Impact of overhead shade intensity and cocoa variety on the Micro-climate and productivity of cocoa farms in two ecological zones of Ghana

Abstract

Given the conflicting observations on the effect of shade on cocoa yield, understanding how different cocoa varieties respond to varying shade systems is essential for optimizing cocoa production and ensuring the sustainability of cocoa farming systems. This study assessed the yield of different established cocoa varieties in farmers' fields under different shade systems. Two shading regimes, i) no shade and ii) medium shade, and three cocoa varieties, i) Amazon, ii) Hybrid A, and iii) Hybrid B, were used for the study. Micro-climate variables, soil water content, cocoa pod production and dry bean yield were monitored for two growing seasons, 2022/2023 and 2023/2024, in two ecological zones, moist and dry zones. Two-way analysis of variance (ANOVA) was used, while Tukey's HSD method was applied for mean separation at a 0.05 probability level. Soil water content was significantly higher in the medium-shade system compared to the no-shade system. More pods per tree were recorded in the no-shade farms than in the medium-shade farms. The Hybrid B variety produced a greater number of pods (34.4 pods tree−1 yr−1) than the Amazon (27.8 pods tree−1 yr−1) and Hybrid A (29.9 pods tree−1 yr−1) in the first year, and in the second year. The two hybrids had a higher number of pods compared to the Amazon. A higher proportion of the pods were wilted in the medium-shade system (42.1%) compared to the no-shade system (39.9%) in the first year. Rainfall was identified as the most contributing factor for wilting and disease of pods. The dry bean yield of cocoa was higher in the no-shade system than in the medium-shade system in both years. Hybrid B significantly produced the highest yields, 847 and 765 kg ha−1 year−1 for years 1 and 2, respectively, followed by Hybrid A, 725 and 661 kg ha−1 year−1. Amazon produced the least, 586 and 524 kg ha−1 year−1. The study underscores the need for careful shade management and the selection of high-yielding, disease-resistant varieties to optimize cocoa production, particularly in regions with varying microclimatic conditions.