Plant density and thinning regime effect on maize (Zea mays) grain and fodder yield

Abstract

Maize (Zea mays L.) plant density is an important management practice for successful grain and forage production. The objective of this study was to determine the most suitable maize seeding and time of thinning maize as fodder in grain maize crops. Previously the focus in this area has been on grain and silage production, and consequently information on the production of fodder in grain maize crops is limited. This study therefore aims to investigate the growth of high density maize for fodder production through thinning and subsequent grain yield. A plant density experiment in randomised complete block design was carried out at Egerton University, Njoro, using a Kenyan hybrid (H511) where 4 densities (44 444, 88 888, 177 777 and 355 555 plants/ha) and 4 thinning regimes (V4, V6, V10 and VT phenological stages) were used. The densities vary through number of seed per hill (i.e. 1, 2, 4 and 8 seeds/hill, not row or plant spacing) and spacing of 30 cm between the hills within the row and 75 cm between the rows was used. Maize plants were thinned following the appropriate thinning regime to leave 1 plant per hill, giving a plant density of 44 444 plants/ha in all treatments after thinning. Their biomass was then determined. The single plants per hill left, as a normal farmers practice, were used to determine grain yield at harvest. Plant density of 355 552 plants/ha, with a treatment structure of 4 seeds/hill and thinned at the VT phenological stage gave the highest thinning biomass per hectare, while 44 444 plants/ha, with a treatment structure of 1 seed/hill and no thinning, gave the highest grain yield. The thinning regime of the V10 phenological stage and 2 seeds/hill thinned at the VT phenological stage gave appreciable amount of fodder and grain yields. This study has shown that with particular seeding densities and thinning regimes, production of both fodder and grain is possible.