Alternativas para adubação de mudas de abacateiro ´Quintal´

Abstract

The avocado is a fruit of high expression in the fruit scenario in Brazil. One of the factors that limit the rational expansion of this fruit in our country is the difficulty of obtaining high quality seedlings. Therefore the aim of this study was to evaluate the formation of Quintal cultivar avocado seedlings, under greenhouse conditions, with use of slow-release fertilizer and nutrient solution with different doses of NPK. The experiment was conducted by the Division of Fruit Crops Department of Agriculture, Universidade Federal de Lavras-MG in the period from May to October 2009. The treatments consisted of four doses of slow-release fertilizer 15-10-10 (NPK) at a ratio of 4, 8, 16 and 24 kg m-3 of soil used as substrate, and four doses of nutrient solution, where NPK was applied in a mixture of urea, potassium nitrate, and phosphate monoammonium in the same proportion as the other fertilizer. The control was the absence of fertilization. The design was randomized blocks in 2X4 factorial with an additional treatment (control) with four replicates of one experimental plot made up of ten plants. The plants were grafted, using cultivar Fortuna as scion. The rootstock characteristics evaluated were: height (cm), diameter (mm), dry leaves, roots and stems (g), percentage of N, P and K in leaves (%) and grafting success rate (%). Interaction among the factors was significant for the of height, diameter, leaves, roots and stems dry, and grafting success rate characteristics. The use of slow-release fertilizer promoted greater growth and development of Quintal cultivar avocado seedlings compared to nutrient solution, with doses above 8 kg m-3 slow-release fertilizer and nutrient solution were not satisfactory in of 'Quintal' avocado seedlings.