RESPONSE OF MAIZE AND ASSOCIATED WEEDS TO SOME POST·EMERGENCE HERBICIDES

Two field experiments were conducted at the Experimental Farm of National
Research Centre at Shalakan, Kalubia Governorate, Egypt, through two successive
seasons of 2002 and 2003, to study the effect of some post-emergence herbicides on
maize plants and associated weeds. The results showed that hand hoeing twice (21
and 35 days from sowing and Bentazone at 0.230 kg a.i.lfed. applied as post-
emergence were the best treatments in controlling total annual weeds up to 75 days
after maize sowing, compared to the other treatments. Fluroxypyr at 0.080 kg a.i.lfed.,
Triclopyr at 0.192 kg a.i.lfed. or Bentazone at 0.230 kg a.i.lfed. each applied post-
emergence as well as two hand hoeing treatment gave the best broad leaved weed
control more than the other treatments. While, hand hoeing twice and post-emergence
application of Bentazone at 0.230 -kg a.i.lfed. as well as Mo at 0.800 a.i.fed .. gave
acceptable control of annual grass weeds, compared to the other treatments. Hand
hoeing treatment as well as Fluroxypyr, Triclopyr and Bentazone at the high rates
improved the growth of maize plants and resulting in the longest ears, the highest
number of grains/row, the heaviest weight of 100-grain, the highest grain yield per
plant and per feddan as compared with unweeded control. All tested herbicides
including hand hoeing treatment significantly increased oil content in maize grains
when compared with unweeded control.