This cotton-growing season in the San Joaquin Valley will not be a year to remember particularly fondly.
It is almost one growers and pest control advisers would like to forget, if it were not for the lessons learned about how big a role weather plays from start to finish.
Consultant Lowell Zelinski, an organizer of the Central Coast Cotton Conference, told those gathered in Monterey for this year's annual conference that ‘06 held promises in spots, but when the modules were made in the fall, weather again proved it controls all, even in a cotton greenhouse like the San Joaquin Valley.
Zelinski is convinced cotton yields are closely correlated to Degree Day (DD) accumulation in April, and last April wrote the book on ‘06.
“In 2006 we accumulated 72DD for April and the predicted yields then were 1,216 pounds per acre,” Zelinski said. “This is probably close to actual yields this year.
“This also indicates that, even though late April planting conditions were very good, yield potential had already been influenced. It is hard to make up for a poor planting season in mid-March to early April.”
DDs in March and October were the fewest since 1982. May and July temperatures were the highest since '82.
Bottom line: it was cold on both ends of the season and it was searing hot in the middle, which likely created pollen sterility, poor fruit retention in the bottom and middle of the canopy.
“The high DD accumulation in May led many of us to (incorrectly) believe that the planting season wouldn't have had as much of an effect as it ultimately did,” said the cotton consultant.
Fortunately, the pest year was not too troublesome.
Zelinski called it ”fairly typical.” Early season pests were generally light and some growers skipped mite sprays because none were found.
“This is not your typical practice and it doesn't always work out. You'll often have to come back later with a mite spray when the cotton is taller when you skip that first spray.”
The cool spring slowed plant growth and this allowed thrips to cause damage, requiring treatment. This is not typical.
Lygus were light, except in the south alley.
One big reason for the light lygus year was a widely practiced IPM strategy.
“I noticed that almost all alfalfa hay fields next to cotton had uncut strips left during cotton squaring time. This has not always been the case. Ten to 15 years ago, it was rare,” he said.
University of California IPM Specialist Pete Goodell has been preaching this IPM technique for years, and it is obviously paying off in reduced lygus control costs.
Growers have learned leaving hosts for lygus during cotton squaring makes lygus management easier.
Worm pests were spotty. Beet armyworm, western yellow-striped armyworm and cabbage looper were in some fields throughout the year.
“Control of worms was not too difficult because the newer materials worked well,” he said.
This coming season will see more transgenic cotton planted with either Bollard II or WideStrike technologies. Tech fees are reported to be so low as to be affordable in an environment like the San Joaquin Valley where in most years worms are not a major economic pest. Although worm damage is never high, this new technology should offer significant savings in yield from sub-treatment threshold levels of worms. In one variety trial, a WideStrike transgenic Phytogen was the highest yielder and this was attributed partly to work control using this new technology.
Aphids were a season-long problem in some fields. They were easily controlled, but fields that were sprayed early frequently had other insect problems later in the year.
The weather played havoc with weed control in Roundup Ready varieties. “With the good weather early, young cotton grew very quickly,” and precluded growers from putting on a second application of Roundup before the cotton reached the fifth leaf stage.
“With the release of a number of Roundup Flex varieties over the next few years, this will no longer be a problem,” Zelinski said.
In looking head to 2007, Phytogen 725 RF will be the Flex version of Phytogen 72, which last year accounted for about 35 percent of the SVJ Acala upland acreage. Harry Peck of DowAgrosciencs said there would be ample supply of 725RF next season as well as of Phytogen 72, the most popular Acala in the valley.
Peck added the insect resistant Acala, 745 WRF, is being pulled from the San Joaquin Valley Cotton Board trials because of shorter than acceptable length.
However, there is a replacement, 755 WRF, which has a Phytogen 72 background.
The No. 1 pima in the valley, Phytogen 800, will be in adequate supply along with a limited supply of Phytogen 830, an earlier season pima with very similar fiber properties as 800.
It is expected to do well in the northern area of the valley where weather conditions often limit pima acreage.
Phytogen is also bringing along a Roundup Flex Pima, 835RF. Phytogen 810R is being discontinued.
Deltapine's pimas, 340 and 744, followed 800 in popularity. Deltapine also has a newer pima, 343.
California Planting Cotton Seed Distributors, now a part of
Bayer CropScience, has the only Liberty Link Acala in development, C504L. CPCSD also has a popular Acala Flex, Daytona RF, as well as a new pima, Cobalt.
Deltapine also has two new Flex Acalas in development, DPX 200F and DPX 205F.
Acala/uplands to be discontinued in 2007 include Riata RR, Sierra RR, Maxxa, Phytogen 715RF, Phytogen 710RR and Ultima, which is being replaced by Ultima RF.