Improving the efficacy of some ACCase inhibitor herbicides against weeds in saffron (Crocus sativus L.) using adjuvants

In order to improve the efficacy of ACCase-inhibitor herbicides using adjuvants in the control of grassy weeds in saffron cultivation, a field study with 3 replications based on a RCBD was conducted during 2016 -2017. Herbicides of haloxyfop-r-methyl, clethodim and cycloxydim (108, 96 and 120 a.i. ha-1 respectively) was investigated when they were tankmixed with and without Spray Plus (0.3% v/v), Ammonium sulphate (2% w/v), Citogate (0.2% v/v) and Humix 99 (0.25% w/v) as well as a control plot with no herbicide application and hand weeding. Weed species Hordeum murinum L. and Hordeum spontaneum C.Koh. respectiveley with relative density 36.71% and 24.05% obtained the highest weed density in the experimental field. Results showed that hand weeding significantly (14 up to 49%) increased the yield of saffron flower and corn. Adding adjuvants to herbicides Between 27 up to 34% increase their efficacy in weed controling. The herbicids were classified from the aspect of decreasing dry weight of grassy weeds and increasing saffron yield in the order of haloxyfop-r-methyl > clethodim > cycloxydim. Spray Plus and Citogate were the best adjuvant to optimize the efficiency of haloxyfop-r-methyl. while Ammonium sulfate and Spray Plus are recommended to improve the efficiency of clethodim and cycloxydim herbicides. Based on the results of experiment, Humix 99 increased the yield of saffron flowers and corms from 1.5 % (mixing with haloxyfop-r-methyl) up 12 % (mixing with cycloxydim), Although this increase was not significant. Mixing Humix 99 with cycloxydim significantly reduced the weeds dry weight up 30%, But but the its effect was not significant on other treatments.