Agronomic Crop Disease Update

Bob Mulrooney, Extension Plant Pathologist; bobmul@udel.edu

Soybean Rust Update
Rust is developing very slowly despite excessive rainfall in some of the Gulf Coast states. Florida is remaining mostly dry. Rains have delayed some of the sentinel plot planting in LA and MS. There have been no new detections on kudzu since the last report. Those interested in following soybean rust can visit the ipmPIPE website at www.sbrusa.net.

Wheat Head Scab
The good news is that the current forecast for head scab is low for the next 72 hours. For wheat that was flowering from May 7 through May 10 the risk that scab could develop was 56-63%.

Avoid Spray Drift
Most applicators are aware that Quadris and Quilt can be very phytotoxic to certain apple varieties. Be sure that spray drift does not come in contact with apple trees or phytotoxicity can occur. With all the wheat that was recently sprayed we have had several cases of phytoxicity reported.

Soybean Cyst Nematode
It is still not too late to check for soybean cyst nematode especially if susceptible soybeans are going to be planted. Soil test bags with the submission form can be purchased at the Extension offices. If you have a fax machine and need results quickly, test results can be sent via fax if you provide the number on the Nematode Assay Information Sheet. This information sheet can be found on the web at the Plant Clinic Website http://ag.udel.edu/extension/pdc/index.htm.