reddish-brown border. Under favorable conditions (warm, humid weather) , these 

 tiny spots will enlarge within 7 to 10 days after they become visible on the leaf. 

 It takes much longer during dry, cool weather. 



One way to check for the organism that causes southern corn leaf blight is to 

 place infected leaf sections between soaking-wet paper towels. If masses of dark 

 fungus spores are produced within 1 to 5 days, this indicates the possible pres- 

 ence of Helminthosporium maydis. However, further examination is necessary for 

 positive identification. 



Chlorotic (yellow) spots, wrinkled leaves, streaks, or large bleached areas do 

 not necessarily indicate the presence of southern corn leaf blight. Remember, 

 that moisture must be on the leaf surface for at least 6 hours , along with viable 

 spores, before an infection can occur. 



QUARANTINE ON SOYBEAN CYST NEMATODE REVOKED 



The USDA will revoke the Federal soybean cyst nematode quarantine, effective June 

 50, 1971. That action will remove Federal regulations from all states now under 

 quarantine- -Arkansas, Florida, Illinois, Indiana, Kentucky, Louisiana, Mississippi, 

 North Carolina, Tennessee, and Virginia. The nematode can be controlled with a 

 crop rotation system that does not include snap and adzuki beans, lespedeza, com- 

 mon vetch, or lupines. Resistant varieties may also be used in some areas, such as 

 in southern Illinois. 



For more information about the soybean cyst nematode, read Report on Plant Diseases 

 No. 501 (revised) "The Soybean Cyst Nematode Problem." For a copy, contact the De- 

 partment of Plant Pathology (218 Mumford Hall, Urbana, Illinois 61801) or from your 

 county Extension Adviser in Agriculture. 



LOOSE SOD 



Sod root isolations from several specimens received by the Plant Disease Clinic do 

 not show the presence of any pathogen. The root systems look stunted and discolored,' 

 and the upper parts of the plants are dead or dying. Sod showing these symptoms can 

 usually be easily lifted from the soil because of the lack of root penetration into 

 the soil below. The symptoms will be accentuated by moisture deficiency. 



There are eight basic steps for putting in a lawn, seed or sod, that may help avoid 

 the problem. 



Before planting: 



1. Remove debris--such as tin, construction lumber, large rocks, plaster, or 

 pieces of cement. 



2. Make sure the lawn is properly graded. 



5. Find out if sub surface tile drainage is needed. 



4. Remove any large deposits of poor-quality soil that may be covering the top- 

 soil. 



5. Improve soil conditions, if necessary, by adding topsoil, sand, peat, or other 

 organic matter. These materials change the soil conditions, but are expensive. 



