Mineral nutrient content, growth, and yield of papaya (Carica papaya L) as influenced by trench depth and municipal solid waste compost

Papaya (Carica papaya L. cv. Cariflora) plants were cultivated in south Florida in soil trenched at different depths (0, 12.7, 25.4, or 38.1 cm) and amended with municipal solid waste (MSW) compost at rates of 0 (control), 75, or 150 t ha(-1). There was a positive linear relationship between trench depth and plant height six months after transplanting. Plant height was not affected by MSW application rate. Root depth increased as trench depth increased, but trench depth had no effect on root radial length or root volume. Root growth was not affected by MSW rate. Leaf petiole concentrations of Mg and Ni were greater for plants in 38.1-cm trenches than for plants in the non-trenched plots. Concentrations of most nutrients in the leaf petiole were not significantly affected by MSW rate. Total fruit number or weight was not affected by trench depth. There was a positive linear correlation between MSW rate and the number of fruits per plant. This study indicates that trenching calcareous soil for papaya production is not advantageous because of the lack of significant growth and yield responses. However, amending calcareous soil with MSW compost can improve papaya yield with little change in leaf nutrient concentrations.