2014 Field Evaluation Support and Variety Screening Evaluations


This project matches the efforts in a similar named project supported by the California Cotton Incorporated State Support Committee. The difference between the two is that the Cotton Incorporated part of the project is set up to support only Acala and Upland cultivar research, while the CA Cotton Alliance project supplements that support and also allows us to also focus on Pima variety screening and related efforts for Pima production. CA Cotton Alliance funds support the same areas of work as the Cotton Incorporated funded project, but since Cotton Incorporated funds are collected for Upland variety work, the expanded efforts in screening, including Pima, are covered under this same project summary report…

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Extending Efficient Drip Irrigation Management Approaches to San Joaquin Valley Pima Cotton Growers


Irrigation scheduling methods in the irrigated far west are not uniformly accepted and depend on irrigation system, production economics and the management investment the grower is committed to. Most current and successful methods use soil and/or plant-based measurements that are combined with regional estimates of ETa and Kc to calculate best irrigation timing. Growers that make use of the available technology find that the time and financial costs invested in making careful field evaluations improve farm economics. Seasonal cotton water use for optimum yields can exceed 750 mm (30 inches) with typical rainfall contributions less than 15 percent of total season water requirements. Crop water requirements are distributed unevenly across the season with very low ET observed in the 60 days following planting and peak ET observed 100 to 115 days after planting. The highest cotton water use period is from late June to mid August during peak-bloom with daily water use of slightly over 2.0 inches per…


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2013 Cotton Harvest Aid Progress Report


Cotton Harvest Aid Management 2013

This report summarizes the applied defoliation research studies conducted during 2013. This was another unique season due to warm weather causing rapid progression of the cotton crop. Three research trials were conducted on Pima cotton at the Westside Research Center in Five Points, CA. These fields were planted with Phytogen 802RF on April 16, 2013 with a seed rate of 18 lbs/A. The fields received a pre-irrigation, three in-season irrigations, and pressure bomb readings were taken to better manage plant vigor. In addition, the fields received 140 lbs of nitrogen urea plus 14 lbs sidedress of Temik (Aldicarb) on May24, 2013. The fields also received 16 ounces of Mepex (Mepiquat Chloride) on June 19th and again on July 1, 2013. The plots were 65’ in length and consisted of four rows with 40” spacing. In each trial, each treatment had 4 replications.

The objective of these studies was to define the most appropriate conditions for effective defoliation and crop termination. New harvest aids and several tank mix combinations…

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UCCE Approved Acala and Pima Variety Trials


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 California. 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 Valley 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 not show up in tests if companies request that the variety is for a special market and don’t want it in multiple location testing, or when seed supplies are inadequate. The Pima tests focus on approved varieties, but in the past two years have also included a non-approved hybrid that has been of interest due to yield…


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2006 Activities- at Shafter and West Side REC sites. This testing program is maintained for nonAcala Upland cotton varieties at both the UC Shafter and UC West Side Research and Extension Centers in small plot trials which have been conducted since 1998 in response to requests for continuing information on varieties outside of the Approved Acala testing program. The project investigators are appreciative for the participation by seed companies and the UC Research Centers in providing support for ongoing testing ofnon-Acala Uplands. The actual varieties included in 2006 trials are shown in Table 1, but yield and lint quality data will not be available on 2006 studies until December 2006. Summary results will be posted on our UC cotton web site: and in a January 2007 issue of the California Cotton Review…

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Assessment of Fusarium in the San Joaquin Valley: Field Evaluations and Variety Screening


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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Sticky Cotton Prevention – Late Season Insect and Defoliation Management


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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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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The response o f Acala cotton in California to a range o f applied nitrogen treatments are under investigation in a multi-year, multi-site experiment. Goals of the experiment are to identify crop growth and yield responses to applied nitrogen and to provide information to better assess the utility of soil residual N estimates in improving fertilizer management. Results obtainedd uring the first three years o f this project have shown positive responses to increases in applied N across the 50 to 200 lbs N/acre range…


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Bob Hutmacher
.UCCE Extension Agronomist
Department of Agronomy and Range Science
UC Davis I Shafter REC
(661) 746-8020 I fax (661) 746-1619

Cooperators: Ron Vargas, Steve Wright, Bill Weir, Bruce Roberts,
Dan Munk, Brian Marsh, Mark Keeley, Raul Delgado, Scott Perkins

1999 Studies

In 1999, studies are underway at nine locations in the San Joaquin Valley in tests run by our office in cooperation with the six San Joaquin Valley UCCE cotton Farm Advisors.  At the time of writing this report, we have limited data to report, since no final plant mapping data have been analyzed and we are still a way off from defoliation and harvest. Instead, the following will be a brief description of the type of testing program initiated for 1999, and data collection plans.

Two different types of studies are underway this year, (a) a large-scale plot study on grower fields to evaluate varieties in large plots, where adequate seed…

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