-3- 



Eim leaf beetle larvae are feeding on elm foliage , especially Chinese elms. The 

 dirty-yellow to black worms feed on the underside of leaves, skeletonizing them. 

 Spraying the foliage with carbaryl (Sevin) at the rate of 2 pounds of 50 -percent 

 wettable powder is effective. Another treatment about the first of August (this 

 timing is suggested for central Illinois) may be needed for the second generation. 



Aphids are building up on roses, as well as on other flowers, shrubs, and trees. 

 Spraying with malathion or diazinon will give effective control. A repeat applica- 

 tion may be needed later, if populations begin build up again. Follow the direc- 

 tions and precautions listed on the label. 



PLANT DISEASES 



Corn 



Corn smut is unusually prevalent on the stalks and leaves of corn this year. The 

 large galls low on the stalk can kill the plants. These galls also cause extreme 

 deformation that may result in unproductive plants . Galls on the leaves are not 

 particularly harmful. Ears and tassels can be destroyed. Evidently, the weather 

 conditions have been ideal for infection by the smut fungus . There is no chemical 

 control for this disease. 



Soybeans 



Rhizoctonia and phytophthora fungi are now killing seedling soybean plants. 

 Phytophthora damage occurs primarily in low spots in the field. Rhizoctonia damage 

 occurs on both high and low ground. If phytophthora is a problem, the grower should 

 use resistant varieties in the future. 



Septoria brown spot is beginning to appear in some soybean fields. This fungus 

 disease occurs on the lower leaves first, moving upward later in the season. The 

 leaflets turn yellow and have scattered chocolate -brown spots on them. The spots 

 do not fall out. 



Wheat 



Glume blotch is a problem in a number of wheat fields. The disease is recognized 

 by light tan -to -brown lesions on the upper half of the glumes and lemmas of the 

 spikelets. Small dark pycnidia (spore cases) occur on the diseased areas and are 

 diagnostic. Kernels in the diseased heads tend to be somewhat smaller and lighter 

 than those in healthy heads . 



WEEDS 



Just at press time, a flurry of reports started to come in concerning onion-leafing 

 on corn, associated primarily with 2,4-D application. We'll have more information 

 on this in next week's BULLETIN. 



Onion- leafing , malformation in brace roots, brittleness, and elbowing of the stalks 

 are typical symptoms of 2,4-D injury to corn. We have some every year. Overdosing 

 is one cause. If you direct 2,4-D toward the row, be sure to adjust your rates so 

 you don't apply more than the recommended rate on the area actually treated. Also, 

 injury may be more likely if you spray during hot, humid weather. Some hybrids 

 are more sensitive than others to 2,4-D. It may pay to check with your seedsman 

 before you spray. 



