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United States Department of Agriculture

Agricultural Research Service


Location: Crops Pathology and Genetics Research

2011 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 ARS scientists, 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 the Principal Investigator, 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.

3. Progress Report
Established in support of Obj.1 of in-house project-the goal being to demonstrate alternatives to MB in key crop systems & regions dependent upon MB. The goal of this project is to develop, test, & demonstrate optimized IPM strategies for management of almond replant problems in Merced Co. w/out the use of MB. Follow up work was performed in 10/2010 for the trial established in 01/2010. This included nematode sampling of plots, tree vigor evaluation, & trunk dia. measurements. All trees were evaluated for bacterial canker, a disease that commonly occurs in sandy soils with high nematode counts. A 2nd site for an almond replant trial was located in Merced Co. at a commercial field site with sandy soil & a history of ring nematode infestation. Fumigant treatments were applied and were designed to evaluate efficacy of alternative fumigants to MB and fumigant alternatives. The established trial included a main plot testing soil fumigants and steam spot treatments, and a 2nd & 3rd plot testing fumigant alternatives, which included a commercially available biocontrol agent and a spot treatment of Brassica Seed Meal(BSM). Within the main plot, treatments were applied to 8 tree rows of the cultivars ‘Nonpareil,’ ‘Sonora,’ & ‘Aldridge,’ and were either an 8- to 11-ft-wide strips of the land centered over future tree rows. The strip treatments included a non-fumigated control, a fumigated control(MB, 400 lb/acre), TeloneII(340lb/acre), & TeloneC35(540lb/acre). The steam treatment heated the soil to over 200F and maintained a soil temp. of over 150F for at least 6hrs post treatment. There were 5 replicate plots, with the plots containing one 8 tree row of each variety. The plot was established in a randomized block design. A 2nd experiment testing the commonly used practice of backhoeing was established within the rows of the cultivar ‘Nonpareil.’ Soil disruption through the use of a backhoe was compared to an untreated control & a C35 strip treatment. The C35 was applied using the row strip treatment described previously. Tree sites were excavated with a backhoe to an estimated volume of 64 cu.ft.(4’x4’x4’hole). Each treatment block consisted of 8 replicate trees of 5 blocks. A 3rd trial was initiated to test available products for disease suppression. Products applied included BSM applied at 0.87lbs./tree site(12000lbs/acre) and 50grams of Soilguard Biofungicide(Certis). Spot treatments were applied to the tree planting site, using a 30”dia. custom designed auger. The auger was placed over the center of the tree site and provided delivery of the treatment as a liquid suspension, to a 24”depth. Distribution of the product was throughout the planting hole due to the mixing action of the auger and the ability for the auger to keep the treated soil within the treatment site. Treatments will be compared to an untreated, augered hole. Five blocks of 2 replicate trees of each treatment were established. Trees were planted in January, 2011. Initial measurements were taken before bud breaks. The project is monitored by maintaining a complete file of the agreement, reviewing annual reports, and conducting regular meetings with the cooperator.

4. Accomplishments

Last Modified: 10/17/2017
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