain A line plants, a part of the earhead-shed pollen due to the removal
of sterility due to parental impurity (or) developmental variation or temperature.
Irrigation
Critical stages for irrigation are primordial initiation, vegetative, milky and
maturity stages.
Designated diseases
1. Kernal smut
2. Head smut
The seeds are treated with captan or thiram @ 2 g/kg of seed and pack it in
cloth bag at 12% moisture content for short term storage and 8% moisture content
in 700 gauge poly ethylene bag for long term storage (or)
The seeds can also be treated with halogen mixture @ 3 g/kg of seeds. The
halogen mixture is prepared by mixing CaOCl 2 and CaCO3 +Albizzia amara at the
rate of 5:4:1 and this mixture is kept in an air tight plastic container for 1 week.
After one week the mixture is used for seed treatment.
The treated seeds can be stored upto 12 months under open storage and
upto 18 months in moisture vapour proof containers, provided it is not infested by
the storage insects.
Types of contamination
Presence of B line in A line called as pollen shedders
Presence of A line in Bline called as off type
Presence of R line in B line called as rogue
Presence of B line in B line called as rogue
Presence of B line in Rline called as rogue
Presence of B line in R line called as rogue
Pollen shedders and off type cause physical contamination.
occurance of rogue cause physical and genetical contamination.
Whereas,
Seed standards
--------------------------------------------------------------------------------------------Standards
Foundation seed
Certified seed
---------------------------------------------------------------------------------------1. Physical purity % (max)
98.0
98.0
2. Inert matter % (max)
2
2
3. Other crop seed (max)
5/kg
10kg-1
4. Weed seeds (max)
5kg-1
20 kg-1
-1
5. Other distinguishable
10 kg
20 kg-1
varieties (max)
6. Ergot disease (max)
0.020%
0.040%
(by number)
7.Germination (mini)
%
75
75
8. Moisture content (max)
a. moisture pervious container
12.0
12.0
b. moisture vapour proof container
8.0
8.0
--------------------------------------------------------------------------------------------Mid -storage correction
Old seeds with declining viability may be upgraded and soaked for 6 hours in
double the volume of Na2 HPo4 (3.59 g/100 l water) and dried back to 8% moisture
content.
Hybrids
1000 m
200 m
Season
The best season is October -December.
Seed rate
Varieties
: 3.75 kg /ha
Hybrids
: A line 3.125 kg/ha
R line 0.750 kg /ha
Spacing
Varieties
45 x 20 cm
Hybrids
A line 45 x 20 cm and R line 45 x solid row.
Removal of ergot affected seeds and sclerotia to prevent primary infection.
Dissolve 1 kg of common salt in 10 liters of water. Drop the seeds into the
salt solution. Remove the ergot and sclerotia affected seeds, which will float. Wash
seeds in fresh water 2 to 3 times to remove the salt on the seeds. Dry the seeds in
shade
Pre-sowing Seed Management
Use graded seeds for sowing.Treat the seeds with three packets (600 g ) of
Azospirillum or pellet the seed with arappu leaf powder.
Nursery Preparation
Nursery area required is 7.5 cents / ha. Apply 750 kg FYM and incorporate
by ploughing. Sow the seeds in raised bed. Form beds at 3 m x 1.5-m breadth.
Open rills at 15 cm gap to 1 cm deep. Sow the seeds and cover them with 500 kg
FYM.
Apply phorate 10 G 180 g or carbofuran 3 G 600g mixed with 2 kg of moist
sand, spread on the beds and work into the top 2 cm of the soil to protect the
seedlings from shootfly infestation.
Age of seedlings
Transplant the seedlings at the age of 15-18 days old.
Main field preparation
Form ridges and furrows at 45 cm gap. Plant the seedlings at 20 cm gap
within the ridge.
Planting ratio
F.S
C.S
Border rows
F.S
C.S
: 4:2
: 6:2
: B line 4 rows
: R line 8 rows
Varieties
Before flowering 1
During flowering 1
Before harvest 1
CS
0.10
0.10
0.10
0.10
0.04
Storage
Treated seeds packed in cloth bag or polyethylene bags (700 gauge) will
maintain viability upto 15 months under ambient conditions.
Mid-storage hydration - Dehydration for prolonging shelf life of seeds
Seeds that show a decline in vigour and germination during the early period
of storage should be soaked for 3 hours in double the volume of Na 2HPO4 (36 mg/lit
of H2O). The seeds after soaking should be dried back to 8% moisture content and
dry dressed with thiram (or ) captan @ 2g/kg of seeds to maintain shelf life upto 10
months with minimum loss in vigour and viability.
Seed standards
-------------- ------------------------------------------------------------------------------Parameters
Foundation seed
Certified seed
--------------------------------------------------------------------------------------------1. Physical purity (%) (min)
98
98
2. Inert matter (%) (max)
2
2
3. Other crop seeds (max)
10 kg-1
20 kg-1
4. Weed seeds (max)
10 kg-1
20 kg-1
5 Germination % (min)
75
75
6. Moisture content (%) (max)
a. Moisture pervious
12
12
b. Moisture vapour proof
8
8
--------------------------------------------------------------------------------------------Important Varieties:
CO 7, WCC 75, and K3.
Important hybrids in cumbu
KM 1
MS 5141 A x J 104
KM 2
MS 5141 A x K 560 -D-230
X4
MS 5141 A x PT 1921
X5
PB 111A
x PT 1921
X6
732 A
x PT 3095
X7
111A
x PT 1890
H B1
Tift 23A(USA) x BIL -3B
HB 3
"
x J 104
HB 5
"
x
K 559
UCH 11
732 A x PT 3075 (TNAU)
COH(cu) 8
732 A x PT 4450
Synthetics : If more than 5 parental lines are combined ,which are having general
combining ability e.g., CO 7, ICMS 7703
Composite: 3-5 inbreds with no general combining ability are mixed and
multiplied. e.g., WCC 75 (ICRISAT).
SEED PRODUCTION IN RED GRAM VARITIES AND HYBRIDS
Botany
Axillary or terminal raceme borne on long peduncle. The flowers are yellow
or purple. Based on the back of the standard petal colour, the variety is identified.
Flowers are papilonaceous, bracteate, barcteolate, clayx five, gamosepalous and
corolla with keel petals free stamens (9+1) diadelphous and didynamous, ovary
superior with a few ovules. Fruit is a pod.
Anthesis usually occurs, between 8 a.m to 5. 00 pm. Fertilization occurs five
hours after pollination. Red gram is an example for often cross-pollinated crop. The
cross-pollination occurs mainly due to bees and thrips. Pigeon pea is an often crosspollinated crop where natural out crossing is recorded upto 40-70%.
Varieties: Under isolation the crop is raised and by open pollination seeds are
allowed to set.
Season
Varieties
Adipattam (June - August)
SA 1, CO4 and CO 5
Puratassipattam (Sep. November)
CO 5, COH 1 and COH 2
Summer (February-March)
CO5, COH 1, COH 2, SA1, CO3 and
BSR1
Particulars of redgram varieties / hybrids
Particulars
Parentage
SA1
Pureline
CO 3
Mutant
BSR 1
Pureline selection
COH 1
MS T 21 x
COPH 2
MS CO5 x
Duration
(days)
Yield kg/ha
Rainfed
Irrigated
100 seed wt
(gm)
Seed colour
selection
from
Tirupattur
180
CO 1
ICPL 87109
ICPL
83027
130
from
Mayiladumparai,
Madurai
180
115-120
120-130
1250
8.5
1180
1400
7.2
0.75 to 1 kg of
green pods/plant
12.0
936
1500
10.3
1050
9.0-9.4
Pale
reddish
brown
Reddish
brown
Reddish brown
Light brown
Tan brown
Hybrids
The tool employed for production of hybrid seed is genetic male sterility
system (GMS) where male sterility is maintained in heterozygous stage following
the test cross principle, there would be male fertile and sterile plants in the ratio of
1:1.
Common hybrid
ICPH 8
COPH 1 (Non-DT)
COPH 2(Non-DT)
Female
Male
MS Prabhat DT
MST 21
MS CO 5
Foundation seed
200
200
Certified seed
100
100
Spacing
Varieties
45 x 30 cm
90 x 30 cm
Hybrids
45 x 15 cm
Seed treatment
Treat the seeds with carbendazim or thiram @ 2g/kg of seed 24 hours before
sowing (or) with talc formulation of Trichorderma virdie @ 4 g/kg of seed (or)
Pseudomonos fluorescens @ 10 g/kg of seed. Bio control agents are compatible
with biofertilizers. First treat the seeds with bio control agents and then with
rhizobium. Fungicides and biocontrol agents are incompatible.
Fungicide treated seeds should be again treated with a bacterial culture.
Treat with Rhizobial culture CC 1. There should be an interval of atleast 24 hours
after fungicidal treatment for giving the bacterial culture treatment. For red lateritic
soil rhizobial culture VPR 1 is effective.
Three packets of Rhizobial culture are sufficient for treating seeds required
for one ha. The bacterial culture slurry may be prepared with rice kanji. Dry the
bacterial culture treated seeds in shade for 15 minutes before sowing.
Planting ratio
The male and female seeds are sown in 1:4 ratio or 2:8 (COPH 1) and 1:6
(COH 2) for maximization of yield. Sow 2 rows of male line all around the field as
border row.
Synchronization treatment
1. The pollen parent ICPL 87109 should be sown one week after sowing the female
parent (MST 21) in COPH 1
2. The field should be bordered with sunflower to increase the seed yield by
attracting honey bees
Season
The optimum time for taking up the hybrid seed production is first fortnight
of June or first fortnight of December.
Seed production in different stage
Varieties
: Breeder seed - Foundation seed - Certified seed
Hybrids
: BS- multiplication of A(female) and R (male) under isolation
FS - Multiplication of A(female) and R (male) under isolation
CS - A and R crossed to produce hybrid seed.
Manures and Fertilizers
Compost
12.5tons ha-1
25:50: NPK kg ha-1
Basal
25:50: NPK kg ha-1
Supplementary foliar application
Spray 250 litres of aqueous solution containing urea, DAP, muriate of potash
and potassium sulphate at 10.0, 2.6, 1.75 and 1.4 kg respectively with addition of
succinic acid at 40 g and teepol at 120 ml per hectare on the 55 th and 70th day after
sowing. The spray application should be made only in the afternoon.
NAA application
Apply 40 ppm of NAA (40 mg / lit) which may be advantageously mixed with
urea and spray.
Irrigation
1st irrigation immediately after sowing and 2nd 2-3 days after sowing.
Subsequent irrigations at 8-10 days interval.
Roguing
In male sterile line or female parent
Remove the male fertile plant by examining plumby and yellow colour of
anthers at the time of 1st flower formation, one day before flowering.
Remove immature pods set in the plants from time to time to induce
continuous flowering and to ensure pollen availability for longer period.
Pollination
1. To supplement pollination 5-8 beehives may be arranged per ha.
2. To have the availability of pollen from the male parent for a prolonged
period, clip off pods from the male parent. This will induce more
flowering.
3. The whole plot should be bordered with sunflower to increase the bee
activity to effect cross-pollination.
Pre harvest sanitation spray
The pod borer attack and bruchid infestation starts from the field. To avoid
this 3 sprays at 10 days interval should be given before the harvest. The chemical
recommended is endosulphan or malathian (0.07%)
Harvesting
Female parent MS T
21
Indeterminate(NDT
)
115-120
height 126
Pollen
parent
ICPL 87109
Determinate
(DT)
100-110
F1 hybrid COH 1
78
106
Indeterminate
(NDT)
115-120
(cm)
Inflorescence
Axillary raceme
Flower
1. Corolla
Yellow
2. Back
of Yellow with light
Standard
red vein at the
petal
base
Pod colour
Green with purple
streaks
when
young and brown
at maturity
Terminal raceme
Axillary raceme
Yellow
Yellow
Yellow with red to
Red to crimson dark red veins
red
throughout
Light green with
light
streaks
when young and
brown
at
maturity
12.0
Hundred
seed 9.0
weight (g)
Colour of seed
Reddish brown
Light brown
Hybrid seed production of COPH 1 pigeon pea
For hybrid seed production, a ratio of 4:1 of male sterile and pollen parent is
adopted. Sufficient isolation distance i.e more than 250 meters for the hybrid seed
production plot is needed. There should not be any pigeon pea crop within a radius
of 250 meters from the seed production plot. Since, the male sterility is maintained
in heterozygous state following the test cross principle, there would be fertile and
sterile plants in the ratio of 1:1 in the male sterile population. It is therefore
imperative to remove the male fertile plants in the male sterile population before
flower opening. The roguing should be done thoroughly to avoid contamination by
the pollen from any left out fertile plant.
Production and maintenance of male sterile lines
Genetic male sterility is utilized in hybrid seed production. In case of pigeon
pea the male sterile line will segregate in 1:1 ratio of fertile to sterile. For the
maintenance of the male sterile population, the male sterile plants have to be
identified and tagged and the fertile plants have to be retained without tagging. The
male sterile lines will be pollinated naturally by the pollen from the male fertile
plants in the population through insect pollinators. After maturity, the seeds from
the tagged male sterile plants are collected and will be used for producing male
sterile lines again or for producing hybrid seeds.
The main difference between the hybrid seed production and the male sterile
line maintenance is during hybrid seed production the male fertile plants from the
sterile population are to be rogued off, while they are retained during male sterile
line maintenance.
Foundation seed
Certified seed
Varieties
CO4, KM2, VBN1,2, TMV1, CO 5
CO 5, KM2, VBN1, K1, VBN 2
KM2, TMV 1, ADT 5, CO5, T9, CO4
Particulars
Parentage
Duration( days)
Yield kg/ha
Rainfed
Irrigated
100 seed wt (gm)
Seed colour
CO 4
Mutant of CO 1
70
KM 2
Derivative of T 9 x L 64
60-65
VBN 1
KM 1 x H 76-1
60-65
640
1040
690
-
700
850
5.7
Black & dull
4.0
Black with green mottling
4.6
Black
Land requirement
The land should be fertile and it should be prepared to fine tilth. Land should
be free from volunteer plants.
Isolation (m)
Foundation seed
Certified seed
10
5
Seeds and Sowing
The seed should be selected from an authenticated source. The off colour
seeds should be removed from normal coloured, since they record lower
germination. Only graded seed should be used.
In green gram and black gram
the hard seed percentage may exceed 10% at a time. At that time seeds should be
scarified with commercial sulphuric acid for 2 minutes and should be washed
thoroughly and used for sowing.
Seed treatment
The seeds are to be treated with Trichoderma sp. @ 4g/kg of seeds or
Pseudomonos fluorescence @ 10 g/kg of seed (or)
The seeds have to be treated with fungicide (thiram @ 2.5 g/kg) and
insecticide (carbaryl @ 200 mg/kg) before sowing for early protection against
diseases and insects.
The seeds should be treated with 3 packets of multi strain Rhizobium
culture /ha of seeds to facilitate natural nitrogen fixation by the plants.
In dry land sowing the seeds can be soaked in 1/3 volume of 100 ppm of zinc
sulphate (black gram) for 3 hours and should be dried back to original moisture
content by shade drying.
Spacing 25 x 15 cm
Seed rate 20 kg ha-1
The seeds should be dibbled 3-4 cm depth at the side of the ridges.
It can
be grown in all 3 seasons but June-July is the best season. But sowing should be
taken up in such a way that maturation period does not coincide with rain, which
will increase the off coloured seed per cent in the seed lot. In summer production,
hard seed content will increase compared to other season.
Manures and fertilizers
Compost FYM
Basal
Foliar spray: With micronutrients on 25th and 40th day after sowing.
Composition of micronutrients mixture
Urea
7.5 kg
K2SO4
1.05 kg
DAP
1.95 kg
Succinic acid
40 g
K2O
1.313 kg
Teepol
125 ml
The composition was diluted in 250 litre of water/ha and given as spray to
the crop at 25 and 40 days after sowing.
Water management
First irrigation immediately after sowing and 2 nd 2-3 days after sowing.
Subsequent irrigation 10-15 days interval. Apply KCl at 0.5% as foliar spray during
vegetative stage if there is moisture stress
Roguing
Field standards
(Maximum permitted %)
1. Off types
2. Plants affected by seed borne diseases
FS
0.10
0.10
CS
0.20
0.20
Seed standards
-------------------------------------------------------------------------------------------Characters
FS
CS
-------------------------------------------------------------------------------------------Physical purity (max) %
98
98
Inert matter (max) %
2
2
-1
Other crop seed (max)
5 kg
10 kg-1
Weed seed (max)
5 kg-1
10 kg-1
Other distinguishable varieties (max) 10 kg-1
20 kg-1
Germination (min)%
75
75
(including hard seed)
Moisture content (max)%
(a) Open storage
9.0
9.0
(b) Moisture vapour proof storage
8.0
8.0
SEED PRODUCTION IN GROUNDNUT
Principle
Seeds are produced by self-pollination and fertilization. Here cross-pollination
does not occur because the stigma remains enclosed in the keel petal even in fully
opened flower.
Method of seed production
The crop is raised under isolation and seeds are allowed to set by selfpollination.
Stages of seed production
Breeder seed -
Foundation seed
Certified seed.
C. Varieties:
1. Spreading
: TMV 1, 3, 4.
2. Semi-spreading : TMV 6, 8,10.
3. Bunch
: TMV 2,7,9,11,12, ALR 1, 2, VRI 1, 2, 3, 4,
JL 24, CO 1, 2, BSR 1.
Dormant varieties
TMV 7
CO 1
VRI 2
Seed colour
- 10 days
- 10-15 days
- One week
Light rose
Rose
Red
Red blotched with white
Land requirement
:
:
:
:
The selected land should not have been grown with the same crop in the
previous season if grown it should be undergone the certification standards.
Isolation distance
Foundation
3m
Seeds and sowing
Certified
3m
Seed rate
: Rain fed
140 kg /ha
: Irrigated
125 kg /ha
Increase the seed rate by 10% for bold seeded varieties like JL 24, CO2 and
TMV 10.
Seed treatment
1. Treat the seeds with Trichoderma virdie 4 g /kg. This can be done just
before sowing. It is compatible with biofertilizers. But should not be
treated with fungicides.
2. Treat the seeds with Thiram or mancozeb at 4 g/kg of seed or carboxin or
carbendazim @ 2 g / kg of seeds.
3. Treat the seeds with 3 packets (600 g/ha) of Rhizobial culture TNAU 14
using rice kanji as binder.
4. If the seed treatment is not carried out apply 10 packets/ha (2000 g) with
25 kg of FYM and 25 kg of soil before sowing.
5. Seed treatment will protect the young seedlings from root-rot and collar
rot infection.
Pre sowing seed hardening
The seeds are soaked in 0.5% CaCl2 solution (50% seed volume) for 6 hours.
After 6 hours seeds are spread over moist gunny bag and covered with another
moist gunny bag for 20-24 hours. After 24 hours, the seeds with sprouted radicle
(just visible expression of radicle) should be separated and dried under shade. It
should be repeated for 2-3 times, with 2 hours interval and all the viable seeds with
expressed radicle emergence should be separated and dried under shade and used
for immediate sowing. Thus the viable and dead seeds are separated. The
remaining seeds can be dried to original moisture content and stored for 7-10 days.
To break dormancy the seeds are treated with 200 ppm ethrel.
Spacing
Bunch
Spreading Semi spreading-
25 x 15 cm.
60 x 25 cm
45 x 15 cm.
12.5 t/ha
40:40:60 kg /ha
10 kg/ha
12.5 kg /ha
Deficiency of nutrients
1. Calcium: Deficiency of calcium results in ' Pops'. In this disorder, early seed
abortion occurs and although an apparently normal pod matures it contains
either no seed or minute shrivelled remains of seeds. Another disorder ' Dark
plumule' results in the seeds when split open showing a plumule, which is black.
The normal plumules are light cream in colour.
2. Boron: Boron deficiency increased single compartment nuts. The shells are
often cracked. Hollow heart in the kernels is produced. When the cotyledons of
the seed are separated a knurled hollow is observed between them, which is
sometimes darkened, or off coloured. This hollow heart leads to the invasion of
seed borne pathogens as the seed develop.
Roguing
Roguing should be done from vegetative phase upto harvest based on the
colour of leaf, size and shape of the pod, seed number per pod, and testa colour of
seed.
Intercultural operations
The soil should be stirred well at the time of flowering for easy penetration of
peg and this should be coincide with gypsum application.
Irrigation
It should be given once in 15 days and it is must during flowering, pod
formation stage and seed filling stage.
The seeds are separated using decorticator and the moisture content will be
16% at that time.
Seed grading
Seeds are graded using round perforated metal sieves of 18/64" to 20/64".
Seed drying
Graded seeds are dried to 7-8% moisture content
Seed treatment
Treat the seeds with 2 g thiram / kg of seed. Pods can also be stored by
treating the pods with thiram @ 2 g/ kg of pod. Pods can also be stored in gunny
bags along with calcium chloride at 250 gm for 30 kg of pod placed in a plastic
container. In general, pods can be stored for 18 months and seeds for 8months.
Seed standard
The graded seed should possess the following characters for certification and
sale as certified/ truthfully labelled seeds
-------------------------------------------------------------------------------------------Parameter
Foundation seed
Certified seed
-------------------------------------------------------------------------------------------Physical purity (min) %
96
96
Inert matter (max) %
4
4
Germination (min)%
70
70
Moisture content (max)%
(a) Open storage
9
9
(b) Moisture vapour proof storage
5
5
-------------------------------------------------------------------------------------------
Season
Isolation distance
Foundation seed
Varieties
400 m
Hybrids
600 m
Certified seed
200 m
400 m
12.5 t/ha
60:45:45 kg /ha
Field standards
Foundation seeds
Off types
0.1 %
Certified seeds
0.2%
Harvesting
The change of head colour from green to lemon yellow is the indication of
physiological maturity. The heads are harvested separately.
Drying
Heads are dried to moisture content of 15-18 % for threshing.
Processing
Seeds are first graded by specific gravity separator. Then size graded by
round perforated sieve with a specification of 9/64" (3.5 mm).
Seed standards
The graded seed should possess the following characters for certification and
sale as certified/ truthfully labelled seeds
-------------------------------------------------------------------------------------------Parameter
Foundation seed Certified seed
-------------------------------------------------------------------------------------------Physical purity (min) %
98
98
Inert matter (max) %
2
2
Germination (min)%
60
60
Moisture content (max)%
(a) Open storage
8
8
(b) Moisture vapour proof
5
5
storage
------------------------------------------------------------------------------------------Dormancy
If the seeds are fresh (1 to 5 months old) germination will be low due to
dormancy. Hence the seeds should be soaked in aqueous solution of ethrel @ 300
ppm for 8 hours or in 0.5% KNO3 for 16 hours.
Hybrids
BSH -1
KBSH 1
MSFH 1
MSFH 8
MSFH -17
TCSH 1
Varieties
: April - May
Land requirement
Previous crop should not be the same crop, if it is the same crop, it should be
of the same variety and have undergone certification.
Seed and sowing
a. Seed rate
b. Spacing
c. Isolation distance
: 3-4 kg / ha
: 30 x 30 cm
: Foundation seeds
100 m
Certified seeds
50 m
Foundation seeds
0.1 %
Certified seeds
0.2%
Intercultural operation
Earthing up should be done to prevent lodging before flowering stage.
Irrigation
Once in 15 days and it is must during flowering and capsule filling stage.
Harvesting
Harvest when 75-80% of the capsules start yellowing and bottom 1 or 2
capsules have dehised. At this stage, the pod moisture content will be 50 to 60%
and seed moisture content 25-30%.
Method of harvest
The whole plant is cut at ground level, bundled and stacked inversely to
provide humidity.
Stacking and drying
Stacked plants are left in the threshing floor for 3 days to bring down the
moisture content to 15 -18%.
Threshing Is done manually by beating with pliable bamboo sticks.
Processing
The seeds are size graded using round perforated metal sieve of 5/64" to
4/64" depending upon the variety.
Seed treatment and storage
Seeds can be treated with captan / thiram @ 2 g / kg of seeds, stored well
up to 2 years in polythene bags (700-gauge thickness) and 9 months in gada cloth
bag under open storage conditions.
Seed standards
The graded seed should possess the following characters for certification and
sale as certified/ truthfully labelled seeds
-------------------------------------------------------------------------------------------Parameter
Foundation seed Certified seed
-------------------------------------------------------------------------------------------Physical purity (min) %
97
98
Inert matter (max) %
3
3
Other crop seed (max)
%
1
1
Weed Seed (max)
1
1
Germination (min)%
80
80
Moisture content (max)%
(a) Open storage
9
9
(b) Moisture vapour proof storage
5
5
------------------------------------------------------------------------------------------Seed colour
Varieties
TMV 3, 4, 5, 6 VRI 1
Paiyur1, Co 1,
SVPR 1
Seed colour
Brown
Black
White.
population. Eg. VP 1. This problem was successfully overcome with the exploitation
of the NES system.
NES system
This line is normally pistillate under moderate temperature but produces
interspersed staminate flowers under high temperature. In crossing fields (hybrid
seed production plot) usually one or two roguing of the female line are sufficient to
ensure that all flowering plants are pistillate to remove off types that appear.
E.g. The original population of VP 1 was thoroughly screened under high
temperature to eliminate the monoecious plants as well as early revertants.
The seed setting in the selected totally pistillated lines are facilitated by the
production of interspersed male flowers under the influence of environment
sensitive genes. India is the largest producer of castor in the world. In India,
Gujarat is the leading state followed by Andhra Pradesh.
Varieties
SA 1, SA 2, TMV 4, 5, 6, CO 1, Aruna, Bhagya and Sowbaghya.
Hybrids
The development of N type pistillate line, N 145-4 has led to the exploitation
of hybrid vigour in USA in 1950. A 100% pistillate line TSP 10 R (Texas S- pistillate
10) was released in 1962 in USA. Another stable pistillate line (NES 1, based on
environmentally sensitive staminate flower character in combination with recessive
sex switching gene released at Davis, California in 1964, is now used.
In India, Gujarat first started hybrid seed production in mid sixties.First
hybrid in India was released in 1968 in Gujarat as GCH3 (Gujarat castor hybrid)
using TSP 10 R x JI 15.
Indigenous pistillate line VP 1 was developed at Vijapur and using this
GAUCH was released in 1973. But it is susceptible to wilt and root rot diseases.
Hence another hybrid GCH 2 was released in 1985. Another hybrid GCH 4 was
released in 1986 and is in cultivation.
Hybrids
GCH 3
GAUCH 1
GCH 2
GCH 4
TMVCH 1
Female
TSP 10 R
VP 1
VP 1
VP 1
LRES 17
x
x
x
x
x
Male
JI 15
V 19
JI 35
48-1
TMV 5
Land requirement
Well drained fertile soil should be selected. The crop cannot tolerate alkalinity
and salinity. It performs well with medium to deep sandy loam and heavy loam soils
are highly suited for seed production.
Isolation distance
Foundation seed
600 m
Certified seed
300 m
Season
Rabi / Winter - Hybrid seed production. Summer and kharif provide ideal
male promoting environment for undertaking seed production of the variety, male
and female parents of hybrids. Kharif and summer encourages good expression of
less productive plant which could be easily eliminated through timely roguing.
Female parents when raised in male promoting environment produce
environmentally sensitive staminate flowers, which are very essential for selfproduction of the female parents.
Seed and sowing
Seed rate
: 10 kg / ha (varieties)
2 kg / ha male and 5 kg/ ha female for hybrids.
Spacing
Varieties
Hybrids
Planting ratio
: 90 x 20 to 90 x 60 cm
: 90 x 40 to 90 x 60 cm
3:1 or 4 - 6:1
Fertilizer
: Basal
40:60: 40 NPK / ha
No bloom
Signle bloom - Bloom only on stem
Double bloom- On stem, petioles, and lower sides of leaves
Triple bloom - On all parts.
Stages of inspection
1.
2.
Certified seeds
0.2%
1.0%
The graded seed should possess the following characters for certification and
sale as certified/ truthfully labelled seeds
-------------------------------------------------------------------------------------------Parameter
Foundation seed
Certified seed
-------------------------------------------------------------------------------------------Physical purity (min) %
98
98
Inert matter (max) %
2
2
Other crop seed &Weed Seed (max)
Other distinguishable variety seeds
5 / kg
10/kg.
Germination (min)%
70
70
Moisture content (max)%
(a) Open storage
8
8
(b) Moisture vapour proof storage
5
5
------------------------------------------------------------------------------------------
which is the anthesis time, the flowers of selected male parent are plugged and
dusted on the stigma of the emasculated flower on opening the cover. It is again
covered with different coloured cover to avoid pollination with other pollen and to
identify the emasculated and dusted flower from the rest. The pollen from a single
flower is enough to dust 4-5 female flowers. The pollen receptivity of the stigma is
for 46 hours. For easy identification of selfed boll from emasculated and dusted boll
the bract can be removed while emasculating owing to the little contribution of
bract to seed set and seed yield.
Particulars of varieties/hybrids
Varieties
Parentage
MCU 5
MCU7
MCU 11
LRA 5166
K10
K11
Suvin
Jalyalaxmi
TCHB 213
SVPR 1
Savitha
HB 224
Season
Irrigated
/ Rainfed
Multiple cross
X ray irradiation of x L
1143 EE
Aug- January
Irrigated
Jan- Feb. to May Irrigated
- June(summer) (Rice
fallows)
MCU 5 x Egyptian Aug
- Irrigated
hirsutum hybrid derivative September
Laxmi x Reba B.50 x AC Sep-October to Rainfed
122
Jan - February
K9
x
11876
hybrid Sep-October to Rainfed
derivative
Jan - February
(0794-1-DX
11876)
x Oct- March
Rainfed
(0794-D
x
11450)
Multiple Hybrid derivative
Hyrbid derivative from the Aug - February
Irrigated
cross Sujatha x St.Vincent
Interspecific hybird of DS Aug-February
Irrigated
28 G. hirsutum x SB 425
(VF) G. barbadense
Interspecific
hybird
of Aug-February
Irrigated
TCH 1218 G. hirsutum x
TCB 209 G. barbadense
MCU 7 x AC 129/2
February - July
Summer Irrigated
T7 x M 12 (Intra hirsutum Aug-February
hybrid)
It is an
interspecific Aug-February
hybrid
involving
G.
hirsutum
x
G. barbadense
Seed
yield
(kg/ha)
1850
1330
2200
725
726
1100
1020
2880
2215
Irrigated
15-16 Qtl.
Of
kapas /ha
1800
Irrigated
2000
Season
Winter crop
:
Aug - Sep
summer crop
:
Feb - March
Seeds and Sowing
Seeds should be obtained from an authenticated source with tag and bill.
Pre-sowing management
The seeds can be hardened with 1% prosopis and pungam leaf extract for
rainfed/summer sowing to resist water stress problem.Use of delinted seed is better
than fuzzy seed to avoid diseased and injured seed.
Seed rate
Varieties
Hybrids
Male
Seed treatment
Treat the seeds with azospirillum at 3 packets (600 g/ha) and 2 kg of
azospirillum / ha mixed with 25 kg of FYM and 25 kg of soil and applied on the seed
line. This saves 25 % nitrogen besides increasing yield.
Spacing Varieties
Hybrids
1. Long duration
:90 x 30 cm
: 120 x 60 cm
2. Short duration :60 x 30 cm
: 90 x 60 cm
Hybrids - Planting ratio
8:2 but here it is block system where flowers of 2 parts of male is sufficient
to dust 8 parts of female parent. The male and female parents are raised at an
isolation of 5 m to avoid genetic and physical contamination.
Isolation (m)
Foundation seed
Certified seed
Varieties
50
30
Hybrids
50
30
Manures and fertilizers
Compost
:
12.5 tons/ha
Total
:
100:50:25 NPK kg/ha
Basal
:
50:50:25 NPK kg/ha
Top dressing :
25:0:0 NPK kg/ha
(40-45 days after sowing)
25:0:0 NPK kg/ha (70-75 days after sowing)
Foliar spray
Spray DAP 2% (for female parents, spray on 60,70,80 and 90 th days after
sowing. (Soak 5 kg of DAP in 25 liters of water over night and supernatant liquid
should be taken and mixed with 475 liters of water for spraying 1 hectare).
Micronutrient application
Mix 12.5 kg of micronutrient mixture formulated by the Department of
Agriculture Tamil Nadu with enough sand to make a total quantity of 50 kg for one
hectare.
NAA application
Spray 40 ppm of NAA (40 mg of NAA dissolved in 1 liter of water) at 40 /
45th day using high volume spray liquid in 1125 liter /ha. Repeat the same dose
after 15 days of first spray.
Topping
Arrest terminal growth by nipping the terminal 10-12 th node for controlling
excessive vegetative growth.
Rouging
The crop should be rouged for off types, selfed plants, from vegetative phase
to harvest phase depending on plant stature, leaf size, leaf colour, hairiness, stem
colour, flower colour, petal spot, pollen colour, number of sympodia, boll size, boll
shape, pittedness etc. to maintain genetic purity.
Field standards
Off types
Irrigation management
Once in 10 days. Critical periods are boll formation to boll maturation stages.
Specific problems
Boll shedding will occur either due to extreme dry climate or lesser
frequency of irrigation or physiological disorder. By spraying 40 ppm of NAA and
cycocel at 20ppm, this can be minimized.
Harvesting
The seed attains physiological maturation 45 days after anthesis. The
initiations of hair line cracks on the dried bolls are the physical symptoms of
physiological maturation. At that time, the moisture content will be 30-35%. The
bolls are harvested as pickings in cotton. Due to continuous flowering habit once
over harvest is not practiced. As and when the bolls burst with hairline cracks the
bolls are collected and dried. Normally five to seven pickings can be practiced in a
crop. But early 4-5 pickings are recommended for seed purpose.
Harvest in the morning hours upto 10 to 11 a.m. only when there is moisture
so that dry leaves and bracts do not stick to the kapas and lower the market value.
Pick kapas from well burst bolls only. Remove only the kapas from the bolls and
leave the bracts on the plants. As kapas is picked, sort out good puffy ones and
keep separately. Keep stained, discoloured and insect attacked kapas separately.
Kapas sorting
Kapas is sorted manually to pick good quality seeds. Hard locks are to be
removed (Kapas without proper bursting and lint is light yellow in colour), since
these kapas mostly result in poor quality seeds, due to boll worm or other insect
attack. Skewed bolls or ill filled or nonviable seeds are formed if stigmatic lobes are
not pollinated.
Ginning and certification
1. Gin the crossed kapas in separate gins erected in authorised seed processing
units or farm gins under the close supervision of the authorities concerned to
ensure purity and avoid seed damage.
2. Sieve the seed in two types of mesh to remove small, shrivelled seeds, broken
seeds and clean perfectly from any dirt or dust.
3. After ginning, the seeds should be dried well and cleaned by hand picking. After
cleaning, certification agency will take sample for testing germination and
genetic purity test. Minimum germination 65% and genetic purity 90% should
be maintained.
4. Certified seeds would be bagged in one kg bag, sealed and details regarding its
origin, germination, physical purity per cent and genetical purity percent,
besides season of production are passed on to sale agencies or respective
producers for commercial sale.
5. Uncertified seeds would be procured by the concerned Department or Agency at
the market rate for the ordinary cotton seeds for further multiplication. This
step is essential to avoid unauthorised sale of substandard uncertified seed.
Processing
The ginned seeds (or) the fuzzy seeds are graded by hand picking and by
pressing on wire-mesh sieves to remove the under sized seeds and dust.
Acid delinting
Fuzzy seeds will clog with one another. So for easy handling the seeds are
delinted using H2SO4 @ 100 ml/kg of seed for 2-3 minutes. After acid treatment,
the seed should be washed thoroughly for 3 to 4 times with fresh water. From the
floaters, mature seeds without any visible damage can be picked and added to the
sinkers.
Procedure
Weighed quantity of fuzzy seeds are taken in a plastic container and required
quantity of the acid is added. Stir well with wooden rod till a shiny black colour
appears (Tar like) wash with more of water (5-6 times) and shade dry the seed to
reduce the moisture content to 12% before further handling.
Processing of delinted seed
The free flowing delinted seeds can be graded using 10/64" round perforated
metal sieve, which is recommended as standard sieve in OSAW cleaner cum grader
for cotton. The seed can also be graded by specific gravity method by using
floatation technique using water. The seeds will separate into floaters and sinkers.
The sinkers are good seeds. From floaters, reddish (immature) and damaged (seed
with insect hole) are removed. The brownish seeds which are good seeds are hand
picked and used for sowing.
Seed standards
Characters
Foundation
seed
Certified seed