Pruning and Fertilization of <i>Theobroma Cacao</i> L. and of Shadow Trees Affect the Flowering and Fruiting of Cacao

Cacao (Theobroma cacao L.) crop faces problems worldwide associated with low productivity due to diseases, lack of fertilization and absence of pruning. The aim of this study was to evaluate the effect of sanitary pruning of cacao, pruning of shade trees and fertilization on cacao flowering and fruiting. The study was carried out in a 40-year old cacao plantation in the Experimental Field of the Colegio de Postgraduados, Campus Tabasco (17˚ 59' 23.98'' N and 93˚ 37' 10.24'' W), at 24 masl, in Cardenas, Tabasco, Mexico. Shade tree and cacao tree pruning (both with and without pruning) and fertilization (without fertilizer and with K and NPK) were the evaluated factors and levels. There were 12 treatments with three repetitions including four trees per repetition. The assessed variables were the number of healthy, diseased and damaged fruits; number of healthy and diseased developing cacao fruits (chilillos); and number of flowers per tree. Analysis of variance indicated a significant effect of the interaction among the three evaluated factors on healthy fruits at 24 months after applying the treatment; on damaged fruits and healthy chilillos at 18 months; and on diseased chilillos at 18 and 24 months. Regarding the number of flowers, the interaction among the three factors had an effect at 6, 12 and 18 months. The best interaction of factors for increasing the number of healthy fruits was pruning of shade trees, no pruning of cacao trees and fertilization with K. The interaction of K with cacao tree pruning and with or without shade tree pruning decreased the number of diseased chilillos. The conclusion is that cacao pruning combined with K fertilization increased the number of flowers and decreased the number of diseased chilillos.