CHAPTER I

THE PROBLEM AND ITS BACKGROUND

Introduction

One-third of the rural population in developing countries live in arid

and semi-arid regions, which encompass 54% of the agricultural area

worldwide. Approximately 1 billion people are subjected to water scarcity

(Hogan Tolmasquim, 2001; Rocga Soares,2015).

Lettuce generically known as Lactuca sativa L. is extensively consumed as

part of salad; therefore, it is among the widely cultivated vegetables

across the globe (Christopoulo et al., 2015). Due to lettuce's high

nutritional content, including its vitamins, minerals, and folate, numerous

studies have been motivated to investigate its effectiveness while also

maximizing its use (Amoozgar et al.,2017)

The utilization of brackish water for hydroponic lettuce cultivation

is gaining attention in regions facing freshwater scarcity. A study by( Ma et

al. (2019) specifically investigates the feasibility of using brackish water in

hydroponic lettuce production. The researchers explore the influence of

various factors, including salinity levels, on lettuce growth. This study's

findings can provide valuable insights into the adaptability of romaine

lettuce to brackish water conditions.

Several studies have highlighted the significance of pH in

hydroponic systems. For instance, Smith et al. (2018) demonstrated that

maintaining an optimal pH range in hydroponic solutions enhances

nutrient availability, resulting in improved lettuce growth. Furthermore, the

work of Johnson and Brown (2020) emphasized the importance of water

quality management, including pH control, to mitigate the adverse effects

of salinity on hydroponic crops.

This research aims to contribute to the existing body of

knowledge by systematically examining how romaine lettuce responds to

different pH levels in brackish water within a hydroponic framework. By

addressing this critical knowledge gap, we seek to provide evidence-based

recommendations for optimizing lettuce production in hydroponic systems

using brackish water, thereby promoting sustainable agriculture in water-

scarce regions.
 Objectives of the Study

The study will generally focus on the growth of romaine lettuce in different

pH levels of brackish water under a hydroponic system. The study had the

following objectives: 1. To

evaluate the growth of romaine lettuce under a hydroponic system using

different levels of brackish water, in terms of growth:

1.1. Plant weight;

1.2. Plant height; and

1.3. Number of leaves

2. To determine the lettuce's highest survival in different treatments

3. To determine the physicochemical parameters.

Significance of the Study

The results of the study may provide specific information to those

people who live in the villages near the SPAMAST campus, where most of

the water sources are brackish. This study must be relevant and

beneficial, as it can help people generate income by growing lettuce,

which is well suited to the available water they have, aside from that it

may benefit the following:

Students

Students can gain practical knowledge and skills related to

hydroponic agriculture, Salinity level management, and the effects of

brackish water on plant growth.

Teachers

This study can be used as an educational tool to demonstrate the

principles of hydroponics, plant adaptation, and water quality

management. Teachers can incorporate it into their curriculum to enhance

student's understanding of biology and agriculture.

School organization

They can use the findings to engage in eco-friendly initiatives, they

may even implement the hydroponic system in school to grow fresh

produce plants.

Farmers

This is a significant aid to farmers as they can utilize it towards the

discovery of novel agricultural techniques, specifically those involving the

utilization of any water resources unique to their locality.

Future researcher

This study can serve as a foundation for future research on

sustainable agriculture, waste resource management, and crop

adaptability. Researchers can build upon this work to explore more

complex questions and refine techniques.

Scope and Limitations of the Study

This study is designed to investigate the growth of lettuce plants

(Lactuca sativa) under varying Salinity levels of brackish water, with a

comprehensive evaluation encompassing several key parameters, including

plant height, biomass (weight), morphological characteristics, and leaf

dimensions. The research aims to provide a thorough understanding of

how different pH levels in brackish water affect the growth and

development of lettuce plants. We'll diligently provide optimal conditions

of growth, closely monitoring their development into thriving leafy greens.

And carefully managed environmental factors, nutrient levels, and growth

phases, ensuring the optimal progression towards the desired date when

the leaves reached the peak flavor and nutritional value.

 Definition of Terms

The following terms will be defined to be understood easily and as used

in the study.

Adaptability- Refers to the ability of an organism, system, or individual

to adjust or change in response to varying conditions, circumstances,

or environments. It involves the capacity to thrive, survive, or

function effectively in the face of changing situations. Adaptability is

a fundamental trait that allows living organisms and complex

systems to respond to challenges, uncertainties, and opportunities.

Brackish water - Refers to the water occurring in a natural environment

that has more salinity than freshwater, but not as much as

seawater. It may result from mixing seawater and freshwater, as in

estuaries, or it may occur in brackish fossil aquifers.

Coco peat-

Hydroponics- refers to the technique of growing plants using a water

based nutrient solution rather than soil, and can aggregate

substrate, or growing media, such as vermiculture, coconut coir, or

perlite. Hydroponic Solution- refers to the

pH levels- often referred to simply as "pH," is a measure of the acidity or

alkalinity of a substance, typically a liquid such as water. The Ph

scale ranges from 0 to 14, with 7 considered neutral.

PPT- refers to how many parts, or grams, of salt there are per thousand

parts, or kilogram(1,000g), of seawater.

Romaine lettuce - refers to a type of salad lettuce. It comes from the

same plant family as other types of lettuce. The name "romaine"

suggests that the lettuce might have originated in Rome. It also

grows well in a Mediterranean climate. Romaine lettuce leaves are

long and taper toward the root of the lettuce.

Salinity- refers to the concentration of dissolved salts, primarily sodium

chloride (table salt), in water. It is typically expressed as the

amount of salt (in grams) dissolved in a unit volume of water (often

in parts per thousand, or ppt, or parts per million, ppm). Salinity is a

critical parameter in various environmental, agricultural, and scientific

contexts and plays a significant role in the physical and chemical

properties of water.

Vermicast- refers to the end-product of the breakdown of organic matter

by earthworms.
 CHAPTER II

REVIEW OF RELATED LITERATURE

Natural Pest Control

Several studies have shown that it is possible to use brackish

waters to produce lettuce hydroponically, and the tolerance to salts may

be higher than that obtained in conventional cultivation in soil. (ALVES ET

AL. 2011; Dias et. al., 2011; Paulos et. al., 2010; et. al., 2010; Soares et.

al., 2010) Lactuca sativa is a member of the Lactuca (lettuce) genus

and the Asteraceae (sunflower or aster) family. Lettuce is closely related

to several Lactuca species from southeast Asia (Zohary et al., 2012).

Lettuce was first cultivated in ancient Egypt for the production of oil

seeds. This plant was probably selectively bred by the Egyptians into a

plant grown for its edible leaves (Katz & Weaver).

Lettuce is most often used for salads,

although it is also seen in other kinds of food, such as soups, sandwiches,

and wraps; it can also be grilled (Hugh Fearnley Whittingstall, 2013).

Conservation of soil and water resources is very important for the

sustainability of agriculture production and the environment. Nowadays,

soil and water resources are under great pressure due to the increasing
population at the growing demand for food. Coupled with urbanization,

soil and water quality are deteriorating, and it causes a lot of problems in

agricultural production.

Hydroponics

Hydroponics is a technique of growing plants in nutrients with or

without the use of an Inert medium such as gravel, vermiculture, rock

wool, Peat moss, saw dust, coir dust coconut fiber, etc. To provide

mechanical support. The term Hydroponics was derived from Hydroponics

the Greek words "Hydro" which means water and ponos means labor and

means water work. The word hydroponics Was coined by Professor

William Gericke in the Early 1930s; to describe the growing of plants with

Their roots suspended in water containing mineral Nutrients. Researchers

at our University Developed the nutriculture system in 1940. During the

1960s and 70s, commercial hydroponics farms were Developed in Arizona,

Abu Dhabi, Belgium, California, Denmark, Germany, Holland, Iran, Italy,

Japan, Russia, the Federation and other countries. Most hydroponic

systems operate automatically to control the amount of water, nutrients,

and Photo period based on the requirements of different plants

(Resh,2013)
 Salinity Tolerance

It is worth highlighting that plants exposed to salt, and stress

reduce water consumption, as observed by Paulus et al.(2012) for

lettuce(cv. Veronica), in which salt stress compromised water use

efficiency and its relative content, In addition, for restricting the growth of

the photosynthetically active area of the plant, It minimizes Carbon

fixation and consequently biomass production (Negrao; Schmockel;

Tester,2016), thus leading to disadvantages in water and physiological

relationship of plants.

Several studies have shown that it is possible to use brackish waters to

produce lettuce hydroponically, and the tolerance to salts may be higher

than that obtained in conventional cultivation in soil. (Alves et al. 2011;

Paulo et, al., 2010; Soares et, al., 2010)

Several studies have also investigated the use of brackish water in

hydroponic systems for lettuce production. The effect of different levels of

brackish water on the growth and yield of lettuce in a hydroponic system.

The study showed that lettuce could tolerate brackish water up to a

certain level and that the use of brackish water had no negative effect on

lettuce growth and yield under the experimental conditions. Niu et al.

(2019) Furthermore, a study investigated the use of brackish water in

hydroponic systems for the production of lettuce, tomato, and cucumber.

The study showed that the use of brackish water had no negative effect

on plant growth and yield and that the use of hydroponic systems

significantly increased crop productivity compared to soil-based systems.

Abdelhamid et al. (2020)

Plant tolerance against stresses at the whole plant can be

defined as maintaining the ability of growth and metabolic process under

adverse stress conditions. (Munns and Tester 2008).

Plants are categorized as either glycophytes or halophytes

depending on how well they tolerate salt conditions. A halophyte salt

condition is a naturally evolved salt-tolerant plant that has adapted to

grow in saline environments. Species of halophytes that require saline

conditions to survive are called obligatory halophytes (Singh et al., 2014).

Adaptability

Salinity is a problem that has been getting worse over the years in

several regions of the world threatening and compromising crops, where

the adaptability of good quality freshwater) water is scarce, the option

found in by-products is the use of high-salinity waters in their growing

areas (Singh, 2015). The use of saline waters in hydroponic cultivation

might be an alternative, assuming that the plants grown in this system are

usually more tolerant to salinity, According to Tavakkoli et al., (2010)

plants growing in saline soils not only have cope with the effects of a soil

solution that may be high in salt but also with the effects of the soil matric

potential whereas water uptake in hydroponics is only affected by the

osmotic potential of the nutrient solution. Thus, recently several types of

research have been carried out aiming at the use of saline waters in the

hydroponic system (D'Imperio et al., 2018; Lemos Neto et al., 2018).

Salinity Effect

Among environmental stressors, salinity is one of the most

detrimental factors leading to severe losses in crop yield and quality

(Aslam et al., 2017; Grieve et al., 2011). According to Fao (2015), more

than 100 countries are affected by soil salinization and their extent is

estimated at 1 billion ha, worldwide. Several research studies report a

constant increase in soil salinization due to both natural causes and

improper agricultural practices (Adhikari et al., 2019; Molina–Montenegro

et al., 2020). In addition to seawater intrusion, agriculture in coastal

regions is further exacerbated by salt spray and salt deposition produced

by saline aerosols during storms of high winds (Ferrante et al., 2011; et

al., 2011).

Soilless Cultivation

In particular, the technological advancement of closed soilless

(hydroponic) cultivation systems (SCS; e.g., nutrient film, floating, and

pot-and-sacs-systems) based on recirculating nutrient solutions has

maximized productivity per unit area notably in terms of water use

efficiency, by maximizing root contact with the nutrient source while

minimizing evaporation and nutrient runoff (Treftz and Omaye, 2016).

Despite the high capital investment and technological proficiency required

for managing soilless systems, their expansion is propelled by the efficacy

of optimized year-round production and standardized product quality.

Lettuce Health Benefits

According to Kim et al., (2016) lettuce, a low-calorie, low-fat, and

low-sodium salad vegetable, is a good source of fiber, folate, vitamin C,

and important minerals like iron. Other naturally occurring phytochemicals

and vitamins that are known to promote health are also plentiful in
lettuce. These include glycosylated flavonoids,

hydroxycinnamic acids, sesquiterpene lactones (such as lactucin and

lactucopicirin), carotenoids, group B vitamins, ascorbic acid, and

tocopherols. Lettuce secondary metabolites are potentially associated with

many health-beneficial properties, including anti-free radical, anti-

inflammatory, antidiabetic, anticancer, and anti cardiovascular diseases

(CVDs) effects (Kim et al., 2016).

Production Trends of Lettuce

According to estimates from the UN's Food and Agriculture

Organization (FAO),1.1 million hectares of lettuce were used to produce

23.6 million metric tons (mmt) of commercial lettuce in 2010. China

dominated production with 12.6 mmt or slightly over half of the total, and

the U.S. in the second place, produced 4.0 mmt, or another 17%. The

other nations with harvests of more than 800,000 metric tons were Spain,

Italy, and India. The FAO compiles statistics on the output of lettuce and

chicory (PCARRD,2007).

In the Philippines, Benguet, Bukidnon, and Cavite are the main

regions where lettuce is farmed(Tagaytay). In 2010, the country produced

3,634.12 MT from 465.98 hectares, with the Cordillera region producing

1,486.15 MT from a production area of 160 hectares (BAS,2010). In

Region XI, lettuce production declined in 2018 from 61 metric tons

produced in 2017 to 59 metric tons produced in 2018 in an area harvested

of 11 hectares (PSA,2019)

Related Study

There has been a lot of research related to the soil cultivation of

lettuce using hydroponics in brackish water. The said studies that utilized

laboratories are as follows:

Soares et al., (2007) reported in their Studies in the literature

confirm that the use of brackish water is related to the crop tolerance to

salt stress, and most of them were performed with lettuce crops (Lactuca

sativa L.), which stands out in Brazil as the most produced vegetable in

the hydroponic system Nutrient Film Technique (NFT).

In another study by Machado and Serralheiro, 2017: Xu and

Mou, (2015) stated the effect of salinity on crops depends on several

factors such as the level of salt concentration, the duration of the

exposition, the plant phenological stage, and the genotype. These aspects

vary among species and varieties of a given crop.

Signore; Serious; Santamaria, (2016) Niu; Sun; and

Masabani, (2018) Proposed the technique of hydroponics (cultivation

without land use) as an alternative to the use of brackish water. Soares et

al., 2007; Dias et al., (2011) In cultivation hydroponics, the response

of plants to salinity is better than in soil, considering the greater

availability of water for plants, since in hydroponics the matric potential

tends to zero

In the study developed by Tesi; Lenzi and Lombardi (2003), with

lettuce in a DFT hydroponic system and different recirculation frequencies,

it observed that oxygen deficiency (nutrient solution) not aerated caused a

reduction significant in the fresh mass of the head and roots, dry mass of

the head and diameter of the head. According to Tesi, Lenzi, and

Lombardi (2003), the dissolved oxygen content tends to to decrease with

the increase in the temperature of water.

 Conceptual Framework

INDEPENDENT VARIABLE DEPENDENT VARIABLE

GROWTH PERFORMANCE OF ROMAINE LETTUCE

-Plant height

-Plant weight
-Number of leaves

-Width

-length

-Highest plant survival

DIFFERENT SALINITY LEVEL OF

BRACKISH WATER AS TREATMENT

T1- Control- Freshwater

T2-5 ppt salt water

T3-10 ppt of salt water

T4-15 ppt of salt water

T5- Chemical nutrient

Figure 1 Diagram Showing the Conceptual Framework of the Study.

The conceptual framework shows the relationship between the

independent variable and the dependent variable of the study. The

different pH levels of brackish water which are the four treatments is

considered to be the independent variable. The dependent variable

includes the growth of lettuce plants in every treatment.

Hypothesis

Ho1. There is no significant difference salinity level of brackish in lettuce

under the hydroponics system leading to the various plant height numbers

of leaves and overall yield.

Ho2. There is no significant difference in the romaine lettuce plant height

using different levels of brackish water under a hydroponics system.

CHAPTER III

METHODOLOGY

Research Locale

This study will be conducted at Southern Philippines Agri-business

Marine and Aquatic School of Technology, Poblacion Malita, Davao

Occidental. The researchers chose this place to conduct the study because

of the availability of equipment, materials, facility, and the area that the

researchers will need in the conduct of the study, the SPAMAST hatchery

campus in Malita stands as a bastion of research excellence. This vibrant

locale serves as an invaluable hub for advancing hydroponics knowledge

and hatchery methodologies. Surrounded by the rich biodiversity of the

region, our research endeavors here are uniquely positioned to contribute

sustainable practices in the hydroponics industry. The campus not only

provides a dedicated space for scientific inquiry but also cultivates an

environment of collaboration, enabling researchers to address pressing

challenges and explore innovative solutions.

Figure 2. Map of SPAMAST Malita, Davao Occidental.

Research Design and Treatment

This experimental study will be using Completely Randomized

Design (CRD) to assign different salinity levels of brackish water in each

styro box. There will be four treatments and each treatment has a

different percentage of salinity levels of brackish water. The study used

150 seedlings of romaine lettuce divided into 3 replications. Treatment 1

uses as the control which uses fresh water, treatment 2 uses 5ppt,

treatment 3 uses 10ppt, treatment 4 uses 15ppt, and treatment 5 uses

chemical nutrients. The spacing of the plant ranges from 6 to 8 inches

apart.

TREATMENTS
Treatment 1 –Control- fresh water

Treatment 2 –5 (PPT) of Saltwater

Treatment 3 –10 (PPT) of Saltwater

Treatment 4 –15(PPT) of Saltwater

Treatment 5- Chemical nutrient

Table 1. Different treatments of romaine lettuce at different levels of

brackish water.

Saltwater

The seawater needed for this experimental study will be obtained

from the SPAMAST campus, while the tap water will be sourced from

within the SPAMAST campus premises and will be utilized in this

experiment.

Process of mixing Saltwater and tap water

Collecting Saltwater

Mixing tap and saltwater

Measuring the range of salinity level

Transferring to styro boxes

Final proceeding
Figure 3. Process of combining salt and tap water

Materials Procurement and Preparation

Brackish water preparation

The researchers will prepare the right ratio of brackish water to

obtain the right amount of saline level of the water in each treatment, the

first treatment has a 5% salinity level, treatment 2 has 10%, treatment 3

has 15% and treatment 4 has 20% to have.

Romaine Lettuce

Due to the rarity of its variety, it is somehow hard for the

researchers to find the seeds in any agricultural-based shops here in

Malita Davao Occidental. Therefore, we obtained the seeds through the

assistance of a popular Farm located at Brgy. Little Baguio Malita Davao

Occidental.

Styro box

To meet the requirements of our study, we purchased sixteen boxes

of styro from the Citi Star store in Malita that have a 25cm length and

25cm width. We the researchers find styro boxes that are fit and perfectly

suitable for our study.

Cultural Management and Practices

Nursery Establishment

The area will be cleaned properly by installing a semi-greenhouse

type of venue. The experimental area is around 3.5 meters generated in 4

blocks. Each row represents treatment. 1,2,3 and 4. Each styro box had

10 romaine lettuce plants per treatment. There were a total of 160

romaine lettuce plants for the 16 styro boxes.

Sowing

The researchers prepare seedling trays for the cultivation of

romaine lettuce seeds, utilizing vermicast to expedite the germination

process.

Transplanting

The lettuce plant will be transplanted in the wholes of the cups

after transferring it from the seedbed per styro boxes, 10 each per styro

box 8 inches apart to allow sufficient space for plant growth.

Harvesting

Romaine lettuce is typically ready for harvest when the heads reach

a mature size and have a firm, compact shape. This usually occurs

between 60 to 70 days after planting. But also, growing conditions, and

your desired maturity level.

Lighting and temperature

The research study will be placed at the hatchery in front of the

SPAMAST campus, which has controlled lighting and temperature that are

needed for the lettuce to grow well. We will monitor the growing

environment and adjust as needed to ensure a safer and proper

environment for our plants.

Pest and disease management

Romaine lettuce is susceptible to a variety of pests and diseases,

such as aphids, plea beetles, and other insects, since pesticides are not

the focus of the study we will monitor the plants for signs of pests or

diseases and take appropriate action, such physical ways of treatments

without using any chemical.

Data to be gathered

Plant height (mm)

Measuring the lettuce height at the end of the week. After 1 week

since the plant transferred to the styro boxes, monitoring its height

adaptability in brackish water.

Plant weight (gram)

After the desired period to harvest the romaine lettuce plant in

each treatment, the researchers will keep track of recording the weight of

the plant using a weighing scale measuring the weight of the lettuce in

grams. This will determine which treatment has the higher yield of

romaine lettuce.

Number of leaves

We the researchers will count the number of plant leaves weekly,

and record every plant leaf in each treatment. This will serve as one of the

bases on which treatment the lettuce plant is suitable.

Statistical Treatment

Analysis of the data will be conducted using the Analysis of

Variance or (ANOVA) in a Complete Randomize Design (CRD) to test

whether the treatment obtained a significant difference. Once the ANOVA

is conducted, a post-hoc test called Tukey's honest significant differences

(HSD) test will be employed. Tukey's HSD test allows for multiple pairwise
comparisons between which specific treatments differ significantly from

each other.

Ethical Consideration

The ethical purposes, the researcher writes a courtesy letter asking

for permission to conduct the study. The researcher personally handed the

letter to the adviser for checking and correction. After permission from the

adviser and head Education Department, the researcher started

conducting the study.