Effect of Time of Auxin Herbicides Application on Yield and Yield Components of Wheat

Document Type : Research Paper

Authors

Agronomy and Plant Breeding Dept., University of Tehran

Abstract

To investigate the effect of  four growth regulator herbicides in various stages of wheat growth, two field and one greenhouse experiments were conducted in Tehran and Golestan provindes.Treatments included 2,4-D (20% SL), 2,4-D+MCPA (67.5% SL), Bromicide MA (bromoxynil+MCPA) 40% EC each at 1.5 L/ha and Duplosan Super (dichlorpop-P+mecoprop+MCPA) 60% SL at 2.5 L/ha applied at the following growth stages of wheat: First tiller (Zadoks 21), last tiller (Zadoks 29), second node (Zadoks 32), and boot swollen (Zadoks 45). In the greenhouse, early milky (Zadoks71) stage was also applied. Field experiments were randomized complete block design with 4 replications, while in the greenhouse, the experiment was in the form of completely randomized design with 5 replications. Data recorded included, yield and yield components. Results indicated that 2,4-D, 2,4-D+MCPA and dichlorpop-P+mecoprop+MCPA may be applied safely at the stages of first tillering up to the second node (Zadoks 21 to 32). Bromoxynil+MCPA was safe to be applied at any stage of growth (Zadoks 21 to 45). In Varamin, none of the treatments caused any damage to the crop.

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