Evaluation of Various Herbicides in Weed Control of Gladiolus, Gladiolus Callianthus, and Iris, Iris graminea, Fields in Mahallat Town

Weeds are one of the main pests of ornamental flower fields. To study the effects of various herbicides in weed control of gladiolus and iris fields, trials were carried out during 2011-2012 at Mahallat Ornamental Plants Research Center, Iran. Weed control treatments included triflusulfuron methyl (DF 50% ) 40 g/ha, oxyfluorfen (EC 24%) 2 and 0.75 l/ha, ioxynil (EC 22.5%) 3 l/ha, paraquat (SL 20%) 3 l/ha, oxadiazon (SL 12%) 3 l/ha, diuron (WP 80%) 2 kg/ha, atrazine (WP 80%) 1 and 1/5 kg/ha, pendimethalin (EC 33%) 3 l/ha, imazethapyr (SL 10%) 0.75 l/ha, nicosolfuron (SC 4%) 2 l/ha. The main weeds in gladiolus field were Convolvulus arvensis, Salsola kali and Amaranthus retroflexus and in iris field were Sisymbrium irio, Hordeum spontaneum and Nonnea persica. Crop injury resulting from the application of herbicides in iris was little or not at all. Use of ioxynil treatment caused phytotoxicity in gladiolus flower. The most effective herbicides in controlling weed density and dry weight in both gladiolus and iris fields were atrazine 1.5 kg/h and 1 kg/h with one hand weeding before flowering with 90% and diuron with 80% reduction in weed number and dry weight respectively. The effect of oxyfluorfen on weed control in gladiolus and iris cultivations was comparitively good but less than ioxynil and diuron treatments.