It’s been a tough season for wheat so far. It started wet and has stayed wet, so for a crop that doesn’t do well in saturated soil, we’re struggling in a lot of fields. Most fields are showing a brownish red tint instead of the green that we’re used to.
A closer look at the plants shows the older leaves have a purple tint to them and some are necrotic.
This is indicative of phosphorus deficiency. The grower’s soil test showed sufficient levels of P, so this is probably being caused by the cold, wet soil. In a large number of fields the wheat is poorly tillered as well. While this can be an effect of P deficiency, its also an indicator that we need to add some nitrogen. To double check this, we can do a tiller count. We want to see at least 50 tillers per square foot, so on a 7.5″ spacing, so we would need to count the number of tillers in 19″ of row (7.5 x 19 = 144 square inches or 1 square foot). Here is a picture of some wheat plants that have been dug up so the tillers are easier to distinguish.
If we are below 50 tillers, it would be a good idea to apply 30-40 lbs of N now and another 30-40 lbs before jointing starts in the spring. For more information on fertility and wheat production, take a look at Clemson’s Wheat Cheat Sheet: Wheat_CHEAT_sheet_2015-16