Smellmelon is an invasive weed in the Golestan and Mazandran provinces of Iran. In a series of experiments, germination of freshly harvested seeds, cardinal temperatures, plant burial depth, and distribution and chemical control of smellmelon were evaluated to assist us in developing a management program to help growers manage this weed more effectively. The optimal seed germination temperature was estimated at 32.7 C by a two-piece segmented model. Mature fresh seeds of smellmelon exhibited no dormancy, whereas mucilage of the seed negatively affected germination. The greatest seed sowing depth from which seedlings emerged was 5 cm. Geographical distribution of smellmelon occurred up to an elevation of 350 m above sea level, whereas the density of smellmelon decreased at elevations higher than 151 m. Imazethapyr reduced plant growth and the reproductive capacity of smellmelon. Germination of seed from smellmelon plants treated with imazethapyr was significantly reduced compared with seed treated with bentazon or bentazon plus acifluorfen. A combination of tillage of deeper than 5 cm, early planting time, and the use of imazethapyr can reduce smellmelon competition in various field crops.

Field studies were conducted during the 2004 and 2005 growing seasons to evaluate the effects of various herbicides on smellmelon control and soybean yield response. Pendimethalin applied pre-emergence (PRE) alone controlled smellmelon no better than 70%, whereas pendimethalin plus imazethapyr, flumioxazin, or cloransulam applied PRE provided almost complete smellmelon control (99%). Pendimethalin applied PRE followed by acifluorfen applied early postemergence (EPOST) provided similar control. Glyphosate alone applied late postemergence (LPOST) provided complete control (100%), and pendimethalin followed by glyphosate applied EPOST controlled smellmelon at least 95%. Most herbicides increased soybean yield over the nontreated check.

Field studies were conducted from 1998 through 2000 to determine the influence of crop rotation and level of herbicide system for johnsongrass, entireleaf morningglory, and smellmelon control in glyphosate-resistant cotton and corn. Three different crop rotation schedules were used including cotton–cotton–cotton, cotton–corn–cotton, and corn–cotton–corn. Herbicide systems involving various degrees of input levels (low, medium, and high) were compared with a conventional standard program. In 1998, weed control ranged from 80 to 95% for all herbicide systems when the rotation was corn–cotton–corn. In 1999 and 2000, the low-input herbicide system controlled entireleaf morningglory 76 to 78% late in the season. Decreased smellmelon control (78%) was also observed with the conventional standard during this same period. In the cotton–corn–cotton rotation, late-season entireleaf morningglory control decreased each year in the low-input system, regardless of crop. In 2000, late-season evaluations indicated lower weed control of all three species with the conventional standard program compared with the other input systems. Yield data from 2000 suggested that corn and seed cotton yields were influenced by crop rotation.