Effects of Temperature Change on Efficacy Rates of Herbicides Applied to an Exotic Weed Quamoclit coccinea Moench

Do Jin Lee1   Hyun Hwa Park2   Yong In Kuk2,*   

1Department of Agricultural Education, Sunchon National University, Suncheon 57922, Korea
2Department of Bio-oriental Medicine Resources, Sunchon National University, Suncheon 57922, Korea

Abstract

This study was conducted to evaluate the degree to which changes in temperature affect the efficacy of herbicides when applied to the exotic weed Quamoclit coccinea Moench using both soil and foliar application. Through studies like this, we hope to learn which weed control techniques will be most effective in the future as climate change continues to impact agriculture. Control value of Quamoclit coccinea Moench were highest in studies using growth chambers with high, constant temperatures (25, 30, and 35℃). Generally, as growth chamber temperatures increased, so did control rates as was observed in studies using soil applications of herbicides ethalfluralin, metolachlor and linuron. In studies using foliar application herbicides bentazone, glufosinate-ammonium and mecoprop also had increased control values as growth chamber temperatures increased. However, herbicide alachlor (soil application) and herbicide glyphosate-isopropylamine (foliar application) were not effective regardless of temperature conditions. Overall, the highest control value (100%) of Quamoclit coccinea Moench resulted from studies using bentazone, glufosinate-ammonium and mecoprop at each recommended dosage in growth chambers at 30℃ and 35℃. In greenhouse conditions where temperatures fluctuated but were measured as average daily temperatures, increases to greenhouse temperatures resulted in increases in control rates. This was especially true in studies using soil applications of herbicides ethalfluralin, metolachlor, alachlor and linuron with average greenhouse temperatures of 24, 26, and 28℃. In the case of foliar application herbicides in greenhouse conditions, average temperatures of 24℃ and 26℃ produced the same control value of Quamoclit coccinea Moench whereas control values by all foliar application herbicides at an average temperature of 28℃ were significantly higher. Overall, herbicide efficacy of Quamoclit coccinea Moench increased as temperatures in both the growth chamber and greenhouse increased.

Figures & Tables

Fig. 1. Daily average temperature (A, 24℃; B, 26℃; C, 28℃) during experimental period in greenhouse.