Investigations on Maize in the Libyan Arab Republic I. Effect of Plant Spacing and Nitrogen Level on Growth and Yield of Maize (Zea mays L.)

Abstract

In a two-year field experiment (1972, 1973), the effect of nitrogen level and plant spacing on the grain yield and its components, plant height and stover production were studied in Libya using the open-pollinated Early American variety commonly cultivated in Egypt. Addition of 52 and 104 kg N/ha significantly increased grain yield over 0 nitrogen level by 28 and 51% in 1972 and by 35 and 82% in 1973; whereas stover yield was significantly increased by 38 and 52% in 1972 and by 50 and 92% in 1973. Plant spacing significantly affected grains and stover production. At all nitrogen levels in both years, the optimum plant spacing was 35 cm in rows 70 cm apart (42857 plants/ha). However, the highest grain yield of6.18 and 5.92 tons/ha was obtained with 104kgN/ha and 35 cm plant spacing. On the other hand, stover production was the highest with the narrowest spacing (30 cm) and 104 kgN/ha.

Size of kernel, length, diameter and height of topmost ear, plant height and diameter of the sixth internode were significantly increased with increasing nitrogen level and plant spacing.