Responses of growth, yield and disease assessment indices of taro [Colocasia esculenta (L.) Schott to integrated nutrient management in Umudike, Southeastern Nigeria

Abstract

A three – year field study was carried out in 2015, 2016 and 2017 cropping seasons at the Forestry Research Institute of Nigeria, Eastern Research Station, Okwuta in Umuahia South Local Government of Abia State to evaluate the responses of growth, yield and disease assessment indices of taro (NCe 003) leaf blight to various combinations of poultry manure and NPK fertilizer. The experiment was factorial laid out in randomized complete block design with three replications. Factor A was poultry manure which consisted of three levels of 0, 5 and 10 t ha-1 while factor B was NPK 20: 10: 10 fertilizer and comprised also three levels of 0, 300 and 600 kg ha-1 to get nine treatment combinations. Data were taken on the following crop attributes: Leaf area/plant, leaf area index/plant, dry matter yield, harvest index/plot and assessment of cocoyam disease/plot. Results obtained showed that response to integrated nutrient management was statistically the same for most of the measured attributes. However, the interaction between 600 kg ha-1 fertilizer x 5 t ha-1 PM gave the highest significant difference (p≤0.05) on the leaf area (261.80 m2) at 16th week after planting (WAP) in 2017 cropping season. In 2016, the residual effect of poultry manure significantly (p≤0.05) increased the corm dry matter production (26.89 g) and harvest index (77 %) from the plots that received 10 t ha-1 poultry manure in 2015.Conclusively, this study shows that application of 10 t ha-1 poultry manure which significantly affected leaf area index (LAI), increased dry matter yield (DMY) and harvest index (HI) of taro which are good descriptors for assessing crop yield.