You know it has been a bad year when you drive by a cotton field in the fall and are not sure if it has been picked. That was the kind of cotton year it was in 2005 in the San Joaquin Valley, a stark contrast to module-busting 2004.
Long time cotton consultant Lowell Zelinski told Central Coast Cotton Conference in Shell Beach, Calif., it was not only a year of stark contrast to the season before, but also a year of considerable variability in the valley.
Zelinski, director of the annual California cotton conference on the coast, said he monitored fields planted just days apart, but by July looked like their planting dates were separated by weeks, seemingly without explanation.
“I had two fields planted four days apart. On July 10 one field was 10-inches tall and two weeks from bloom. The adjacent field was in full bloom at the same time,” said Zelinski.
Much of the problem went directly to lousy spring planting weather that was clearly the reason fields that yielded four bales in '04 eked out just 2.5 bales in 05.
To compound the problem and in contrast to the cool spring, July was hotter than the tip of a Roman candle on the 4th of July. When it's hot, cotton doesn't pollinate. However, pollen sterilization may have been a bigger problem than most SJV growers realize.
Zelinski says scientists generally agree when temperatures exceed 80 degrees at night, cotton suffers from sterility.
“Everyone knows SJV cottons do not travel well across the Cotton Belt, and I think warmer temperatures elsewhere have a lot to do with that,” said Zelinski.
Zelinski says the temperature threshold may be only 70 degrees when SJV cotton varieties experience sterility problems.
“SJV varieties may be more susceptible to temperature variability,” said Zelinski. Seed counts of only five to six per loc this season versus the normal 9 to 10 may be testimony to Zelinski's theory When the SJV heat spell broke in '04, cotton began setting more fruit. However, just as quickly as it turned hot, it turned cool. “We set a big crop in August and September, but there was not enough heat after that to finish the crop and we had a high percentage of bolls half done.”
It was a costly lesson in weather. “Good-yielding years are cheap to grow and poor yielding years are expensive to grow,” said Zelinski.
The reason for the big '05 bills was insects, according to Pete Goodell, regional University of California IPM advisor.
Thrips took squares early in '05 and “that almost never happens,” said Zelinski. The weather even played havoc with weed control, precluding Roundup ground applications due to wet ground. Many resorted to air and the result was the highest level of drift complaints in recent years.
It was a lygus year with the late rains and continued weed growth, but Goodell said control measures were usually good. Kern County's lygus problems were worse than other areas.
There were more mites and aphids later because all the beneficials died. Pacific and Two-Spotted were the later mite species. The hot weather exasperated the mite problems.
Worms were a problem and some growers got a look at the first Bollgard Acala for the valley. It works on small worms, but Goodell said “when you have snakes cross the road” from alfalfa field, Bt cotton will not stave off problems.
“Whiteflies and aphids in the fall were not as bad as everyone expected from high aphid populations earlier,” said Goodell. “However, whiteflies were a huge problem in the desert cotton growing areas.” Desert problems were reportedly attributed to very high populations reducing amount of time a pesticide application held insects in check.
There were concerns that they may be another sticky cotton problem from late season whiteflies, but Goodell said he does not expect that to be a problem in the San Joaquin Valley cotton now moving to the textile mills. “However, there may be some sticky cotton from the edge of urban areas.