-5- 



fe suggest adjusting the rates to organic-matter levels on these corn herbicides: AAtrex 

 atrazine) , Princep (simazine) , prometryne, Lorox (linuron) , and Lasso. Thus, combinations 

 rhich contain one or two of these herbicides --such as Primaze, Londax, Sutan- atrazine, 

 .amrod- atrazine, and atrazine- linuron- -are also affected by the level of organic matter. 



reflan, Planavin, Lasso, and Lorox are soybean herbicides that are affected by the organic- 

 latter level in the soil. Lorox tolerance to soybeans is close, so no more than one pound 

 if Lorox SOW -(50 percent ai) is suggested for each percent of organic matter. This will 

 laximize control and will minimize injury. 



VY BEANS FOR SEED 



hese preemergence herbicides are presently cleared for use on soybeans for seed, or on re- 

 ilanted beans: Ramrod, Londax (a mixture of Lorox and Ramrod), and Preforan. They are not 

 o be sold for use in food, feed, or oil markets. 



PLANT DISEASES 

 'HEAT 



eptoria leaf blotch . The situation is about the same as last week. Older leaves are 

 ellowed or dead, and black specks (pycnidia of the Septoria fungus) are common in older 

 pots on spring- formed leaves. 



oil-borne mosaic . Last week, gage wheat showed some yellowing and mottling of leaves. 

 he wheat is growing out of this now, and the new leaves are a healthy green. No further 

 i.amage is expected. Mosaic is only serious in cold weather in low, wet areas where sus- 

 eptible hard wheats are grown. 



' j'owdery mildew . This can now be found in light amounts within about a third of the fields 

 s far north as Jasper County. Mildew is prevalent only in heavily fertilized fields. We 

 xpect the disease to move north during the coming week. 



eaf or stem rusts . There is no evidence of these at present. 



LFALFA 



spring black stem . This is common now in southern Illinois within the counties sampled- - 

 hite, Jefferson, and Hamilton. Look for dark, slightly sunken areas on the stem and leaf 

 etioles. Small, dark spots will also show on the leaves, Many of these leaves will be 

 urning yellow and dropping off shortly. 



rown rot . Some of this is evident, along with heaving damage. Crown- rotting fungi enter 

 hrough wounds caused by heaving, frost damage, and other types of winter injury. Abundant 

 oil moisture is keeping these plants alive. But some plants will probably die during 

 oisture-stress periods later on. 



LOVERS 



; ields look good so far. The only diseases evident are the viruses . Symptoms vary, depend - 

 ng on the virus and the species of clover. Infected plants are usually stunted or dwarfed 

 nd are "bunchy," with yellow and mottled leaves. Regular or irregular yellow patterns may 

 evelop along the veins of the leaves. 



