Fertility

Fertility

A soil test is fundamental. pH 5.8 - 6.4. Over liming causes Mn deficiency and potential winter kill.

Nitrogen

20 lbs at-plant + 70 - 80 topdress (90 to 100 lbs total) is a good starting point for dryland wheat. There is no substitute for experience with N response on your soil and rotation. N application is critical prior to jointing. Splitting spring N applications can reduce leaching, but usually does not increase yield.

Excessive N can increase disease, lodging and drought stress during head fill. Apply 10 - 15 lb sulfur; ideally about 1/3 at planting and the rest at topdress. If clay is within 12” of surface, there is little chance of a response to applied S. Fall-apply P and K to the high range by soil test (apply 80 lb/ac P or K if soil test is low; 40 lb/ac P or K if soil test is medium). K can be split fall and early spring on sandy soil. Breaking the hardpan greatly reduces S and N deficiency risk.

Growth Regulator

Cerone (ethephon 4lb/gal) is labeled at 0.5-0.75 pt/ac (applied from flag leaf emergence to early boot) to prevent lodging. This product should only be considered on irrigated wheat because drought stress during headfill will result in severe yield loss from Cerone application.

Head Population

Our target head population is 60 heads per ft2 (6" rows = 30 heads/row ft, 7" rows = 35 heads/row ft, 8" rows = 40 heads/row ft. The typical reasons for falling short on head count include N deficiency due to rate, timing, leaching, or hardpan; and poor seedling vigor from deep planting. Waterlogged soils during tillering also reduce stem count by depriving the roots of oxygen.

Irrigation: Avoid drought stress during early kernel formation by applying 1” at early boot. Make a second application about 10-14 days later if no rainfall occurs. Avoid irrigation during early bloom to reduce the risk of scab.