-3- 



Aphids are now abundant on the undersides of leaves on tulip trees (also called yellow 

 poplar) . These aphids secrete a sugary substance called honeydew that makes the leaves 

 sticky. Shortly after the appearance of the honeydew, a black sooty fungus will de- 

 velop on it. The leaves will take on a very dark green or black appearance, and many 

 of them will fall. 



These aphids are readily controlled with sprays of 1 quart of 57-percent malathion 

 concentrate to 100 gallons of water or 1 tablespoon per 1 gallon of water. Apply 

 right away. There is no evidence that natural enemies are present to any extent. 



Mimosa webworms are also abundant now. Examine the leaves of mimosa or locust trees 

 for signs of rolled up leaves or nests in which these green worms may be hiding. If 

 they are common, apply a spray of carbaryl, malathion, or Bacillus thuringiensis (Bio- 

 trol, Dipel, or Thuricide) . Brown foliage, a result of webworm feeding, will soon 

 be evident. 



Pressurized sprays sold in cans as aerosols are to be applied as a mist to a plant. 

 If used as a direct wetting spray, leaf tissue along the edge of the leaves will be 

 burned and will turn brown. Properly applied sprays from pressurized cans will pro- 

 vide good control of pests such as aphids on roses, but leaf damage will occur if 

 the spray is applied improperly. 



WEEDS 



WEED CONTROL IN GRASS PASTURES 



Pasture land is probably the most neglected acreage on Illinois farms. Permanent 

 grass pastures are often poorly fertilized and overgrazed. They are frequently al- 

 lowed to grow tall with weeds that will crowd out the last remnants of the desirable 

 forage species. Some of the weeds that grow may also produce toxic substances or 

 may contain high quantities of nitrates that can injure or kill grazing livestock. 



A small investment in herbicide and fertilizer can improve both the yield and the 

 quality of the forage harvested by livestock. 



Many pasture weeds can be controlled by repeated applications of 2,4-D, a relatively 

 inexpensive treatment. Apply a half to a full quart per acre (the 4-pound- per- gallon 

 preparation) of 2,4-D amine or ester when weed leaves are grown, but before the weeds 

 blossom. This treatment will be less effective after mid- July or August when the 

 weeds have already matured and have produced their annual seed crop. 



Persistent, perennial weeds such as Canada thistle need to be treated again whenever 

 the lush, new regrowth occurs. Two to three treatments this year, followed by another 

 treatment next spring may be required for satisfactory control. A balanced fertiliza- 

 tion program will help desirable forage species compete with the weakened weed infes- 

 tation. 



For weeds and brush that are not adequately controlled with the use of 2,4-D, it may 

 be necessary to use 2,4,5-T or mixtures of 2,4,5-T and 2,4-D. The use of 2,4,5-T on 

 grass pastures is still registered, although the registration of 2,4,5-T for some 

 other uses has been cancelled. 



Be sure to follow the grazing restrictions when applying any of these herbicides. 

 Keep dairy cattle out of pastures treated with 2,4-D or MCPA for seven days after 

 application, and do not graze pastures treated with 2,4,5-T for six weeks after the 

 treatment has been made. Beef cattle should not be allowed to graze on treated pas- 

 tures within two weeks of slaughter. 



