Chateau herbicide has drawn attention this year for its control of annual morning glory in blackeye bean trials at the University of California's Shafter Station, according to Kurt Hembree, Fresno County farm advisor.
Although Chateau, a Valent product whose active ingredient is flumioxazin, is not registered for use on dry beans in California, Hembree said data gathered in this and future trials could help it gain registration for that purpose.
“At this point it looks like a double-hit with Chateau may be a good strategy against morning glory, and we need to get Prowl or something else into the program to get the grasses,” he said during a recent blackeye field day at the Shafter site.
Annual morning glory, whose dense foliage dotted with blue flowers can engulf a stand of blackeyes, is more common in Kern County than the northern part of the San Joaquin Valley. It is particularly difficult to control once its stems develop.
Among his various treatments this season, Hembree said he got best results by applying Chateau, first postplant preemergence and then postemergence directed after the second irrigation, on the blackeye plot for burndown and residual activity against the weed.
He said applying the postemergence directed treatment after the first irrigation and before vines closed may have been even better.
He plans to continue the trials next year, comparing timing of a postemergence directed spray after the first irrigation with one made after the second irrigation.
Hembree pointed out that while the Chateau applications were successful on blackeyes, they were not so in his trials with garbanzos, which showed high sensitivity to the material.
His trials on blackeyes this year at the Kearney Agricultural Center at Parlier also indicated good prospects for Outlook, a dimethenamid material from BASF that is strong against nutsedge and nightshade but not harmful to the crop. It is registered for dry beans elsewhere but not in California.
In the continuing process to develop an improved blackeye variety to replace the industry standards, CB 46 and the larger-seed CB 5, Jeff Ehlers, plant breeder at UC, Riverside, showed plots of the two leading candidates, Shafter 50 and Shafter 49.
Shafter 50, whose complex pedigree includes African cowpeas, has comparable yield potential, better early cut-out resistance, larger seed size, resistance to root knot nematode, and resistance to Fusarium Race 3.
Of particular note is the larger seed size of Shafter 50, which Ehlers said could give California producers an edge over their Texas counterparts in the marketplace. “It would be hard for Texas to produce such a large seed with the direct combine system they use.”
Shafter 49, which also has African traits, has greater resistance to the nematode and to early cut-out, along with resistance to both Fusarium Races 3 and 4. Its seed size is intermediate between CB 46 and Shafter 50.
Both have been put through canning evaluations and found to be comparable to CB 46 in that respect.
The first crosses for the two improved cultivars were made in 1998, and last year they were in large-scale field trials. They were selected from lines planted at the Shafter station in 2003 and named accordingly.
“We believe the best way to go is to select for new, more robust varieties for the southern SJV with the long-season conditions we have here at the station,” Ehlers said.
Commercial-scale plantings this year are expected to provide clean-out data on the new lines.
Ehlers said breeder-seed stocks are being produced and additional cooperating growers may be involved with growing test strips. Once breeder seed is accumulated, the next steps are production foundation and certified seed supplies.
Meanwhile, other blackeye plots on the station are being used for his preliminary yield testing on 22 new varieties with Shafter 50 and CB 46 as checks and for a planting of a new version of CB 46 having improved nematode resistance.
Ehlers' research has been supported by the California Dry Bean Advisory Board.
In a discussion of lygus bug control, a perennial headache for blackeye growers, Carol Frate, Tulare County farm advisor, said her trials in her county this year and another in San Joaquin County in 2005 have failed to produce conclusions about use of the pyrethroid Warrior in comparison with traditional organophosphate products.
“The problem is both the efficacy of what you spray and its residual activity,” she said. “Most materials we've been using do not have a lot of residual activity. So you can spray your beans and in a week if someone cuts alfalfa you have lygus again.”
In the San Joaquin County trial, bean yields were greater and damaged seed was less with Warrior than with the organophosphate Dimethoate.
In Frate's Tulare County trial, pending harvest data, she said differences in lygus counts were not that great between either of the two materials and an untreated check.
The obstacle with pyrethroids in the southern San Joaquin Valley, she noted, is their common use in cotton. As these products are applied, lygus develop increased resistance during the season. Particularly in Kern County, pyrethroids can also bring on flares of spider mites.
With that in mind, Frate added, “the efficacy of pyrethroids on lygus in this area may not be as good as it was shown to be in northern California, and as the season progresses, your control of lygus with pyrethroids may decrease.”
If a grower does choose to use a pyrethroid for lygus on blackeyes, she recommended it be used early in the season.