EFFECTS OF VARIETIES AND INTRA-ROW SPACING ON GROWTH, YIELD COMPONENTS AND GREEN COB YIELD OF MAIZE (Zea mays L.) UNDER SUPPLEMENTARY IRRIGATION AT GULISO, WESTERN ETHIOPIA

Abstract

Determination of optimum plant population and the use of improved varieties in combination with appropriate agronomic practices are important components of maize production package for maximizing productivity. In connection with this, information is lacking on optimum plant population under supplementary irrigation condition during the off-season in Guliso District. Therefore this study was conducted during December 2017 to May 2018 under supplementary irrigation at Gulliso district, West Wollega Zone of Oromia Regional State, to determine the effects of variety and intra-row spacing on growth, yield components and green cob yield of maize (Zea mays L.). The experiment was conducted in factorial arrangement of four intra-row spacing (20, 25, 30 and 35 cm) with corresponding plant densities of 66,667 plants ha-1(20 cm),53,333 plantsha-1(25 cm) ,44,444 plants ha-1(30 cm) and 38,093 (35 cm) plants ha-1.Three maize varieties (BH546, Shone and BHQPY-545) in RCBD. The main effect of variety was highly significant (P<0.01) on days to 50% anthesis, days to 50% silking, stand count, and plant height, and significance (P< 0.05) on ear diameter and number of ears ha-1. The highest ear diameter (4.29 cm) and ears ha-1 (5792) were recorded from BH546. The maximum number of days to 50% anthesis (82), days to 50% silking (86.58), and the tallest plant height (263 cm) were recorded from variety shone, while the maximum stand count (96.60) was recorded from variety BH546. Similarly, the main effect of intra-row spacing was highly significant (P< 0.01) for leaf area, leaf area index, stand count percent, ear diameter and ears per hectare. The highest (6291.35 cm2) leaf area was recorded from 35 cm intra-row spacing at 38,093 plant density1,while the highest (62,222) ears ha-1 was recorded from 25 cm intra-row spacing with 53,333 plant density, and the highest (4.29 cm) ear diameter and highest (97.92) stand count percent were recorded from 35 cm intra-row spacing at 38,093 plants ha-1. The interaction of variety and intra-row spacing was highly significant (P<0.01) on yield components and yield of maize. The highest (1.75) average number of ears per plant was recorded from varieties BH546 and BHQPY-545 at 35 cm intra-row spacing. The highest (35 cm) ear length was recorded from BH546 at 35 cm intra-row spacing. Generally, leaf area, stand count, ears per plant, ear length, and ear diameter showed a decreasing trend with decreasing intra-row spacing. Based on these results, it can be tentatively concluded that the variety BH546 could be used at plant density of 53,333 plants ha-1 and (25 cm) intra-row spacing is best to get the highest green cob yield of maize under supplemental irrigation during the off-season in the study area. However, the study should be repeated under at more locations to come up with reliable recommendation.