COTTON VARIETY CHOICES, IRRIGATION, NITROGEN AND DISEASE MANAGEMENT FOR PRODUCTION EFFICIENCY IMPROVEMENTS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1021566
• Project Start Date: Dec 11, 2019
• Project End Date: Sep 30, 2024
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIVERSITY OF CALIFORNIA, DAVIS
410 MRAK HALL
DAVIS,CA 95616-8671

Performing Department
Plant Sciences

Non Technical Summary
This project supports the mission of the Agricultural Experiment Station by addressing the Hatch Act area(s) of: soil and water conservation and use; plant and animal production, protection, and health; sustainable agriculture.Grower production management decisions and the quality of the cotton crop produced in CA benefit from up-to-date information on varietal differences in yield, quality performance, and relative disease tolerance for the two major types of cotton (Acala and Pima cotton) produced in the state of California. Variety evaluations provide information on yield performance, fiber quality, important for impacts on profitability. Information gained on newly-recognized fungal organism, including potential varietal susceptibility and resistance. Improved variety choices, improved irrigation management options, and better understanding of acceptable nitrogen management practices for cotton can productivity, crop quality and profitability under the production conditions and constraints existing in California. Improved nitrogen management is of interest to growers from a profitability standpoint and for efficient resource utilization, but increasingly, nitrogen management also is under scrutiny to improve efficiencies in providing adequate nitrogen to meet crop requirements while avoiding losses and potential for groundwater nitrate contamination. Improved N management requires both a better understanding of the amount and timing of plant N needs, as well as knowledge of soil characteristics and how irrigation management can impact N uptake and losses. Since availability and cost of irrigation water is of increasing interest as a major constraint to crop production in the arid and semi-arid west, improved irrigation practices are also needed, including improved understanding of cotton responses to targeted deficit irrigation (flood, furrow or drip) when water supplies are limited by drought or when alternative uses of limited irrigation water (for other crop choices or other uses) are more cost-effective than full irrigation of the cotton crop. This research should help provide field evaluations of specific, reduced water application, reduced water use options for cotton production in the San Joaquin Valley.Germplasm evaluations for race 4 Fusarium resistance/tolerance to date have shown: (1) most available commercial Pima varieties and many experimental from public and commercial programs continue to exhibit more severe symptoms and higher levels of mortality than most Upland varieties; (2) multiple companies or breeders have released multiple moderate to highlyresistant commercial Pima varieties; (3) four USDA-ARS/Univ. CA experimental cultivars with moderate to high resistance have been identified and released for breeder use, and another six are in late stage testing; and (4) most Acala / Upland germplasm tested, while less severely impacted than most Pima varieties, have been routinely infected at a high percentage and with measureable damage in terms of stunting and/or plant mortality associated wtih race 4 FOV when present in soil at infested field sites or when inoculated in greenhouse trials. Prior project evaluations have demonstrated that inoculum levels of race 4 FOV can build to damaging levels even when only Upland cotton has been grown in prior years (no prior history of growing the more susceptible cultivars of Pima). Results from our field FOV resistance screening studies should be useful to and utilized in further genetic evaluations and to identify sources of host plant resistance useful to breeders. Development of host-plant resistance is currently considered the most economic and effective strategy for managing FOV in California cotton production regions.

Animal Health Component

70%

Research Effort Categories

Basic

20%

Applied

70%

Developmental

10%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
102	0110	1020	10%
111	0210	1010	10%
111	1711	1020	10%
202	1710	1080	10%
202	1711	1080	10%
204	1710	1081	10%
204	1711	1081	10%
212	1710	1081	10%
212	1711	1081	10%
212	1711	1160	10%

Knowledge Area
212 - Pathogens and Nematodes Affecting Plants; 204 - Plant Product Quality and Utility (Preharvest); 102 - Soil, Plant, Water, Nutrient Relationships; 111 - Conservation and Efficient Use of Water; 202 - Plant Genetic Resources;

Subject Of Investigation
1711 - Long fiber cotton; 0110 - Soil; 0210 - Water resources; 1710 - Upland cotton;

Field Of Science
1160 - Pathology; 1081 - Breeding; 1010 - Nutrition and metabolism; 1080 - Genetics; 1020 - Physiology;

Keywords

cotton

pima cotton

upland cotton

disease resistance

fusarium

race 4 fusarium

fungal pathogens

varieties

cultivar

nitrogen

nitrogen management

fiber

irrigation

deficit irrigation

nitrogen uptake

fiber quality

Goals / Objectives
With a long history of production in California, cotton currently remains an economically viable annual crop option in the San Joaquin Valley region, and in areas of the southern California desert areas and Sacramento Valley due to crop characteristics of: (1) moderately high heat tolerance; (2) high soil salinity tolerance relative to many other agronomic crops; and (3) moderate water use and relatively good production potential even with imposed deficit irrigation. All of these characteristics have been useful in defining the limits of and suitability of cotton production areas in the past, and as water limitations intensify and some crops need to be shifted to more marginal, moderately salinized soils, cotton may remain a workable, profitable choice in places where other crops might fail. As with all crops, the degree to which the crop retains or expands acreage will in large part be dependent upon the realization of acceptable commodity prices to cover and reflect current production costs.Objectives for this project include: (1) valley-wide variety evaluations to provide assessments of relative growth and maturity habits, yield and fiber quality under a range of soil, salinity and irrigation conditions provided at Research Center and grower field sites; (2) improved understanding of nitrogen (N) utilization, uptake and removal with harvest, focused mostly on modern Pima cotton cultivars, including impacts of drip versus flood/furrow irrigation on these measures of utilization; (3) evaluation of Pima cotton responses to mild to moderate deficit irrigation management; (4) greenhouse and field evaluations to assess relative varietal differences in susceptibility to race 4 of the fungal pathogen Fusarium oxysporum f. spp. vas infectum; and (5) joint efforts with USDA-ARS geneticist to make and test crosses, selections for improved tolerance or resistance in Pima and Upland cotton cultivars to race 4 Fusarium oxysporum f. spp. vas infectum.For over 10 years, more than 70% of California's cotton acreage has been planted to Pima cotton varieties, with recent years reaching over 85% of total acreage in Pima (USDA-Economic Research Services). As a premium-quality cotton, Pima commands a significantly higher price than Acala or non-Acala Upland cotton, so Pima is likely the type of cotton most producers will plant in future years. However, it requires a 2-3 week longer growing season than most Acala varieties, and there are known differences in sensitivity to insect pests, impacts of plant water stress on fruiting, and plant responses to management practices such as use of plant growth regulators. The focus on more Pima plantings has been evident for a number of years, and University of California researchers and growers are both aware of some of the differences apparent between dominant Acala varieties versus widely-planted Pima varieties, and this helps define the continuing need for University run variety trials since for cotton, both yield information and fiber quality analyses are important in determining profitability. Variety evaluations provide information on yield performance, fiber quality, important for grower choices that impact profitability. Producers have the benefit of independently-conducted varietal production comparisons across regions which better identify potential for production or quality improvements and acclimation to their production conditions. Information gained on a major, well-recognized fungal organism (Fusarium race 4) in in-situ field evaluations as well as plants for host plant resistance evaluations will be important for identifying resistant varieties with potential for use by cotton growers in California and well as for other production areas/states as the disease spreads.Nitrogen management issues have become a key issue for many CA growers due to concerns generated by groundwater nitrate contamination that have been linked to agricultural practices both in crop production and animal agriculture production. Regulatory approaches to limit groundwater nitrate contamination have focused on approaches to better match crop fertilization practices (both inorganic, synthetic fertilizers and animal manures and compost applications) to actual crop nitrogen (N) uptake and removal. To meet needs for data on uptake and removal of N in cotton crops, studies are being initiated to measure these nutrient removal characteristics in modern cotton cultivars, focusing mostly on Pima cotton uptake and removal under moderate to high yield conditions under both drip and furrow irrigation.In many areas of the state, it also is apparent that water limitations in terms of cost and availability represent a formidable constraint to continued crop production. Evaluations of irrigation management options that include less total water and shorter production seasons are needed to assess suitable production systems, yield potentials and profitability in order to assess where cotton might fit into farm rotation options with new constraints on commodity price, input availability and price for inputs such as irrigation water. These newer evaluations must include Pima due to the potential for higher prices for this commodity and suitability and demand for this product in the export market.

Project Methods
Variety trial evaluations will be conducted in field-scale trials on grower fields and in smaller replicated trials at the West Side REC University Research Center in the San Joaquin Valley, with yield, fiber quality and plant growth characteristics evaluated at all the sites. All samples from trials will be processed using our mini-gins, with fiber sample quality evaluated using USDA HVI criteria at the USDA Classing office in Visalia, CA.Alternative nitrogen and irrigation management practice experiments will be conducted at University Research Centers; at West Side REC primarily, and when appropriate or if adequate funding levels are achieved also at the Kearney REC site (sandy loam soil). The approaches will be to evaluate a range of nitrogen application amounts under both furrow and drip irrigation to determine impacts of nitrogen application amounts and irrigation method on crop N uptake and removal with harvest. Deficit irrigation approaches using drip irrigation and furrow irrigation will be evaluated for Pima versus Upland varieties in separate studies in order to assess relative impacts of water-saving irrigation management practices on relative yield levels and impacts of any deficit irrigation practices on fiber quality. In both irrigation and nitrogen field studies, water applications will be metered, and pre-planting and post harvest soil samples will be analyzed to a depth of 8 feet in order to be able to provide estimates of total crop water use (applied water plus soil water use) for each irrigation treatment and soil nitrate-N changes associated with a range of N applications.Assessments of relative tolerance of cotton Pima and Upland germplasm to Fusarium oxysporum vas infectum (race 4) will be evaluated both in naturally infested field sites on private farms, and also in greenhouse evaluations done using root dip inoculations done at concentrations of 106 spores/ml. Based on prior field experiences, plants will be grown from seed to approximately the 7-8 weeks after emergence for disease damage ratings and survival. Evaluation of severity of plant foliar symptoms and degree of vascular staining and plant stunting will be used as relative indicators of tolerance to these races of Fusarium. If field sites with problems with this race of Fusarium become available for evaluations, selected varieties identified in the greenhouse evaluations will also be evaluated in the field to compare relative rankings. Selected experimental entries from USDA-ARS and UC joint efforts will be evaluated, and better performing materials will be utilized in breeding efforts for public germplasm improvement. These joint projects work together to both identify resistant varieties to reduce the production of inoculum and disease damage, and to contain and slow the rate of expansion of the disease inoculums (field sanitation and prevention of seed production in infested fields). These Fusarium race 4 efforts mentioned are a part of a joint long-term project with USDA-ARS cooperators in Lubbock, Texas which has goals of making selections and crosses for improved host plant resistance to race 4 Fusarium oxysporum vas infectum as part of a disease resistance improvement program.

Progress 12/11/19 to 09/30/20

Outputs
Target Audience:The primary target audience includes cotton growers, seed company breeders and representatives, and private consultants working with the cotton industry in California and other cotton producing states, Some of the information developed on varietal performance in CA conditions will be primarily of interest to growers in the region. Other information on Pima cotton production and disease management and breeding for Fusarium race 4 resistance may be of broader interest across multiple cotton-growing states, since those research issues have somewhat limited coverage in other areas. Key cooperators who will interact on these projects include University of CA Farm Advisors, California State University Fresno staff, USDA-ARS cooperators and researchers in other cotton growing locations in the U.S. Primary interest in the general variety trial work is primarily from seed company representatives and breeders, plus growers in California. In terms of the Fusarium race 4 screening work, interest is more broad-based with interest from seed company breeders, two international cotton breeders, researchers from multiple U.S. cotton-producing states, plus representatives contacting us from locations including Australia, Greece, and Uzbekistan. Particularly in the case of the work on the fungal disease, race 4 Fusarium, some other target groups include interested parties in other U.S. states plus cotton industry organizations such as Cotton Incorporated and the National Cotton Council. The information produced relative to Fusarium disease issues with race 4 has been used by Farm Advisors in CA and Arizona for multiple years. Starting in 2017 and continuing currently, the project has responded to inquiries from groups located in Texas, New Mexico, Louisiana, Georgia, and Mexico, including both Cooperative Extension and other land grant and non land-grant universities as well as seed company representatives. Their interest has been in dissemination of University information to industry. This information is provided as web-based information for potential distribution to other cotton production areas in the United States, and to the Cotton Incorporated research group at the national level. We have also directly provided written bulletins distributed by Cotton Incorporated and by Texas A&M University and New Mexico State University, plus powerpoint presentations for use by others as basic information for producers and seed company representatives. Information from Race 4 Fusarium disease resistance screening trials and variety trials is also sent out through via web based communications using the University of California cotton web site (https://cottoninfo.ucdavis.edu). Updates on disease resistance evaluations and variety screening work for fiber quality and other characteristics are also part of multi-state efforts with a primary USDA-ARS research partner located in Lubbock, TX and through seed company representatives who submit varieties for evaluation in these variety and disease screening trials. This participation provides information to breeders of potential use in selection and improvement programs. The project PI also serves as a coordinator for a multi-state effort in cooperation with USDA-ARS to test Pima cotton in 3 locations across parts of the U.S, which then collects fiber and seed quality and yield data. This data is available in a data set managed by the USDA-ARS out of Stoneville, MS. Results from deficit irrigation trials and drip irrigation management trials provide information on both Pima and Upland cotton responses to deficit irrigation, with information made available to growers, irrigation consultants, seed companies, and agency representatives dealing with crop production under limited irrigation water situations, which seem to have become more commonplace in recent years in the western U.S. Changes/Problems:Extra expenses associated with operations under COVID-19 restrictions have come in the form of: (1) new protocols that put limits on staff work locations and duties, particularly those that formerly were done by a team of multiple people; (2) PPE requirements and associated costs, and training; and (3) extra vehicles required for transport to all work sites, since no more than one person is allowed to travel per vehicle. While necessary, these requirements and changes in work environments and methods have greatly increased operating costs and will limit our flexibility to complete tasks within our current operating budgets. For all of our University approved research projects in 2020, we were required to document our work plans and changes in operations under COVID-19 protocols, and submit all of them for upper administration review and approvals. While most projects were eventually approved for 2020, the extra steps and extra expenses have made operations more difficult and resulted in some delays in data collection and analysis. In recent years, we have not been able to identify grower-cooperators sites for Upland / Acala variety trials due to low commodity prices for upland cotton and reduced acreages other than for seed production. Both of these factors have reduced the willingness of growers to take on the extra expense and disruption of their operations that occur with large scale variety trials. We have utilized facilities of the University of CA West Side University research center for all of the Upland cotton variety trial work in 2015 through 2020, and expect that the same situation will prevail in 2021 for Upland variety trials. We will continue to conduct the trials at the University of CA research center at West Side REC, although prices for recharge on the research centers are also going up and these type of issues may limit some of our capabilities to conduct these trials in future years. On a positive note for smaller scale field research trials that require machine harvest yield data, the CA cotton industry and my program provided some funding to make major modifications to our small plot cotton spindle picker for 2020, which was in need of major changes to meet safety requirements of the University which put those field harvest capabilties at serious risk of curtailment prior to these successful modifications. For the Fusarium race 4 evaluations, retention of and maintenance of two field sites has been expensive since we need to pay growercooperators at these sites due to the extreme amount of damage to yield potentials in these severe disease sites. So far the CA cotton industry has assisted with helping cover grower/cooperator supplemental costs and losses associated with the research in the form of a supplemental grant. but this requirement could be problematic in future years if cotton acreage continues to decline and research funds become tighter. The impact of finding FOV-4 disease in cotton in west Texas may have an impact on future options and interest in continuing FOV-4 research in California, but for now our Texas-based USDA-ARS cooperator and California State University Fresno cooperator have indicated that we will plan to continue these field efforts in 2021. What opportunities for training and professional development has the project provided?Variety trial work, disease resistance evaluations, and the deficit irrigation projects were mostly operated and conducted utilizing Staff Research Associates of the University of California and student Field Assistants hired through the UC Davis Plant Sciences Department. Since our research sites and field facilities are located in the San Joaquin Valley of California, the students and other part time help utilized in the project are community college students, students at California State University Fresno or CSU Bakersfield, rather than University of CA students. The field and laboratory work provide opportunities for all staff to become acquainted with field research techniques, requirements for accuracy and care in operating field trials and collecting data, and improved methods of data management. Safety training is also provided, which is important in dealing with on-farm research both in private farm and university settings. Fusarium resistance evaluations mostly in the field, but also in greenhouse settings have been used for student and industry training sessions on identification and screening methods for improving grower, consultant and researcher understanding of what to look for and how to deal with the disease race 4 Fusarium if found in cotton fields. Most of this training was in the San Joaquin Valley of California, but additional information efforts (verbal presentations, written materials or Powerpoint presentations and photos) have also been provided to researchers in other states, including Arizona, New Mexico, Texas and Georgia during the reporting period. Continuing field screening for disease resistance to Fusarium oxysporum race 4 has involved entries provided by various associations with our USDA-ARS cooperator (M. Ulloa) as well as a broad cross section of participating seed companies who provide entries for field evaluations, including advanced lines from breeders all across the US production region. In 2019, the general screening of experimental varieties and commercially available germplasm continued in both public entry evaluations (from companies and private breeders) and also, screening for FOV-4 response of different cultivars provided through public breeders associated with Universities and USDA continued through the Regional Breeder Testing Network entries (RBTN program). These FOV-4 screening evaluations were done primarily in California, but with the assistance of our USDA-ARS breeder/geneticist cooperator, additional screening was done in FOV-4 infested fields in far-west Texas. Several short videos covering aspects of Fusarium race 4 disease symptoms in plants and parameters evaluated in disease screenings have been posted on the University of CA cotton website (http://cottoninfo.ucdavis.edu), with the purpose of providing industry, growers and their representatives with training in recognizing the disease symptoms in the field. How have the results been disseminated to communities of interest?Information delivery has changed due to COVID-19 restrictions and limitations on our activity due to University limits. During the period, information on Fusarium race 4 symptomology, spread of the pathogen, recommended management and containment practices, and results of host plant resistance screening programs has been disseminated using zoom presentation (at 3 industry meetings) as well as through posting of information on UC cotton website. Information was also provided in written form (Guidelines, suggestions for field scouting) and as disease photo identification materials made available to Cooperative Extension representatives in Texas, New Mexico and Arizona as requested. One brochure covering issues with Fusarium was updated in cooperation with USDA-ARS, Cotton Incorporated, Texas A&M University, and New Mexico State University; and an update of a brochure / bulletin on FOV-4 identification and management practices was produced and printed by the CA Cotton Growers Association. For the UC brochure, the project PI provided the text used in the bulletin, some of the photos, and review of the final product. Presentations were made at national meetings at Beltwide Cotton Conferences in Austin (2020) prior to the COVID-related limits, During the reporting period. In California, variety trial yield and quality information, and Fusarium information has been provided using the University of CA Cotton web site:(http:// cottoninfo.ucdavis.edu) and through industry and commodity group websites, such as that of the CA Cotton Growers and Ginners Association as another means of information dissemination. Other written materials have been provided on both variety trial results (at the California Cotton Growers and Ginners Association) and Fusarium disease resistance screening to industry representatives on request and at three meetings during the year to the CA Cotton Alliance board and at the quarterly meetings of the CA Cotton Growers and Ginners Association board. Research and data summaries were presented and discussed via website postings available to growers, field agronomists and plant pathologists. What do you plan to do during the next reporting period to accomplish the goals?The same type of field and laboratory work is expected to continue in 2020-2021 efforts in: (1) variety evaluations (growth, yield, fiber quality) for Upland, Acala and Pima types of cotton, both in research center trials and grower field sites (2) nitrogen management and nitrogen uptake trials in Pima and Upland cotton witll continue, with the nitrogen management trial again conducted both under (a) furrow irrigation management / dry fertilizer application regimes; and (b) subsurface drip irrigation / liquid, injected high frequency fertilization regimes. The 2021 field year is expected to be the final year of a three year set of funded field trials, with the fourth year being planned for data analysis and further reporting. (3) field and greenhouse evaluations of selections and new entries from our USDA Cooperators and seed companies will continue in 2020-2021, with expected locations in two counties where we have identified disease infested sites for the screenings. This work will be conducted as in recent years, with field evaluations utilizing a large crew for management of the research plots and for data collection at intervals through the season at both test sites plus the greenhouses. Seed increase efforts for selections will continue at UC West Side REC and UC Kearney REC locations (field and greenhouse, respectively). We will continue to evaluate possible funding sources and adequacy of staff and resources to conduct further irrigation management/water stress studies or responses to saline irrigations if funding sources can be identified.

Impacts
What was accomplished under these goals? Per the objectives for this project, accomplishments and progress made in the reporting period included: (1) San Joaquin Valley multi-site variety evaluations to provide assessments of relative growth and maturity habits, yield and fiber quality under a range of soil, salinity and irrigation conditions at Research Center and grower field sites. Field research, including both University of CA Research Center and on-farm trials were utilized to evaluate and provide information to growers, seed companies, breeders and industry personnel regarding variety choice options and other crop management options on cotton growth, yield and fiber quality for Pima, Upland and Acala types of cotton. Research Center Pima, Upland and Acala cotton variety trials and on- farm Pima variety trials focused on yield performance, disease resistance/tolerance (Fusarium wilt and Verticillium wilt), and fiber quality components. This information is utilized widely by seed companies for decisions on regional cotton development and choices, and by growers and associated industry in making production decisions. (2) We are conducting a nitrogen management trial with major funding from the CA Dept of Food and Agriculture FREP program, with supplemental funding from CA Cotton Growers and Ginners Association to evauate nitrogen (N) utilization, uptake and removal with harvest, focused mostly on modern Pima cotton cultivars, including impacts of drip versus flood/furrow irrigation on these measures of utilization. The 2020 production year was the second field research year for this project. A large multi-application level nitrogen fertilizer management trial was conducted with multiple Upland varieties and multiple Pima cotton varieties at the UC West Side REC site, with multiple nitrogen application treatments ranging from 0 to 230 lbs of N/acre, adjusted for residual soil nitrate in the upper root zone. Plant samples were collected at peak biomass production to assess plant partitioning of nitrogen, and seedcotton samples were collected from plots at harvest to determine nitrogen removal with harvest, including separation into seed, lint, and gin trash components. At harvest time at four on-farm Pima variety trial locations across the San Joaquin Valley, whole plant samples and harvest samples were also collected to evaluate partitioning and harvest removal of nitrogen in grower field conditions, different locations and soils. The plant and soil samples have been submitted for analyses, but results have not been provided to date. A third year of the same type of trials are planned for 2021 production year, and results from the nitrogen response trials and nitrogen harvest removal evaluationw will be provided to the industry and to the CA Dept of Food and Agriculture Fertilizer Research and Education program as part of outreach when analyses are completed. . (3) Greenhouse and field evaluations were continued in assessments of relative varietal differences in susceptibility to race 4 of the fungal pathogen Fusarium oxysporum f. spp. vas infectum; including cooperative efforts with a USDA-ARS geneticist and multiple state and international partners to make and test crosses, and evaluate selections for improved tolerance or resistance in Pima and Upland cotton cultivars to race 4 Fusarium oxysporum f. spp. vas infectum. Information on varietal susceptibility and relative mortality due to disease was produced, indicating existence of highly susceptible and highly-resistant varieties in Pima, including commercially-available and experimental entries. 2020 disease resistance screening of commercial seed company/breeder cultivars was accomplished and is being summarized for both FOV-4 and verticillium screening sites in a program aimed at providing independent disease resistance screening, and made available in written form and will also be accessible via a University of CA cotton website (https://cottoninfo.ucdavis.edu) later in January, 2021. We continue to provide field assistance and testing locations for our part of a long-term breeding program conducted in coordination with Dr. Mauricio Ulloa of the USDA-ARS (Lubbock, TX), with this effort directed toward evaluations of host plant resistance to race 4 Fusarium oxysporum in cotton. This work over multiple years has produced a collection of higher resistance experimental selections and crosses that in multiple years (continuing in 2020) have: (1) been grown out for continued evaluation in one or two disease infested fields per year in CA; (2) been evaluated in Texas by researchers in 2019 and 2020 for host plant resistance screens race 4 Fusarium-infested fields in far West Texas; and (3) additional field plots were grown out to increase seed supplies for evaluation of selections with good evidence of improved Fusarium race 4 resistance for further field and greenhouse selection screenings. No new projects were initiated in the reporting period involving water stress or irrigation water salinity responses of cotton cultivars (Upland or Pima) due to limited funding approved for the projects, and personnel limitations due to retirements and lack of new funding for this work.

Publications

• Type: Journal Articles Status: Published Year Published: 2020 Citation: Ulloa, M., Hutmacher, R.B., Schramm, T. et al. Sources, selection and breeding of Fusarium wilt (Fusarium oxysporum f. sp. vasinfectum) race 4 (FOV4) resistance in Upland (Gossypium hirsutum L.) cotton. Euphytica 216, 109 (2020). https://doi.org/10.1007/s10681-020-02643-5
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Diaz, J., Garcia, J., Lara, C., Hutmacher, R.B., Ulloa, M., Nichols, R.L., Ellis, M.L. 2020. Characterization of current Fusarium oxysporum f. sp. vasinfectum isolates from cotton in the San Joaquin Valley of California and Lower Valley El Paso Texas. Plant Disease - First Look. 6 October, 2020. https://doi.org/10.1094/PDIS-05-20-1038-RE
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Ellis, M.L., Garcia, J., Lara, C., Hutmacher, R.B., Ulloa, M., Nichols, R.L. 2020. Genotypic Characterization of Current Field Populations of Fusarium oxysporum f. sp. vasinfectum isolates from California. In: Proc. Beltwide Cotton Conferences, Austin, TX, Jan. 8-1-, 2020.
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Ellis, M.L., Diaz, J.,Hutmacher, R.B., Ulloa, M. 2019. The Past and Current Impact of Fusarium oxysporum f. sp. vasinfectum on cotton production in California. National Cotton Council, Proc. Beltwide Cotton Conf., New Orleans, LA.
• Type: Other Status: Published Year Published: 2019 Citation: Identification and Management of Fusarium Wilt Race 4 of Cotton in Texas and New Mexico. 2019. T. Isakeit, M. Ulloa, R.B. Hutmacher, J. Idowu, R.L. Nichols; Cotton Incorporated web publication. https://www.cottoninc.com/cotton-production/ag-research/plant-pathology/identification-and- management-of-fusarium-wilt-race-4/ UPDATED 2019.
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2020 Citation: Lawrence, K., Hagan, A., Norton, R., Hu, J., Faske, T., Hutmacher, R.B., Mueller, J., Small, I., Grabau, Z., Kemerait, B., Jardine, D., Price, P., Allen, T., Meeks, C., Idowu, J., Thiessen, L., Byrd, S., Goodson, J., Kelly, H., Wheeler, T., Isakeit, T., Mehl, H. 2020. Cotton Disease Loss Estimate Committee Report, 2019. National Cotton Council, Proc. Beltwide Cotton Conf., Austin, TX, Jan. 8-10, 2020.
• Type: Websites Status: Other Year Published: 2020 Citation: Hutmacher, R.B., Munk, D., Marsh, B.H., Weir, B.L., Keeley, M., Angeles, J., Frigulti, T. 2020. Lint Yields, Turnouts - Pima and Upland Cotton Variety Trials, San Joaquin Valley of California: 2019 Field Trials. University of California Division of Agriculture and Nat. Resources. website: https://cottoninfo.ucdavis.edu, 11 pp.
• Type: Websites Status: Other Year Published: 2020 Citation: Hutmacher, R.B., Munk, D., Marsh, B.H., Weir, B.L., Keeley, M., Angeles, J., Frigulti, T. 2020. Fiber Quality Analyses - Pima and Upland Cotton Variety Trial, San Joaquin Valley of California: 2019 Field Trials. University of California Division of Agriculture and Nat. Resources. website: https://cottoninfo.ucdavis.edu, 11 pp.
• Type: Websites Status: Other Year Published: 2020 Citation: Hutmacher, R.B., Munk, D., Marsh, B.H., Weir, B.L., Keeley, M., Angeles, J., Frigulti, T. 2020. Fusarium Disease Screening Analyses for Pima and Upland Cotton Varieties: Multi-Site Trials 2019, San Joaquin Valley of California: Field Screening Results. University of California Division of Agriculture and Nat. Resources. website: https://cottoninfo.ucdavis.edu, 11 pp.