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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research Unit » Research » Publications at this Location » Publication #156073
Title: METHYL BROMIDE ALTERNATIVES AND MYCORRHIZAL COLONIZATION IN VINEYARD REPLANT TRIALS

Author
item Schreiner, Roger - Paul
item SCHNEIDER, SALLY - USDA-ARS
item Pinkerton, John
item Bryla, David

Submitted to: International Conference on Methyl Bromide Alternatives and Emissions Reductions
Publication Type: Proceedings
Publication Acceptance Date: 8/28/2003
Publication Date: 11/3/2003
Citation: Schreiner, R.P., Schneider, S., Pinkerton, J.N., Bryla, D.R. METHYL BROMIDE ALTERNATIVES AND MYCORRHIZAL COLONIZATION IN VINEYARD REPLANT TRIALS. Proceedings of the 2003 International Conference on Methyl Bromide Alternatives and Emissions Reductions. 2003. p. 116-1.

Interpretive Summary: The impact of methyl bromide alternatives on mycorrhizal colonization of roots in vineyard replant sites was evaluated in on-going studies at Parlier, CA. We examined the effects of seven pre-plant chemical alternatives, along with untreated controls and methyl bromide, on fine root production and root colonization by arbuscular mycorrhizal fungi (AMF) in self-rooted Thompson Seedless grapevines. We determined the percentage of root length colonized by AMF after the first growing season (Jan. 2002) and in the summer of the second growing season (July 2002). We also examined the impacts of long-term fallowing and Methyl Bromide fumigation on root growth and AMF colonization in another replant trial with vines in their third growing season (planted in 2000). The Methyl Bromide alternatives, Propargyl bromide (shank applied) and Inline, had the greatest negative impact on AMF in grapevine replant soil. These two chemicals in our trial were similar to Methyl Bromide in terms of reducing AMF colonization of roots for at least 13 months after planting. Iodomethane/chloropicrin (shanked) and chloropicrin (drip) treatments also reduced AMF colonization within the first 8 months after planting, but levels of colonization had recovered to the control level by the middle of the second growing season. Treatments did not appear to alter fine root growth in this trial. A 3 year fallow treatment prior to planting grapevines in the second replant study was found to be more detrimental to AMF than was Methyl Bromide fumigation. AMF were apparently introduced with the planting material in both replant studies examined. Therefore, effects of treatments on the indigenous or resident AMF within the treated vineyard soils were probably underestimated.

Technical Abstract: The impact of methyl bromide alternatives on mycorrhizal colonization of roots in vineyard replant sites was evaluated in on-going studies at Parlier, CA. We examined the effects of seven pre-plant chemical alternatives, along with untreated controls and methyl bromide, on fine root production and root colonization by arbuscular mycorrhizal fungi (AMF) in self-rooted Thompson Seedless grapevines. We determined the percentage of root length colonized by AMF after the first growing season (Jan. 2002) and in the summer of the second growing season (July 2002). We also examined the impacts of long-term fallowing and Methyl Bromide fumigation on root growth and AMF colonization in another replant trial with vines in their third growing season (planted in 2000). The Methyl Bromide alternatives, Propargyl bromide (shank applied) and Inline, had the greatest negative impact on AMF in grapevine replant soil. These two chemicals in our trial were similar to Methyl Bromide in terms of reducing AMF colonization of roots for at least 13 months after planting. Iodomethane/chloropicrin (shanked) and chloropicrin (drip) treatments also reduced AMF colonization within the first 8 months after planting, but levels of colonization had recovered to the control level by the middle of the second growing season. Treatments did not appear to alter fine root growth in this trial. A 3 year fallow treatment prior to planting grapevines in the second replant study was found to be more detrimental to AMF than was Methyl Bromide fumigation. AMF were apparently introduced with the planting material in both replant studies examined. Therefore, effects of treatments on the indigenous or resident AMF within the treated vineyard soils were probably underestimated.