Crop clean and bright, but short and fat
Elton Robinson
DRY WEATHER helped make the 1999 cotton clean and bright, but unfortunately, it also made it short and fat.
According to a report from USDA’s Agricultural Marketing Service, the 1999 cotton crop was exceptionally clean and its color grade was the highest since the separation of color and leaf in 1993.
But the agency also reported that the micronaire average for the 1999 crop remained at a high level of 4.5 for the second consecutive season. And the staple length average dropped again to 34.1 thirty-seconds, down from 34.3 in 1998 and 35.1 in 1997. The only classing offices which did not report a lower staple length were Florence and Corpus Christi.
The quality data, compiled from 12 classing offices across the cotton belt, was released during the 2000 Beltwide Cotton Conferences, in San Antonio.
Missouri cotton specialist Bobby Phipps explained that the short staple and high micronaire were related in 1999. “You could see it coming. The day the flower blooms, the cell walls in the ovaries start elongating and make the fiber. The fibers elongate for the next two to three weeks. It takes water for the fibers to elongate and if the plant’s a little water-stressed, the fibers are going to be short. Bloom usually starts around the July 4, and that’s when the drought started.”
The plant starts to deposit photosynthate in the fiber cells, but since there’s less volume in the shorter fiber, it fills up more quickly and starts to thicken, thus the high micronaire (the diameter of the fiber).
Phipps noted that if the season remains dry, the plant might not be able to make enough photosynthate to cause the high micronaire problem and in fact, could lead to low micronaire. He added that high micronaire could be a sign that irrigation was not initiated early enough or often enough.
High color grade
Ninety-one percent of the nation’s crop averaged a color grade of 41 or higher, according to AMS. That’s the highest since the separation of color and grade seven years ago. The classer leaf grade average dropped to 2.8, also the lowest since 1993.
Phipps can’t say for sure why the leaf grades were so low because 1999 didn’t appear to be an exceptional defoliation season. But the high color grades were due to great fall weather with little rainfall. “It stayed dry and you never got the weather that causes staining. The sun helped bleach out the fiber.
“We also didn’t have much insect damage, so you wouldn’t have had many locks with a bollworm or something in them to turn that lint brown. I know it hard locks, but you’re going to drag a few of those into the sample.”
Extraneous matter, primarily bark and grass, were at the lowest percentage levels in over 35 years. The percentage of bark was only 1.7 percent, down from 3.7 percent a year ago. The percentage of grass dropped to 0.8 percent, down from 1.4 percent for the 1998 crop.
Average strength for the 1999 crop was 28.3 grams per tex, up from 28 in 1998. Here’s are more highlights from the report:
Color grade — The Southeast reported that 81.6 percent of its crop was at color grade 41/32 and higher. Texas-Oklahoma reported 94.2 in that category, while the desert Southwest reported 99.6 percent and the San Joaquin Valley reported 99.7 percent.
Classer’s leaf grade — The trend toward leafier cotton reversed in 1999. Three regions had the lowest content since 1993, Texas-Oklahoma, 2.6, desert Southwest, 1.8 and San Joaquin Valley, 2.3.
Extraneous matter (grass and bark) — The 1999 crop had only 1.7 percent bark, the lowest since 1964. Percent grass, at less than 1 percent was the lowest since records on grass were started in 1961.
Micronaire — Micronaire was the highest on record.
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