VEGETABLE CROPS

ABSTRACT: Fungal phytopathogens cause serious losses of crop production worldwide, which causes serious losses of crop production. Bacteria play a role as the biocontrol agents for plant disease control. For this reason, the present study was conducted to determine the antagonistic potential of rhizosphere soil bacteria against selected phytopathogenic fungi. The screenings of potential antagonist isolated bacteria were applied by the dual culture technique with fungi Fusarium oxysporum and Colletotrichum melongenae. Molecular characterization was performed through 16S rDNA sequencing analysis. Sixteen (16) out of fifty (50) isolated bacteria showed different degrees of antagonism (25-67%) against both fungi F. oxysporum and C. melongenae. Among them, four (4) isolated bacteria (isolates A4, C1, C2, and E2) exhibited strong antagonism (more than 50% mycelial growth inhibition) against both fungi. The 16S rDNA sequences of the isolated bacteria A4, C1, C2 and E2 were 99-100% similar to Providencia sp. TT14, Bacillus subtilis 168, Bacillus subtilis RKP-2, and Bacillus amyloliquefaciens IBSDG-11, respectively. Based on the capability for the control of mycelial growth against both fungi, B. subtilis IUBTC2 was selected for optimization of growth characteristics and identification the bioactive metabolites which can enhance plant growth and disease control capacity of plants against the phytopathogenic fungi.

A field trial was conducted during 2011/2012 and 2012/2013 seasons to study the effect of sowing dates, i.e.1st, 16th of September, 1st, 16th of October, 16th October and 1st of November on growth and productivity of sugar pea hybrids, Sugar Lace, Sugar Snap, Snow Wind, Compados, Brotherton and Snow Green under sandy soil conditions. This experiment was laid out in a split plot design with three replicates. Results indicated that sowing on 16th of September for Brotherton hybrid and 1st of October for Compadoss hybrid gave the best  vegetative growth, flowering characteristics, yield and pod chemical constituents.

BACKGROUND: The widespread occurrence of ALS inhibitor-and glyphosate-resistant Amaranthus palmeri has led to increasing use of protoporphyrinogen oxidase (PPO)-inhibiting herbicides in cotton and soybean. Studies were conducted to confirm resistance to fomesafen (a PPO inhibitor), determine the resistance frequency, examine the resistance profile to other foliar-applied herbicides and investigate the resistance mechanism of resistant plants in a population collected in 2011 (AR11-LAW B) and its progenies from two cycles of fomesafen selection (C1 and C2). RESULTS: The frequency of fomesafen-resistant plants increased from 5% in the original AR11-LAW-B to 17% in the C2 population. The amounts of fomesafen that caused 50% growth reduction were 6-, 13-and 21-fold greater in AR11-LAW-B, C1 and C2 populations, respectively, than in the sensitive ecotype. The AR11-LAW-B population was sensitive to atrazine, dicamba, glufosinate, glyphosate and mesotrione but resistant to ALS-inhibiting herbicides pyrithiobac and trifloxysulfuron. Fomesafen survivors from C1 and C2 populations tested positive for the PPO glycine 210 deletion previously reported in waterhemp (Amaranthus tuberculatus). CONCLUSION: These studies confirmed that Palmer amaranth in Arkansas has evolved resistance to foliar-applied PPO-inhibiting herbicide.

The study was conducted at Menschen fur Menschen Foundation Agro Technical and Technology College Demonstration site, Harar, Ethiopia from October, 2015 to February, 2016. The experiment was conducted to determine the yield produced per 50kg sacks filled with a moist and rational mixtures of well fertilized soils for selected vegetable crops grown in multistorey gardening. The experiment consisted of three types of vegetable which were grown each in three 50kg sacks filled with a moist rational mixture of well fertilized soils. Thus, a total of nine 50kg sacks were used for this study. Results of this study indicated that the yield per 50kg sacks filled with moist rational mixtures of soils resulted in 5.0, 4.5 and 7.0 kg for lettuce, Swiss chard and Tomato respectively. As a recommendation, the study suggested that there is a need for more promotion of multi-storey gardens as an urban farming technology to increasing food production for home consumption for disadvantaged groups such as immigrants, HIV-AIDS affected households, disabled people, female-headed households with children, elderly people without pension. This will avert food security problem in the country by having continuous food supply throughout all seasons.