Spray timing trials like the one shown here are conducted each year by the University of Guelph to document the amount of yield loss in corn if weeds are not controlled between the Critical 3 and 8 leaf stage.The corn in the first shot above was sprayed at the ideal 3 leaf stage of corn on June 5th.
Weeds were allowed to continue to grow in this second shot for an extra week until being sprayed on June 12th at the 5 leaf stage of the crop.Even though you'd tend to visually think the crop looks just as good, previous weed control timing studies have shown that there will be anywhere from .5 to 3.3 bu/acre/day yield loss due to the additional week of weed competition.
Weeds in this third shot were not controlled until June 19th when the corn was sprayed with glyphosate at the 7 leaf stage.As you can see leaving weeds to compete with the corn for this length of time has really hurt the crops ability to perform.Though the weeds have been killed and come harvest the grower will have a clean weed free field he will unknowingly have suffered some serious yield loss.
This last shot goes one step further to show the magnitude of impact uncontrolled weeds can have on the crop if spraying is delayed until the 9 leaf stage of growth or in this case June 26th.This is 3 weeks later than the ideal 3 leaf stage that was sprayed on June 5th.Though this is much longer than what most growers would ever leave weeds to compete with a crop it still goes to show just how much weed competition can hurt a crops performance.The take home message here is that for growers to maximize the yield performance of the hybrids they grow they need to keep their crop weed free from the Critical 3 -8 leaf stage in order to maximize yield.
Spray timing trials like the one shown here are conducted each year by the University of Guelph to document the amount of yield loss in corn if weeds are not controlled between the Critical 3 and 8 leaf stage.The corn in the first shot above was sprayed at the ideal 3 leaf stage of corn on June 5th.
Weeds were allowed to continue to grow in this second shot for an extra week until being sprayed on June 12th at the 5 leaf stage of the crop.Even though you'd tend to visually think the crop looks just as good, previous weed control timing studies have shown that there will be anywhere from .5 to 3.3 bu/acre/day yield loss due to the additional week of weed competition. 
Weeds in this third shot were not controlled until June 19th when the corn was sprayed with glyphosate at the 7 leaf stage.As you can see leaving weeds to compete with the corn for this length of time has really hurt the crops ability to perform.Though the weeds have been killed and come harvest the grower will have a clean weed free field he will unknowingly have suffered some serious yield loss.
This last shot goes one step further to show the magnitude of impact uncontrolled weeds can have on the crop if spraying is delayed until the 9 leaf stage of growth or in this case June 26th.This is 3 weeks later than the ideal 3 leaf stage that was sprayed on June 5th.Though this is much longer than what most growers would ever leave weeds to compete with a crop it still goes to show just how much weed competition can hurt a crops performance.The take home message here is that for growers to maximize the yield performance of the hybrids they grow they need to keep their crop weed free from the Critical 3 -8 leaf stage in order to maximize yield.
Visit My Website
ReplyDelete