Phytotoxic residue effects of triasulfuron+dicamba (Lintur 70 WG) on some rotational crops after wheat

One of the negative effects of herbicide residuals is their phytotoxicity on subsequent susceptible crops in rotation. In order to study the phytotoxic residue effects of triasulfuron +dicamba (Lintur® WG70%) on 12 rotational crops, four experiments were carried out at field research stations of Khorasan razavi (Mashhad), Khuzestan (Ahwaz), Fars (Darab) and Golestan (Gonbad-Kavous) provinces in Iran. Rotational crops were planted in sprayed plots (with 170 g Lintur®) or in control plots (without spraying) immediately after wheat harvesting (as second crop) or in autumn. The rotational plants were selected from the summer crops including maize, cotton, mung bean, sesame and soybean, and fall crops including sugar beet, canola, clover, wheat, barley, faba bean and green pea. Results of t-student test showed the significant negative effect of triacsulfuron+dicambba residues on maize at Mashhad, Ahwaz and Darab in terms of root and shoot dry weight and yield (14.6 to 63% yield reduction). Damage to mung bean was significant in Ahwaz and Gonbad (5.6% -29% yield loss). Sesame yield in Ahwaz decreased 46% and soybean and green pea yields in Gonbad decreased by 12% and 16%, respectively. Rapeseed yield was damaged only in Ahwaz (31%) but in Mashhad, Darab and Gonbad the herbicide damage was not significant. Autumn planted sugar beet was significantly damaged in Ahwaz (46% yield) and in Gonbad (5%). The interval between herbicide application and emergence of summer crops was 90-146 days and for autumn crops was 222-311 days, depending on the rotational plants and experimental regions. Herbicide residue of triasulfuron + dicamba did not have significant damage on cotton, clover, wheat, barley and faba beans in related experiments.