San Joaquin Valley cotton growers checked progress of Acala and Pima varieties in PhytoGen Cottonseed test plots near Huron and Stratford in a recent tour hosted by the seed company.
PhytoGen's mid-maturity Pimas, PHY 76 and PHY 57, are full-statured at 45 inches height, have yield potential in the three- to three-and-a-half-bale range, and have performed well over the past several years, according to company breeder Joel Mahill.
At a field near Huron, Mahill said, they can be held in check by irrigation stress management. “When Pimas came into the SJV, we learned early on they do not respond to Pix like Acalas do,” he said, adding that growers who do use the growth regulator apply double the rates used on Acalas and use irrigation stress management to head off excessive vegetative growth.
Once the first and second irrigations are made on PHY 76 and PHY 57, Mahill said, the recommendation is to delay the third irrigation one or two days. “You allow the yellow bloom to come closer to the top of the canopy. You get a little wilting of the canopy, but by late evening it perks back up.”
The practice “does a world of wonders to control vegetative growth,” he added, and it also helps set the fruit.
A significant concern for growers, he said, is the issue of increasing inputs, not the least of which is water. “If we can extend our irrigation scheduling to where we can reduce it by one irrigation it is a benefit, while maintaining the high yield potential.”
At a primary yield test and nursery site outside Stratford, the Mahill and Scott E. Bordelon, research agronomist, pointed out Acala and Pima varieties grown under a stricter irrigation regime than the Huron plot.
Mahill also showed plots of three PhytoGen Roundup Ready Acala experimentals alongside competitors outside Stratford. Labels for Roundup Resistant varieties call for two over-the-top treatments before the fourth or fifth true-leaf stage, followed by a third, post-direct treatment.
The trio, PHX-A 101, 102, and 103, are all slated for San Joaquin Valley Cotton Board trials to continue in 2002 and 2003 for consideration for release in 2004. “We anticipate having a limited amount of seed for 3003, and full availability afterward,” said Mahill.
One of PhytoGen's priority objectives with development of new varieties is avoiding seed coat fragments in the lint, he said. Among the safeguards are years of testing even before new varieties are evaluated in Cotton Board test plots.
PhytoGen 78 Acala, which showed 106 percent of Maxxa yields in 1999 testing and is up for consideration for release next year, is a columnar-type less prone to lodging. Although the plant has a lighter-colored leaf, that has no effect on its performance, said Bordelon.