Source: UNIVERSITY OF CALIFORNIA, DAVIS submitted to NRP
DEVELOPMENT AND ASSESSMENT OF ALTERNATIVE PRE-PLANT FUMIGATION STRATEGIES FOR NUT CROPS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
OTHER GRANTS
Reporting Frequency
Annual
Accession No.
0196988
Grant No.
2003-51102-02055
Cumulative Award Amt.
(N/A)
Proposal No.
2003-04591
Multistate No.
(N/A)
Project Start Date
Sep 1, 2003
Project End Date
Aug 31, 2006
Grant Year
2003
Program Code
[112.C]- (N/A)
Recipient Organization
UNIVERSITY OF CALIFORNIA, DAVIS
410 MRAK HALL
DAVIS,CA 95616-8671
Performing Department
INTERDEPARTMENTAL
Non Technical Summary
The methyl bromide (MB) phaseout presents nurserymen and growers of perennial fruit and nut crops with unique challenges. Although both perennial and annual cropping systems use MB to control a similar mix of pest and disease problems, only the perennial systems involve long production cycles, deep rooting, and low plant densities. MB provides critical control of weeds at perennial crop nurseries and minimizes risk due to nematode pests, known fungal pathogens, and unknown biological factors that cause "replant disease" in nurseries and orchards. There is a general shortage of objective economic data to evaluate efficacy of MB alternatives for perennial crops. The research proposed here involves an interdisciplinary team to assess and demonstrate efficacy of the most promising short-term MB alternatives for use in almond and walnut nursery and orchard systems. Adaptations of the nursery treatments will be tested in commercial almond orchards for control of replant problems. Results of these experiments may provide a basis for reduction in fumigant usage and cost savings in many stone fruit and nut orchards by restricting the area treated to tree sites or row strips. Cost-benefit analyses will be used to determine the overall economic value of MB alternatives for perennial crop nurseries and orchards. Field demonstrations and oral and written reports will be used to demonstrate the results to clientele and facilitate related technical information exchange.
Animal Health Component
65%
Research Effort Categories
Basic
35%
Applied
65%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2051212102015%
2051213102010%
2121212112015%
2121212116015%
2121213112010%
2121213116010%
2131212114015%
2131213114010%
Knowledge Area
212 - Pathogens and Nematodes Affecting Plants; 205 - Plant Management Systems; 213 - Weeds Affecting Plants;

Subject Of Investigation
1212 - Almond; 1213 - Walnut;

Field Of Science
1120 - Nematology; 1160 - Pathology; 1140 - Weed science; 1020 - Physiology;
Goals / Objectives
Objectives 1. To determine effects of promising short-term MB alternatives on vegetative performance of almond and walnut nursery stock at commercial nurseries. 2. To determine effects of the alternatives on weed, nematode, and disease incidence at commercial nurseries. 3. To determine effects of promising short-term MB alternatives on health and productivity of replanted almond trees in commercial orchards. 4. To determine relative benefits of tree-site, row-strip, and broadcast treatments with the alternatives in commercial almond orchards 5. To complete cost-benefit analyses for the MB alternatives at commercial almond and walnut nurseries and almond orchards. 6. To demonstrate the performance of promising MB alternatives to the nurserymen and orchardists and provide them with the key biological and economic information that they need for efficient transition to alternative fumigation strategies.
Project Methods
Four nurseries have been identified for experiments. In August or September 2003 pre-plant fumigation treatments will be applied for one almond nursery trial and one walnut nursery trial. The pre-plant treatments will include a non-fumigated control, methyl bromide-chloropicrin standard (400 lb/A), iodomethane (235 lb/A), Telone (560 lb/A) and Telone plus metam sodium (560 lb/A and 200 lb/A). Pest and pathogen bioassays will be conducted to help determine efficacy of the nursery treatments. Citrus nematode and Pythium ultimum will be buried in nylon bags and tested for viability after treatment. Native nematode populations will be documented for each plot before and after fumigation. Samples of weed species that are perceived to be important problems in nurseries will be buried in small bags in each plot at depths of 1" and 6" before fumigation. After the treatments, the weed samples will be retrieved, and tested for viability. After pre-plant fumigation in August 2003, the nursery plots will be planted with Nemaguard peach rootstock seeds for almond and Northern California black or Paradox hybrid walnut rootstock seeds for walnut. The following spring the peach rootstock will be budded to almond of several different cultivars. The finished almond trees will be dug in November to December 2004. The walnut seedlings will be budded to English walnut in the fall or grafted to English the following spring and dug in fall 2005. The almond and walnut nursery tests will be repeated in the same manner starting one year later (August 2004) at two different nurseries. For each of the nursery trials, midday stem water potential will be monitored periodically during the growing season. The measured values will be compared with standard baseline values for adequately watered almonds and walnuts. The comparisons will used to achieve proper irrigation management and help assess effects of the pre-plant treatments on tree water status. Native weed populations and weed control costs will be documented in the nursery plots in late fall, mid-winter, early spring, early summer, and late summer. Two quadrat (0.5m2) samples will be taken in each plot. The number of weeds will be counted in each sample and recorded by species. The amount of time and cost required for manual control of weeds in each treatment will also be determined by monitoring all weed control costs for each plot. Economic cost-benefit analyses will be completed for each of the nursery experiments and will consider all changes in costs and marketable product yield associated with each treatment. The almond experiments are designed to test three factors: 1) fumigant, 2) treated area/ application method, and 3) use of VIF plastic mulch (for row-strip treatments only). Each almond orchard experiment will include 18 treatments, arranged in a randomized complete block design with four replicate plots per treatment. In each experiment, orchard fumigation treatments will be applied in the fall (September to November) and planted with trees (almond on Nemaguard peach seedling rootstock) in the winter (January).

Progress 01/01/06 to 12/31/06

Outputs
The first almond nursery trial was harvested in January 2005. The walnut nursery trial planted in 2003/4 in Yuba County was harvested in December 2005. During 2004//05 two additional nursery trials were fumigated and planted. Overall, each of the fumigation treatments exhibited similar efficacy in the nursery trials At nursery trial 1 (almond on loam soil), all fumigants provided good control of bagged nematodes and Pythium. The untreated control was significantly smaller in diameter but did not produce significantly less marketable trees. At nursery trial 2 (walnut on clay loam soil), seedling emergence in the untreated control was significantly less than the Telone C35 treatment. Diameter growth was significantly greater in the untreated control compared to all fumigants, but this was likely due to lower plant density and resulting improved light and water conditions. At nursery trial 3 (almond on clay loam soil), emergence was significantly less for the control compared to Telone C35. All fumigants provided good control of bagged nematodes and Pythium at shallow depths, but only methyl bromide and iodomethane/chloropicrin provided decent control of Pythium at lower depths. In nursery trial 4 (almond on loam soil), all fumigants provided good control of bagged nematodes and Pythium except iodomethane/choloropicrin and Inline at the lower depths. Both of the orchard trials are located in Madera County on loam soils. Growth was better in the fumigated plots at the almond following almond replant site but not at the almond following grape site. At the almond following almond trial, all of the chloropicrin containing fumigants had significantly greater growth and yields than the control. Water stress at this site accentuate negative effects of lack of fumigation. In the almond following grape trial, there were no significant growth differences and only Telone II with VIF tarp had a significantly lower yield than the control. There was a large interaction of irrigation and fumigation. When trees were water stressed (at Nursery Trial 1 and Orchard Trial 1), midday stem water potentials dropped off more rapidly in the control and methyl bromide treatments compared to the Telone C35, iodomethane/chloropicrin and chloropicrin treatments.

Impacts
In the third year of the project, information was extended at the Walnut Conference in Bodega Bay, at the 2006 International Conference on Methyl Bromide Alternatives and Emissions Reduction in Orlando, Florida and at the Almond Conference in Modesto. The data on efficacy of methyl bromide alternatives generated will be of much interest to the tree nursery industry as well as growers. The methyl bromide phaseout presents unique challenges for growers of perennial fruit and nut crops. Results of the orchard experiments and the related soil characterizations may provide a basis for reduction in fumigant usage and cost savings in stone fruit and nut orchards by restricting the area treated to tree sites or row strips.

Publications

  • Browne, G., D.Doll, L. Schmidt, J. Connell, B. Holtz, S. Upadhyaya, B. Lampinen, D. Kluepfel, and S. Schneider 2006. Prunus replant disease in California and its management without methyl bromide. 2006 Annual International Conference on Methyl Bromide Alternatives and Emissions Reductions. Nov. 6-9, 2006. The Doubletree Hotel, Orlando, Florida. pp. 61-1 to 61-4.
  • Lampinen, B., G. Browne, S. Schneider, A. Shrestha, B. Holtz and L. Simon 2006. Alternative pre-plant soil fumigation treatments for deciduous tree crops. 2006 Annual International Conference on Methyl Bromide Alternatives and Emissions Reductions. Nov. 6-9, 2006. The Doubletree Hotel, Orlando, Florida. pp. 39-1 to 39-5.
  • Shrestha, A., G.T. Browne, B.D. Lampinen, S. Schneider, L. Simon and T. Trout 2006. Weed species and their emergence patterns under methyl bromide and alternative fumigants in fruit nurseries. 2006 Annual International Conference on Methyl Bromide Alternatives and Emissions Reductions. Nov. 6-9, 2006. The Doubletree Hotel, Orlando, Florida. pp.117-1 to 117-4.


Progress 09/01/03 to 08/31/06

Outputs
The first almond nursery trial was harvested in January 2005. The walnut nursery trial planted in 2003/4 in Yuba County was harvested in December 2005. During late fall 2006, nursery trial 3 and 4 were harvested. Overall, each of the fumigation treatments exhibited similar efficacy in the nursery trials. At nursery trial 1 (almond on loam soil), all fumigants provided good control of bagged nematodes and Pythium. The trees in the untreated control were significantly smaller in diameter but the treatment did not produce significantly less marketable trees. At nursery trial 2 (walnut on clay loam soil), seedling emergence in the untreated control was significantly less than the Telone C35 treatment. Diameter growth was significantly greater in the untreated control compared to all fumigants, but this was likely due to lower plant density and resulting improved light and water conditions. At nursery trial 3 (almond on clay loam soil), emergence was significantly less for the control compared to Telone C35. All fumigants provided good control of bagged nematodes and Pythium at shallow depths, but only methyl bromide and iodomethane/chloropicrin provided decent control of Pythium at lower depths. In nursery trial 4 (almond on loam soil), all fumigants provided good control of bagged nematodes and Pythium except iodomethane/choloropicrin and Inline at the lower depths. Both of the orchard trials are located in Madera County on loam soils. Growth was better in the fumigated plots at the almond following almond replant site but not at the almond following grape site. At the almond following almond trial, all of the chloropicrin containing fumigants had significantly greater growth and yields than the control. These same trends continued in 2007. Water stress at this site accentuated negative effects of lack of fumigation. In the almond following grape trial, there were no significant growth differences and only Telone II with VIF tarp and the Telone C35 treatments had a significantly lower yield than the control in 2007. There was a large interaction of irrigation and fumigation. When trees were water stressed during the year of planting (at Nursery Trial 1 and Orchard Trial 1), midday stem water potentials dropped off more rapidly in the control and methyl bromide treatments compared to the Telone C35, iodomethane/chloropicrin and chloropicrin treatments.

Impacts
Information was extended at the Annual Walnut Conference in Bodega Bay in 2004, 2005, 2006 and 2007. In addition, information was extended at the 2004 and 2006 International Conference on Methyl Bromide Alternatives and Emissions Reduction in Orlando, Florida in 2003 and 2005 and in San Diego in 2004 and 2006. It was also extended at the Almond Industry Annual Conference in Modesto in 2004, 2005 and 2006. The data on efficacy of methyl bromide alternatives generated will be of much interest to the tree nursery industry as well as growers. The methyl bromide phase-out presents unique challenges for growers of perennial fruit and nut crops. Results of the orchard experiments and the related soil characterizations may provide a basis for reduction in fumigant usage and cost savings in stone fruit and nut orchards by restricting the area treated to tree sites or row strips.

Publications

  • Browne, G. Replant disease and lethal Phytophthora canker. 33RD Almond Industry Conference, Dec. 7-8, 2005, Modesto, California.
  • Anil Shrestha, Greg T. Browne, Bruce D. Lampinen, Sally Schneider, Leo Simon and Tom Trout. Perennial crop nurseries treated with methyl bromide and alternative fumigants: I. Effect on weed seed viability, weed densities, and time for hand weeding. 2008. Weed Technology. In press.
  • Shrestha, A., G. T. Browne, B.D. Lampinen, S. Schneider, and L. Simon. Weed population dynamics in perennial crop nurseries as affected by methyl bromide and alternative fumigants. 2005 Weed Science Society of America Annual Meeting.
  • Anil Shrestha, Greg T. Browne, Bruce D. Lampinen, Sally Schneider, and Matthew Ferrari. Effect of alternative fumigants on weed populations in nurseries. Poster number 82. 2004 Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions. Oct. 31-Nov. 3, 2004, Orlando, Florida.
  • Shrestha, A., G. T. Browne, B. D. Lampinen, S. Schneider, L. Simon, and T. Trout. 2005. Weed populations in nurseries as affected by methyl bromide and alternative fumigants. Proc. 2005 Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions, Oct. 31-Nov.3, 2005, San Diego, CA, USA. pp.46-1 to 46-2.
  • Shrestha, A., G. T. Browne, B. D. Lampinen, S. Schneider, and L. K. Simon. 2005. Weed population dynamics in perennial crop nurseries as affected by methyl bromide and alternative fumigants. WSSA Annual Meeting, Feb. 7-10, 2005, Honolulu, HI. Abstr.#72.


Progress 01/01/05 to 12/31/05

Outputs
The first almond nursery trial was harvested in January 2005. The walnut nursery trial planted in 2003/4 in Yuba County was completed with final tree harvest taking place in December 2005. During 2004//05 we fumigated and planted two additional nursery trials, both planted to almond. Overall, each of the fumigation treatments exhibited similar efficacy in the nursery trials for control of bioassay populations of P. ultimum and citrus nematode. Monitoring of plant growth, plant health, natural nematode, weed, and disease incidence will continue through the nursery tree harvests (winter 2004 for nursery trial 1 and winter 2005 for nursery trials 2-4. Both of the orchard trials are located in Madera County on loam soils. Preliminary results suggest that growth is better in the fumigated plots at the almond following almond replant site but not at the almond following grape site.

Impacts
In the second year of the project, information was extended at a Methyl Bromide Alternatives Field Day in Parlier, California, at the 2005 International Conference on Methyl Bromide Alternatives and Emissions Reduction in San Diego, California, and at the . The data on efficacy of methyl bromide alternatives generated will be of much interest to the tree nursery industry as well as growers. The methyl bromide phaseout presents unique challenges for growers of perennial fruit and nut crops. Results of the orchard experiments and the related soil characterizations may provide a basis for reduction in fumigant usage and cost savings in stone fruit and nut orchards by restricting the area treated to tree sites or row strips.

Publications

  • Shrestha, A., G. T. Browne, B. D. Lampinen, S. Schneider, L. Simon, and T. Trout. 2005. Weed populations in nurseries as affected by methyl bromide and alternative fumigants. Proc. 2005 Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions, Oct. 31-Nov.3, 2005, San Diego, CA, USA. pp.46-1 to 46-2.
  • Shrestha, A., G. T. Browne, B. D. Lampinen, S. Schneider, and L. K. Simon. 2005. Weed population dynamics in perennial crop nurseries as affected by methyl bromide and alternative fumigants. WSSA Annual Meeting, Feb. 7-10, 2005, Honolulu, HI. Abstr.#72.
  • Lampinen, B., Browne, G., Schneider, S., Shrestha, A., Holtz, B., and Simon, L. 2005. Alternative pre-plant soil fumigation treatments for deciduous tree crops. Paper no. 44, Proceedings of the 2005 Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions, San Diego, CA.
  • Browne, G. Replant disease and lethal Phytophthora canker. 33RD Almond Industry Conference, Dec. 7-8, 2005, Modesto, California.
  • Shrestha, A., G. T. Browne, B.D. Lampinen, S. Schneider, and L. Simon. Weed population dynamics in perennial crop nurseries as affected by methyl bromide and alternative fumigants. 2005 Weed Science Society of America Annual Meeting.


Progress 01/01/04 to 12/31/04

Outputs
During 2003/04 we fumigated and planted two nursery trials, one planted to walnut and another planted to peach and prune rootstocks, and two orchard trials, one with almond replanted after almond and the other with almond planted after grape. The walnut nursery trial is in Yuba County on a clay loam soil, whereas the peach and prune nursery trial is in Stanislaus County on a sandy loam. Both of the orchard trials are located in Madera County on loam soils. Fumigation treatments also were applied for two additional nursery trials that will be planted in fall 2004, and it is anticipated that 1 or 2 additional orchard trials will be established in 2004-06. In each nursery trial, all fumigation treatments killed most bagged inoculum of Pythium ultimum and all bagged inoculum of citrus nematode. No inoculum of P. ultimum survived at 15 or 30 cm depths in fumigated plots at either nursery, but some survived at 60 and/or 90 cm depths. Mid-winter weed populations were reduced by each of the fumigants.

Impacts
In the first year of the project, information was extended at a Methyl Bromide Alternatives Field Day in Parlier, California and at the 2004 International Conference on Methyl Bromide Alternatives and Emissions Reduction in Orlando, Florida. The data on efficacy of methyl bromide alternatives generated will be of much interest to the tree nursery industry as well as growers. The methyl bromide phaseout presents unique challenges for growers of perennial fruit and nut crops. Results of the orchard experiments and the related soil characterizations may provide a basis for reduction in fumigant usage and cost savings in stone fruit and nut orchards by restricting the area treated to tree sites or row strips.

Publications

  • Shrestha, A., Greg T. B., B.D. Lampinen, S. Schneider, and M. Ferrari. Effect of alternative fumigants on weed populations in nurseries. 2004 Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions. Nov. 3, 2004, Orlando, FL.
  • Lampinen, B., Browne, G., Schneider, S., Shrestha, A., Holtz, B., and Simon, L. 2004. Alternative pre-plant soil fumigation treatments for deciduous tree crops. Paper no. 30, Proceedings of the 2004 Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions, Orlando, FL.


Progress 01/01/03 to 12/31/03

Outputs
Objective 1: Determine effects of promising short-term methyl bromide alternatives on vegetative performance of almond and walnut nursery stock at commercial nurseries. Objective 2: Determine effects of the alternatives on weed, nematode, and disease incidence at commercial nurseries. Objective 3: Determine effects of promising short-term methyl bromide alternatives on health and productivity of replanted almond trees in commercial orchards. Objective 4: Determine relative benefits of tree-site, row-strip, and broadcast treatments with the alternatives in commercial almond orchards Objective 5: To complete cost-benefit analyses for the methyl bromide alternatives at commercial almond and walnut nurseries and almond orchards. Since field plots were just installed in late fall of 2003, there is no data to report on the project at this time.

Impacts
Although this project has just started, the data on efficacy of methyl bromide alternatives generated will be of much interest to the tree nursery industry as well as growers. The methyl bromide phaseout presents unique challenges for growers of perennial fruit and nut crops. Results of the orchard experiments and the related soil characterizations may provide a basis for reduction in fumigant usage and cost savings in stone fruit and nut orchards by restricting the area treated to tree sites or row strips.

Publications

  • No publications reported this period