| dc.description.abstract | Low Soil moisture and weed competition are
often cited as factors which seriously Lf.mi t;
the production of upland rice. A study was
conducted to investigate the effect of
moisture regime and weeding frequency on
,growth and yield of upland rice variety under
Kenyan conditions.
Experiments were~ carried out at Ahero irrigation
Research Station~ between October 1978 and
June 1979. An upland variety IR 442-2-58-2-1-2
was used in the experiments.
The moisture~ regime treatments consisted of
flooding,· intermittent irrigation and rainfed
treatments. The results showed that flooding
-increased growth and yield of rice more than
when ~t was subjected to intermittent irrigafion
or rainfed conditions. The effect of flooding
was shown·to increase shoot dry matter, plant
height, yield components and enhanced early
flowering. The variety thus appeared more
adaptable to flooding than rainfed conditions.
Weeding frequency was composed of Wt W2,W3
and W4 treatments where Wl was weeded at
8,20 and 40 days, W2 at 8 and 40 days, W3 at
20 and 40 days after transplanting. W4 was
unweeded control. Treatments Wl and W3
produced higher tiller number, more shoot dry
weight, higher LAI and more grain yield than
W2 and W
4
. This showed that weeding at 20
days after transplanting (as in Wl and W3) is
more important than any other time of the
growing period.
Weed competition was more serious under
intermittent irrigation and rain conditions
than flooded .condition. It appears therefore
that upland rice would require more vigorous
weed control than ~flooded rice especially
between 20 and 40 days after transplanting. | en |
