Each growing season for spring crops offers different challenges and 2020 is no exception, according to a Golden Harvest agronomist who shared his thoughts during a recent webinar.
Corn and soybean growers in the central regions of the High Plains have experienced one of the most challenging seasons for producers, who have faced near record heat and high winds in June that were in many cases followed by unusual high totals of rain in July, Spencer McIntosh said. Plus cooler temperatures occurred in some regions in late July and early August.
“Soil moisture levels were largely depleted coming out of June. Luckily, we were able to flip the switch for both moisture and temperatures,” McIntosh said. “Most areas began receiving some much needed rainfall by mid-July and cooler than normal temperatures have persisted for much of late July and early August. As par for the course in this area, we have the haves and have-nots as far as rainfall. More scattered showers than widespread rainfall events have left some areas overflowing with rainfall and areas just 20 to 30 miles away hoping to catch a rain.”
Corn crop
In the western region of Kansas he expects irrigated fields to perform better than in 2019 and likely above historical averages. “The drier weather and heat early allowed planting to progress with good emergence, and the early heat stimulated good root development.”
Dryland has been challenging with most areas being impacted by low rainfall. Many areas in western Kansas had to halt planting or were unable to even start planting due to dry soil conditions. A few isolated areas have received timely rains and have good yield potential
In the central region, he expects irrigated fields to perform better than last year and likely above historical averages, he said. The June heat had more of an impact on this area especially in some of the coarser soils and predominantly dryland areas, but the moderate temperatures have allowed pivots to keep pace with water demand better than usual.
“Southern rust moved in earlier than normal, and the weather pattern has supported continued cycling and progression of the disease, which could impact some acres,” McIntosh said. Dryland in north central Kansas is in good shape except for areas that were drowned out by rain. Rains in south central Kansas have been very hit and miss, but most growers should be able to achieve average yields. North central Oklahoma is in very good shape, and this area should be experiencing well above average yields.
Northeast Kansas looks to be in good shape, but southeast Kansas has had a very challenging year. “Excessive rainfall resulted in substantial replant and delayed planting. Corn is far behind normal in development and has seen substantial stress in early reproductive stages. Some corn has already been taken for silage due to poor yield potential in some areas. For the most part, southeast Kansas will likely see yields below historical averages.”
Soybeans
In Kansas and central Oklahoma, yield potential appears to be very good so far, McIntosh said. Irrigated soybeans appear to have very good yield potential. Dryland soybeans are mostly in good condition.
“Most of the earlier or full season soybeans are just beginning seed development, and the later planted and double crop soybeans are in pod development,” he said. “We have had what I would suggest as favorable weather to this point
Improving their yields, quality
For corn, continue scouting fields for southern rust through full dent and up to a third of milk line stage.
“Southern rust can be very aggressive and cycle spore to spore in just over a week,” he said. Consider protecting susceptible hybrids from southern rust flare-ups that could occur prior to the one-third milk line stage.
Continue scouting for pod feeding insects in the soybean crops, he said.
“Stinkbug pressure is high this year, and stinkbug thresholds are very low at one stinkbug per 3 foot of row,” McIntosh said. “Podworms have also began showing up in soybean fields with later planted or fuller season reverse micelles being at the highest risk from podworms.”
The threshold for podworms is one podworm per 1 foot of row. Green cloverworm numbers are also beginning to increase. Cloverworms are primarily just defoliators, so look to take action prior to 35% defoliation or when finding over 10 green cloverworms per foot of row.
Lessons learned for 2021
Only plant into acceptable planting conditions at adequate depth, he said.
“Planting is in my opinion the most critical field operation and the yield limiting factor that we have the most control over,” McIntosh said. “Planting into too cold or too wet soils will most often lead to issues in stand establishment and plant health that will continue to affect the plants through harvest. Avoiding uneven emergence is critical to high yields and has irreversible effects.
“Providing for good seedbed conditions and being as patient as possible until planting conditions are adequate has always proven to be of the highest priority. The past couple of years have really amplified good planting practices as several fields have been planted later than normal due to unfavorable weather and performed well. For we do not know how the weather will play out, but we do know what the effects of poor stand establishment will be.”
Understanding nutrient cycling to provide for crop demand was another piece of advice he offered. With the challenging weather over the past three years, with conditions ranging from extreme drought to flooding, proper nutrient management has been challenging.
“Be sure to understand how these extremes can affect nutrient availability and loss, and how to effectively manage under different weather extremes,” McIntosh said.
Uninvited diseases, pests
In western Kansas, corn rootworm pressure continues to intensify, he said. Continuous dryland corn continues to grow in acreage every year, and much of western Kansas now has large areas with more than four years of continuous corn on dryland fields.
“Corn rootworm management on dryland has been relying almost exclusively on corn rootworm traits up to this point, and we need to see other management tools implemented, McIntosh said. “We are also seeing corn rootworm larvae and beetles develop more tolerance, if not resistance, to pyrethroids such as bifenthrin. Pyrethroids included with fungicide applications during early reproductive stages are seeing beetle populations grow to problematic levels later in the season. It is important to monitor and manage beetle populations in fields through mid-September on fields that will be continuous corn in 2021.”
Corn beetle populations over 50,000 beetles per acre on either irrigated or dryland fields can result in enough egg lay and larval populations that can overwhelm corn rootworm traits in the following year. Further, watch for beetle movement from neighboring fields or even within fields due to silage harvesting or early senescence or dieback by early maturing hybrids.
Other insight
With the vacation of several dicamba herbicide registrations in soybeans, producers have a lot of uncertainty about which direction to go in 2021, he said. At Golden Harvest, offering both Xtend and Enlist trait platforms and having two breeding programs was already challenging, but the vacation of the dicamba labels created even more complexity at least in the short term for the company too. It is still unclear what will happen with the dicamba registrations.
Ultimately, neither dicamba nor 2,4-D alone is a one-size-fits-all solution for weed control. Even if they were, they would likely be short-lived and far more so than glyphosate was anyway.
“I believe both platforms can be successful if incorporated into a herbicide program that focuses on the fundamentals of weed control and managing resistance: implementing multiple modes of action and utilizing residual products,” McIntosh said. “Consequently, using these foundations, whichever technology a producer intends to use can provide effective weed control.”
Dave Bergmeier can be reached at 620-227-1822 or [email protected].
