2015 summary project report
TRANSCRIPT
2015 Summary Project Report
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Published as an industry service by the Members of the California Tomato Research Institute, Inc.
California Tomato Research Institute, Inc.
2015 Research Project ReportsProjects are categorized by project type and listed in order of starting date
Use your bookmarks feature to easily navigate to each project.
Agronomic/Water/Nutrient Mgmt. $34,783
AegerterBrennaEvaluation of irrigation practices on water use, soil salinity,and tomato productivity in the Delta
$13,447
MiyaoGeneInvestigation of Sustaining Tomato Plant Health and Yieldwith Composted Manure & Potassium
$7,000
StoddardScottEvaluating the Nitrogen Budget System in Drip IrrigatedProcessing Tomatoes
$6,575
AegerterBrennaPotential for improved fertigation efficiency via field-basedsensing devices
$7,761
Breeding/Genetics/Varieties $15,000
ChetelatRogerTomato Genetics Resource Center $15,000
Insect & Invertibrate Mgmt. $18,146
TuriniThomasEvaluation of Tactics for Improvement of Stink Bug Control $18,146
Pathogen and Nematode Mgmt. $134,870
NuñezJoeEvaluation of Fungicides, & Others for the Control ofSouthern Blight
$6,250
BeckerJ. OleEvaluation of New Nematicides Against Root-knotNematodes in Processing Tomato Production
$27,118
StergiopoulosIoannisDetection of Aazole and Strobilurin Fungicide ResistantStrains of Tomato Powdery Mildew in California
$27,002
GilbertsonRobert L.Curly Top Research: Objectives Relevant to Tomatoes $70,500
MiyaoGeneEvaluation of Chemical Control of Bacterial Speck $4,000
Weed Control and Mgmt. $70,178
SosnoskieLynnBreaking Bindweed: Deciphering Complex Interactions $24,645
HembreeKurtEvaluating Herbicide Carryover in Sub-surface DripIrrigated Tomatoes
$36,703
SlaughterDavidAutomatic Vision Guided Weed Control System forProcessing Tomatoes
$8,830
$272,977
Project Title: Evaluation of irrigation practices on water use, soil salinity, and tomato productivity in the Delta
Project Leaders: Brenna Aegerter and Michelle Leinfelder-‐Miles, Farm Advisors, University of California Cooperative Extension, San Joaquin County, 2101 E. Earhart Ave. Ste. 200, Stockton, CA 95206, phone 209-‐953-‐6100, FAX 209-‐953-‐6128, email: [email protected] and [email protected]
Summary:
In this three year study, we evaluated water use, soil salinity, tomato yields, and fruit quality in Delta
processing tomato fields under furrow and drip irrigation. At the beginning of the study period, Delta
processing tomato growers had not made the transition to drip irrigation as broadly as growers in other
regions of the state, primarily because the performance of drip irrigation systems in the Delta – with its
organic soils, high groundwater table, and salinity concerns – is not well understood. Within the drip
irrigated field, we evaluated two deficit irrigation programs – the grower’s irrigation program and our
own scheme that was more severe than the grower’s cutback. By intensively monitoring soil and water
salinity, our results illustrate how the soil salinity profiles differ between furrow and drip irrigated fields.
The drip irrigated field had a highly decomposed organic matter layer about three feet below the soil
surface, and under both deficit irrigation schemes, salts primarily moved laterally from the drip tape
toward the furrow, and salts accumulated in the organic soil layer. This occurred using relatively good
quality surface water (<1 dS/m) and applying water just short of estimated crop evapotranspiration. The
soil salinity profiles in the furrow irrigated field illustrate that leaching can occur during the season to
keep salts out of the root zone but uneven distribution down the furrow may not make this an effective
leaching strategy. Conversion to drip irrigation, while expensive, reduces or eliminates water discharges,
and in the Delta, also reduces the quantity of water diverted from surface waterways. As growers face
increased scrutiny from agencies and the public over water use, results such as these provide growers
with knowledge on how soil salinity in the root zone is influenced by irrigation systems. Particularly as
growers cannot count on winter rains to leach the soil profile, this project can help inform Delta growers
on whether to make the conversion to drip irrigation systems.
CALIFORNIA TOMATO RESEARCH INSTITUTE, INC. 18650 E. Lone Tree Road
Escalon, California 95320-9759
Project Title: INVESTIGATION OF SUSTAINING TOMATO PLANT HEALTH AND YIELD WITH COMPOSTED MANURE AND POTASSIUM
Project Leader:
Gene Miyao, UC Cooperative Extension 70 Cottonwood Street, Woodland, CA 95695 (530) 666-8732 [email protected]
Ben Leacox, Field Assistant, UCCE Yolo, Solano & Sacramento counties
Summary: Composted poultry manure applications at 5 or 10 tons per acre did not significantly increase yield in any of the two 2015 tests. Placement on the bed top and shallowly incorporated or trenched into the bed for a deeper placement but above the drip tape did not make a difference in these tests. Placement evaluations were weak due to either 1) high soil K levels or 2) high disease pressure at the test sites. As a result, the comparison was not enlightening.
Potassium (KCl) applications increased yields from 6 to 16% in 2 of the 4 tests. These fields had soil K levels from 144 to ~170 ppm with K levels from 1.9 to 2.2% of the cation exchange.
At a field site with K levels at 219 ppm and 3%, as expected, no yield response was observed and tissue K levels were similar to the non-supplemented control.
The results continue to support that yield increases likely occur in soils with potassium levels below 200 ppm using an ammonium acetate extraction method and in combination with potassium levels not exceeding 2% on the cation exchange capacity, as a secondary indicator.
2015 Research Summary Report Nov 10, 2015 Project Title: EVALUATING THE NITROGEN BUDGET SYSTEM IN DRIP
IRRIGATED PROCESSINC TOMATOES Project Leader:
Scott Stoddard, UC Cooperative Extension 2145 Wardrobe Ave. Merced, CA 95340 209-385-7403; cell: 209-777-7645 [email protected] SUMMARY A nitrogen rate trial was conducted in drip irrigated processing tomatoes cv H9663 to evaluate the use of soil nitrate testing to guide N fertilizer applications. Treatments were 75, 125, 175, 225, and 275 lbs N/A, plus one variable rate treatment based on soil testing. Treatment design was a randomized block with 4 replications; plot size was 1 bed by 125 ft. Soil samples were taken to a depth of 12” every 10 days during the growing season; leaf and petiole samples were taken at the same time to monitor N in the crop. Using soil NO3-N delayed the start of nitrogen fertilizer applications and limited the total amount to 135 lbs N/A. Nonetheless, leaf N was within sufficiency guidelines throughout the growing season. Tomato yield was increased over the 75 lbs/A treatment, but less than the yield from highest N rate. The results suggest that soil nitrate testing was a useful tool to determine the timing of applying N fertilizer in drip irrigated processing tomatoes, but may have underestimated the N requirements in this location. Multiple sample events may be needed throughout the growing season.
Potential for improved fertigation efficiency via field-‐based sensing devices
Project Leader:
Brenna Aegerter, Farm Advisor, UC Cooperative Extension San Joaquin County, 2101 East Earhart Ave. Suite 200, Stockton, CA 95206-‐3924 (209) 953-‐6114, [email protected]
Project Collaborators:
Mark Lundy, formerly UC Cooperative Extension Colusa, Sutter, and Yuba counties, and as of October 1, CE Specialist, Dept. Plant Sciences, University of California, Davis, CA 95616 (530) 752-‐7724, [email protected]
Martin Burger, Project Scientist, Dept. Land, Air and Water Resources, University of California, Davis, CA 95616 (530) 754-‐6497, [email protected]
Summary
We have collected data from four commercial processing tomato fields in 2014 and 2015 where surface renewal evapotranspiration (ET) stations were installed. In addition to the ET data, we have developed nutrient uptake curves from whole plant sampling, as well as measurements of normalized difference vegetation index (NDVI) from both a handheld meter and from aerial imagery (the latter in 2015 only). As it turned out, two of the sites ended up being high-‐yielding, while the other two were low-‐yielding. These two categories of sites were easily separated based on nutrient uptake rates, percent K in the vegetative plant parts, and the NDVI curves. Our study does not have yet have firm conclusions, but we continue to gauge the utility of these technologies to growers and evaluate whether we might improve the efficiency of nutrient applications by scheduling fertigations based on crop measurements (ET or NDVI) rather than on the number of days or weeks after transplant.
Objective
The goal of this research is to explore the use of two field-‐based measurement devices to inform more precise management of water and nutrients in subsurface drip-‐irrigated processing tomatoes.
Project Title: C. M. Rick Tomato Genetics Resource Center
Project Leader: Roger T. Chetelat Department of Plant Sciences University of California Davis, CA 95616 Acquisitions. The TGRC acquired no new accessions this year. We recovered one accession of S. cheesmanii that had formerly been listed as ‘inactive’. Obsolete or redundant accessions were dropped. The current total of number of accessions maintained by the TGRC is 3,833. Maintenance and Evaluation. A total of 1,762 cultures were grown for various purposes, of which 492 were for seed increase (85 of which were of wild species) and 661 for germination tests. Progeny tests were performed on 141 stocks of segregating mutants (e.g. male steriles, homozygous lethals, etc) or various lines with unexpected phenotypes. 170 stocks were grown for introgression of the S. sitiens genome. Other stocks were grown for research on interspecific reproductive barriers. Newly regenerated seed lots were split, with one sample stored at 5° C to use for filling seed requests, the other stored in sealed pouches at -18° C to better maintain long term seed viability. Backup samples of 239 seed lots were submitted to the USDA Natl. Center for Genetic Resources Preservation in Colorado, and 70 were sent to the Svalbard Global Seed Vault in Norway. Distribution and Utilization. A total of 7,041 seed samples representing 2,384 unique accessions were distributed in response to 355 requests from 258 researchers and breeders in 31 countries; at least 18 purely informational requests were also answered. The overall utilization rate was 184% (i.e. number of samples distributed relative to the number of active accessions), an exceedingly high activity for any genebank, and proof that our collection is heavily used. Information provided by recipients indicates our stocks continue to be used to support a wide variety of research and breeding projects. Our annual literature search again uncovered a large number of publications mentioning use of our stocks. Documentation. Data on accessions, genes, images, seed inventory and seed requests were regularly updated. New images, with captions, were added. New seed lots were inventoried, and the quantities of seed available in existing seed lots was updated to reflect current supply. Our database was modified in various ways to improve internal record keeping and work flow. We now link PQ numbers to seed lot information to facilitate online requests for phytosanitary certificates for large requests. A revised list of miscellaneous genetic stocks was published in the Tomato Genetics Cooperative Report (http://tgc.ifas.ufl.edu). Research. The TGRC continued research on the mechanisms of interspecific reproductive barriers and on introgression of the S. sitiens genome. We published a paper on the cloning of a major pollen incompatibility gene, ui1.1, and submitted a paper on natural variation for pollen incompatibility genes in S. habrochaites. We published a method for hybridizing cultivated tomato with S. sitiens, a potential source of tolerance to low temperatures, drought and salinity. (Strong crossing barriers had previously been deterred use of this species for tomato improvement.) We further advanced a set of breeding lines representing the genome of S. sitiens in a cultivated tomato background. Our goal is to develop a set of ‘introgression lines’ – prebred stocks containing defined chromosome segments from the donor genome – that will provide the first breeder friendly germplasm resources for this wild species.
(For full report, go to http://tgrc.ucdavis.edu/reports.aspx)
Research Project Report California Tomato Research Institute
18650 Lone Tree Rd., Escalon, CA 95320 Project Title: Evaluation of tactics for improvement of stink bug control Project Leader: Thomas A. Turini University of California Agriculture and Natural Resources Vegetable Crops Farm Advisor in Fresno County
550 E. Shaw Avenue, Suite 210 Fresno, CA 93710 Tel: (559) 375-3147 Email: [email protected]
Co-Primary Investigators: Frank Zalom Dept. of Entomology and Nematology Univ. of California Davis, CA 95616 Tel: (530) 752-3687 Fax: (530) 752-1537 Email: [email protected]
Peter B. Goodell, PhD Cooperative Extension Advisor, Integrated Pest Management UC Statewide IPM Program 9240 So Riverbend Ave Parlier CA 93654 559/646-6515 office 559/646-6593 - fax [email protected]
SUMMARY Populations of Consperse stink bug, Euschistus conspersus, were moderate in much of Fresno County in 2015 and were present at levels resulting in noticeable feeding injuries in many area, particularly in those with a history of damage. However, by comparison with 2013 and 2014 levels of injury, 2015 had lower levels. Stink bugs in diapause were detected in Fall 2014 near an infested late-season tomato field. They were detected alone or in small groups of up to 16 in damp leaf litter. The area seems to be somewhat isolated and it does not extend throughout the permanent crop in which it was detected. In early 2015, stink bugs were first captured in pheromone-baited traps in mid-April. They reached detectable levels in a few commercial fields in May. While the earliest detections of stink bugs were in traps, the traps failed to consistently represent the population densities present in the canopy at later stages of population development. Populations densities were very high insecticide trials conducted at the West Side Research and Extension Center and levels of damage were substantial. In insecticide efficacy trials, only treatments with lambda cyhalothrin (Warrior II) showed substantial reductions of stink bug damage. Drip applied neonicotinoid insecticides did not reduce damage done by stink bug. OBJECTIVES
• Document sources of stink bug and seasonal population dynamics in Central CA processing tomatoes
• Assess efficacy of insecticides and insecticide rotations against Consperse stink bug
Title: Evaluation of Fungicides, Bio-Pesticides and Soil Amendments for the Control of Southern Blight of Processing Tomatoes. Project Leader: Joe Nunez, Vegetable/Plant Pathology Advisor, UC Cooperative Extension, 1031 So. Mount Vernon Ave., Bakersfield, CA 93307. Office: 661-868-622, fax: 661-868-6208, Email: [email protected] Summary: A canopy lifter/sprayer implement was constructed that could lift a fully developed tomato canopy while moving down the row and spray fungicides on top of the 60 inch bed and at the base of the tomato plant. A trial was conducted at a grower’s field with a history of southern blight to test the effectiveness of applying various fungicides with the canopy lifter/sprayer from mid to late season for the control of southern blight of tomato. Four applications were made at a 3 week interval from 6/16/15 to 8/18/15. On 8/31/15 five plants per plot was dug up and rated for southern blight infection. The trial was heavily infected with curly top virus which made evaluation of the trial difficult. Due to the trial’s overwhelming infection with curly top virus there were very few plants with any southern blight. Therefore there were no differences among fungicide treatments from the non-treated control in regards to southern blight control. Introduction and Objectives: In the past several seasons there have been growing reports of tomato processing fields severely infected with southern blight in the Southern San Joaquin Valley. Yields of processing tomatoes infested with southern blight are often severely reduced. Often fields will be left out of tomato production due to the incidence and severity of southern blight.
Research Project Report 2015 California Tomato Research Institute, Inc. 18650 Lone Tree Rd., Escalon, CA 95320
Project Title: Evaluating the next generation of nematicides
Project Leaders: J. Ole Becker, Department of Nematology, 1463 Boyce Hall, UC Riverside, CA 92521, (951) 827 2185, [email protected]
Antoon Ploeg, Department of Nematology, 1463 Boyce Hall, UC Riverside, CA 92521, (951) 827 3192, [email protected]
Joe Nunez, UCCE Bakersfield, CA
Summary: Tomato field trials with root-‐knot nematode-‐susceptible cultivar Halley 3155 were
conducted at the University of California South Coast Research and Extension Center (SCREC) and at Shafter to evaluate the efficacy of several novel soil nematicides on the Southern root-‐knot nematode Meloidogyne incognita (rkn) population development and their effect on plant health as well as crop yield. The products were applied at different rates, times, or formulations according to the manufacturer's recommendation. A non-‐treated check served as a control. By the middle of the season at SCREC, the three nematicides Nimitz, BCSAR83685, and Dp1 showed good efficacy against rkn as indicated by a root gall rating. Mitigation of galling was observed in some treatments until harvest. Although average yield increased in some of the nematicide treatments by up to 20% over the non-‐treated control, due to considerable variability within replications, none of the treatments differed significantly from the control.
The rkn infestation at the Shafter trial was higher than at SCREC, which in combination with warmer soil temperatures in the Central Valley resulted in considerably higher disease pressure. Only BCSAR83685 and Dp1 showed a convincing performance; efficacy of Nimitz was less than in recent years. As at SCREC, overall nematicide treatments increased average yield but did not test significantly different among the treatments. Introduction and objectives Root-‐knot nematodes in CA processing tomato production have been responsible for an estimated 10-‐20% yield reductions, despite the wide-‐spread use of resistant tomato cultivars or nematicides (Koenning et al, 1999). Disease damage can be in part attributed to secondary fungal pathogens and associated microbes that accelerate root tissue senescence and root death. The increasing occurrence of Mi-‐1 gene resistance-‐breaking root-‐knot nematode strains in CA processing tomato production fields (Roberts, 1995, Kaloshian et al., 1996, Williamson and Kumar, 2006) is considered a growing problem not only because of the yield damage potential to the individual farmer but the danger of wider dissemination of these strains.
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CALIFORNIA TOMATO RESEARCH INSTITUTE
18650 Lone Tree Rd, escalon, CA 95320
ANNUAL REPORT 2015
Project Title:
Monitoring of azole and strobilurin fungicide resistant in
tomato powdery mildew
Project leader:
Ioannis Stergiopoulos
Assistant Professor, Department of Plant Pathology, University of California Davis
578 Hutchison Hall, One Shields Avenue, Davis, CA 95616-8751
Phone: 530-400-9802, fax: 530-752-1199
email: [email protected]
Project Collaborators:
Brenna Aegerter
Cooperative Extension Farm Advisor, UCCE, San Joaquin County
2101 E. Earhart Ave. Ste. 200, Stockton, CA 95206
Phone: 209-953-6100, fax: 209-953-6128
email: [email protected]
Gene Miyao
Cooperative Extension Farm Advisor, Yolo-Solano-Sacramento counties
70 Cottonwood Ave., Woodland, CA 95695
Phone: 530-666-8732
email: [email protected]
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Abstract
Powdery mildews are obligate biotrophic fungi that cause extensive diseases in crops. In tomato, powdery mildew infections are caused by the species Leveillula taurica and Oidium neolycopersici, which are associated with the disease in field and greenhouse grown tomatoes, respectively. Control of the disease
mainly relies on the use of sulfur-dusts and chemical control agents such as strobilurin (QoI) and azole fungicides. However, the continuous use of fungicides increases the danger for fungicide resistance development and in 2014 we have reported that strains with mutations that confer resistance to QoI
fungicides, such as the notorious G143A substitution that leads to complete resistance, are already present in California. Based on these findings, the goals in the current study were first, to monitor the frequency and spread in California of L. taurica strains with potential resistance to azole and strobilurin fungicides,
and second, to conduct fungicide field trials in order to evaluate the degree to which currently used fungicide products select for more resistant strains. Our studies showed that strains with the G143A mutation in cytb that confers high levels of resistance to strobilurin fungicides are abundantly present in the fields. However,
in most cases resistance was associated with mitochondrial heteroplasmy for the cytb gene, suggesting that it is not yet complete but rather correlates with the portion of mitochondria in each strain carrying the mutated cytb allele. Furthermore, we have seen a gradual increase over the growing season in the number
of strains carrying higher rates of the mutated G143A allele, suggesting selection for more resistant phenotypes.
2015 Annual Progress Report Project Title: Improved understanding of beet curly top disease and new approaches for disease management Project Leader: Robert L. Gilbertson, Professor of plant Pathology Department of Plant Pathology University of California-Davis Davis, CA 95618 Phone: 530-752-3163 E-mail: [email protected] Cooperating personnel: Li-Fang Chen, Ozgur Batuman, Maria Rojas, and Tom Turini Introduction:
In 2015 we continued our research on curly top disease in processing tomato in response to the 2013 outbreak, which caused losses of ~$100 million. We continue to try to better understand the factors that resulted in this outbreak and to find ways to minimize these outbreaks in the future. One of the ways we are doing this is through the application of new biotechnological tools for detecting BCTV (PCR and DNA sequencing) and screening plants for resistance to BCTV (agroinoculation) allows for new approaches to disease management. The long-term goal of this research is to develop an effective curly top virus integrated pest management strategy that targets multiple points in the disease cycle rather than only one (the leafhopper vector).
Our curly top research continues to focus on objectives that specifically involve tomatoes (funded by the CTRI) and objectives that address crops other than tomato (funded by CDFA through the Curly Top Virus Control Board). The objectives of the CTRI-funded curly top virus research are to 1) continue to search for and assess resistance to curly top in a tomato breeding line and other tomato germplasm possessing genes known to confer resistance to whitefly-transmittted geminiviruses (i.e., the Ty genes), 2) assess the level of curly top in processing tomatoes in 2015 and determine the BCTV strains that are involved and 3) assess the potential for developing novel strategies for interfering with leafhopper feeding on tomato plants.
Page 1 of 4 California Tomato Research Institute
CALIFORNIA TOMATO RESEARCH INSTITUTE, INC. 18650 E. Lone Tree Road
Escalon, California 95320-9759
Project Title: EVALUATION OF CHEMICAL CONTROL OF BACTERIAL SPECK
Project Leader(s)
Gene Miyao, UC Cooperative Extension 70 Cottonwood Street, Woodland, CA 95695 (530) 666-8732 [email protected] Janet Caprile, UC Cooperative Extension 75 Santa Barbara Road, 2nd Floor Pleasant Hill, CA 94523-4215 [email protected]
Brenna Aegerter, UC Coop Ext. 2101 E. Earhart Ave, Suite 200 Stockton, CA 95206-3924 [email protected]
Objectives: Evaluate foliar applications of chemicals for bacterial speck control.
Background: Bacterial speck is often a problem when rainy, cool weather conditions persist in the spring. Control is challenging especially when multiple rain events trigger the onset and development of the disease. Plant resistance that once was effective has been near completely overrun. Most spray control programs are based around the use of copper, which has provided moderate control at best.
Procedures: Two field tests were established: one in Brentwood/Byron area with Simoni and Massoni and the other at Armstrong on the UC Davis campus.
Materials included Kocide, Dithane, Actigard, Oxidate, Regalia, Agriphage and Serenade Max. All included copper as a tank mix except the phage treatment. Multiple applications were made during the season. Sprays were applied with hand-held equipment. A non-ionic surfactant was added.
Disease development was minimal at the Brentwood site with a fruit yield assessment abandoned, as a result. At UC Davis site, the disease level was moderate.
The Davis site was transplanted on March 26th with variety BP2 on single plant lines on beds centered on 5 feet. Sprinklers were used initially to establish the stand. Thereafter, irrigation was by an off-centered, surface, drip system. Treatment applications were initiated on April 4 and were repeated last on June 5th for a total of 5 applications.
At Davis, a timer-controlled, microsprinkler irrigation system kept foliage intermittently wet using short durations, multiple times during the evening to encourage disease development. The pathogen was post treatment sprayed on 2 occasions to inoculate plants. Rainy conditions at the test sites alone were not sufficient for disease development in 2015.
Page 2 Bacterial speck control
Bacterial speck infection occurred in first week of May, 6 weeks after planting during early flowering and progressed moderately. Some plant stunting occurred. Results: At the 1st disease rating, infection level was 16% in the nontreated controls. Treatments with similar disease levels as the controls were Agriphage and Oxidate, at 16 to 17%. In a second rating 2 weeks later, the best treatments were: Actigard-Kocide, Kocide alone, Regalia-Kocide, SerenadeMax-Kocide, Dithane-Kocide, and Oxidate-Kocide. Marketable fruit yield was variable. Two pairs of nontreated controls were included in the trial design that illustrated the high variation within the test (with an average of 32.6 vs 24.7 tons per acre). Mean separation among treatments was poor. The highest arithmetic average yield was from treatment Kocide alone at 39.3 marketable tons per acre and 51.2 total fruit biomass tons/A. Fruit quality parameters of color, Brix and pH were statistically similar to each other. Level of immature green and pink colored fruit was high. Fruit ripening was slow at this site. Further delaying the harvest would have increased the level of rots as a trade off. Our test was not able to demonstrate treatment combinations that improved bacterial speck control substantially over the copper treatment of Kocide.
TITLE: Breaking bindweed: Deciphering the complex interactions among weed, water, herbicide and crop to improve Convolvulous arvensis control in processing tomato. PROJECT LEADER: Lynn M. Sosnoskie, Assistant Project Scientist 259 D Robbins Hall, University of California - Davis Department of Plant Sciences, MS-4 One Shields Avenue Davis, CA 95616 (229) 326-2676 [email protected] CO-PI: Bradley D. Hanson, Extension Weed Specialist 276 Robbins Hall, University of California - Davis Department of Plant Sciences, MS-4 One Shields Avenue Davis, CA 95616 (530) 752-8115 [email protected] BUDGET TOTAL: $24,645
SUMMARY:
Field bindweed (Convovulous arvensis) is a deep-rooted perennial that is difficult to control once it has become established. Greenhouse and field studies were conducted in 2015 to address two of the CTRI’s 2015 Research Priority areas (1) Weed Control (e.g. field bindweed) and (2) Agronomy and Soil/Water Management (e.g. transplant quality, crop safety, and implications of drip irrigation on crop and pest development).
By Objective: Objective 1. Evaluate the efficacy of sub-surface applications of trifluralin (Treflan) for
the suppression of more deeply buried field bindweed rhizomes. Results: Trifluralin applied broadcast using spray blades positioned at a depth of 4 inches below the surface of the bed top significantly reduced field bindweed cover in the treated plots; however, significant crop injury resulted which also compromised yield. The study will be repeated in 2016 to evaluate the timing of spray blade applications, relative to tomato planting, on crop injury and bindweed suppression.
Objective 2. Describe how the residual activities of pre-emergence/pre-plant
incorporated herbicides applied for bindweed control are affected by irrigation strategy. Results: Field bindweed cover in the untreated plots ranged from 30-50% at 1 week after treatment to 90-100% at 4 weeks after treatment. At 3 to 4 weeks after treatment, weed cover
in the S-metolachlor-, rimsulfuron-, and sulfentrazone-treated plots ranged from 50 to 80% in the furrow- and drip-irrigated systems; in the sprinkler-irrigated plots, field bindweed cover did not exceed ~40% in any of the herbicide treatments. Although drip-irrigation can reduce labor costs, prevent some disease development, improve water use efficiency, and aid in weed control efforts by reducing surface wetting and, therefore, weed seed germination, it is not effective at activating many residual herbicides. Growers with significant field bindweed problems should be mindful of how their irrigation protocols may affect herbicide performance
Evaluate the use of a commercial ethylene inhibitor to reduce transplant shock in
tomato and improve early-season crop competitiveness relative to field bindweed. Results: There were no differences in the growth and development of untreated tomatoes and tomatoes that were drenched with a 50 ppm solution of 1-MCP 24 hours prior to transplanting on 10 April. For tomatoes that were planted in May, the use of a 1-MCP drench treatment reduced fruit yields by 16%. Conversely, for tomatoes planted in June, 1-MCP improved weights by 25%. The disparate results among planting dates were attributed to local environmental conditions following transplanting. In May, the use of a 1-MCP drench reduced tomato yields; 25 of 31 days in May experienced daily temperatures that were at or below the 20 year average. The use of a 1-MCP drench in June-planted tomatoes improved mean plant yields; according to archived weather data, 20 or more days in June were at or above the 20 year record. Studies will be repeated in 2016 to evaluate the effects of growth regulators on crop competitiveness and yield.
Describe the interactions between glyphosate and divalent metals; specifically, evaluate
the potential for using foliar micronutrient fertilization to prevent or correct glyphosate drift injury. Results: In general, applications of Zn or Mn plus Zn prior (PRE) to glyphosate reduced tomato injury at 14 days after treatment, but were unable to completely mitigate herbicide damage. Studies will be conducted in the field in 2016 to evaluate the effects of glyphosate and foliar micronutrient applications on crop yield in a commercial setting
Project Title: Evaluating Herbicide Carryover in Sub-surface Drip-irrigated Tomatoes Project Leader: Kurt Hembree, Farm Advisor, UCCE, Fresno County
550 East Shaw Ave., Suite 210-B, Fresno, CA 93710 Office phone: 559-241-7520; Cell phone: 559-392-6095 Email: [email protected]
Co-investigator: Tom Turini, Farm Advisor, UCCE, Fresno County
550 East Shaw Ave., Suite 210-B, Fresno, CA 93710 Office phone: 559-241-7529; Cell phone: 559-375-3147 Email: [email protected]
Summary: In this study, detectable amounts of pre-plant herbicides in the soil was influenced by herbicide active ingredient and method of irrigation used. After the initial herbicide treatment in 2013, about 0.15 ppm of pendimethalin remained in the soil after harvest, while no trifluralin could be detected. Also, it appeared that adding sprinkler irrigation water helped to dissipate herbicides better, especially in the upper 3″ of soil, compared to where only drip irrigation was used, but it did not eliminate residues completely. Following winter, and before herbicides were re-applied in 2014, 1/3 (or 0.005 ppm) of the pendimethalin found at harvest in 2013 still remained in the soil profile, indicating some carryover occurred. Trifluralin did not appear to carryover into the next season as pendimethalin did. We had less than 3″ of total rainfall during winter in 2013/14 which probably did not help breakdown pendimethalin residues further. However, this amount of herbicide carryover did not negatively affect tomato plant growth or yield. By harvest 2014, pendimethalin was found in the upper 3″ of soil at 0.15 to 0.30 ppm (nearly twice that found in 2013 at the same time). Trifluralin was also found at slightly higher levels (0.05 ppm) than in 2013. We could not tell if there was more or less herbicide detected before treatment in 2015 than 2014 since we were unable to statistically analyze 2015 samples. While data was not analyzed in 2015, plant growth and yields looked similar to that in the previous two seasons. Since we were not seeing a negative impact on tomato health or production after a relatively low level of herbicide carryover into 2014, it is still not clear if excessive herbicide carryover explains what we were observing in grower fields. Injury observed in those damaged fields is more likely attributed to plants either being planted too shallow, or herbicides incorporated too deep. In either case, one would expect to see injured tomato plants under those conditions based on prior experiences with some pre-plant herbicides like trifluralin or pendimethalin. Perhaps tilling the soil more deeply and frequently, along with planting deeper, will help resolve this issue, as was done in previous years before buried drip was introduced.
Project Title: Automatic Vision Guided Weed Control System for Processing Tomatoes Principle Investigator: David C. Slaughter, Professor
Biological & Agricultural Engineering Department University of California Davis, CA 95616 (530) 752-5553 [email protected]
Cooperators: Steven Fennimore, Ken Giles, Thuy Nguyen, Burt Vannucci, Leland Neilson,
Ryan Billing, and Vivian Vuong, University of California, Davis
Abstract/Summary: The overall goal of this project is to develop a novel computer-vision guided technique for automating weed control in processing tomato. The specific objective of this project for 2015 was to develop a field prototype for the computer vision portion of the automated machine. This computer vision system will be used to automatically control the pair of within-row mechanical weed hoes shown in figure 1.
Figure 1. High-speed miniature hoe system for automated within-row weed control. Our team at UC Davis has developed a novel technology for creating a unique crop marking system that allows a computer vision system to readily distinguish tomato plants from weeds, including nightshade. This new technology does not involve use of biotechnology or transgenes. Experimental trials conducted on the UC Davis campus farm show that the new method for high-speed machine vision recognition of transplanted processing tomato plants when grown outdoors in the field, has a success rate approaching 100%.
Background: Previous methods of using computer vision for automated weed control in row crops are typically based upon simplistic approaches, such as defining the crop as the largest green object in the view or by defining weeds to be the plants that are not growing in a grid-like plant spacing. While these methods can sometimes be successful under ideal conditions, they are not reliable when used on a real farm. The novel approach developed at UC Davis uses a much more robust approach at automatic computer recognition of the crop through the implementation of a technique called crop signaling. In crop signaling, a unique, visual crop identifier is applied to the crop at planting, since at this time there is no ambiguity in identifying the crop plants. The signal persists until the time when hand weeding is required. In this case, the computer vision system is then designed to search for the plants possessing the unique crop signal and identifies them as tomato plants.
Results:
Several crop signaling materials were evaluated in 2015 and we were successful in identifying materials that met the performance objectives of: sufficient signal to noise ratio to allow highly accurate discrimination between the crop signal and weeds, is non-toxic when applied to crop plants, and has a minimum signal effectiveness lifetime of six to eight weeks. When available, different formulations of the materials were also evaluated and their environmental robustness (e.g. resistance to signal degradation) was compared when exposed to the natural outdoor environment of a farm in California for the target lifetime of six to 10 weeks post germination. Three implementations of the crop signaling technology were successfully developed and two of which were tested in tomato fields in on the UC Davis campus in the 2015 growing season and the third was tested in the laboratory. Crop signaling implementations designed for conventional and organic production were both tested in 2015. In-field, signal degradation rates for each field implementation method was characterized, and two formulations of the material were found to meet the target in-field performance objectives. Field results show that signal degradation rates of the best materials were acceptable, below 0.5% per day, under full sun and sprinkle irrigation exposure with degradation under drip irrigation being slightly superior (i.e. less degradation) to sprinkle irrigation treatments. Both implementations are compatible with existing transplanting technologies. Two prototype computer vision systems were constructed and tested in the field. In the final design tested in 2015, computer vision recognition of the tomato plants with crop signaling technology was excellent at 3 weeks after planting, and continued to perform with nearly 100% accuracy up until canopy closure along the row. The final design included both gigabit speed digital camera technology as well as robust solid-state illumination control, optimized to maximize the signal to noise levels of the crop signaling technology used in the field. In field trials, the signal strength was sufficient to allow the computer vision system to travel at speeds above 2 mph, meeting the economic target for an automatic intra-row weeding machine established in 2012.