Abstract:
Dairy farmers in central Kenya grow maize for forage
and food. They use maize planting density, weeding
regimes and thinning to regulate the quantity of forage
from both maize and weeds. The objective of this work
was to evaluate the effects of weeding and planting
density on maize forage and grain yield and quality
of forage. Field experiments were conducted at the
Kenya Agricultural Research Institute, Muguga for
two seasons (October 2001 to August 2002). Weeding
regimes included: maintaining the plots weed free by
hand weeding throughout the growth period (W1), not
weeded (W2), herbicide (W3) and hand weeding twice
(W4). The maize planting densities were 9 plants/ m
(D1) and 18 plants/ m2 (D2). The experimental design
was randomized complete block design replicated four
times. Maize in both D1 and D2 was thinned to 4 plants
/m2 at tasseling stage and the thinnings were assessed as forage. Stover and weeds with forage value and maize
yield were assessed at harvest. Thinnings biomass was
higher where weeds were controlled (W1, W3, W4)
and in D2 than D1. Maize grain yield was higher in D1
than D2. Maize thinnings had higher digestibility and
crude protein than stover. Herbicide was more effective
in controlling weeds than hand weeding twice, but
considered less safe for forage maize. Although not
weeding reduced forage and grain yield, at least 55 %
of the weeds were edible and of high quality and could
be used as forage and vegetable, but the weed forage
productivity was much lower than that of maize. In
conclusion, dairy farmers could practice D2 coupled with
W4 as a means of increasing forage quantity and quality
while ensuring moderate maize grain production.
