Influence of Different Organic Fertilizers on Growth, Yield, Quality, and Element Content in Lettuce (Lactuca sativa var. longifolia)

Abstract

This study was performed in order to determine the effects of pigeon manure, chicken manure, and vermicompost on lettuce’s (Lactuca sativa var. longifolia) yield, vegetative growth, element content, and quality characteristics. The study was carried out in greenhouse. In the study, 0% (control), 0.50% pigeon manure, 0.50% chicken manure, and 0.50% vermicompost were applied via drip irrigation. The treatments began 20 days after the seedling planting, at 10-day intervals and four times. The experiment was set up with four replicates as per the randomized blocks experimental design. As per the research findings, the chicken manure significantly increased the lettuce’s average head weight and total yield compared to the control and two other treatments. Even if the pigeon manure and vermicompost increased the yield parameters similar to chicken manure, they were statistically in the same group as the control. The pigeon manure again significantly increased the chlorophyll amount, root’s fresh and dry weight, leaf’s K and Zn content, leaf color’s L value, and fruit juice’s pH content compared to control. On the other hand, vermicompost generated the highest results for the leaf’s Ca and Pb content. The Pb content in the lettuce leaves increased in all the organic fertilizer treatments compared to control, and the highest Pb content was obtained by the vermicompost, chicken manure, and pigeon manure, respectively. The treatments’ effect on the leaf’s Ni content was found to be insignificant. But the vermicompost increased the leaf’s Ni content compared to the control. The treatments’ effect on leaf color’s a* and b* values, brix degree, head diameter, head height, leaf relative water content, and Na, Mg, Cu and Mn contents was again found to be insignificant. In conclusion, it is recommended to apply 0.50% chicken manure in greenhouse lettuce cultivation to obtain large heads and high yield. To achieve bright-colored plants, high chlorophyll content, high root fresh and dry weight, and high potassium and zinc content, 0.50% pigeon manure is suggested. However, 0.50% vermicompost is not recommended for greenhouse lettuce cultivation due to its potential to increase the Pb and Ni heavy metal content in the leaves.