Affiliation:
1. Universidade Federal do Rio Grande do Sul, Brasil
2. Universidade Estadual de Londrina, Brasil
Abstract
ABSTRACT Environmental conditions can influence herbicide metabolism and interfere with the evolution of weed resistance. This study aimed to evaluate the effect of thermal regimes on the control of barnyardgrass (Echinochloa crus-galli) susceptible and resistant to herbicides of the imidazolinones chemical group. Factor A (biotypes) consisted of one biotype that is susceptible and one that is resistant to imazethapyr; factor B (dose) comprised six imazethapyr doses between 0 and 800 g ha-1 for the resistant biotype and between 0 and 100 g ha-1 for the susceptible biotype; factor C (temperature) consisted of four thermal regimes (16/16 ºC, 25/25 ºC, 16/25 ºC and 25/16 ºC) to which the plants were submitted before and after the herbicide application. Concerning the resistant biotype, the highest control levels were observed in the thermal regimes with temperature fuctuation, especially at 25/16 ºC. At the recommended imazethapyr dose (100 g ha-1), the herbicide resulted in a control level over 90 % at 25/16 ºC and less than 50 % at 16/16 ºC, in the resistant biotype. The shoot dry mass was reduced by more than 80 % at 25/16 ºC and 16/25 ºC and less than 30 % at 16/16 ºC. The temperature conditions to which the plants are subjected in the pre- and post-application period interfere with the level of imazethapyr resistance in barnyardgrass.
Subject
Agronomy and Crop Science
Reference26 articles.
1. Eighteen years of Clearfield™ rice in Brazil: what have we learned?;AVILA L. A.;Weed Science,2021
2. Rising atmospheric CO2 concentration affect weedy rice growth, seed shattering and seedbank longevity;BALBINOT A.;Weed Research,2022
3. Superoxide dismutase and stress tolerance;BOWLER C.;Annual Review of Plant Physiology and Plant Molecular Biology,1992
4. Differential expression of genes associated with degradation enhancement of imazethapyr in barnyardgrass (Echinochloa crus-galli);DALAZEN G.;Journal of Agricultural Science,2018
5. Climate change scenarios increase the growth and resistance of barnyardgrass to imazethapyr;DALAZEN G.;International Journal of Agriculture and Biology,2020