Two field experiments were conducted during 1989 and
1990 seasons at the Demonstration fields of Kafer—Saad,
Domietta Governorate, to study the effect of seeding rates
(30,40,50,60 and 70 kg/fed.) and some weed control treat
ments (unweeded, hand—weeding, thiobeazyl bentazon and
thioberizyl + bentazon) on growth and yield of rice. Seeding
rate bad no significant effect on heading date, stem lengthY
flag leaf area, and weight of 1000—grain. Whereas increas
ing seeding rate from 30 to 60kg/fed. decreased signifi
cantly the panicle length, paincle weight, number of
grains/panicle and weight of grains/paniclo. On the other
hand, increasing seeding rate caused significant increase in
the number of shoots and panicle—bearing shoots/m2 as well
as yields of grain, straw and biological. Increasing seeding
rate from 30 to 40,50,60 and 70 kg/fed. significantly
increased grain yield/fed. by 20,32,29 and 36% and by
12,28,25, and 22% in the first and second seasons, respec
tively.
Thiobenzyl alone or fallowed with bentazon delayed head
ing date of rice plant, produced the shortest plants, and
gave the maximum values of : number of ghoots/m2, number of
panicle—bearing shoots/m2, flag leaf area, panicle length,
weight of panicle, number of grains/panicle and grain
yield/fed, while the unweeded and bentazon treatments gave
the lowest values. The relative grain yields were 413, 388,
in the second season for bentazon + thiobenzyl, thiabenzyl,
326 and 293% in the first season, and 258, 255, 248 and 215%
hand—weeded and bentazon, treatments, respectively as com
significant on number of shoots/m2, number of panicles/m2
and grain yield/fed in both seasons |
