Influence of Topping, Side Branch Pruning and Hill Spacing on Growth and Development of Cotton (Gossypium barbadense L.) in the Southern Guinea Savanna Location of Nigeria

Abstract

Two field experiments were carried out at the Teaching and Research Farm, University of Agriculture, Makurdi, Nigeria, during 2000 and 2001 seasons on Pima S2 cotton cultivar, to study the effects of hill spacing of 30, 35 and 40cm (plant population) and plant growth alteration treatments i.e. topping, side branch pruning at 120cm height, topping + pruning at 100cm height, topping + pruning at 120cm height on some vegetative and fruiting habits, earliness and seed cotton yield and its components.
Generally the combined data clarified that wider hill spacing increased number of monopodia, main stem internodes, sympodia, additional fruiting branch bolls, retended bolls, fruiting sites, percentage of bolls on vegetative branches, open bolls, boll weight and seed cotton yield. While it decreased final plant height, number of aborted sites, days to first open boll, earliness percentage and number of unopen bolls. However, plant alteration treatments had a positive effect on most studied traits and reversely depressed number of monopodia, aborted sites and earliness percentage compared with the control. Within plant alteration treatments, there were significant divergences. The results indicated that topping plants at 120cm height increased number of retended bolls, fruiting sites, days to first open boll, open boll, unopen bolls and seed cotton yield. Side branch pruning at 120cm height increased final plant height, monopodia, main stem internodes, sympodia, earliness percentage and boll weight. Topping + pruning at 100cm height only decreased number of aborted sites. Topping + pruning at 120cm height increased additional fruiting branch bolls, percentage of bolls on vegetative branches, boll weight and seed cotton yield. Topping at 120cm height and 40cm hill spacing resulted in the highest number of retended bolls and seed cotton yield.