Dave Nanda, a plant breeder with more than 50 years of experience and currently Director of Genetics and Technology for Seed Consultants, Inc., provides the tips. They are based on what he’s seen and learned firsthand about corn.
1. Plant alternate strips of two hybrids two to three days different in pollen shed when possible. This may give a striped pattern to your field if you have aerial images flown during the season to check on plant health. That’s not a concern, and the possible advantage is spreading the pollination period on each end compared to one hybrid alone. That could be extremely important if it turns hot when corn is pollinating. In the future, a twin-hybrid planter (also called multiple-hybrid planters) may be helpful on any type of soil provided the hybrids are similar in height, maturity, disease tolerance and harvestability.
2. Use narrower rows or twin rows. This may be best considered if you’re thinking about upgrading planters. This technique is most likely to pay off with shorter hybrids with more upright leaves and increased tolerance to higher populations, drought and stress.
3. Match seeding rates. Match the right population to the right hybrid. Don’t plant all hybrids at one population. If possible, vary seeding rate on-the-go to match soil types.
4. Move up plant populations gradually. Your goal may be increasing populations per acre over time, depending on where you are now. Do it by pushing seeding rates up gradually over time. Yield comes from (number ears per acre) x (number kernels per ear) x (kernel weight).
There is a limit on how many kernels we can put on a single cob and the weight of each kernel. Thus, the only way to keep increasing yields is by increasing the number of ears per acre.
(Source – http://farmprogress.com/story-4-ways-improve-corn-yields-0-110064)