2023 Southern Region Recap. What happened and how did it potentially impact our crops?

Every year growing conditions impact our crops differently. This article is going to break down some of the conditions the southern region experienced this season and how these potentially impacted our crops.

Planting conditions

NE KansaS - Manhattan

            First two weeks of April brought air temperature highs in the 50°F -80°F until an April 20^th – 23^rd cool down. The highs for these few days were in the 50s with lows in the 30s. The soil temperatures at 2inch planting depth during this time fell into the low 50s- 40s. This cool spell was also accompanied with about an inch of rainfall. Any corn or soybeans emerged before this cold spell were subject to cold injury. Corn and soybeans planted 24-48 hours before this cold spell were subjected to cold water imbibition, reduction in stands, and reduced seedling vigor. Corn and soybeans planted 3-5 days ahead of this cool spell took longer to emerge and set in the soil until the air and soil temperatures began to warm up again.

SE KansaS – Parsons

            The first two weeks of April saw similar conditions to Manhattan KS with the same cold spell falling April 20^th-23^rd and night air temps in the 30s. Soil temperatures stayed in the 50s so the risk of cold-water imbibition from planting right before this cold snap was lower. The biggest risk from this cold spell was potential frost injury to any corn or soybeans that emerged above the soil surface prior to this cold snap. This cold injury resulted in stunted plants and reduction in stands where the freeze was hard enough.

NW KansaS – Colby

            Soil temperatures did not consistently remain in the 50s at a 2-inch depth until May 5^th. There was 4-5 inches of rain that fell May 10-18^th which slowed some planting. This rain did not pose a risk of cold-water imbibition but did drag out planting dates for some operations.

SW KansaS - Lakin

            Soil temperatures remained in the 50s at 2-inch depth starting May 2^nd. There were 3-4 inches of rain that fell on May 14-21^st. This pushed some operations planting dates into June, so these fields were potentially pollinating during some of the heat we saw in July and August timeframes.

Rainfall for 4 Kansas locations for 2023 growing season

Rainfall started out strong in May and June for areas of the state but dropped off for most geographies in the August and September timeframes (when most of the corn and soybeans were pollinating or filling grain).

For corn, drought during the pollination and grain fill periods can affect the plants differently. Lack of water during or directly after pollination can cause spotty kernels to develop as well as tip-back on the ears. Lack of rain during grain fill not only decreases the nitrogen available to our plants, it can also cause poor test weights and stalk cannibalization.

For soybeans, lack of rain depends on the RM and what stage the plants were at. Lack of rain during flowering causes more blooms to drop. Lack of rain during grain fill causes seeds to not fill and results in flat pods. Poor water availability later in grain fill can cause soybeans to develop “BB” beans (small bean seeds the size of BB pellets).

SW & NW KansaS - Colby and Lakin 

Rainfall for western portions of Kansas started out high in April – June months. This favorable early season moisture condition caused roots to not develop as deep to search for moisture. When rains slow or stop (like they did around the Colby area), the roots are not deeply established to reach deep in soil profile for late season moisture. This heavy early season rain also contributes to heavy nitrogen leaching. The less developed roots, along with potentially less available nitrogen early season, poses a risk for late season nitrogen deficiencies. This heavy early season rain did however help reduce some populations and feeding of the corn rootworm larvae. Soils that sat saturated and underwater for consecutive days will reduce CRW populations by either drowning out larvae or causing poor egg survival.

Temperatures for 4 Kansas locations for 2023 growing season during corn and soybean pollination/grain fill

Corn and soybeans that were pollinating during these hot spells (day temperatures above 95°F or night temperatures above 75°F) are at risk for aborted or jumbled corn kernels, small soybean seed or blank soybean pods. Day time temperatures above 95°F stops pollen shedding and dries out silks, so pollination for corn stops altogether. Areas like eastern portions of Kansas that also had nighttime temperatures over 75°F had poor recovery of the crop overnight.  Soybeans especially were more prone to sun scald during these hot nights and days.

NE KansaS - Manhattan

Manhattan July 24^th-28^th (5 days) and August 19-25^th (7 days) were bad weeks for pollination. During these heat spells, hot daytime temperatures were accompanied by night temps above 75°F during this time frame. Plants stressed and did not recover at night. These hot spells were also accompanied by lower rainfalls which also caused poor recovery from the heat stress. Manhattan area saw the most nights with temperatures above 75°F (10 nights in 2023).

SE KansaS - Parsons

Parsons heat spells above 95°F were July 25^th – August 4^th (11 days of consecutive heat). Another heat spell occurred August 19-25^th (7 days). During both these heat spells, night temperatures were above 75°F. This contributed to poor crop recovery overnight. During this timeframe, soybean crops were at risk of aborting blooms and not filling seed. If the corn was already pollinated, it translocated less nutrients to kernels, so test weights would be lower and with potentially cannibalized stalks to move nitrogen to the seed.

NW KanaS - Colby

Colby heat spells above 95°F were July 23-28^th (6 consecutive days) and August 18-25^th (10 days). Pollination during these times would have been poor for the corn plants, but nighttimes were cool for crops to recover. This could result in pollination dragging out longer for plants pollinating in these timeframes or potentially spotty kernel fill. This excessive heat accompanied by later season drought could also pose a risk for stalk cannibalization and weaker ear shanks due to plants pushing nutrients to the grain.

SW KansaS - Lakin

Lakin area saw the most days with temperatures above 95°F (23 in total for the 2023 growing season).  Temperatures above 95°F were observed July 16-19 (3 days), July 23-August 2^nd (11 consecutive days), August 11, August 18-25^th (8 days) and August 31^st.  Notably, nighttime temperatures did drop below 75°F in this area, so some recovery could happen overnight.

Other Environmental Conditions

Hail

Areas of the footprint saw sporadic hailstorms in both early and late growing season. Hail injury to corn and soybeans can vary depending on the stage of the crop and severity of the hailstorm. A good article to look at that discusses hail injury to corn is available at Purdue-HailInjuryCorn. Some of these hailstorms also impacted the severity of disease we observed in some of our crops. Any time a plant is wounded by hail these open wounds allow additional entry points for pathogens.

Sudden Death Syndrome

Sudden death syndrome (SDS) was observed heavily in portions of northeast Kansas. Areas that retain water or have poor draining areas are subject to higher rates of SDS infection. The infection begins shortly after planting but foliar symptoms don’t show up until later in the season. Foliar fungicides are not effective on the SDS pathogen.  The best options for SDS prevention are utilizing soybean varieties with high tolerance and seed treatments. A good article discussing seed treatment options is available at TheDirt-IlevoSoybanSeedTreatment. If a field has a history of SDS or is poor draining, utilize a variety that has a strong SDS score and seed treatment that is effective for SDS control.  

Dectes Stem Borer

Dectes Stem Borer has also been present in high levels across Kansas. This is a beetle pest that lays eggs at the base of the soybean plants. The larvae then hatch and burrow into the soybean plant and up the soybean stem. This pest is responsible for soybean lodging and causes soybeans to dry down odd because there are no vascular tissues to continue moving nutrients to the seed. There are no insecticides labeled for this pest, the best management options are to rotate and monitor fields for timely harvest. A further in-depth article on this pest is available at TheDirt-DectesStemBorer.

As we wrap-up harvest and look to making decisions on product placement and performance, take a moment to think about how a variety or hybrid handled conditions on your farm. In a year like this with variable rains, hail, heat and pests, it’s important to take it all into thought when selecting seed for next year. If you have questions about hybrids or varieties best suited for your acres, reach out to your local Hoegemeyer DSM or Tier 1 Dealer.

Sources

KstateMesonet

TheDirt-Drought on TestWeightofCorn

Purdue-HailInjuryCorn

TheDirt-IlevoSoybanSeedTreatment

TheDirt-DectesStemBorer