Kentucky’s Fall 2018 Winter Wheat Crop Condition

Carrie Knott — Extension Grain Crop Specialist
From UK Wheat Science Group

In early-October, Kentucky winter wheat planting began with excellent conditions. Average daily temperatures were well above the 30-year average, soil conditions were adequate to support rapid seed germination and seedling establishment, and for much of the state precipitation did not impede planting (Tables 1 and 2). Weather conditions quickly changed in mid- and late- October. Average daily temperatures were below average and soil conditions were too wet to allow drills to be used to plant the wheat (Tables 1 and 2). Unfortunately, cool and wet conditions continued throughout November and early- December (Tables 3 and 4).

These weather conditions prevented many thousands of acres of wheat from being planted in Kentucky this fall. It also resulted in very dramatic developmental differences in Kentucky’s wheat crop. In general, if wheat was planted in early-October it has tillered well and appears to have very good stands (Figure 1A). However, if wheat was planted in mid- to late- October (or later) very little tillering has occurred and stands appear very thin with delayed development (Figure 1B). In some cases, wheat planted in late-October or later has not yet emerged. This delayed development is probably due to the cool conditions that occurred after planting.

The cumulative growing degree days (cGDD) from October 1 to December 6 ranged from 1198 to 1384 across Kentucky (Table 5). The difference between the actual cGDD this year and the 30-year average cGDD ranged from +6 to -217, which equates to a 0 to 12 day delay. In general, Western Kentucky had fewer cGDD than the 30-year average, while the southern tier and central part of the state had similar or slightly greater cGDD this year. However, given that early-October average daily temperatures were well above average across the state, it is probably better to examine the cGDDs beginning in November. From Nov 1 to Dec 6, cGDD were 22 to 220 less than the 30-year average. This resulted in wheat being delayed by approximately 2 to 16 calen-dar days as of Dec 7.

This delay may or may not result in problems for the wheat crop later next spring and will depend entirely on the winter weath-er conditions. As of Nov 15, NOAA’s three month predicted forecast for Kentucky is an equal chance for the daily average tem-peratures to be normal, above normal, and below normal (Figure 2). Essentially, there is no good prediction of our winter weather at this point. This will require that we wait until spring to determine crop condition. In the spring, prior to Feekes 3 growth stage, the number of wheat stems per square foot will need to be determined. This will allow producers to determine which management decisions will be necessary for a profitable 2019 wheat crop.

For the wheat that has yet to emerge, it will eventually emerge, but the question will be same as all other wheat crops this year: Are there adequate stands to support profitable yield?