Deltapine 555 BG/RR is a little lower in length uniformity, but it compares favorably in fiber quality with most other varieties grown in Georgia and other regions of the Cotton Belt, Delta and Pine Land's vice president of technical services says.
Tom Kerby, lead agronomist for D&PL and a former University of California Extension cotton specialist, was invited to speak at a Georgia Cotton Update session at Cotton Incorporated's Engineered Fiber Selection System Conference in Memphis, Tenn., earlier this summer.
As they did at the 2004 EFS Conference, textile mill representatives again complained that Georgia cotton does not spin as well as growths from other states. Since Delta 555 BG/RR is the most popular variety grown in Georgia, it has been singled out for criticism — unjustly, according to Kerby.
“The variety has good general quality but has fiber length uniformity that is a little lower than many other varieties grown,” said Kerby. “Our large plot data from commercial farms using gins with lint cleaners suggests Georgia quality of DP 555 BG/RR is similar or better than other regions of the United States.”
Kerby says Deltapine 555 BG/RR, or the “Triple Nickel” as it is often called, and DP 458 B/RR did experience quality problems in the 2002 and 2003 seasons, but DP 555 BG/RR staged a comeback in 2004.
“If you look at staple for the Georgia crop in recent years, there was a substantial dip in 2002 and 2003 and a fairly substantial increase in staple in 2004,” he said. “Strength in 2004 also was up substantially compared to recent years, even succeeding 1995, which was the previous high year.
Micronaire jumps, then settles
“Micronaire jumped up to an average of 4.9 in 2002, but has since settled back into the more desirable range of 4.3 to 4.4. 2002 was a year to remember for micronaire — in a negative way.”
Georgia growers saw a slight dip in length uniformity when DP 555 BG/RR came into play in 2003, but, in 2004, Georgia's length uniformity was slightly higher than average, according to figures compiled by USDA's Agricultural Marketing Service.
Kerby says DP 555 BG/RR has been gaining ground in Georgia — it was planted on 33.5 percent of Georgia's cotton acres in 2003 and 55.7 percent in 2004 — because it produced lint yields of 1,200 pounds or better in 2002, 2003 and 2004.
“DP 555 obviously has been a popular variety in Georgia because of yield,” he said. “At the same time, staple has been relatively good at 35.5; strength has been good at 29.0 grams per tex-plus; and micronaire at 4.4. Length uniformity at 81 has been the weakest characteristic.
“But our review of data from a wide number of locations and environment shows no significant interactions between how DP 555 BG/RR and DP 458 B/RR responded across these 692 environments.”
Large, commercial field tests with DP 555 BG/RR ginned using lint cleaners shows a wide range of quality factors across the Cotton Belt over the last three years.
Staple, for example, ranged from a low of 34.2 in the central Texas Blacklands to a high of 36 in the south Delta region of Louisiana and Mississippi. The average for south Alabama, south Georgia and Florida was slightly below that of Arizona, California and the Mid-South.
Fiber strength for DP 555 BG/RR ranged from a high of 29.8 in the south Delta region of Louisiana and Mississippi to a low of 27.4 for the Trans Pecos area of Texas and the central Texas Blacklands. Micronaire ranged from an average of 4.7 in south Texas to a low of 3.7 in the southern High Plains of Texas.
“You would expect the staple to be shorter in Texas because of the scarcity of water and other factors,” Kerby noted. “And those conditions could be a similar factor in strength and micronaire.”
Length uniformity also was higher in the Mid-South and Southeast, averaging around 81.5 for those regions compared to a high of 80.8 for Arizona and a low of 79.5 for the Trans Pecos region of west Texas for the three years of data.
The comparisons also show a decline in Rd readings or whiteness in the Southern Southeast region of south Alabama and south Georgia, a factor that may be attributable to delays in harvesting.
“We've been participating in a delayed harvest study with Craig Bednarz at the University of Georgia and Stanley Anthony of the USDA-ARS Ginning Laboratory at Stoneville, Miss.,” he said. “And the University of Georgia results from Dr. Bednarz indicate delayed harvest can be associated with some reductions in fiber quality.
“Results of University of Georgia tests with Phillip Roberts also indicate that stink bugs can also be associated with fiber quality reductions.” (Bednarz and Roberts also reported on their research at the EFS Conference.)
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