Observations of soybean rust in southern states indicate that the pathogen (Phakopsora pachyrhizi) is beginning to move northward towards Illinois. Based on current movement, soybean rust likely will arrive in Illinois again this year, but it may not be in the state early enough to cause any yield losses. Late-planted fields would be the most at risk to losses caused by soybean rust. In general, once soybean plants reach the R6 stage (full seed stage),…
Southern rust of corn has now been observed in different areas of Illinois. Southern rust is one of two different rust diseases of corn that can be observed in the state (the other is known as common rust). Because nearly every corn hybrid grown is susceptible to southern rust, yield reductions can occur if infection takes place early enough in the season. Late-planted corn fields are at the highest risk for yield losses associated with southern rust and should be scouted for the presence of this disease. …
On the morning of August 12, Russ Higgins, University of Illinois Extension Commercial Agriculture Educator, Northern Illinois Agronomy Research Center, sampled soybean fields in DeKalb, Grundy, Kendall, and LaSalle counties. In four of seven commercial soybean fields, he detected soybean aphids in low numbers. Typically, Russ found one to two aphids per leaf. He also noted that beneficial insects were abundant within the soybean fields.
The economic threshold for soybean aphids remains at 250 aphids per plant with 80% of plants infested. …
Late planting and weather that continues to be cooler than normal into August has many wondering if the corn and soybean crops will reach maturity and harvest moisture within a reasonable time this fall. Crop conditions remain good for both crops, but crop development, including pod formation and filling in soybean and grain fill in corn, remains well behind normal. Corn is 10 days to 2 weeks behind normal, and soybeans are 2 to 3 weeks behind normal.…
Recently, we have identified populations of Palmer amaranth in several Illinois counties. The density of many populations is relatively low, and often these plants occur only in small patches. However, a few scattered plants this year can lead to severe infestations within only a few years.
We continue to accept tissue samples from suspected Palmer amaranth plants and use tools of molecular biology to identify whether the sample is Palmer amaranth or another species of Amaranthus. …
We are starting to get reports that corn pollination might not have been as successful as expected in parts of Illinois. While the weather was generally favorable during the peak period of pollination, it was warm during the third week of July, and soil water may have been limiting during this period in some fields. Thus we would expect to see this in the areas with low rainfall in July.
This is not the lack of silking that we saw in many areas under the drought of 2012.…
White mold of soybean (a.k.a. Sclerotinia stem rot), caused by the fungus Sclerotinia sclerotiorum, is a disease that can occur in the northern half of the state in cool, wet years. The most recent white mold epidemic in Illinois occurred during the 2009 season, where several fields in the northern half of the state were affected.
The white mold fungus overwinters in the soil as, small, black, and dense structures known as sclerotia. …
The third week of July brought above-normal temperatures to much of Illinois. This is expected to be temporary, with temperatures the fourth week expected to return to normal. Because soils in most areas had enough water to carry the crop through the week, we don’t think the high daytime temperatures were much cause for concern.
By July 14, 21 percent of the Illinois corn crop was pollinating. This included most fields planted before May 10 to 15.…
The 2013 Brownstown Agronomy Research Center Field Day, presented by the University Of Illinois Department Of Crop Sciences, will be held on Thursday, July 25. Extension researchers and specialists will address issues pertinent to the current growing season. Tours will start at 8 a.m., with the second and third groups leaving the headquarters around 8:20 a.m. and 8:40 a.m. The tours will last about two and a half hours and will be followed by lunch provided by U of I Extension.…