| Popis: |
Field experiments were conducted in 1993, 1994, and 1999 to determine the response of field corn and grain sorghum to simulated drift of pyrithiobac. Pyrithiobac at 0.0, 1.05, 2.1, 4.2, and 8.4 g ai/ha (equivalent to 0%, 1.5%, 3%, 6% and 12% of the recommended rate) was applied in mid-postemergence (MPOST; 5–7 leaf corn; 4–6 leaf sorghum) or late-postemergence (LPOST; 8–10 leaf corn; 6–8 leaf sorghum). Visual injury symptoms included stunting, purple-leaf coloration, and onion leafing. Pyrithiobac reduced corn yields from 11% to 84% and grain sorghum yields from 33% to 94% depending upon the timing and dose. Generally, pyrithiobac applied MPOST caused more visible injury than when applied LPOST. However, this did not always cause greater yield losses. These results indicate that if pyrithiobac drift occurred from cotton fields to corn and grain sorghum, significant yield losses could occur depending on the amount of drift and stage of crop growth. |
Full Text from ScienceDirect