Harvesting Infected Wheat for Hay
Harvesting Rust-Infected Wheat for Hay
May 28, 2015
Wheat fields are turning yellow prematurely across southern Nebraska, due to stripe and leaf rust, among other diseases. (See CropWatch stories in May.) When the upper most leaf, the flag leaf, becomes heavily infected, grain yield losses can exceed 30%, making it necessary to consider other options than grain production.
Baling hay or chopping silage are two options. Rust pustules are not toxic to cattle although sometimes the spores can irritate respiration. However, it can be difficult to make good silage from this wheat. Rusty leaves dry out rapidly so it can be hard to get the best moisture content for silage packing and fermentation.
Usually it is best to harvest rusty wheat hay just before heading to retain reasonable forage quality. As plants mature further, quality can decline rapidly. Digestibility of rust-affected cells is much lower than that of normal cells. Fortunately, protein doesn't seem to be affected greatly. Properly made, rust-infected hay should not deteriorate in the bale any more than normal.
Be sure to have the forage tested before feeding so you can develop rations accordingly. It is likely that nutrient concentration will differ from typical wheat.
Also consider the impact of removing the wheat residue. Leaving adequate residue in the field helps retain soil moisture, boosting yield of your next crop.
Extension Forage Specialist