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Effect of pH on Green Pea Germination Objective: To determine how pH affects the germination of green peas and to examine the degree of germination within each pH level. We will do this by using various buffer solutions (along with distilled water) to grow green peas. Hypothesis: We expected that the group of peas that encountered a pH of 7 to have the most and highest degree of germination. Materials: tap water buffer solutions pH 3,5, 7, 9,11 distilled water 50 greens peas trays paper towels beakers Procedure: 1. Wrap 25 peas (25 peas = 1 group) in paper towels.
Place each group in trays, making sure that the groups have room to grow independently of each other. 2. Pour 10 mL of tap water and 30 mL of distilled water or buffer solution onto each group of peas 3. Add tap water accordingly to keep peas moist 4. After one week, add another 20mL of distilled water or buffer solution onto each group of peas. 5. Observe amount of germination and degree of germination (length of the shoots) Data as of 6/16/2010 pH 3 pH 5 Distilled Water pH 7 pH 9 pH 11 Number Germinated 17 22 23 22 21 24 Number not Germinated 8 2 2 3 4 1 Number of peas with shoots that were at least 1 inch long 9 14 5 5 4 Analysis of Data and Conclusion: We used distilled water as the control group of our experiment because water would be commonly used to water such plants. The variables between the control and experimental groups was the pH levels (3, 5, 7, 9, 11, and distilled water); other factors such as number of peas and amount of solution used were kept the same for each group as validity factors. We focused on measuring two things: the number of peas that germinated per group and the number of peas whose germination resulted in shoots at least an inch long.
The group with pH 11 had the most germination, but the distilled water had the most peas with shoots over an inch long. We also researched after conducting the experiment that the peas had an ideal pH of about 6. The pH of distilled water ranges from 5. 6 to 7, averaging out at 6. 3. Since distilled water had the closest pH to that of 6 for the peas, we would expect a parabolic graph of our data. This was true for our shoot length data. For the number of peas that germinated, the data was also parabolic until the pH 11 group’s data was graphed.
However, all of the groups of peas had very close numbers of total germination, so the pH 11’s graphical abnormality can be attributed to random chance. The pH 11 group did have the smallest number of peas with shoots at least an inch long; this data still helps in confirming that the ideal pH for growing green peas is still around 6. Our hypothesis was proved incorrect. Out of the experimental groups, it was the group with a pH of 5 that had the greatest amount of 1 inch shoots and the second most number of germinated peas.