THE EFFECT OF NITROGEN FERTILIZER DOSAGE ON THE GROWTH AND YIELD OF NEW HYBRID MAIZES PLANTED IN SPRING SEASON 2019 IN HOANG HOA DISTRICT, THANH HOA PROVINCE

Abstract

In recent years, the planted area of hybrid maizes increased rapidly due to the increased consumer demand and has brough about high economic efficiency for producers. Therefore, finding a new short-term hybrid maize variety with high productivity and quality, proactively producing hybrid seed is one of the main goals of the breeders. For maizes, nitrogen fertilizer is an important nutrient for productivity and quality. Nitrogen fertilizer is active in the growth and development of maize. The dosage of nitrogen fertilizer affects the growth and development prameters of maize breeds such as tree height, number of leaves and the possibility of being infected by pests and diseases. Among the nitrogen fertilizing rates, the application rate of 175 kg N/ha basis (10 tons of manure + 90 kg K₂O + 90 kg P₂O₅) reached the highest growth and development values. Depending on the kinds of pest, the diseases at different levels of fertilizer, the level of harm of the pest, the disease to the maize breeds are also different. At no nitrogen fertilization level, the density and incidence of disease were lowest in all maizes. At the dosage of nitrogen fertilizing 200 kg N/ha on T8 variety, the highest density borer was 5.1%, leaf spot disease was 5.6% and shabby dry disease was 5.4%. Nitrogen fertilization has an effect on the yield and yield components of maizes such as the length of corn, diameter of corn, number of seeds per row, number of rows per corn, weight of 1000 seeds, theoretical yield and actual yield. At the dosage of fertilizing 175 kg N/ha basis (10 tons manure + 90 kg K₂O + 90 kg P₂O₂) the actual yield of the maizes was highest with QT55 maize breed yield was 8.52 tons/ha.