Take the Time to Wander Crop Variety Plots 
ounty fairs, field days, vacations and other activities
are taking their toll on the number of patrons down at the Wander Inn.
Hopefully, some of those ‘other’ activities include wandering through
crop variety plots.
Crop variety test plots offer all sorts of information to growers, only part of which is reflected in the yield results book that is handed out at the conclusion of the growing season. Wandering plots now gives you an opportunity to look over other variety characteristics important to your variety selection decisions.
Any signed crop variety test plot is fair game. The fact that the
seed company took the time and effort to put up variety signs tells you that
they encourage visitors. Take along a notepad to take notes on. If you have a
copy of the company's current variety description brochure, bring it along too.
Compare the relative heights (both plant and ear) among corn
hybrids. High ear placement increases the risk of stalk lodging later because
of the higher center of gravity.
Compare the relative stalk size among corn hybrids. Thicker stalks
are generally correlated with better standability later on. Split a few stalks
and check the thickness of the rind. Again, thicker stalk rinds are generally
correlated with better standability later on.
If you walk variety test plots closer to harvest, you can also make
comparative notes among hybrids for their relative stalk health and integrity.
By late August or so, you can pinch lower stalk internodes and check for stalk
rot development. Hybrid differences for stalk rot development often reflect
differences for tolerance to stresses in general.
Compare the relative leaf health among corn hybrids. This year in
particular has been conducive for the development for a number of leaf
diseases, most notably common rust. In notill test plots, pay particular
attention for hybrid differences for gray leaf spot infestation. If you find a
disease you are not familiar with, ask a local Extension educator, crop
consultant, or industry agronomist to identify the causal organism for you.
Another facet of leaf health is the so-called 'stay green'
characteristic that reflects a hybrid's ability to simply remain viable longer
than others. Generally speaking, 'stay green' hybrids have a higher tolerance
to stress factors than others. If little leaf disease is visible, yet some
hybrids' leaves are 'shutting down' while those of comparable hybrid maturities
are remaining green, the latter are likely 'stay green' hybrids.
Shuck a few ears and compare the relative ear size among corn
hybrids. Kernel row number is strongly determined by a hybrid's genetics.
Number of kernels per row (ear length) is more influenced by 'environmental'
factors and can indicate a hybrid's tolerance to various stress factors.
Obviously, we would all like to shell 30,000 ears with 22 kernel rows each and
40 kernels long. Genetically, kernel row number may vary from as few as 12 to
as many as 22. Numbers of kernels per row may vary from the low 20's to the
mid-40's, some of which is genetically determined, some of which reflects a
hybrid's response to growing conditions.
Later on as ears fill out more completely, compare the relative
'tightness' of the husk leaves. Fewer husk leaves, thinner husk leaves and
looser husk leaves are all conducive to faster grain moisture loss during field
drydown.
Compare the relative uniformity of plant appearance among corn
hybrids. Given some of the early season stresses this year on initial stand
establishment in many corn fields, hybrids in a test plot whose plants appear
more uniform one to another may indicate better early season vigor than hybrids
exhibiting a mixture of healthy and runty plants.
Happy Wandering!
For other information about corn, take a
look at the Corn Growers Guidebook on the World Wide Web at
http://www.kingcorn.org