Light rain last week helped sustain crops in Michigan, but after several days of 90-degree temperatures and another week of equally hot weather predicted, crops are showing signs of moisture and heat stress.

Paul Gross, Michigan State University extension educator in Isabella County, said until now central Michigan has received adequate rainfall, but with steady high temperatures the need for additional precipitation is going to become critical.

“We have had just enough rain,” Gross said. “By the weekend, if the temperatures stay hot, we’re going to start to see some rolling on the headlands.”

According to last week’s report from the Michigan field office of the USDA’s National Agricultural Statistics Service (NASS), corn is in the rapid growth stage with warm weather, and soybeans are variable in growth stage with low numbers of aphids present.

Gross said there was much corn planted early in the spring that is at the 10- to 12-collar leaf stage. “I was in corn today that was up to my shoulders,” he said. “I expect in some of the earlier-planted corn, we’ll see a tassel or two before the Fourth of July.”

“Soybeans are beginning to canopy, and overall the crop looks good,” he added.

He said some farmers are experiencing pest pressure, but they are not widespread. “We have had some armyworm problems and cutworm problems, but they have been isolated occurrences.

“Overall, the crop conditions are good, but we’re in need of rain, especially with as advanced as they are in the growth stage,” he said. “On lighter soils, it’s going to be tough – the heavier soils with more water-holding capacity seem to be more forgiving.”

In other crops, dry bean planting is mostly complete, wheat harvest is beginning in southern Michigan and sugar beets in central Michigan continue to look good.

The tropical storm that dumped rain on Florida did not send any much-needed moisture to Indiana farmers last week. In fact, the weather pattern shut off any chance of moisture.

“Tropical Cyclone Debby closed the Gulf of Mexico as a moisture source for the Midwest,” said Drew Lerner of World Weather, Inc. “This means we’ll move deeper into pollination without significant amounts of relief.”

Drought conditions have spread over most of the state, with 55 counties currently under burn bans, according to the Indiana field office of NASS. Record-setting heat added to the assault last week.

Pollination has already started within the state, but with extreme temperatures and no rain, pollination success will vary widely from field to field and even within fields. Some fields could suffer complete pollination failure, said Bob Nielsen, Purdue University extension corn specialist.

“I don’t know how much worse it could be in terms of a corn crop coming into pollination around the state,” he said.

But even successful pollination could suffer if triple-digit temperatures combine with drought stress to cause plants to abort kernels in the next few weeks.

Purdue agricultural economist Chris Hurt estimated corn yields could already be down by as much as 14 percent from what was projected at the beginning of the season. Early-season numbers estimated Indiana’s corn crop would yield about 166 bushels per acre. That number is now down to 142.

Fifteen percent of the soybean acreage is blooming. Current projected soybean yields are down 12 percent, from 49 bushels projected per acre at the start of the season to 42.5 now.

The continued general lack of rainfall throughout Illinois is causing crops – most notably, corn – in some areas of the state to exhibit ongoing signs of moisture stress, according to NASS’ Illinois Weather & Crops  report for June 25.

“Topsoil moisture continues to be a concern for many. It is currently rated at 43 percent very short, 41 percent short and 16 percent adequate,” the report stated.

As has been the case all spring, southwestern and southeastern Illinois farmers are praying for rain, with topsoil conditions rated 96 percent very short and 4 percent short in both regions. In central Illinois (41 percent very short, 46 percent short) and western Illinois (12 percent very short, 62 percent short) conditions aren’t quite as arid, according to Patrick Kirchhofer, manager of the Farm Bureau office in Peoria County, which is situated near the dividing line for USDA’s west and central Illinois regions.

“It is a dry growing season so far, but the Peoria area has had a few rains that other parts of the state did not get. Even though we are short of rainfall in this area, we are a little bit better off than others,” said Kirchhofer.

“Overall the crops look decent, and that can be attributed to genetic improvement in seed over the past 10 years. If we would have had this corn crop 20, 30 years ago it would have been much more deteriorated from the dryness.”

Corn conditions statewide were rated at 8 percent very poor and 14 percent poor, which is not bad considering the U.S. Drought Monitor included segments of Illinois in its weekly report. Kirchhofer fears the condition of corn in central Illinois, however, could deteriorate rapidly if the U.S. Weather Service’s forecast for 90- and 100-degree temperatures and little to no precipitation through July 2 came true.

“The hot weather will sap a lot of the moisture out of the ground and will take a toll on the corn crop, which is just entering the tasseling stage, a critical stage for pollination. If we could get some cool nights and get some dew on in the mornings, it would relieve some of the stress. But dew has been very minimal,” Kirchhofer said.

Soybeans in bloom averaged 11 percent, according to NASS, compared to 1 percent in 2011 and 3 percent for the five-year average. Soybean conditions were rated at 7 percent very poor and 14 percent poor.

The winter wheat crop is 97 percent ripe, 32 percent ahead of last year’s pace, while the oat crop is 67 percent filled with 42 percent yellowing and 11 percent ripe, the report stated.