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ARS Home » Pacific West Area » Davis, California » Crops Pathology and Genetics Research » Research » Publications at this Location » Publication #274432

Title: Evaluation of non-fumigant alternatives to methyl bromide for weed control and crop yield in California strawberries (Fragaria ananassa L.)

Author
item Samtani, Joseph - University Of California
item Ajwa, Husein - University Of California
item Weber, John - University Of California
item Browne, Greg
item Klose, Susanne - University Of California
item Hunzie, Jonathan - University Of California
item Fennimore, Steve - University Of California

Submitted to: Crop Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/27/2010
Publication Date: 1/1/2011
Publication URL: http://www.sciencedirect.com/science/article/pii/S0261219410002681
Citation: Samtani, J.B., Ajwa, H.A., Weber, J.B., Browne, G.T., Klose, S., Hunzie, J., Fennimore, S.A. 2011. Evaluation of non-fumigant alternatives to methyl bromide for weed control and crop yield in California strawberries (Fragaria ananassa L.). Crop Protection. 30:45-51.

Interpretive Summary: Conventional strawberry fruit production relies heavily on pre-plant soil fumigation to control soilborne pests and pathogens before each planting cycle. The previous standard for soil fumigation, methyl bromide (MB), has been phased out and is only allowed for applications under a critical use exemption process. In California, USA, agricultural fumigant use regulations hinder the complete transition from methyl bromide (MB) to alternative fumigants. Alternative fumigants such as 1,3-dichloropropene (1,3-D) and chloropicrin (Pic) are being used on approximately half of California conventional strawberry production fields. Geographic use limits and buffer zones set by the California Department of Pesticide Regulation for 1,3-D + Pic restrict a more complete replacement of MB. Due to the regulatory constraints and public resistance to fumigant use, it is necessary to develop fumigant-free strawberry production systems. Trials were conducted during the 2007/2008 and 2008/2009 strawberry growing seasons at Salinas and Watsonville, California. Non-fumigant treatments including steam, mustard seed meal (MSM), Muscodor albus, and furfural, fertilizers including Mustard Products & Technologies fertilizer and stabilised urea, and fungicide treatments including AG3(NP), fludioxonil + mefenoxam (mfx), and mfx + thiophanate-methyl were evaluated for weed control and strawberry fruit yield, and compared to MB + Pic (MBPic) standard soil fumigation and an untreated control. Steam treatment applied pre-plant to achieve soil temperature of = 70 °C for 20 min. up to 25 cm soil depth consistently provided weed control similar to the MBPic standard soil fumigation. Use of oxyfluorfen herbicide prior to fungicide applications in 2008/2009 improved weed control compared to fungicide treatments alone in 2007/2008. Strawberry yields in steam treated plots with the exception of steam alone in 2007/2008 at Salinas, were comparable to MBPic. At Watsonville in 2008/2009, treatment effect on strawberry yields was insignificant. Yields in furfural and MSM treatments were comparable to MBPic only in some years or sites. With the exception of steam, none of the treatments can be considered viable replacement to MB.

Technical Abstract: In California, USA, agricultural fumigant use regulations hinder the complete transition from methyl bromide (MB) to alternative fumigants. Alternative fumigants such as 1,3-dichloropropene (1,3-D) and chloropicrin (Pic) are being used on approximately half of California conventional strawberry production fields. Geographic use limits and buffer zones set by the California Department of Pesticide Regulation for 1,3-D + Pic restrict a more complete replacement of MB. Due to the regulatory constraints and public resistance to fumigant use, it is necessary to develop fumigant-free strawberry production systems. Trials were conducted during the 2007/2008 and 2008/2009 strawberry growing seasons at Salinas and Watsonville, California. Non-fumigant treatments including steam, mustard seed meal (MSM), Muscodor albus, and furfural, fertilizers including Mustard Products & Technologies fertilizer and stabilised urea, and fungicide treatments including AG3(NP), fludioxonil + mefenoxam (mfx), and mfx + thiophanate-methyl were evaluated for weed control and strawberry fruit yield, and compared to MB + Pic (MBPic) standard soil fumigation and an untreated control. Steam treatment applied pre-plant to achieve soil temperature of = 70 °C for 20 min. up to 25 cm soil depth consistently provided weed control similar to the MBPic standard soil fumigation. Use of oxyfluorfen herbicide prior to fungicide applications in 2008/2009 improved weed control compared to fungicide treatments alone in 2007/2008. Strawberry yields in steam treated plots with the exception of steam alone in 2007/2008 at Salinas, were comparable to MBPic. At Watsonville in 2008/2009, treatment effect on strawberry yields was insignificant. Yields in furfural and MSM treatments were comparable to MBPic only in some years or sites. With the exception of steam, none of the treatments can be considered viable replacement to MB.