Effect of Simulated Indaziflam Drift Rates on Various Plant Species

Abstract

Indaziflam is a PRE herbicide for control of annual grass and broadleaf weeds in numerous settings, including managed roadsides, railroads, and noncroplands. There is a need for new and improved PRE herbicides for herbaceous vegetation management along roadsides; however, off-target crop injury via spray drift is a concern because of the close proximity of roadside applications to the wide array of crops grown throughout the southeastern United States where indaziflam is used. Greenhouse research was conducted to evaluate the effect of PRE and POST simulated indaziflam spray drift rates on the growth of cotton, bell pepper, soybean, squash, tobacco, and tomato. Simulated indaziflam spray drift rates were 100, 20, 10, 5, or 2.5% of a 73 g ai ha−1 application rate, whereas other herbicide treatments included for comparative purposes were applied at 10% of a typical North Carolina roadside vegetation management application rate. These included sulfometuron (4 g ai ha−1), aminocyclopyrachlor + metsulfuron (11 + 3.5 g ai ha−1), clopyralid + triclopyr (21 + 63 g ai ha−1), or aminopyralid (12 g ai ha−1). In general, plant growth responses varied among herbicides and application timings. Across all evaluated parameters, indaziflam at the 10% simulated drift rate adversely effected plant growth similarly or less than all other herbicides when applied PRE (squash and tomato), POST (bell pepper and soybean), and PRE or POST (cotton and tobacco). No clear trends were observed regarding indaziflam application timing, as PRE squash and tomato, and POST bell pepper and soybean applications were safer than their respective alternative timing, and no significant differences were detected between timings on cotton or tobacco. Across application timings, plant susceptibility to indaziflam-simulated spray drift rates ranked cotton < tobacco < tomato < squash < pepper < soybean. Finally, it should be noted that the lowest simulated indaziflam drift rate (2.5%) caused greater than 20% root mass reduction on cotton (POST), bell pepper (PRE and POST), soybean (PRE and POST), squash (PRE), and tomato (POST). Although this research supports indaziflam use along roadsides, it still poses an off-target plant injury risk. Future research should evaluate techniques to minimize spray drift from roadside pesticide applications.

Seleção de espécies bioindicadoras para o herbicida indaziflam

“…ha -1 ), constatouse que as plântulas de beterraba e pepino não emergiram Guerra et al (2014), demonstrando serem espécies importantes na detecção desse herbicida no solo. Já Jeffries et al (2014), simulando deriva após 70 dias depois a aplicação de 1,8 g ha -1 de indaziflam observaram efeitos negativos em plantas de tomate.…”

“…ha -1 ) (Figura 6). Jeffries et al (2014), verificaram reduções na altura das plantas sob simulação de deriva do herbicida indaziflam e que essas reduções foram acompanhadas dos sintomas de fitointoxicação, corroborando os resultados desse trabalho. 3 DAE Y= 100,00/1 + (x/2,62)^0,54 R 2 =0,99 Y= 100,00/1 + (x/2,52)^0,58 R 2 =0,99 Y= 100,00/1 + (x/1,77)^0,69 R 2 =0,99 Y= 100,00/1 + (x/1,69)^0,99R 2 =0,99 3 DAE Y= 100,00/1 + (x/13,83)^2,26 R 2 =0,99 Y= 100,00/1 + (x/9,79)^1,69 R 2 =0,99 Y= 100,00/1 + (x/7,81)^1,53 R 2 =0,99 Y= 100,00/1 + (x/6,28)^1,63 R 2 =0,99 3 DAE Y= 100,00/1 + (x/5,32)^0,95 R 2 =0,98 Y= 100,00/1 + (x/3,17)^1,00 R 2 =0,98 Y= 100,00/1 + (x/0,98)^0,88 R 2 =0,99 Y= 100,00/1 + (x/0,60)^0,85 R 2 =0,99 Figura 6.…”

“…O indaziflam é absorvido pelas raízes e pelos tecidos da parte aérea, inibindo o crescimento da raiz por meio da interferência na formação da parede celular e na divisão celular, logo, com os danos no sistema radicular das espécies avaliadas houve consequentemente redução no crescimento da parte aérea e total das plantas. Segundo Jeffries et al (2014), mostram que a redução de matéria seca de parte aérea, raiz, altura de plantas e injúrias das plantas são a taxas semelhantes, comprovando comportamento análogo entre os órgãos das plantas testadas neste estudo.…”

Saflufenacil and indaziflam herbicide effects on agricultural crops and microorganisms

“…For cotton, the most sensitive crop, 2.5% of the commercial dose caused a 20% reduction in the root mass (Jeffries et al, 2014).…”

Mobility, Degradation, and Uptake of Indaziflam under Greenhouse Conditions

“…Information on the fate and transport behavior of indaziflam is required to minimize off-target plant injury risk (Jeffries et al, 2014). Previous studies reported a decrease of indaziflam injury to bermudagrass with increasing organic matter and clay contents under laboratory conditions (Jones et al, 2013a(Jones et al, , 2013bSchneider et al, 2015).…”