Fusarium w.ilt of cotton in California has been considered a potentially serious fungal disease caused by the organism Fusarium oxysporum vas infectum (also called ”FOV”) for many decades in several areas of the San Joaquin Valley (SJV). In the past, however, damage associated with FOV in SJV cotton has been notable only in areas with the combination of: (a) moderate to high populations of one or more specific races of FOV (usually race 1 ); (b) soils with a sandy or sandy loam texture; and (c) where root lrnot nematodes were present in high-enough populations to cause some significant root damage. Past research generally indicated that FOV damage was worst when both FOV inoculum and nematodes were present in relatively high…
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Preventing sticky cotton is crucial in producing quality cotton. Late-season populations of cotton aphid and Silverleaf whitefly can produce significant amounts of honeydew when populations build. These pests are of most concern from mid-boll filling through harvest, when insect populations build and threaten exposed lint. Pest management guidelines for cotton aphid and silverleaf whitefly focus on strategies to use once threshold pest populations are reached, with the approach varying with the composition of the developing population (nymphs, adults), crop growth stage, and with the presence of exposed lint. Current pest management guidelines for whitefly and aphid can be interpreted as meaning defoliation is the final event of the season. This is based on the assumption…
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Maximizing application efficiency (Ae) of irrigation systems depends mostly on the irrigation manager’s ability to:
1. Reduce and/or eliminate runoff.
2. Reduce deep percolation below the root zone.
3. Overcome the infi ltration variability of the soil surface.
4. Optimize irrigation scheduling.
Presently, the subsurface drip irrigation (SDI) method is the only method capable of giving a manager this…
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1. Abstract
A three-year field study is requested for the Shafter Research and Extension Center to evaluate the utility of modifications in specific management practices (planting date, irrigation rate and cutoff date management, and harvest aid timing and practices) on the development of and level of seed coat fragment problems (measured by several methods). These field evaluations would be done in several varieties previously identified (in SJV Cotton Board tests) as differing (low, moderate, high) in tendency to produce seed coat fragments as measured by several methods. The evaluations would focus on determining if a specific mix of management practices could be identified that would increase the consistency in expression of seed coat fragment problems. This could serve to both identify production management practices to avoid in years or with varieties more prone to development of seed coat fragment problems as well a…
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Project Summaries. Seed treatment evaluations were done in 2004 at Shafter and West Side REC test locations for several reasons:
(1) to have a California location to participate in tests done at a national level for new and continuing seed treatments for cotton as part of the National Standards Seed Trt Test; and
(2) for University of California trials on select treatments likely to be widely available, or under consideration for future use under CA cotton production conditions by several large seed treatment companies
Prior to 2001 , these trials were done in conjunction with CA Cotton Planting Seed Distributors and consulting Plant Pathologist Dr. Dick…
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Project Summary . This project at Shafter REC is part of a multi-location trial that has been conducted for over five years to evaluate the potential of a change in cotton planting configurations on growth, yield potential and quality. The bulk of the field evaluations in years prior to 2002 were done by two main groups: (1) Dr. Bill Weir of UCCE – Farm Advisor Emeritus from Merced County in cooperation with San Juan Ranch and Bowles Farms in western Merced County, and (2) trials conducted by Hntmacher, Keeley and Delgado with cooperation from staff for multiple years at Shafter…
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Variety trial yield and fiber quality results are the focus of these trials conducted at both Shafter and West Side Research and Extension Centers. As the yield and fiber quality data for the current year does not become available until well after the field day, a listing is provided of both the entries included in the 2004 field trials as well as a data
summary of the 2003 efforts (provided as an example of ongoing data collected in this trial).
2004 Activities- at Shafter and West Side REC sites. This testing program was downsized to small plot trials at UC Shafter and UC West Side Research and Extension Centers…
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The objectives of these studies with Acala and Pima varieties are to evaluate approved Acala varieties and Pima varieties submitted for testing under different environmental conditions and management across the San Joaquin Valley region of Califomia. In order to provide a reasonable limit on the number of varieties in the tests, the entries include newly-approved varieties (approved by the San Joaquin VaJJey Cotton Board) for the current year, varieties released last year that are in their second year of testing, plus the top 4 or 5 previously-approved varieties (in terms of planted acreage). The new varieties are the focus of tests, but only remain in tests for a minimum of two years following release unless that variety moves into the top 4 or 5 varieties in planted acreage. Released varieties also may…
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1998 was a year which brought many changes in the variety situation in the CA cotton industry. Many o f the management recommendations currently in place for CA Upland cotton are based upon years of research on varieties such as SJ-2, GC-510 and Maxxa. The introduction of some potentially widely-different varieties which were developed in environments outside of CA in most cases represents a real challenge in terms o f identifying the most suitable management practices for best results under SJV conditions. These “newly-available” varieties that will come into CA will have the name designation “CA Upland”…
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1998 Studies
The objectives of these studies with Pima are to evaluate approved varieties under different environmental conditions and management. The studies are part of a regional Beltwide Pima variety evaluation that includes Texas, New New Mexico, Arizona and California, and are supported in part through the California Crop Improvement Association. In addition to five grower fields, two UCCE Research Center test locations were used in the 1998 trials, the West Side and Shafter Research and Extension Centers of the University of California. The West Side location is in…
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