Response of Maize Genotypes to Combinations of Nitrogen and Humic Acid Fertilization

Abstract

The field experiment was carried out in the experimental field of Ibn Al-Bitar Preparatory Vocational School in Al-Hussainiya District-Holy Karbala governorate during the spring season 2021, with the aim of evaluating the performance of six maize genotypes (5018, Bahouth 106, Al-Maha, Fajr 1, Al-Furat and Sarah) under the effect of four levels of fertilization (160 N kg.ha-1, 160 N kg.ha-1 with humic acid, 320 N kg. ha-1 and 320 N kg.ha-1 with humic acid) using the split-plot arrangement with in Randomized complete blocks design (RCBD) with three replications, where the genotypes of maize represented the subplots and fertilization as the main plots. Leaf area, some characteristics of tassel, pollen vitality, number of ears per plant, number of grains per ear, weight of 500 grains, yield efficiency and grain yield were studied. Analysis of variance for fertilization levels showed highly significant differences for leaf area, number of grains per ear, weight of 500 grains, grain yield, and showed significant differences for pollen vitality. As for the genotypes, they were highly significant for all studied traits. The interaction between the two experimental factors was highly significant for each of the leaf area, weight of 500 grains, yield efficiency, and grain yield. The results showed that the interaction between the Furat genotype and the fertilizer level of 320 N kg.ha-1 with humic acid was significantly superior, achieving the highest leaf area of 6850.00 cm2, weight of 500 grains 194.33 gm, efficiency yield of 297.00 gm.m-2, and grain yield of 10848 kg.ha-1.