Location: Crops Pathology and Genetics Research2013 Annual Report
1a. Objectives (from AD-416):
1. Develop, test, and demonstrate optimized integrated pest management (IPM) strategies for management of almond replant problem in Merced County without methyl bromide (MB). 2) Contribute to educational outreach to foster grower utilization of program findings in Merced County.
1b. Approach (from AD-416):
1. In collaboration with G. Browne, B. Lampinen, and S. Upadhyaya, an almond replant trial (almond to be replanted after removal of old almond trees) will be conducted in Merced County at a commercial field site with sandy soil and a history of ring nematode infestation. 2. In collaboration with Browne, treatments designed to evaluate efficacy of fumigant alternatives to MB will be applied to replicate mainplots-- 8- to 11-ft-wide strips of the land centered over future tree rows (strip treatments) or to 5 ft x 6ft rectangles of land centered over future tree planting sites (a spot treatment). The strip treatments will include a non-fumigated control, a fumigated control (MB, 400 lb/treated acre), Telone II (340 lb/treated acre), Telone C35 (540 lb/treated acre). The spot treatment will include Telone C35 (540 lb/treated acre, equivalent to approximately 54 lb/orchard acre). All of the treatments will be applied in fall 2009, and selected fumigant treatments will be tested with and without preceding summer-long rotations with sudan grass (in the absence of sudan grass rotations, the ground will be cultivated or sprayed periodically to maintain it relatively free from weeds). 3. At least two treatments designed to evaluate efficacy of non-fumigant alternatives to MB will be applied to 5 x 6 ft subplots centered over future tree planting sites and within the main plots. The subplot treatments may include treatments with steam and Brassica seed meal, steam, Trichoderma formulations, and fungicide and oomycete treatments. 4. Tree trunk diameters, visual disease severity ratings, and nematode samples will be collected at least two times per year. 5. Educational outreach will be achieved via a UCCE/ARS-hosted field demonstrations day at the trial site in Madera County. Documents Specific Cooperative Agreement with UCCE Merced County.
3. Progress Report:
The project was stablished in support of Objective #1 of the in-house project, which is to demonstrate alternatives to Methyl Bromide in key crop systems and regions dependent upon Methyl Bromide. The goal of this project is to develop, test, and demonstrate optimized Integrated Pest Management (IPM) strategies for management of almond replant problems in Merced County without the use of Methyl Bromide. Evaluation of the fumigant trial established in January, 2010, was conducted. This included nematode sampling of plots, tree vigor evaluation, collection of yield data, and trunk diameter measurements. All trees were evaluated for bacterial canker in late spring (April, 2013), a disease that commonly occurs in sandy soils with high nematode counts. Yields were taken in August, 2012; nematode sampling was performed in October, 2012; and end of year growth measurements were taken in January, 2013. All fumigant treatments produced more yield than the control. Methyl Bromide row strip (RS), Telone-II RS, Telone-II-C35 (C35) RS, and C35 spot treatments produced 100%, 70%, 95%, and 75% greater yield than the control, respectively. Nematodes were detected in all plots, but populations were not different. Follow up work was performed throughout the year on the second fumigant trial within Merced County. This trial, established in 2011, included the evaluation of the pre-plant fumigant, steam, and tree site applied treatments. Observations of disease severity were taken throughout the year (Fall, 2012, Summer, 2013). Nematode sampling was performed in October, 2012. End of year growth measurements were taken in January, 2013. In 2011, no nematodes were detected in the fumigant treatments and control. Sampling in 2012, detected nematode populations in all plots, with C35 RS having the lowest population (6% of the non-fumigated control). Nematode populations were not significantly different within the sampled plots. Follow up work was performed throughout the year on the third fumigant trial within Merced County. This trial, established in 2012, included evaluation of the pre-plant fumigant, steam, and tree site applied fumigation. Observations of disease severity were taken throughout the year (2013). Nematode sampling was performed in October, 2012. End of year growth measurements were taken in January, 2013. Nematodes were detected in all plots except the C35 RS. In plots where nematodes were detected, counts ranged from 100 nematodes/500 grams of soil in the control to 5 nematodes/500 grams of soil in the Telone-II RS. Nematode populations were not significantly different within the sampled plots. A field day showcasing the fumigant trial established in 2011, was held on April 25th, 2013. This meeting was used to demonstrate the impacts of pre-plant soil fumigation on almond tree growth to 52 representatives of California Environmental Protection Agency (EPA), California Department of Food and Agriculture, California Air Board, local agricultural commissioner offices, and farmers. The meeting received great reviews and has raised awareness of fumigant alternatives to methyl bromide and the impacts of not fumigating. This is planned to be repeated in 2014. Three talks presenting the information of fumigant alternatives to methyl bromide were presented at annual almond meetings and local pest control advisor training. Two posters showcasing the work were displayed, one at the Annual Almond Board of California Conference held in Sacramento, California, and the second at the American Phytopathological Society Annual meeting held in Providence, Rhode Island. Assistance was also provided for conducting measurements and sampling of previously established fumigant trials within Madera and Fresno counties.