Issue No. 19, Article 5/August 1, 2008
2008 Wheat Crop in the Books
Even with the damage to the 2007 Illinois wheat crop from the early April freeze, high prices going into last fall and decent planting conditions helped wheat acreage to rebound, with about 1.2 million acres planted in the fall of 2007, the highest since 1998. Harvest of the 2007 corn and soybean crops was relatively early, and wheat planting was timely in most areas. There were some wet areas, but in general it was a favorable fall for wheat, and the crop condition in most areas was good heading into dormancy.
The winter was relatively benign, with the only challenges to the wheat crop coming from high rainfall in some areas, and both standing water and ice. This caused serious damage to the crop in some areas of northern Illinois, including to our variety trial near DeKalb. That trial was abandoned as a result of uneven injury that ruled out getting useful data.
March 2008 was cool and wet, in contrast to the warm and dry conditions in March 2007. April continued to be cool and wet, with slow growth and considerable concern about loss of nitrogen in many fields. The weather in May continued this trend, and the lack of warm temperatures delayed heading by a week or more in the southern part of the state and by two weeks or more in central and northern parts. As an example, the median heading date in the Brownstown trial was May 19, which is about two weeks later than normal.
While cool temperatures delayed development, they also limited the production of disease inoculum and favored the growth of wheat, so the crop was in very good condition by early June. Fungicides were applied on many acres, especially for control of Fusarium head scab. Perhaps due to lack of inoculum, this disease was not very damaging in Illinois in 2008. Some leaf diseases appeared late, but fungicide application in some trials produced little yield response. In one trial we conducted at Urbana with nitrogen rates and fungicides, raising the N rate from 0 to 80 lb in the spring (following 40 lb at planting) increased the yield from 87 to 112 bushels per acre, but regardless of N rate there was no effect of Headline applied at flag leaf or of Folicur at heading, nor of the combination of both fungicides. That's a relatively large response to N compared to other research we have done, and it may reflect some loss of N.
Barley yellow dwarf virus, which is carried into fields by aphids, appears to have been at a very low level in 2008; seed treatment fungicides produced little or no yield increase, either because aphids were not a factor or perhaps because aphids did not carry BYDV when they came into fields. Entries made in the variety trials using both insecticide-treated and untreated seed showed little difference in yield, as you can see in the tables of the variety trial results at vt.cropsci.uiuc.edu/wheat.html.
Normal temperatures returned in June, but harvest took place one to two weeks later than normal, reflecting the late heading but a more or less normal length of filling. Yields in most areas were surprisingly good given the wet spring weather. The July crop report indicates that statewide yield was 66 bushels per acre, which is only one bushel less than the record-high yield of 67 in 2006. Even this favorable yield figure is lower than I expected based on reports from farm fields and from our research trials.
With doublecrop soybeans off to a good start (though facing the same problems as other late-planted soybeans) and wheat prices that remain favorable, we expect interest in wheat to remain high this fall. Issues that we might face include late development and harvest of corn and soybean, especially in the wheat-intensive areas where many fields of both crops were planted (or replanted) late.
Seed should be in good supply given the good yields this year, but it might pay to start looking for your chosen varieties soon. The cool temperatures this spring helped the crop to tiller extensively, and we saw less response to increasing the seeding rate than we have seen in some years. I would still plan to use at least 30 seeds per square foot, or about 1.3 million per acre. This is 100 lb of seed if there are 13,000 seeds per lb. Most seed this year will likely be larger than this, which will mean more pounds of seed per acre to get the same number of seeds.--Emerson D. Nafziger