NWRC June 2007 Newsletter, Crop Sciences, University of Illinois

JUNE WEATHER:			Soil Temperature (^oF)
	Air Temp. (^oF)	Humidity (%)	4" (Bare)	4" (Sod)
Monthly Average High	80.8	99.0	79.7	76.3
Monthly Average Low	60.0	63.3	70.3	69.8
Observed High (date)	91 (16,18)	100 (most)	88 (17)	82(17,18,28)
Observed Low (date)	48 (9)	30 (23)	64 (6,7)	64 (7)

2007 Precipitation (in inches)

Month	Monthly Total	Monthly Departure from Average	Since January 1 Total Accumulation	Since January 1 Total Departure
January	1.14	-0.48	1.14	-0.48
February	1.48	-0.42	2.62	-0.72
March	4.41	+1.56	7.03	+0.84
April	2.87	-0.89	9.90	-0.05
May	2.94	-1.33	12.84	-1.38
June	4.25	-0.01	17.09	-1.39

Growing Degree Days (Base 50)

Month	Monthly Total	Monthly Departure from Average	Total Accumulation Since April 1	Total Departure Since April 1
April	179	+7.4	179	+7.4
May	520	+126.3	699	+126.3
June	604	-2.5	1303	+123.8

Crop Progress

Corn

Most of our corn is tasseling with lengthy silks emerging. An application of fungicide was applied to two studies as a split-plot treatment. While there is very little if any foliar diseases present in the corn, there have been a lot more hours of wet leaves compared to the previous two years at this time. The longer leaves are wet, the better chance there is for a fungal spore on the leaf to germinate and successfully infect the leaf. Another factor that plays a significant role in the disease cycle is the susceptibility or resistance of a hybrid to a specific disease. The hybrids that are more susceptible to a foliar disease are more likely to show an increased yield response to a fungicide application.

The research at NWRC includes check plots to determine if a treatment had an effect. With the introduction of yield monitors and availability of weigh wagons, farmers can determine if treatments, such as foliar fungicides have had an effect on their farm. Having the applicator leave an unsprayed strip or 2 in a field will result in information that can help in future decisions. Without the check strips, it is very hard to determine is the treatments actually paid for themselves.

The topic of fungicides on corn were addressed very well by Carl Bradley and Matt Montgomery in Issue 11, Article 6, and by Emerson Nafziger in Issue 14.
http://www.ipm.uiuc.edu/bulletin/

Stand counts have shown very good emergence in the corn. Average stand counts for studies are between 93 and 98%.

The corn in no-till is still lagging behind the tilled plots, with tassels emerging 3-4 days later. In one tillage study the highest stand counts were with no-till.

Soybeans

The 15" split-row soybeans were beginning to canopy by June 20, while the 30" rows may canopy the 2nd week of July. Previous research has shown that soybeans drilled or in 15" rows canopy 3 weeks before 30" rows, similar to this year. There have been years that were drier that the 30" rows never did canopy.

The post-emerge spraying for soybeans if essentially done, with good results. It was discovered that it takes a few more days of patience to see if volunteer corn will be controlled by products such as Fusion compared to non-RR volunteer corn control with Roundup.

Stand counts in a no-till soybean study planted with a split-row planter showed very good emergence. The average stand efficiency was 95% of the seeding rate.

No soybean aphids have been caught in the aphid suction trap nor found on plants in the soybean rust Sentinel plots. Neither has there been soybean rust spores caught in the spore trap or leaves infested with the fungus found in the Sentinel plot to date. There is a little Septoria brown spot showing up on the lower leaves of some varieties. With the soybeans at R2-3, the next few weeks are the critical time for soybean rust infestation. As mentioned previously, we have not had favorable conditions for development of a foliar disease such as soybean rust the last couple of years. However, the prolonged hours of leaf wetness that has occurred recently is a signal that this is a time to be vigilant in monitoring soybean fields. The spores still have to get here, so reports from Sentinel plots and spore traps farther south should give an early warning of potential outbreak of rust.

August is the time to place yellow sticky traps in soybean fields to determine if the corn rootworm variant will be present in that field with next year’s corn crop. A couple of sources of the Pherocon AM traps are Gemplers (www.gemplers.com) (800-382-8473) or Great Lakes IPM (www.greatlakesipm.com) (800-235-0285).

Small Grains

Wheat harvest was completed July 3. The average yield was 76 bu/acre, with plot yields averaging from 46 to 108 bu/acre. Some of the stands showed evidence of a difficult growing season. One of the varieties planted at NWRC had leaf rust infesting much of the flag leaf during grain fill. A fungicide application would have probably be very profitable in this case. There was very little head scab, even in a study that was planted to favor its development.

The oats look very good and are turning with a little green left. They will probably be harvested in the next week.

Field Day

The annual field day at NWRC will be on August 21 this year. The first tour will leave at 8:00 AM and the last tour will leave at 9:00 AM. A tour will take 2 to 2½ hours to complete. The topics and speakers are listed below. CCA credits have been applied for.

Higher corn Population and Nitrogen Mgt	Dr. Emerson Nafziger
Managing P and K for Continuous Corn	Dr. Fabian Fernandez
Fungicides for Corn and Soybeans	Dr. Carl Bradley
Herbicide Updates	Dr. Aaron Hager
Soybean Cyst Nematode Management: The Rest of the Story	Dr. Eric Adee

Weather Trivial

It is rare to have an “average” month, but I think June qualified. The rain fall was within 0.01" of the 30 yr average and the GDU’s within 2.5 units.

Return to previous page.