Drought stress can cause significant corn yield reductions, particularly when it occurs after the V13 growth stage.
At V13 and beyond, drought stress can negatively impact silking, pollination, and kernel fill, with the greatest loss in yield associated with drought stress that occurs around the silking (R1) period. Drought stress causing four or more consecutive days of visible wilting during this period can lead to yield loss as high as 9 percent per day. Plants weakened by drought stress are also more susceptible to disease and insect damage, which can further compound yield losses.
What Options Do Corn Growers Have for Combating Drought Stress?
Although farmers can't control the weather, they do have options that can help them improve plant health and strengthen their crop's stress tolerance in the face of drought.
Some of these approaches include:
- Strobilurin-containing fungicides.
Strobilurin-containing fungicides have known beneficial effects on corn development, even in the absence of disease.
- Foliar nutritionals.
Foliar nutritionals can be added to fungicide applications for even stronger plant health effects. Nutrient absorption in the leaf tissue is highly efficient and can partially make up for shortfalls in root absorption when the soil is dry. In addition, applying relatively small amounts of foliar nutritionals can prompt plants to work harder at extracting nutrients from the soil and can increase drought tolerance.
- Foliar- or soil-applied biostimulants, biologicals or plant hormone technologies.
Products in this category can stimulate the plant and/or soil microbes to improve crop tolerance to drought stress and allow energy to go into yield, rather than stress response.
A recent Kansas field trial also shows a visual improvement with foliar-applied Terramar on 12-leaf corn that was experiencing both drought and heat stress. The benefits can be seen both above and below the soil, with a healthier looking plant that has a greater stalk diameter, larger root ball, deeper roots, and heavier brace roots. What's more, the Terramar treated plants had 57% greater soil penetration, pulling at the 55 cm level on the water probe measurement, compared to the untreated plants that were not yet pulling at even the 45 cm level when measurements were taken.
With many areas of the nation currently experiencing hot, dry weather, it's the right time to consider these tools as a way to potentially reduce the total impact of drought conditions.
Learn more about the benefits of the marine-based technology found in Terramar by downloading the corn and soybean bulletin.