The spring of 2017 has provided Ohio’s growers with many challenges, and as the growing season continues, sound management of crops will be critical to diminish potential problems and maximize yields.
Patterns of wet weather and large rainfall events have caused planting delays, emergence problems, and required replant of both corn and soybeans in many areas. Due to large rain events this spring, many fields were flooded. While both corn and soybeans can survive flooding/ponding for a period of time, several factors determine the length of time plants can survive. Young corn plants can usually survive two to four days in flooded conditions. Death of corn plants is more likely prior to the V6 stage of development because the growing point is still below the soil surface. Soybeans can usually survive two to four days completely submersed. If weather is cool (mid 60s or cooler) plants are more likely to survive several days of flooding. If temperatures are warm (mid 70s or warmer) plants may not survive 24 hours under flooded conditions. Ponding of six or more days can result in significant stand losses and death of all plants where ponding has occurred. Although ponding/flooding has the potential to impact stands, crops can survive under the right conditions.
Cold rainfall events in 2017 have been a reminder of the importance of conditions during the first 24 to 48 hours after planting. During this period seeds imbibe water required for germination. A cold rain during this critical time can cause cold shock and imbibition injury to seeds. Fields that were planted right before rains this year had reduced stands and needed to be replanted. Heavy rains also resulted in hard crusts on soil surfaces that kept seedlings from emerging and caused corn plants to leaf out underground.
Pests are also a concern for both corn and soybeans. Early winter annual weed growth in fields provided an attractive place for the high number of black cutworm moths to lay their eggs. Purdue Extension entomologist Christian Krupke said: “Remember, corn is one of the black cutworm’s least favorite foods. It just so happens it is the only plant remaining by the time larvae have emerged and weeds have been killed.”
Cutworm damage can occur in both tilled and no-tilled fields, as well as to insect resistant GMO corn. While the insect resistant traits are still effective, insects need to feed on the plants in order to die, consequently, high numbers of cutworms can still result in reduced stands of GMO corn.
Bean leaf beetle could also be a concern this year due to the warm winter. High numbers of bean leaf beetle could especially be an issue in fields that emerge first. Scouting will be important to determine if bean leaf beetles are present and if a rescue treatment is warranted.
Weather has created challenges for Ohio’s winter wheat growers as well. Growers have observed the development of diseases such as powdery mildew and Fusarium head blight (scab). Barley Yellow Dwarf Virus has also been present in some fields, a result of feeding by aphids carrying the virus. Due to warmer-than-normal weather in late winter/early spring, wheat development has been two to three weeks ahead of normal and growers should expect an early harvest.
In areas where head blight has developed, growers should adjust combines properly clean out lighter grains impacted by scab. Research performed by the Ohio State University showed that adjust fan speeds between 1,375 and 1,475 rpm and shutter opening to 3.5 inches resulted in the lowest discounts at elevators due to low test weight, damaged kernels, and mycotoxin levels in grain. Extreme cold weather in March caused freeze damage to wheat heads, which has resulted in blank heads and could significantly impact yields. Wheat producers should walk fields prior to harvest to determine if head scab and/or freeze damage has impacted their wheat and to assess the extent of the damage.
As corn and soybean planting wraps up and wheat harvest begins, growers should continue to scout fields for pest and disease issues. Timely scouting and the employment of sound management practices will allow growers to minimize problems while maximizing yields for the 2017 crop.