This article is written by Dr. Josh Lofton
Oklahoma State University Cropping Systems Extension Specialist
Determining wheat yield loss:
The question on to how to manage wheat production that has suffered high potential yield loss can be quite challenging. High disease pressure and periods of dry conditions have been the main focus of this season’s wheat crop, but the recent storms have added to these issues with fields having >50% lodged wheat. While this may be a great concern when viewing this crop initially, a lodged or damaged wheat crop may still have decent yield potential. It is important to remember that, 50% lodging does not necessarily represent 50% yield loss. Many times the wheat crop will stand back up days or weeks after a lodging event. Overall, for a questionable stand of wheat, the best course of action might be to keep the stand and get the most yield possible from the crop. If you are considering planting a crop after failed or abandoned wheat, there are some important considerations before making the jump.
Insurance potential for a replacement crop
This will be the biggest catch for terminating a current wheat crop for a replacement summer crop. In many scenarios, once the wheat crop has begun to head this will be considered a double crop situation. In this instance many companies will not allow insurance to cover the following crop. Even if insurance is available for this double-crop scenario, at least three year yield potential numbers are frequently the minimum needed to receive this support. The best first steps for a grower to take when evaluating their fields planting of a replacement crop after a termination or hay is to check on their individual coverage and talk to their representatives before any action is taken.
Things to consider before moving into a summer crop:
One of the most important considerations for determining if and what potential crop could be planted following a non-harvested wheat crop is the chemistries used during the year. Table 1 gives rotational restrictions on some commonly used winter wheat herbicides. While this provides a summary or shortened list of herbicides and their rotational restrictions, producers should check individual labels if other herbicides were used. It should also be mentioned that minor plant injury could occur past the stated months following application given differences in soil conditions such as pH, soil moisture, and soil temperature.
Heavy wheat residue:
One thing that needs to be decided is how the grower will manage the heavy wheat residue associated with the failed crop. Certain situations exist that may result in limited to no residue (i.e. haying or heavy disease pressure); however, most producers will be faced with high residue load which may potentially be heavily matted and may pose challenges for producers to plant through. In these situations, producers may need to resort to tillage. The amount and intensity of tillage will greatly depend on the amount of residue left in field. In high residue situations, producers may need to run one or several primary tillage practices followed by a secondary or finishing tillage event. However, in lower residue conditions or if the producer has access to no-till equipment, no tillage may be needed to achieve a successful stand.
Overall cropping system:
When deciding to terminate an existing wheat crop and/or to plant a successive crop, decisions need to be evaluated at a systems level. Growers need to ask themselves whether this makes sense within their system and if it fits into their long-term system goals. If the original intent for the system was to double-crop following wheat harvest, it needs to be determined if the remaining economic benefit without the yield from the wheat crop. This may be at least partially alleviated if any profit can be made from the wheat crop (i.e. hayed) but needs to be evaluated on a specific field basis. The next question will be what the successive crop would have originally been? If a summer crop is planted, some systems will need a winter fallow as to not overstress the system, harvest the summer crop prematurely, or plant the successive winter crop past the appropriate timeframe. In this case it needs to be determined if that is suitable for the long-term system goals. Many of these scenarios exist and each could be beneficial or not within individual systems; however, growers need to evaluate these individually and determine what works best for their current situation and their long-term production goals.
Overall, the decision to move to a replacement crop can be very challenging. It cannot be stressed enough that in most situations maintaining the existing crop is likely the best option for most producers.
Cropping Systems Extension Specialist
376 Agricultural Hall