Macronutrients effects on growth of "seedlings" of guaranazeiro (Paullinia cupana var. sorbilis)

Abstract

One experiment on the nutrition of guaraná (Paullinia cupana var. sorbilis Ducke) were conducted in the State of Amazonas, with the purpose of studying the effects of substrate and supply of nutrients in the growth and nutrient content of seedlings. The two objectives were attained by means of a pot experiment in which "guaraná" seedlings were grown in three different, specially mixed substrats, namely: (a) sand + loam + chicken manure; (b) sand + loam + cattle manure, and (c) sand + loam. The experimental unit consisted of ten seedling individually planted in plastic containers. Three of these units were prepared for each substrate and the seedlings growing in each received a foliar application of water as needed and nutrient solution at 15 and 30 days intervals, respectively. An extra unit was added, using sand + loam + nutrient solution as substrate, thus comprising ten treatments. Substrate and leaf chemical analysis were conducted to evaluate treatment effects. If was verified that the seedlings grown in the cattle manure substrate showed better than growth and balance of macronutrients when compared with the substrates which had no organic matter. The application of nutrient solution (foliar or mixed in) had no effect on the growth and macronutrient content of the seedlings leaves. Symptoms of nitrogen defficiency were observed in all treatments. Nutrient content of the leaves varied from the defficiencly level to that of 'luxury consumption".