Soil types evaluated for best fit Growers got a first-hand look at five PhytoGen Cottonseed varieties, including two to be considered for release in 2001, at a recent field day in Corcoran, Calif.
One of the two candidates, PHY 76 Pima, was developed with the goal of finding a variety that will mature earlier than PhytoGen's PHY 57 Pima, released in 1995, while maintaining PHY 57's high and stable yields.
In the company trials at 13 San Joaquin Valley locations from 1996 through 1999, PHY 76 yielded 1,292 pounds or 112 percent of the yields of the standard, Pima S-7, at those locations. However, in trials of the SJV Cotton Board at nine valley locations in 1998 and 1999, PHY 76 yields averaged 1,089 or 98 percent of S-7.
Match to soil type "For that reason," said PhytoGen's Dave Anderson, "we wanted to expand our testing program this year to learn what ground this cotton is best suited for and whether there were aberrations in testing." He urged growers to keep abreast of data from this year's trials and to evaluate it with S-7 in their own fields.
PHY 76, which shows fiber qualities equal or superior to S-7, is scheduled for SJVCB consideration for release in March 2001.
Scheduled for the board's review at the same time is PHY 72 Acala. It averaged 113 percent of the Maxxa standard yields in 1998 and 1999 SJVCB tests at 15 locations, and 115 percent of Maxxa in PhytoGen trials during 1996-999 at 16 locations.
Its agronomic qualities include a wilt rating of 130 percent of the standard, and its fiber qualities include fiber elongation 117 percent of the standard, although its fiber uniformity is 99 percent of Maxxa. It is slightly taller and has about the same maturity as the standard.
Phytogen's John Palmer said they do not release a variety unless it achieves at least a 6 percent improvement over the standard. In only one company trial, did it show less yield than Maxxa, at Lost Hills in 1998 when the yield on highly saline soil was 97 percent of Maxxa.
"Optimum yields is about all you have to know about PHY 72," he added. "This variety has a smaller boll packed with lint and a smaller seed. Because of the smaller seed you have to be careful not plant at the same rate as Maxxa."
Niche cotton Turning to PhytoGen 33 Acala, Palmer said it is a niche cotton for tough, salty or alkaline ground. It showed yields 103 percent of Maxxa in University of California trials at 16 valley locations in 1998 and 1999 and 105 percent of Maxxa in company trials at 17 locations in 1997-99.
"It requires more water management, such as you might give the old SJ-2, and lots more Pix, probably double what you'd apply for Maxxa. It puts the early bolls well off the ground so the picker can reach them."
Another benefit of PhytoGen 33 is high seed yields. Seed supplies are limited, and the company expects PHY 72 to eventually replace it.
PhytoGen 78 Acala, in the early stages of development, showed 106 percent of Maxxa yields at 1999 SJVCB trials at four valley sites. An early maturity variety, it placed high the board's screening program last year and has two more years of board testing ahead of it.
Joel Mahill, PhytoGen's station manager and breeder at Corcoran, noting the goal of the breeding program is to achieve highest possible yields, said PHY 78 registered a 119 percent yield rating against Maxxa in company tests at 12 locations in 1997-99.
Highly adaptive "But its strength is not only in yield potential. It has adaptability to conditions up and down the valley. Adaptability, or the accumulation of positive, favorable traits, is as much genetically controlled as yield, or fiber properties or boll size," he said. Various genetically modified traits of Bt resistance and herbicide tolerance are being introduced to it.
Mahill said PHY 78, which also has good wilt tolerance, could fill the need for an earlier maturing Acala in the valley.
PHY 57 Pima, also known as PSC 57, was released in 1995 and showed 102 percent of the yield of Pima S-7 in SJVCB trials in nine locations during 1995-97 and 107 percent of the yield of Pima S-7 in company trials at 16 locations during 1996-99.
PHY 57 is taller and five to seven days later in maturity than S-7 and gin turnout slightly less than the standard. HVI Fiber elongation tests show a 14 percent advantage over S-7 but a micronaire reading of 94 percent of S-7.
PHY 57 requires experience and skill in water management, and to regulate vegetative growth, bloom should be visible before irrigation.