Micro-Climate Conditions, Weed Diversity, Flowering and Yield of Young Cacao Plants as Affected by Shade Regimes

Abstract

Experiments were conducted in 2015/2018 in two cacao plots established in 2012 and 2013 in Akure, Nigeria to investigate micro-climate conditions, weed densities, flowering and yield of cacao as affected by shade regimes. Established cacao plots under three plantain (Musa spp) shade regimes consisting of No-shade, Moderate and Dense shade were used. Air and soil temperature, relative humidity and Photosynthetic Active Radiation (PAR), weed population and species diversity, cacao flowering and pod production were measured. From the results, air and soil temperature measurements under No-shade plots had a significantly higher mean values (32°C) and soil (28°C) compared with moderately shaded [air, 30°C and soil, 26.5°C] and densely shaded [air, 30°C and soil, 26°C] plots in2015 and 2016 measurements but under 2017 measurements, no significant difference in the soil temperature of the plots under dense shade, moderate and the no-shade which were ascribed to canopy close-up of the cacao that led to reduced transmitted light through the canopy to the understories species. The vigour of weeds under no-shade plots were significantly higher compared with dense and moderately shaded plots. In 2013 established cacao plot, flower production was higher significantly in no-shade compared with those in moderate and dense shaded cacao plots in 2015 and 2016 measurement. Pod production under No-shade were significantly higher compared with other treatments in 2016 and 2017. Cherelle wilt rate was higher in shaded plots compared with the no-shade plots. Pod yield parameters were significantly higher under No-shade plots compared with shaded treatments during the three years of data measurement. Air temperature between 30°C to 33.7°C during flowering and fruit/pod setting was found to have positive influence on bean yield in cacao. The study concluded that excessive shade decreases yield of cocoa, while increases in temperature and relative humidity boosts some physiological processes for pod production in Cocoa