Eficiência do fertilizante nitrogenado de liberação controlada nas características agronômicas e produção de sementes do quiabeiro

Abstract

The quality and quantity of okra seed production demand much nitrogen fertilization, whoselosses can be decrease with controlled-released sources. In this sense, we evaluated agronomic characteristicsand yield of okra cultivar Santa Cruz 47 after nitrogen fertilization with controlled-released and conventionalurea. A randomized block design was used with four replications and 2x5+2 factorial arrangement, involvingtwo nitrogen sources (conventional and controlled-released urea) and five nitrogen levels (48, 72, 96, 120and 144 kg.ha-1), more two control treatments (without nitrogen application and a 100% controlled-releasedurea). We analyzed final plant height, insertion height of first fruit, number of fruits per plant, number of days from anthesis to harvest and seed production. The use of controlled-release polymer urea in soils withhigh organic matter delay the occurrence of the phenological stage of harvesting the fruits destined to seedproduction. The production of seed and fruits per plant decreased with increment of nitrogen doses.