Effects of Spacing on Growth and Green Cob Yield of Maize Under Supplementary Irrigation in Eastern Ethiopia

Abstract

Maize (Zea mays L.) is an important grain crop of the world and it ranks second, after wheat in area cultivated and first in total production and productivity. In Ethiopia, maize has increasingly become a popular crop with steady growth in production area and yield. However, green cob maize production packages, including its appropriate spacing, are not yet determined. Evidences on effects of inter and intra-row spacing on growth and green cob yield of maize are not well explored. Therefore, this study was conducted at 9° 26' N latitude and 42° 03' E longitude, at an altitude of 1980 m a. s. l), Ethiopia from October 2020 to January 2021 to determine the effects of inter and intra-row spacing on growth, green cob number and biomass yield of maize (melkesa-II maize variety) under supplementary irrigation. The experiment was laid out in a randomized complete block design with factorial combination of four inter-row (55 cm, 65 cm, 75 cm, and 85 cm) spacing and three intra-row spacing (20 cm, 25 cm and 30 cm) with three replications. Data were collected on growth, green cob number and biomass yield and analyzed using SAS, (2002). The experiment result revealed that leaf area index, number of cobs per plant, cob length, number of cobs harvested per hectare and above ground fresh biomass yield and their interactions were highly significantly (P<0.01) affected by inter and intra-row spacing while cob diameter was significantly (P<0.05) affected by inter and intra-row spacing. The highest cob number harvested (90313 ha^-1) was recorded at narrowest inter and intra-row spacing of 55 cm x 20 cm while the lowest cob number harvested p (45098 ha^-1) was recorded from at widest inter and intra-row spacing of 85 cm x 30 cm (Table 8). Similarly, the highest fresh biomass yield of 31.27 and 28.66 ton ha^-1 was obtained at 55 cm and 65 cm inter-row spacing respectively. In general, significantly higher number of marketable green cobs and above ground fresh biomass yield were obtained at closer inter-and intra-row spacing for melkesa-II maize variety tested in the study area. Therefore, it can be concluded that spacing combination of 55 cm x 20 cm favored attaining of higher green cob number and above ground fresh biomass yield of melkesa-II maize variety in the area under irrigation.