Sally A. Flis, Ph.D. – Feed and Crop Support Specialist, Dairy One
Looking back, last year in July, my blog post was about harvest variability. Well, this year does not look any less variable. Atypically for the Northeast, we are talking about not enough rain instead of too much! Much of NY is in some stage of drought and corn is tasseled and has ears at less than 5 feet tall. So, this year I am going to talk about how to evaluate drought stressed corn for harvest and inventory planning.
The corn grain yield reduction due to drought is highest in the silk to blister kernel stage, but corn in much of NY has been experiencing drought stress since vegetative growth and lots has started to tassel despite little vegetative growth. This can make corn silage yields 50 to 90 % of expected for the hybrid. Depending upon stress levels, it may or may not have ears. Looking at the corn is the only way to know how to evaluate harvest management or potential yield. Corn that does not form any ears will be wetter than a corn that has ears, as no grain has formed to draw the moisture from the stalk. This makes it very important to check dry matter before harvesting. If the corn is short and did form ears, keep an eye on how big the ears get and the ratio of ear to stalk. This will likely be very different than in optimal growing conditions. More ear, starch, and less stalk can change how the feed ferments, how it dries down, and how the ruminal fermentability of the starch changes during feed out.
With or without ears, yield will be lower than planned in drought stressed corn. If the corn has no ears, now is the time to start planning on how and when to purchase the energy you are going to need to replace the lack of grain. Likewise, begin planning for the loss of feed volume. Hay markets in the West have been depressed this year, but the unplanned expense of bringing in forage to replace lost harvest needs to be evaluated to avoid frustration this winter. Things to think about when purchasing replacement feed are price, quality, and where are you going to store the feed.
The other important part of inventory planning and management is what do you have right now? How far can you make it before you have to use the less than ideal forage you may be harvesting this fall? Do you have storage space to keep the new forage separate from the stored forage? Keeping forages stored separate makes the management of feed out easier.
There never seems to be a perfect growing season. Weather and soil type are the two biggest contributors to variability of crops, both of which we have little control over. So, the next best step is to monitor crops and fields as they are growing and determine harvest management plans to deal with inventory and crop variability.