Effects of Shade Regimes and Varying Seasons of Irrigation on Survival, Developmental Pattern and Yield of Field Grown Cacao (Theobroma cacao)

Abstract

Investigations were conducted on the field to examine the effects of varying seasons of drip irrigation and shade regimes on field survival, development and yield of cacao at the teaching and research Farm of Federal University Technology Akure, Nigeria between 2012/2013 to 2014/2015 growing seasons. The shade treatments are (dense, moderate and no-shade) and the varying seasons of irrigation are (three, two and one seasons of continuous dry season drip irrigation). From the results, it was discovered that combined effects of moderate and dense shade with continuous three years irrigation enhances field survival and establishment of cacao but with a significantly lower effects on growth parameters like stem girth, branch number, and canopy size compared to those with continuous three years irrigation under open-sun. More so, plant height of cacao plants were significantly positively influenced by dense and moderate shades but with thinner stem girth compared with open-sun plots with thicker girth, higher branch number, and better canopy sizes at first and second growing season. In the third year, open-sun plots with two and three continuous dry season irrigation were significantly higher in plant height, girth, branch number and canopy sizes. In addition, increased cacao percentage survival were significantly influenced by irrigation and shade. Meanwhile, stand mortality were highest under dense and moderate shaded plots without irrigation in the second and third dry season (67%), followed by those without irrigation only in the second dry season (58%) and (52%) in those without irrigation in only the third dry season. Pod production were significantly higher with open-sun treatments that were irrigated throughout the three dry season with the average pod production of 12, 67 and 169 pods/plant in the 1st, 2nd and 3rd year. Moderate and densely shaded cacao was significantly lower in pod production compared to those under open-sun.