Influência de adubação nitrogenada e irrigação com água residuária sobre comprimento e peso da radícula do algodoeiro herbáceo.

Abstract

The development of the root system is a very important factor, among others, for sustentation or fixation of the plants to the soil; a root system well developed avoids the falling of the plants, mainly when the aerial part reaches considerable heights. The objective of this research was to evaluate the influence of the nitrogen manuring and of the irrigation with wastewater on length and weight of the root of herbaceous cotton plant cultivated in sandy-clay-loam soil. The results showed that the irrigation with wastewater promoted larger length and weight of the roots than with water of provisioning, and that the weight increased lineally with the increase of the applied doses of nitrogen. The plants that just received wastewater presented root length corresponding to the one obtained by the plants that received foundation manuring with phosphorus and potassium and dose of nitrogen of 240 kg ha-1. The same happening in relation to the weight of root plants where the irrigation with wastewater promoted weight superior to the one obtained by the plants that received the largest dose of nitrogen, becoming evident, in what concerns the weight of the root of herbaceous cotton plant in those edaphic-climatic conditions, that the use of wastewater substituted completely the mineral manuring up to 320 kg ha-1 of nitrogen.