CHEMICAL CONTROL OF COMMON MALLOW, MALVA NEGLECTA, IN SAFFRON FIELDS

Common mallow, Malva neglecta with fast growing potential and broad leaves is one of the most hazardous weeds, which compete with saffron. In order to find a suitable herbicide, the field experiments were conducted during 2005-2006, at the Agricultural Research Station of Zahak-Zabol. The experiments were designed as a randomized complete block with six treatments and three replications, in a six-year-old saffron field. The herbicide treatments were scheduled after harvesting of saffron flowers, when the weed was in 3-5 leaf-growth stage. The treatments were included: Ioxinil (EC 22.5%) at 3 L/ha, Bromoxinil + MCPA (EC) at 1.5 L/ha, Oxyfluorfen (EC 24%) at 1.5 L/ha, 2,4-D + MCPA (SL 67.5%) at 2 L/ha, Metribuzin (WP 70%) at 0.75 kg/ha and control (without spray). The efficiency of the herbicides was calculated using the standard method EWRC at 10, 20 and 30 days after spraying and the weed dry weight was measured 30 and 60 days after spraying. The results showed that Metribuzin (without loss in saffron) controlled common mallow completely. This treatment prevented re-growth of weeds until the end of the growth season (saffron leaves become dry naturally). Treatment of Oxyfluorfen completely controlled the weed, but after 10 days common mallow and other weeds, Vicia villosa, Malcolmia africana and Hordeum sp. appeared gradually. Oxyfluorfen induced necrotic damages on saffron leaves, which were tolerable for the plant. The treatment with 2,4-D + MCPA severely damaged the saffron, with chlorosis appearing from the bases and their elongation (10 cm longer than control).