Farmers are generally perceived as a conservative lot, unwilling to take chances on anything less than a “sure thing” in the tough economic times they face today.
Nevertheless, cotton producers are continuing to experiment with some rather unconventional practices such as double-cropping cotton behind wheat. And researchers are falling in right beside them.
Agronomists at the North Mississippi Research and Extension Center in Verona planted cotton behind wheat in 2008 and found they were able to harvest a crop, although yields were lower compared to conventional cotton with nearly the same planting date.
One of the biggest differences between the double-cropped and mono-crop cotton plots planted on approximately the same day was that the wheat stubble in the no-till cotton planted behind wheat increased the first fruiting branch node location, says Normie Buehring, an agronomist with Mississippi State University.
“The first fruiting branch node for the mono-crop cotton May 20 and June 5 plantings was node 6 with node 7 for the cotton planted in wheat stubble with all nitrogen rates,” he said.
“The wheat stubble had an impact on cotton maturity. The cotton in the wheat stubble percent open bolls at defoliation ranged from 29 percent to 37 percent and was lower than the 58 percent open for mono-crop cotton with the same planting date.”
A speaker at the National Conservation Systems Cotton & Rice Conference, Buehring said the single-crop cotton had similar yields with that planted in mid-May, averaging 1,223 pounds of lint per acre compared to 1,279 pounds for the early June planting.
“Those yields were approximately twice those of the zero nitrogen check treatment and about 36 percent higher than cotton planted in wheat stubble with the same N rate and planting date,” according to Buehring.
The latter was planted into wheat that produced an average yield of 62 bushels per acre, which results in a higher amount of residue than is normally found with the recommended seeding rates for no-till wheat.
Rainfall was extremely variable during the 2008 season, Buehring noted. It was 10 percent and 62 percent of normal for June and July and 179 percent and 133 percent of normal for August and September.
“Observation notes indicated that the May planted mono-crop cotton first flower date was July 9 with a July 29 first flower date for the June planted mono-crop cotton and an Aug. 1 first flower date for the June cotton planted in wheat stubble,” he said.
“The N rates (30, 60 and 90 pounds of nitrogen per acre) showed no difference in total harvestable bolls per plant and plant height, but all treatments had more harvestable bolls than the zero-nitrogen check and were taller at maturity.”
The May-planted cotton was defoliated Sept. 25 and harvested Oct. 1. The double-crop and mono-crop cotton planted in early June was defoliated with Prep and Folex on Oct. 22 with a repeated application on Oct. 30 and harvested on Nov. 6.
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