Fusarium wilt is on the increase throughout cotton production regions of the High Plains, especially in the sandier soil areas south and west of Lubbock.

“Because Fusarium wilt is becoming more of a problem for cotton producers and new varieties are being released every year, we conduct tests annually to evaluate varieties for Fusarium wilt tolerance,” said Jason Woodward, plant pathologist with Texas AgriLife Extension Service, Lubbock.

In 2007 Woodward and his colleagues, Max Batla, Texas AgriLife Extension Service, Lubbock; and Terry Wheeler, Texas AgriLife Research, Lubbock, conducted variety tests on Fusarium wilt infested soils in Dawson and Terry Counties. Thirty-two varieties were evaluated at each location.

“We analyzed Fusarium wilt incidence, lint yields, loan values, net returns, and fiber properties for each location. We determined net returns per acre by multiplying the cotton lint yield by the respective loan value, and then subtracting the seed and technology fees.”

Dawson County

The percent Fusarium wilt range for this test was 2.1 to 38.1, and averaged 13.6. There was a significant relationship between Fusarium wilt levels and lint yields (r = - 0.66).

Lint yields ranged from 437 to 1210 pounds per acre, and averaged 863. Net returns ranged from $210 to $656 per acre, and averaged $449.

The lint yields, net returns, and Fusarium wilt ratings for the top five varieties were:

–FiberMax 1840 B2F (1210/546/2.5)

–Deltapine 174 F; (1207/656/6.3)

–Deltapine 143 B2F (1131/599/14.3)

–Stoneville 5283 F (1112/588/14.9)

–Deltapine 164 B2F (1108/590/2.1).

“Differences in yields and net returns for these varieties were not statistically significant,” Woodward said.

Terry County

“Fusarium wilt ratings in this test ranged from 1.2 to 9.2, and averaged 4.0,” Woodward said. “And as was the case in the Dawson test, Fusarium wilt ratings and lint yields were well correlated (r = -0.73).”

Lint yields ranged from 318 to 1916 pounds per acre, and averaged 1321. Net returns ranged from $114 to $1081 dollars per acre, and averaged $708.

Lint yields, net returns, and Fusarium wilt ratings for the top five varieties were:

–Deltapine 174 F (1916/1081/2.8)

–Deltapine 143 B2F (1695/859/3.1)

–Deltapine 164 B2F (1673/873/3.1)

–FiberMax 1840 B2F (1660/819/2.1)

–FiberMax 1880 B2F (1547/820/2.2).

FiberMax 1880 B2F was significantly lower in yield than Deltapine 174 F.

The net return for Deltapine 174 F was significantly higher than those of the other four varieties. Net return differences among the other four were not significant and differences in Fusarium wilt ratings were similar.

“It is noteworthy that four of the top-yielding varieties in the Terry County test also performed well in the Dawson County test,” Woodward said. Those varieties include: FiberMax 1840 B2F, Deltapine 174 F, Deltapine 143 B2F, and Deltapine 164 B2F.”

Fiber properties

The Dawson County test average values for the fiber properties were: Micronaire - 4.26, Length - 1.13, Uniformity - 80.8, and Strength - 28.3.

The Terry County test average values for the fiber properties were: Micronaire - 3.83, Length - 1.14, Uniformity - 81.3, and Strength - 29.6.

For additional information about these tests, visit http://lubbock.tamu.edu/.