Cumulative Effect of Annual Additions of Undecomposed Leaves and Compost On the Yield of Eggplant and Tomatoes

For three years, undecomposed leaves were applied on a sandy terrace soil (Windsor, CT) and a loamy upland soil (Mt. Carmel, CT) in spring or fall. Yields of eggplant and tomatoes from these plots were compared to yields from plots amended with fully mature leaf compost and unamended controls. All plots received equal amounts of fertilizer. Eggplant responded consistently in all years at both sites with the greatest yields from plots amended with compost and the smallest yields from plots amended with leaves in the fall. With tomatoes, the amended plots (leaves or compost) had greater yields than the control plots all three years at Mt. Carmel. At Windsor, however, the leaf-amended plots had reduced yields in 1993 compared to the controls following similar yields in 1992. The reduction in eggplant yields from plots amended with leaves in the fall appear unrelated to nitrogen immobilization as nitrogen concentrations were greater or similar to the unamended control plots throughout the growing seasons. The possible role of phenol phytotoxicity from the fall-applied leaves is discussed.