Variety Testing: A Guide for Seed Choice
Ellen Phillips, Extension Educator, Countryside Extension
Center, 708-352-0109, firstname.lastname@example.org
As farmers begin planning for 2004, University of Illinois variety
trials can help guide them in making their seed selection. These
trails offer yield information over a wide range of soils and
climatic conditions. While reviewing one year’s data provides
sound information, studying several years’ data at different
locations is better. Each testing site also provides inherent
variability in soil types, harvesting conditions, timeliness of
and amount of rain, etc. Different environmental conditions can
affect the seed being tested. Variety differences can reflect
how well hybrids can yield even in stressful environments. If
a hybrid consistently out yields others at different test locations
and different years, it indicates a good variety and should be
In the 2003 Variety Trials, there were 370 corn hybrid entries
from 51 different seed companies that were tested at 12 sites.
There were 134 conventional soybean varieties and 661 Roundup-resistant
varieties tested at 13 different sites throughout Illinois Regional
corn yield averages in northern, west central and east central
trials were over 200 bushels per acre. Soybean yields were much
lower than normal due a hot, dry August as well as pressure from
disease and insect pests.
When evaluating the yield results also look at the moisture level
in the grain when they were harvested. Different moisture levels
can be found between early, medium and late varieties. Two hybrids
might be planted and harvested on the same date, yet the medium
season variety might have 15 percent moisture while the full season
hybrid may have 19 percent moisture at harvest. The additional
drying requirements or yield losses, if field dried, may result
in greater profit losses. Grain moisture, percentage of erect
plants, oil and protein content, and plant population data are
included in the University of Illinois Variety Trail information.
When comparing soybean varieties look at maturity, lodging and
plant height. Equally valuable is to evaluate the disease resistance
of the hybrid or variety.
Using statistical tests to compare varieties can be a useful
tool. University of Illinois Variety data lists the Least Significant
Difference (L.S.D) from the trails. To compare two hybrids or
varieties, calculate the difference between them, if it is greater
than the tabulated L.S.D. value, the hybrids or varieties are
assumed to be significantly different.
Copies of the University of Illinois Variety Trial results are
available at Extension offices and at the website: http://vt.cropsci.uiuc.edu/.