Corn, soybean crops in northern Plains show moxie

Corn and soybean growers in the northern Plains have experienced atypical conditions but despite those challenges yields have been holding up, according to Nebraska DEKALB Asgrow Technical Agronomist Josh Erwin.

Corn growers who were able to get their crop planted in mid to late April developed good stands before a cold snap delayed growers.

“At planting time it seems like every year there is always a planting window challenge,” said Erwin, who is based near Norfolk, Nebraska, and covers 14 counties in northeast Nebraska. He also keeps tabs on crops in Nebraska, Kansas and eastern Colorado.

Overall the stands were pretty good despite the timing of challenges, he said. In early May the crop had to stay in the ground 14 days longer than normal but seed treatments that include fungicides and insecticides helped to provide solid emergence.

“There were a lot of areas across my region, as well as Kansas and western Nebraska, where the rains were challenging,” Erwin said. “They were tough for some growers and yet some regions had timely and plentiful rains. In a lot of ways we’d say it was a normal year.”

In the areas he observes, growers had timely but not excessive moisture in the early part of the growing season.

By midseason, the crops experienced a higher than normal solar radiation, he said, and it takes sunlight to grow crops. Some of the initial corn yields were as high as 300 bushels per acre in pockets. Soybeans have also seen extremely high yields in 60 to 70 bushels per acre.

“With both crops, when we got into dry areas the yields varied greatly,” Erwin said.

The farther north he travels in his area the drought was well documented, although the longer season soybeans performed better than early season beans because timely rain fell later in the growing season, allowing them to take advantage of that moisture.

Erwin said that scenario reinforced an important point about the need to take a diversified approach to selecting seed so that a grower is prepared and not all of his eggs are in one basket.

Disease pressure was less prevalent, although gray leaf spot and southern rust, both fungal diseases, were found in higher levels in southeast Nebraska and northeast Kansas, the technical agronomist said. The reduction in disease pressure is helping boost yields, and favorable amounts of humidity can boost yields even in a dry season.

The genetics today have improved drought tolerance and that’s what has helped growers in many areas.

The higher than normal growing degree-days sped up the growth of both crops in August and early September.

“Across the geography we’re about seven days ahead of schedule for maturing and with warmer September temperatures we were able to get pretty good dry down across both crops,” Erwin said. “Some of the irrigated corn we’re taking out today is lower 20s and dryland is about 16% to 17%.

The technical agronomist said soybeans and corn still had challenges that growers need to take into account as they look to finish up this harvest and prepare for 2022.

Soybeans

Humidity coupled with irrigation for growers may unfortunately spur white mold and sudden death syndrome. “Both diseases thrive in good moisture and humidity. This year soybeans had good growing conditions and vegetative growth.” The humidity can increase white mold severity and he urges growers to select seed with good tolerance ratings for white mold.

Applying Delaro, a fungicide, at the R1 and R3 stages can help. Also, water management is critical and for irrigators. They can reduce the application of water so the plant’s canopy can dry, he said. Unfortunately, once a field gets white mold, it is difficult to get rid of because it often shows up in the lower areas of the field.

Sudden death syndrome, a soil-borne fungus, can cause significant yield losses, he said.

Having a variety with an effective seed treatment for SDS and genetics with good ratings is the best management strategy, he said.

White mold and SDS will stay in the field from year to year, so it’s important to be proactive and deploy management strategies, such as crop rotation.

The other challenge in growing soybeans involves weed control and that means addressing waterhemp, Palmer amaranth, kochia and pigweed. Investing in herbicide traits like XtendFlex can help provide flexibility in options.

“But really it takes a solid weed management program,” Erwin said. “Weeds are no longer easy to control. We need strategies with multiple modes of action and residuals both in pre-emerge and post-emerge applications. The best way to control weeds is to never let them get above the ground. To do so you need good residual properties.”

Palmer amaranth can grow 6 inches a day, which means it takes nutrients, space and yields. It can cause 30% loss in yields and produces seed at such a rate that the following year makes it even more of a challenge than the previous one.

Corn

Rootworms continue to be one of biggest challenges over the past couple of years in Kansas and Nebraska.

“We have a lot more corn on corn especially in areas where feedlots are present. With the past several mild winters, the pressures have really increased,” he said. “Rootworm are one of the more adaptive insects we have. They have figured out ways to get around technologies. Insecticides used in the 1990s for adult beetle spraying developed resistance after a short time.”

Below ground single mode of action traits were a breakthrough, but we have seen pocketed resistance to these as well, he said. Researchers started to stack proteins for multiple modes of action below ground and that was significant but the rootworm has proven to be a worthy foe. Crop rotation has helped, but the Northern Rootworm have adapted to an extended diapause, causing a delay in hatch of some of the eggs.

A new technology, DEKALB SmartStax Pro with RNAi Technology, targets the rootworm with a new mode of action, different from the proteins used today providing growers with the first trait stack with three modes of action for rootworm, he said. It will be available in limited quantities in 2022 and more widely available in 2023.

“We’re excited about this new tool coming to help growers,” he said, adding that it still requires farmers to use solid rootworm management strategies including crop rotation, selecting genetics with aggressive roots, and controlling adult beetles.

While the corn crop overall appears to be outstanding with lower than normal disease pressure, growers still need to check stalk quality and take note of any rot. When corn is stressed, its first task is to stay alive and it will do everything it can to fill the ear, meaning it can rob nutrients from the stalks if the crop is short on fertility … Higher yield areas will likely use more nutrients from the soil as well. He advocates growers conduct regular soil tests.

Dave Bergmeier can be reached at 620-227-1822 or [email protected].