Silks are usually pollinated very soon after they emerge. After fertilization and when 

 the silks are drying, there is apparently less risk of injury from 2,4-D. However, 

 fertilization is followed by a period of rapid nutrient uptake and movement of food 

 materials to the grain. Stress conditions or injury of various kinds during this stage 

 may interfere with normal kernel development. 



Although weeds will usually be large, "tough," and harder to kill with 2,4-D, spraying 

 can be resumed after the grain is well on its way and in the dough stage . The dough 

 stage begins about 5-1/2 weeks after silks begin to emerge. During the dough stage, 

 the silks are dry, kernels are still developing, and starch is accumulating. 



But remember that by the time corn reaches the dough stage, many weeds already will have 

 done most of their damage through competition for nutrients and moisture. Many weed 

 seeds will also be developed sufficiently to be viable. However, the late spraying may 

 make harvesting a little easier. 



2,4-D AND CORN INJURY 



Quite a bit of corn was injured by 2,4-D this year. Some that was sprayed before the 

 winds of June 16-17, was lodging because it lacked brace roots and because of stalk 

 brittleness. 2,4-D injury occurs every year, but it appears to be more common during 

 Seasons of highly variable weather where we have cold-wet spells followed by very warm 

 weather. Some corn hybrids are more susceptible than others. 



Some of the precautions with 2,4-D are: 



1. Be sure and use the proper rate. The rate varies with formulation and type, 

 the standard formulation now is 4 pounds per gallon, but there are still some 

 2-pound-per-gallon and other formulations. It requires less of the ester type 

 of 2,4-D than of the amino form. 



? 



Use drop nozzles if corn is more than 8 to 12 inches tall. If drop nozzles are 

 directed into the row, Use proportionately less material. Directed application 

 is not the broadcast rate on the corn. 



5. Check nozzles for proper gallonage, and calibrate the sprayer. You may have the 

 right proportions in the sprayer, but if you put too much volume (gallonage) , you 

 will have too high a rate. 



4. Do not spray corn after tasselling, the work is No-No from tassel to soft dough. 



FENCE-RON WEED CONTROL 



Xow is the time to push weed control in fencerows. Dalapon (Dowpon) can be used to 

 control grasses and prevent seed production. You can add 2,4-D to control the broad- 

 leaved weeds . 



WEEDS IN SMALL GRAIN STUBBLE 



With the small grain harvested, weeds such as foxtail and ragweed now have a chance for 

 more- vigorous growth. If you don't plan to work the fields for a while, consider clip- 

 ping or spraying to reduce the production of weed seeds. If you don't have a grass or 

 legume seeding, consider spraying. A low-cost application of 2,4-D can check most broad- 

 leaved weeds. A few pounds of dalapon (Dowpon) per acre- -alone or added to 2,4-D- -can 

 reduce the seed production of grasses considerably. The smaller the grass, the less 

 dalapon you'll need. If weeds have made much growth, it may pay to clip or chop the 

 stubble before spraying. 



