EFFECT OF NITROGEN FERTILIZER, DEFOLIATION AND PLANT DENSITY ON MAIZE GRAIN YIELD

Document Type : Original Article

Authors

1 Field Crops Research Institute, Agricultural Research Center, Giza, Egypt

2 Department of Agronomy, Faculty of Agriculture, Suez Canal University, Ismailia, Egypt

3 Central Laboratory for Design Research and Statistical Analysis, Agricultural Research Center, Giza, Egypt

Abstract

The present investigation was carried out during 1998 and 1999 seasons at Zarzoora Experimental Station (EL-Beheira governorate) to study the effect of nitrogen level (zero, 100, 120 and 140 kg N/fed) and defoliation on maize yield at IS days after silking (no defoliation, de‌foliation below topmost ear leaf, defoliation above topmost ear leaf and defoliation of all leaves as well as plant densities (16000. 20000 and 24000 plants/fed.). The experiments were arranged in split-split plot de‌sign with three replications. The results obtained in combined analysis were as follows. 1. Planting maize at the rate of 24000 plants/led significantly Increased plant height, barren plants% and lodged and broken plants %. but de‌creased stem diameter. % plants with two ears, ear length. ear diame‌ter, no. of kernels/row and ear weight. 20000 plants/fed. recorded the highest grain yield, whereas 16000 plants/led gave the lowest. 2. Increasing nitrogen level up to 140 kg Med increased most of the characters of maize under study i.e. plant height, ear height, stem di‌ameter, two-eared plants %, ear length, ear diameter, no. of kerneW row and ear weight. whereas barren plants %. lodged and broken plants % were decreased. Shelling % and no. of rows/oar were not significantly affected. Grain yield increased by 168.6. 214,21 and 220.26 % of unfertilized maize by increasing nitrogen fertilizer to 100, 120 and 140 kg N/fed. respectively. 3. Stem diameter, plants carried two ears %, ear length, ear diameter, no. of kernels/row and ear weight were significantly affected by defo‌liation treatments, the highest values for these characters were ob‌tained by umiak:dialing of maize plants. While, plant height, ear height, no. of rows/ear and shelling % were not significantly affected by defoliation. Barren plants % and lodged and broken plants % gave