DEKALB® Brand Corn Product Response to Irrigation and Seeding Rate

TRIAL OBJECTIVE

• Because corn products have different responses to plant population and water availability, producers should choose the corn products that help maximize their return based on the irrigation availability for each field. Factors to keep in mind are pumping costs versus the overall potential yield.
• Knowing the field production potential and irrigation capabilities can help determine the corn products to plant and the seeding rates for those products. In a fully irrigated environment, in which the amount of water applied meets the evapotranspiration needs of the crop, a higher seeding rate and a longer-season corn product can have a higher yield potential. In a limited irrigation environment, one key is to plant a corn product with high yield potential using lower seeding rates.  
• The objective of this study was to determine the yield response of key DEKALB® brand corn products for the region based on seeding rates and irrigation amount.   

RESEARCH SITE DETAILS

• Five DEKALB® brand corn products were planted at 24,000, 32,000, 36,000, 40,000, 44,000, and 50,000 seeds/acre under full irrigation (100% FI). At 50% of FI, the same corn products were planted at 18,000, 28,000, 32,000, 36,000, 40,000, and 48,000 seeds/acre.
• The yield goals for these experiments were 250 bu/acre for the 100% FI and 190 bu/acre for the 50% of FI treatments.
• Each corn product at the selected seeding rate was replicated twice in each irrigation treatment.
• This location was irrigated with a center pivot system with nozzles placed in the crop canopy.
  • 10 inches was applied to the 100% FI treatment
  • 5 inches was applied to the 50% of FI treatment
• 15 inches of rainfall was received at the Mingo, KS site during the growing season.
• This trial was replicated at Bethune, CO but received severe hail damage (100% defoliation at R3) and was not harvested for yield data.

UNDERSTANDING THE RESULTS

• Yield per thousand plants (YPT) was the highest at the lower seeding rates for each irrigation treatment; however, yield was not maximized at these seeding rates. This study shows that keeping the YPT around 7 to 8 bu/thousand plants is more likely to obtain a higher yield for that corn product in a particular-growing environment.
• Averaged across all corn products and seeding rates the extra 5 inches of irrigation applied to the 100% FI treatment yielded an extra 16.2 bu/acre (252.4 bu/acre [100% FI average yield] minus 236.2 bu/acre [50% of FI average yield]).
• Across all products at the 50% of FI rate, the highest yield was achieved at the 36,000 seeds/acre seeding rate (244.8 bu/acre). At the 100% FI rate, the highest yield was observed at the 44,000 seeds/acre seeding rate (265.7 bu/acre).

KEY LEARNINGS

• Because the number of farms with limited irrigation has increased due to reductions in pumping capacity or restrictions on the amount of water producers can pump over a certain time frame, it is imperative that Bayer tests corn products under varying irrigation rates to help provide better corn product recommendations by irrigation capacity.

   

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