Chapter I INTRODUCTION Background of the Study Philippines is an agricultural and tropical country producing a variety of vegetation. Small communities even those located in the city practice organic farming to save more, ensure quality and inexpensive produce. Organic farming is a method of livestock and crop production without the use of fertilizers, pesticides, growth hormones, antibiotics and genetically modified organisms. But this still does not ensure the same quality of produce and there are many factors to consider that may affect the growth of the plant (Far Eastern Agriculture, 2012). Pondus Hydrogenii or more commonly known as pH indicates a solution’s acidity or alkalinity. Acidity is essential for life forms on earth as it often determines the characteristics, quality, absorbability and solubility of different substances. With the correct acidity, enzymes function to control biological processes in organisms. A demonstration of the importance of pH is that a small fluctuation in the blood’s acidity can be jeopardizing (Fondriest Environmental, 2013). Varieties of plants have different tolerance for pH levels. Some may flourish in mildly acidic, neutral, or alkaline environments. Water is another factor that affects the pH level of the environment of the plant. Abelmoschus esculentus (okra plant) is a vegetable known for its high dietary fiber content. Usually consumed by diabetics, and has many more benefits. It grows best on loamy soil, needs full exposure to sun, therefore, height is an important factor, and its peak season is at summer time. This research study aims to see the effect of different pH levels of water to the growth of an Abelmoschus esculentus (okra plant) 1 and to determine which pH level is best to achieve optimum plant height (Tong, 2016). Statement of the Problem This study primarily aims to help contribute information about the effect of different pH levels of water (1.0, 4.0, 7.0, 10.5, and 14.0) to the growth of Abelmoschus esculentus (okra plant) and determine which pH level is best for the growth of the A. esculentus. Specifically, it aims to answer the following questions: 1. How do different pH levels of water affect the height of A. esculentus? 2. Which pH level of water is best to achieve optimum plant height of A. esculentus? Initial hypotheses are the following: 1. There will be no significant difference on the effect of different pH levels on the height of the plant. 2. Acidic pH levels produce optimum plant height. Alternative hypotheses: 1. Different pH levels will have a significant effect on the height of the plant. 2. Basic pH levels produce optimum plant height. 2 Significance of the Study The researcher’s purpose for conducting this study is to find out if pH level of water affects the growth of an Abelmoschus esculentus (okra plant) and which pH level of water is best to achieve optimum height. The community may receive benefits from this research study especially households or communities that practice organic farming. Further research may be conducted to validate of the effect of pH levels of water to the growth of an A. esculentus (okra plant) and different ways to raise or lower the pH level of the environment fit for the pH preference of the plant. Scope and Delimitations The focus of the study is the effect of different pH levels of water to the growth, specifically the height of Abelmoschus esculentus (okra plant) and determine which pH level produces optimum plant height. It used water with pH levels ranging from 1.0, 4.0, 7.0, 10.5, and 14.0. Calamansi juice (citric acid) and baking soda may be used as substitute for sulphur and agricultural lime respectively to raise or lower the pH level of water. It does not include other tests of other pH levels of water, tests on other types of plant, and different amounts of water, besides the one used in the experiment. This study only used pH meter to determine the pH level of water, soil pH tester for the pH of soil, method of measuring height via ruler. This study was conducted for 14 days including data collection. 3 Definition of Terms Abelmoschus esculentus - scientific name of the cultigens vegetable plant okra or okro or in English – speaking countries ochro or ladies’ fingers. It is a flowering plant in the mallow family. It is valued for its edible green seed pods. Acidity - the amount or level of acid present in substances such as water, soil or wine. Acidity often determines the characteristics, quality, absorbability and solubility of many substances. Agricultural lime - a soil additive made from pulverized limestone or chalk, which has the primary active component of calcium carbonate used to increase alkalinity of soil. It is also called aglime, agricultural limestone, garden lime or liming. Alkalinity - the quantitative capacity of an aqueous solution to neutralize an acid. This usually measures the basicity or how “strong” the bases are in a solution Cultigen - a plant that has been altered by humans through a process of selective breeding. pondus Hydrogenii - the indicator of acidity or alkalinity of a particular solution. The pH value usually varies between 0 and 14. A solution with a pH value ranging from 0 to 7 is considered an acid and a value in between 7 to 14 is alkaline. A pH value of 7 is considered neutral. 4 Sulphur - a pale yellow, odorless, brittle solid, which is insoluble in water but soluble in carbon disulphide. Sulphur is essential to life. It is a minor constituent of fats, body fluids, and skeletal minerals. This is can also come in powdered forms usually used in agriculture to lower pH levels of soil. 5 Chapter II REVIEW OF RELATED LITERATURE Abelmoschus esculentus (okra plant) Okra, also known as “lady’s fingers” and “gumbo,” is a green flowering plant that belongs to the same family as hibiscus and cotton. The term “okra” commonly refers to its edible seedpods. It contains potassium, vitamin B, vitamin C, folic acid, and calcium, it also has low calories and has high dietary fiber content. Okra has been suggested to help lower cholesterol and manage blood sugar in cases of type 1, type 2, and gestational diabetes (Watson, K., 2016). According to P.S. Tong (2016), the okra plant has been cultivated for nearly centuries originating from Africa and now widely cultivated in tropical or sub-tropical countries. There are numerous uses for this plant such as: source of food pertaining to the vegetable itself and its flower buds; using its mucilage to different dishes, clarifying sugar cane juice in making molasses, and glazing paper in China, okra leaves can also be used as cattle feed, roasted okra seeds as substitute for coffee and it can also be used to extract edible oil; its seeds, fruits, mucilage and roots are used in some medical practices and lastly, its stem yields an inferior fiber that can be used in creating cord and paper. Okra prefers well-drained, sandy soils that are high in organic matter, but it can be grown in a wide variety of soils. Okra can tolerate a pH range of soil from 5.8 to 6.8 and grows best in full sunlit area. It is recommended to plant when soils have warmed up to at least 65 degrees F at a 4-inch depth (Westerfield, R., 2014). 6 pH level The pH (pondus Hydrogenii) indicates a solution’s acidity or alkalinity. A solution with a pH value of 0 to 7 is acid and one of 7 to 14 is alkaline. A pH value of 7 is considered neutral. The pH of tap water is generally a little higher due to the presence of calcium. Acidity often determines the characteristics, quality, absorbability and solubility of many substances. This is how enzymes, which are responsible for almost all biological processes in organisms, work, but only with the correct acidity (Fondriest Environmental, 2013). One of the most important factors determining the pH value in a solution or in the substrate is the buffering capacity. The buffering capacity in this instance means that there is a balance present that continually restores itself. The buffering capacity and the substrate’s acidity depend on its composition and freshness. The presence of organic material, calcium and bicarbonate generally determine the pH. Clay always contains calcium carbonate and has a relatively high pH value which is difficult to change, while peat and sandy soils are acid (Fondriest Environmental, 2013). The plant itself has great influence on the acidity. The roots will secrete either acid or alkaline substances depending on the crop’s stage of development, the food available, the differences in root temperature and light intensity. So the pH of the root environment constantly fluctuates. A sophisticated feeding balance during the different phases of development will keep the pH in the root environment within acceptable limits (Tiamson, et. al, 2015). When cultivating in substrate pH values of between 5.0 and 6.4 are generally fine for the root environment depending on the plant. There will not be any adverse effects if the values are a little higher or lower. Immediate adverse effects will only be seen with values lower than 4 and 7 higher than 8. pH values lower than 4 often cause immediate damage to the roots. In addition, heavy metals, including manganese and iron are absorbed so well that they can poison the plant (necrosis). Values between 7 and 8 are not immediately harmful for the plant. Nutrients such as iron, phosphate, and manganese are less available then which will lead to deficiencies such aschlorosis and developmental problems in the long run (pH acidity, n.d.). 8 Chapter III RESEARCH METHODOLOGY Research Design The study utilized the Randomized Complete Block Design (RCBD) (See Appendix B) because only one (1) independent variable was manipulated in the study: the pH level of water 1.0, 4.0, 7.0, 10.5, and 14.0 respectively. The variables that remained constant throughout the study were the following: the amount and pH level of soil used, amount of water, growth time, calamansi juice (citric acid) as substitute to sulphur to lower pH, baking soda as substitute to agricultural lime to raise pH, plastic cups used as pots, measuring method via ruler, location of testing, process for testing soil pH via soil pH tester and the process of testing through pH meter. Preparation of the Set-up Twenty (20) A. esculentus seeds were soaked in 30 ml of tap water for 12 hours in a bowl. There were 5 set-ups namely set up A for water with pH level of 1.0, set up B for water with pH level of 4.0, set up C for water with pH level of 7.0, set up D for water with pH level of 10.5, set up E for water with pH level of 14.0. Each set up was placed in a plastic cup with their respective labels. Each cup was filled with 150 grams of soil of the same pH level then 4 seeds were sown per set-up. Each set-up was repeated twice to conduct 3 trials. 125 ml or ½ cup of tap water was prepared per set up. The pH level was tested and adjusted with baking soda or calamansi juice accordingly per set up. Each set-up was watered 20ml once with their respective assigned pH levels daily. 9 The set-up was divided into 5 groups: set-up A, B, C, D and E respectively. Each group had three (3) cups to represent trials 1, 2 and 3. The cups in each set-up was labeled accordingly: A1, A2, A3 for water with pH level of 1.0, B1, B2, B3 for water with pH level of 4.0, C1, C2, C3 for water with pH level of 7.0, D1, D2, D3 for water with pH level of 10.5, and E1, E2, E3 for water with pH level of 14.0. Set-up C will be the control group while set-ups A, B, D and E will be the experimental group. Data Collection Daily height of each plant was measured and recorded in a span of 14 days. Collected data from each set-up was presented in a data table and the average measures of height (mean) of the plants were calculated. Average plant height was presented in a graph and average daily height was shown in a time-series graph. Analysis For the analysis of the data, this study used the F-test and the Tukey test as the statistical tool to see if there is any significant difference between the mean heights of plants in each set-up. The data was compared and the tallest average plant height and shortest plant height were determined. The pH levels from shortest to tallest plant height produced was then ranked. For each set-up the tallest and shortest plant height achieved in each level was identified. Lastly, the research question and hypotheses was addressed then the conclusion and results were formulated and discussed respectively. 10 Chapter IV RESULTS AND DISCUSSION The effect of different water pH levels in the growth of A. esculentus was investigated, focusing on the height of the plant. The height of each plant in the different set-ups was measured and recorded after 14 days of exposure to the water samples. The average daily height of the plants in each set-up is shown in Table 1.1 Table 1.1 The Effect of Different pH levels on the Average Daily Height (cm) of A. esculentus SET-UP DAY 1 DAY 2 DAY 3 DAY 4 DAY 5 DAY 6 DAY 7 DAY 8 DAY 9 DAY 10 DAY 11 DAY 12 DAY 13 DAY 14 A - 1.0 B - 4.0 C - 7.0 D - 10.5 E - 14.0 0 0.77 1.8 2.97 4.23 5.63 6.13 6 6.67 6.67 6.9 7.17 7.17 7.17 0 0.5 1.83 3.67 5.16 6.67 7.5 8 8.5 8.5 8.83 9.17 9.67 10.33 0 0.17 0.67 1.5 2.67 4.5 5.67 7.8 8.33 8.5 9.1 9.83 10 10 0 0.93 1.73 3.83 4.17 5.17 5.5 3.17 3.17 0 0 0 0 0 0 0 0 0.17 0.33 0.33 0.33 0 0 0 0 0 0 0 The data shows the averaged growth rate of the plants of trials 1, 2 and 3 of each set-up in a span of 14 days. Set-ups A, B and C grew progressively each day while set-ups D and E yielded plants but then withered on the 9th and 7th day respectively. According to the data gathered Set-up B with the pH level of 4.0 achieved the tallest average height of 10.33 cm; 0.33 cm higher than set-up C, the controlled group, 11 and 3.16 cm than set-up A. Ranked second is Set-up C with 10 cm, Setup A with 7.17 cm, and ranked last with the shortest average height is Set-up D and E with 0 cm. Figure 1.1 Average Daily Height (cm) of A. esculentus for 14 days The data does not seem to support the first initial hypothesis stating that there will be no significant difference on the effect of different pH levels on the height of the plant but supports the second hypotheses which states that acidic pH levels would produce optimum plant height. Table 1.2. Height of each set-up per trial on final day (day 14) DAY TRIAL 1 14 2 SET-UP A (1.0) 0 cm Wilted 11.5 cm Damaged leaves 10 cm SET-UP B (4.0) SET-UP C (7.0) 5.5 cm 10.5 cm 13.5 cm 10.5 cm 12 cm 9.5 cm 3 SET-UP D (10.5) 0 cm Wilted 0 cm Wilted 0 cm Wilted SET-UP E (14.0) 0 cm Wilted Wilted Sprout no established roots Wilted Sprout no established roots The best pH level to achieve optimum plant height would be Setup B with a 4.0 pH level achieving the tallest height 13.5 cm on Table 2, trial 2 and with the average height of 10.33 cm in Table 1. Though Set12 up A has the second tallest height of 11.5 cm, Set-up C is recommended as all plants in the trials are healthy and achieved an average height of 10 cm while Set-up A trial 2 yielded damaged leaves and Set-up A trial 1 wilted. Figure 1.2. Height of each set-up per trial on final day (day 14) The data shows that on day 14, Trial 2 of set-up B yielded the tallest plant height among the other trials of other set-ups. Trials 2 of set-ups A, B and C produced the tallest plant height each in their own respective set-up. Detailed Computations on Appendix C SET-UP A (1.0) 0 cm 11.5 cm 10 cm SET-UP B (4.0) 5.5 cm 13.5 cm 12 cm SET-UP C (7.0) 10.5 cm 10.5 cm 9.5 cm SET-UP D (10.5) 0 cm 0 cm 0 cm SET-UP E (14.0 0 cm 0 cm 0 cm ππ΄ = 3 Μ π΄ = 7.17 π π2 π΄ = 39.083 ππ΅ = 3 Μ π΅ = 10.33 π ππΆ = 3 Μ πΆ = 10 π ππ· = 3 Μ π· = 0 π ππΈ = 3 Μ πΈ = 0 π π2 π΅ = 18.083 π2 πΆ = 0.375 π2 π· = 0 π2 πΈ = 0 13 Analysis of the mean height was done with the use of the F-test or one-way ANOVA with a critical value of 3.48 at 0.05 level of significance. The obtained F-test value was 6.96 which prove that there is a significant difference among the mean height of the okra plants watered with the different water samples (See Appendix C). The Tukey’s Honest Significant Difference test was utilized to see where the difference lies, using the critical value of 4.65 at 0.05 level of significance. The resulting πΉπ‘ value of 1.44 showed that there is no significant difference between the mean height of okra in the set-up C (control group: pH 7.0) and those watered in set-up A (pH 1.0). Comparison of the means of control group (set-up C) and set-up B (pH 4.0) with πΉπ‘ value of 0.17 also showed that there is no significant difference between the two means. The same is true with the comparison of the means of set-up A and D and E; set-up A and B; and set-up D and E with the πΉπ‘ values of 3.66, 1.61, and 0 respectively. The statistically significant difference was found to exist between the means of control group (Set-up C) and Set-up D and E (pH 10.5 and 14.0), with the πΉπ‘ value of 5.11 (See Appendix D). The same is true with the comparison of the means of set-up B and D and E; the πΉπ‘ value of 5.27. From the results, the values that surpassed the critical value in the Tukey test mean that pH levels have a significant difference to one another; proving that the second alternative hypothesis was correct. This also proved the second initial hypothesis was correct as acidic pH levels produced the optimum plant height with a 10.33 cm average and 13.5cm individually in pH level of 4.0 compared to basic pH levels, but did not have a significant difference with the control group. 14 Chapter V SUMMARY, CONCLUSION AND RECOMMENDATIONS Summary The study aimed to compare the effect of different pH levels on A. esculentus (okra) plant. The focus of the study is the effect on growth in terms of growth rate and height, statistical analysis using F-test of oneway ANOVA proves that a significance difference exist between the mean height with the obtained F-test value of 6.96 at a critical value of 3.48 and 0.05 level of significance using the Tukey test, with the critical value of 4.65 at 0.05 level of significance, statistically significant difference was formed to exist between the mean height of the following set-ups: 1) B and D; 2) B and E; 3) C and D; and 4) C and E with πΉπ‘ values of 5.27, 5.27, 5.11, and 5.11 respectively. Conclusion Analysis of the results led to the following conclusions: 1. The data gathered showed support with the second alternative hypothesis in which that pH levels does have a significant difference on plant height with an F-test value of 6.96. 2. The results seem to support the second initial hypothesis in which lower pH levels yielded taller plant height specifically pH levels of 4.0 and 7.0 compared to pH levels of 10.5 and 14.0 as seen in the πΉπ‘ values of 5.27, and 5.11 respectively. 3. A pH level of 4.0 is best to yield optimum plant height for Abelmoschus esculentus (okra) plant as seen in the experimentation with an average of 10.33 cm and 13.5 cm in trial 2 individually. 15 4. The results lead to debunking the second alternative hypothesis as seen that basic pH levels do not produce optimum plant height with an average height of 0 cm. Recommendations By using this study as a reference, the researcher recommends the following: 1. Use of different type of plants for more variation and comparison. 2. Use other different levels in the pH scale for more data in the between group variance. 3. Use pots instead of plastic cups and extend experimentation duration to have data on long-term effects of the different pH levels. 16 BIBLIOGRAPHY Journals Tong, P.S. (2016). Okra (Abelmoschus esculentus) – a popular crop and vegetable. Utar Agriculture Science Journal. Vol. 2, No 3, pp. 3941. Books Tiamson, M.E., Avissar, Y., Choi, J., Jurukovski, V. and Wise, R. (2015). Plant Adaptations to Life on Land. General Biology. (pp. 218 – 219). Open Stay College Phil. Adaptation 2016 Vibal Group. Online Journals Maghirang, R. G., De La Cruz, R., and Villareal, R. (2011). 4 How Sustainable is Organic Agriculture in the Philippines [PDF]. Trans. Nat. Acad. Sci. & Tech. (Philippines) Vol. 33 (No. 2) ISSN 01158848. p. 289 – 295 Westerfield, R. (2014). Home Garden Okra [PDF]. UGA Extension Circular 941. extension.uga.edu/publication Online News Articles Far Eastern Agriculture. (2012, May 8). Organic farming: The future of Philippine Agriculture. Retrieved from: http://www.fareasternagriculture.com/crops/agriculture/organicfarming-the-future-of-philippine-agriculture Fondriest Environmental, Inc. (2013, November 19). pH of Water. Fundamentals of Environmental Measurements. Retrieved from: http://www.fondriest.com/environmentalmeasurements/parameters/water-quality/ph/ >. pH acidity: what it does to your plants. (n.d.) Retrieved from: http://www.canna-uk.com/ph_acidity 17 Watson, K. (2016, January 26). Benefits of Okra for Diabetes. Retrieved from: https://www.healthline.com/health/diabetes/okra#2 18 APPENDIX A Schematic Diagram START Step 1: Soak 20 seeds in 20 ml of tap water in a bowl for 12 hours. Step 2: Label each cup A1, B1, C1, D1 and E1. Repeat this step twice but changing the numbers for each trial. Step 3: Fill the cups with 150g of soil with the same pH level. Step 5: Adjust the pH levels with calamansi juice or baking soda accordingly per cup. Step 6: Water 20 ml of the water samples to the set-ups once, measure & record for 14 days for 3 trials. Step 7: Create tables, graphs, organize and analyze the data. Step 8: Report the results. 19 Step 4: Sow 4 seeds per cup. Prepare ½ cup of water for each set-up. APPENDIX B Documentation Measuring soil pH Adjusting pH level 1.4 Adjusting pH level 10.5 Measuring 150g of soil Adjusting pH level 4.0 Adjusting pH level 7.1 Adjusting pH level 14.1 20 DAY 1 DAY 2 DAY 3 DAY 4 DAY 5 DAY 6 DAY 7 DAY 8 21 DAY 9 DAY 10 DAY 11 DAY 12 DAY 13 DAY 14 22 APPENDIX C Detailed Computations F- Test SET-UP A SET-UP B (1.0) (4.0) 0 cm 5.5 cm 11.5 cm 13.5 cm 10 cm 12 cm ππ΄ = 3 ππ΅ = 3 πΜ π΄ = 7.17 πΜ π΅ = 10.33 2 π π΄ = 39.083 π 2 π΅ = 18.083 N= 15 k= 5 d.f.D. = 10 d.f.N = 4 Critical Value: 3.48 SET-UP C (7.0) 10.5 cm 10.5 cm 9.5 cm ππΆ = 3 πΜ πΆ = 10 2 π πΆ = 0.375 SET-UP D (10.5) 0 cm 0 cm 0 cm ππ· = 3 πΜ π· = 0 π2π· = 0 πΌ = 0.05 πΜ πΊπ = 5.5 π 2 π΅ = 80.15085 π 2 π = 11.5082 F-Test Value: 6.96 SET-UP E (14.0 0 cm 0 cm 0 cm ππΈ = 3 πΜ πΈ = 0 π2πΈ = 0 (0 − 7.17)2 + (11.5 − 7.17)2 + (10 − 7.17)2 π π΄= = ππ. πππ 3−1 2 2 (5.5 − 10.33) + (13.5 − 10.33) + (12 − 10.33)2 π2 π΅ = = ππ. πππ 3−1 2 2 2 (10.5 − 10) + (10.5 − 10) + (9.5 − 10) π2 πΆ = = π. πππ 3−1 2 2 2 (0 − 0) + (0 − 0) + (0 − 0) π2 π· = =π 3−1 2 2 2 (0 − 0) + (0 − 0) + (0 − 0) π2 πΈ = =π 3−1 2 Μ πΊπ = π π2 π΅ = π2 π΅ = ∑ πΜ 7.17 + 10.33 + 10 + 0 + 0 = = π. π π 5 3(7.17 − 5.5)2 + 3(10.33 − 5.5)2 + 3(10 − 5.5)2 + 3(0 − 5.5)2 + 3(0 − 5.5)2 4 320.6034 4 = ππ. πππππ π2 π = ∑[(3 − 1) 39.083 + (3 − 1) 18.083 + (3 − 1) 0.375 + (3 − 1) 0 + (3 − 1) 0] ∑[(3 − 1) + (3 − 1) + (3 − 1) + (3 − 1) + (3 − 1)] π2 π = 115.082 = ππ. ππππ 10 π 2π΅ 80.15085 = = π. πππππππππ π 2π 11.5082 23 APPENDIX D Detailed Computations Tukey’s Honest Significant Difference Test Rank 1 2 3 4 5 6 7 SET- UP Tukey Test Values ππ B vs. D B vs. E C vs. D C vs. E A vs. D A vs. E A vs. B A vs. C B vs. C D vs. E 5.27 5.27 5.11 5.11 3.66 3.66 1.61 1.44 0.17 0 π΄ π£π . π΅ = ππ = π΄ π£π . πΆ = ππ = π΄ π£π . π· = ππ = π΄ π£π . πΈ = ππ = π΅ π£π . πΆ = ππ = π΅ π£π . π· = ππ = π΅ π£π . πΈ = ππ = πΆ π£π . π· = ππ = πΆ π£π . πΈ = ππ = π· π£π . πΈ = ππ = 7.17 − 10.33 √11.5082 ÷ 3 7.17 − 10 √11.5082 ÷ 3 7.17 − 0 √11.5082 ÷ 3 7.17 − 0 √11.5082 ÷ 3 10.33 − 10 √11.5082 ÷ 3 10.33 − 10 √11.5082 ÷ 3 10.33 − 10 √11.5082 ÷ 3 10 − 0 √11.5082 ÷ 3 10 − 0 √11.5082 ÷ 3 0−0 √11.5082 ÷ 3 = /−π. ππ/ = /−π. ππ/ = /π. ππ/ = /π. ππ/ = /π. ππ/ = /π. ππ/ = /π. ππ/ = /π. ππ/ = /π. ππ/ = /π/ 24 Critical Value = 4.65 πΌ = 0.05