Yesterday (8/23/13), I received reports of neck blast (Picture 1) in western Greene County, AR. We visited two fields of CL151 and a field of Francis where all were confirmed to have the disease. The Francis field and one of the fields of CL151 were at grain fill; and the other field of CL151 was at early milk stage. Leaf blast was not observed prior to this finding of neck blast and Stratego (19 fl oz/A) had been applied once at early boot in the CL151 fields. The situation could have been worse without the fungicide application, but it could have been better if a fungicide had also been applied a second time at 25 to 50% heading. Generally for neck and panicle blast, application of fungicides will not be beneficial after fields have fully headed. As a result, no fungicide application was recommended for these fields.
The CL151 fields are both primarily surrounded by trees; such fields are prone to blast if planted with susceptible varieties and a deep flood cannot be maintained.
This ALERT is for late-planted fields with blast-susceptible varieties in blast-prone areas. If you have rice fields at booting to early heading, the crop could still benefit from a fungicide application. TIMING is important. Once the head is completely out of the boot, a fungicide application has no benefit for prevention of neck or panicle blast. Remember, fungicides are only preventative in these situations.
Higher rates of nitrogen encourage most diseases of rice. In two of the three fields we visited yesterday, the Francis field and one of the CL151 fields, substantial levels of false smut were found (Picture 2).
My appreciation goes to Dave Freeze and Mike Simmons who stayed in the fields with us until dark (Photo left). There was more to see in the field and that was big (Photo right)!