Sunrise Field Scout                                           05/11/2010
Corn: Did the frost hurt the crop? I doubt that it has. It needs to get down below 28 degrees before serious damage occurs. I haven’t seen any evidence that these light frosts are causing a problem.  Observed a few plants being cut off this week by cutworm. Once this cutting reaches 3% an insecticide treatment is warranted. Pyrethroid compounds such as Grizzly are very effective. This initial cutting usually prunes off the whorl leaf which plants can recover from. Later cutting retards the plant so much that it becomes like a late emerger. Each plant lost in 17.5 feet equates to a 6 BPA loss. Insecticide costs are about $6 to 8. Slugs may become a problem in no till fields. They usually make small round holes in the leaves and start stripping them later. Baits can be applied to control them but they are pretty costly. Usually the crop will out grow the feeding if weather conditions are favorable.  A lot of very nice stands out there. Some are very uneven due to planter problems: doubles, triples, skips, and uneven spacing. This can be caused by a number of things: speed, worn meters, poor depth control, vacuum settings, etc . Now would be a good time to evaluate your emergence to make corrections for next year. Weeds are starting to come in fields that didn’t have timely rain fall.
Beans: Did the frost hurt the crop? Again temps would have to get below 30 degrees for much injury to occur. I have already seen unifoliate leaves and the terminal bud frozen on plants that shot out 2 new stems from the cotyledon axils. If you have some singeing on early leaves give the plant a chance to recover. You may find there is no need to replant. We will loose way more plants  to phytophtora this year on soils that get saturated.
Wheat: Did the frost hurt the crop? This call is much tougher because at early boot stage 30 degrees for about 2 hours is all the plant can stand. A few years ago we had some of this injury. It looks like an atrazine carryover problem. It usually shows up about a week after the fact and seems to accelerate with warmer temps. If it’s extensive enough planting another crop is justified.  A lot of powdery mildew observed in some fields. These varieties must be very susceptible and they need to be sprayed ASAP. Do not wait until the flowering stage and try to control head scab with the same trip. What’s there now is more devastating than the head scab might be. For those who want to spray for head scab there is a model predictor at www.wheatscab.psu.edu. If the weather continues to be wet and humid we have good potential for scab this year because of all the problems we had last fall with DON in the corn. The same organism that caused that can cause head scab and it is present out there on the stalk residue now. Headline + Caramba, and Prosaro are products of choice. You need full spray coverage at flowering. These materials are about 90 percent effective if applied properly.
Alfalfa: Alfalfa weevil larva are still out there eating. We need to spray or cut within the next week or else suffer the consequences. Grizzly is very effective @ 3.84 oz. The PHI is 7 days.
Contact Jerry Cunningham in Green Springs at(419)-639-2242 or call his cell (419)-680-0103