Harvest Aids Recommended for Winter Wheat - UNL CropWatch, June 19, 2013

Published before 2015

June 19, 2013

Weeds overcoming dryland wheat in mid June

Weeds overcoming wheat

Figures 1-2. Poor stands of winter wheat in drought stricken fields provide little competition for weeds, particularly broadleaf weeds. Harvest aid treatments may be necessary to ease harvest, reduce or prevent weed seed production, and to avoid dockage. (Photos by Robert Klein)

Poor winter wheat stands in drought stricken southwest and western Nebraska offer little competition for weeds, which are taking full advantage of the opportunity this year.

Broadleaf weeds grow rapidly, especially in fields with little competition from wheat toward the end of the growing season. In addition, the growth stage of winter wheat is behind normal which means harvest will be late and weeds will have even more time to develop.

Timely control earlier in the season would have limited yield loss from weeds competing with the growing crop for space, light, nutrients, and soil water. Now these weeds can complicate harvest and even result in price dockage at the elevator. If not controlled just prior to harvest, the cut-off weeds will be almost impossible to control post-harvest.

Using a harvest aid, weed control treatment can make harvest easier, as long as it isn’t applied too early. (This can be detrimental to grain quality.)

Several herbicides are labeled as harvest aids to be used as pre-harvest treatments. Use only herbicides labeled for this application and follow all the application information and pre-harvest intervals listed on the label. Always check labels because failing to follow the label could result in crop destruction and severe penalties.

Table 1 lists several harvest aid treatments for winter wheat. When planning applications, always be alert to potential herbicide drift problems.

Robert Klein
Extension Western Nebraska Crops Specialist, West Central REC, North Platte

Table 1. Harvest aid treatments for winter wheat.

Herbicide	Rate/Acre	Application Time	Remarks and Approximate Cost per Acre Broadcast
Aim EC	1-2 oz	Apply after winter wheat is mature, but at least 3 days before harvest	Aim is a very quick-acting herbicide and provides a rapid desiccation of green foliage, which is often a primary goal of a pre-harvest treatment. However, Aim has limited translocation and thus plants may not die, and often will begin to regrow eventually. Always apply with 1% v/v crop oil concentrate in a minimum spray volume of 5 gal/acre for aerial application and 10 gal/acre for ground application. Cost: $8.00 - $16.00
Ally XP + 2,4-D Amine (4L)	0.1 oz 4.0-8.0 oz	After dough stage	Preharvest interval of 10 days. Add surfactant at 1 qt/100 gallons of spray solution. Check Ally XP for rotation restrictions. Cost: $2.00 - $2.75
2,4-D Ester (4L) or Glyphosate	32 oz 32 oz	Hard dough 7 or more days before harvest	Rescue treatments for control of late broadleaf weeds. To reduce breakage with 2,4-D, all green color should be gone from joints. Only certain brands of 2,4-D are labeled for this use. Be extremely careful in using 2,4-D ester if temperatures are in the 80s and higher because of volatilization. Cost: 2,4-D $4.50; glyphosate $2.75

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