For control in corn and soybeans , apply carbaryl at 3/4 pound or toxaphene at 1-1/2 

 pounds per acre. Do not feed toxaphene- treated corn or soybeans as a forage to dairy 

 cattle or to livestock being fattened for slaughter. Do not harvest soybeans as grain 

 for 21 days after treatment with toxaphene. Carbaryl has no waiting period or other 

 restrictions when used as directed. 



LIVESTOCK 



Under "Face Flies" in last week's bulletin (No. 10), the statement "Dust bag treatments 

 with insecticides like ciodrin or Coral do give effective control of face flies" should 

 have read "Dust bag treatments with insecticides like ciodrin or Coral do not give ef- 

 fective control of face flies." 



HOMEOWNER PROBLEMS 



Picnic beetles continue to plague home vegetable gardeners. They are damaging the ker- 

 nels of ripening sweet corn. They will swarm to overripe vegetables or fruit. 



To help reduce the problem, pick fruits and vegetables before they become overripe. 

 For control on sweet corn, apply carbaryl (Sevin) as a spray 'to the ear zone and leaf 

 axils. To mix, use 2 tablespoons of the 50-percent wettable powder per gallon of water. 

 Do not expect to control the beetles that are deep in the silks; the insecticide will 

 not reach them. 



Additional treatments every 4 or 5 days may be needed to prevent further infestations. 

 This treatment will also help prevent infestations by corn earworms and corn borers. 

 Carbaryl or malathion may be used on other vegetables or fruits if picnic beetles pre- 

 sent a problem. Follow the directions on the label for dosage, waiting period, and 

 other restrictions. 



WEEDS 

 2,4-D, POSTEMERGENCE IN CORN 



Weeds are still bad news in some fields where adequate cultivation and spraying have 

 not been possible. 2,4-D is about the only spray to consider for corn at this late 

 date. 



Most 2,4-D labels say, "Do not apply from tasseling to dough stage." This statement is 

 apparently based on early research which showed that spraying at certain critical stages 

 might interfere with development of grain. In one Iowa study, 2,4-D was sprayed on 

 corn plants at various stages. Applying 2,4-D when tassels were beginning to emerge 

 resulted in inhibition of ear shoots. And application of 2,4-D 1 to 4 days before silk 

 emergence caused severe inhibition of seed set on the developing ear. 



Each year, 2,4-D causes some brittleness and breakage of corn, some onion- leafing, and 

 some malformation of brace roots. But we have had very few reports from farmers' fields 

 of 2,4-D affecting ear and grain development. Perhaps this is partly because of pre- 

 cautions to avoid spraying during the critical period, more resistant hybrids, and mini- 

 mals amounts of 2,4-D applied directly to the corn leaves. 



But it still seems safest to avoid spraying during the critical stages, especially dur- 

 ing early development of the ear shoots (this is about the time tassels begin to emerge) 

 and just before silks emerge. 



