Adubação orgânica e mineral na cultura da melancieira no semiárido Paraibano: segundo ciclo de cultivo.

Abstract

The search for fertilizer alternatives that reduce or even eliminate the use of manufactured mineral fertilizers is a reality among small and medium northeastern farmers. The objective was to evaluate the morphological and physiological responses of watermelon in a successive cultivation, application of NPK doses using different mineral and organic fertilizers proportions. The experiment was conducted in an area of the Federal University of Campina Grande (FUCG), Campus Pombal - PB (6th 48 '16 "S and 37º 49' 15''W) during the period from October 2013 to January 2014 . The design was a randomized block design with four replications in a factorial 3x5 where the factor (A) were allocated different concentrations of nutrients N, P and K (50, 100 and 150% of NPK recommendation for watermelon) and factor (B) five proportions of mineral and organic fertilizer (100/0, 75/25, 50/50, 25/75 and 0/100). It was evaluated: Gas exchange, dry mass of leaves, stem, fruits and total dry mass production, soluble solids and titratable acidity. A concentration of 50% of NPK recommendation for the culture of watermelon was the most efficient in increasing the physiological characteristics. Á higher photosynthetic rate (16,61μmol m2 s-1) was hit with the 50% concentration applied in the proportion 100/0. The different concentrations and ratios of NPK fertilizer (mineral / organic) provided no significant differences in growth, production and fruit quality of watermelon.