Influence of Metam Sodium on the Dissipation and Residual Biological Activity of the Herbicides EPTC and Pebulate in Surface Soil under Black Plastic Mulch

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• 作者：Carrie L. Stiles ; Carl E. Sams ; Darren K. Robinson ; David L. Coffey ; and Thomas C. Mueller
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2000
• 出版时间：October 2000
• 年：2000
• 卷：48
• 期：10
• 页码：4681 - 4686
• 全文大小：62K
• 年卷期：v.48,no.10(October 2000)
• ISSN：1520-5118

文摘

Metam sodium is a potential replacement for methyl bromide, which is used to control soil pests.Metam sodium rapidly breaks down in the soil to form methylisothiocyanate (MITC). Dissipationof the herbicides EPTC and pebulate in a silt loam soil under plastic mulch in the absence andpresence of metam sodium was examined in field experiments in 1998 and 1999 at Knoxville,Tennessee. EPTC half-life (DT₅₀) was 9 d, but when applied in conjunction with metam sodiumDT₅₀ increased to 22 d. Similarly, average pebulate DT₅₀ was 8 d and increased to 23 d when appliedin conjunction with metam sodium. This increase in herbicide DT₅₀ with the addition of metamsodium is thought to be due to a reduction in soil microorganisms that degrade EPTC and pebulate.EPTC applied with metam sodium injured tomato plants and reduced total crop yield more thanEPTC, pebulate, or pebulate with metam sodium. The increased tomato injury may have been relatedto the greater and prolonged activity of EPTC and slower EPTC dissipation in the presence of metamsodium or MITC.Keywords: Methyl bromide replacement; Vapam; metam sodium; pebulate; EPTC; soil; persistence;weed control; tomato; MITC