CORN EMERGENCE EVALUATION

Lawrence,* M.W. 1; Flanagan, R.D. 2;

1. Senior Extension Agent-ANR, Chesapeake, Virginia 23322.

2. Extension Agent-ANR, Virginia Beach, Virginia 23456.

This evaluation asks, will corn seeds that germinate sooner produce plants that yield more? Three years of on-farm tests were conducted in Chesapeake, Virginia from 2016 to 2018. Seven separate test plots were set up at three separate farms. At these separate farms, different production practices, varieties, equipment, soils and dates of planting were used. At each site, a forty linear foot of planted row was flagged each day between 11:00 a.m. and 1:00 p.m. for the next twelve days. Beginning on the first day of emergence (defined as coleoptile visible above the soil line) and each day thereafter, a colored flag was placed beside each emerging seedling. A red flag for 1st day, a blue flag for 2nd day, and a yellow flag for seedlings on or after the 3rd day. When corn reached maturity, ears were hand harvested, segregated by flag color and shelled with an old-time crank style single ear sheller. Corn from all red flags, blue flags, and yellow flags were counted and weighed. Average weights per ear were calculated for each grouping. Calculating yield advantage was based on using a standard final plant population of 38,000 plants/acre multiplied times average wt./harvestable ear for each of the emergence dates. Using a 38,000 plant population showed 8.3 more bu./acre for corn emerging on day 1 vs. day 2. A yield advantage of 7.0 bu./acre for corn emerging on day 2 vs. day 3. A yield advantage of 15.3 bu./acre for corn emerging on day 1 vs. day 3 and after.