Effects of watering frequency and soil types on growth and yield of kgengwe (Citrullus lanatus var. Citroides)

Abstract

There is now a growing realization by government and other role players in Botswana of the importance of indigenous plants as alternative food crops to enhance food security and biodiversity. Experimental research was conducted at the Botswana University of Agriculture and Natural Resources (BUAN), to evaluate effects of watering frequency and soil types on growth and yield of kgengwe (Citrullus lanatus var. Citroides). Four levels of watering frequency (2 days, 4 days, 6 days, and 8 days) and three types of soils (sandy, sandy loam and sandy clay loam) were laid out in a split-plot design with three replications. There were significant differences in the watering frequency for seedling emergence, leaf area, stem dry weight, leaf fresh weight, leaf dry weight, root length, root fresh weight, root dry weight, plant fresh weight and plant dry weight to test the effect of watering frequency. The highest watering frequency produced the highest stem fresh weight, stem dry weight, leaf fresh weight, leaf dry weight, root dry weight, root fresh weight, plant fresh weight and plant dry weight. The lowest watering frequency produced the lowest plant biomass except for stem dry weight. The watering frequency showed significant effect on transpiration rate and light intensity and no significant effect in photosynthesis, chlorophyll, stomata conductance and carbon dioxide. High transpiration rate was found in the three days watering cycle and lowest in four days watering frequency. There were significant differences in all the plant biomass parameters, with die sandy loam soil giving the highest stem fresh weight, stem dry weight, leaf fresh weight, leaf dry weight, root length, root fresh weight, root dry weight, plant fresh weight, plant dry weigh, number of flowers per branch, number of male flowers per branch, number of female flowers per branch and light intensity. There were positive and negative correlations between die measured parameters, The highest leaf fresh weight, leaf dry weight, plant fresh weight and plant dry weight was found in the interaction between sandy loam soil and highest watering frequency.