Department of Plant Sciences,
NDSU, Fargo, ND
2001 Section 18 registration has been granted for Raptor for control of nightshade and Reflex for control of common ragweed. Reflex also controls nightshade.
In field studies, Reflex and Spartan herbicide provided excellent broadleaf control with adequate dry bean safety. Both herbicides are PPO inhibitor mode of action herbicides. Reflex controls pigweed, cocklebur, mustard species, and ragweed. Ragweed infestation is increasing with Minnesota growers indicating ragweed as one of the three worst weeds on over 50% of the dry bean acres in 1998 and 1999. Ragweed did not register as a problem in North Dakota in 1998 but increased to 22% in 1999. Spartan controls most small-seeded broadleaf weeds. FMC Corporation may register Spartan on dry beans as early as 2003 or 2004.
Studies were conducted to evaluate kochia control from Reflex. ALS resistant kochia has become a major problem in the dry bean growing area of North Dakota. Reflex was applied at 0.5, 0.75, and 1 pt/A to 3 inch kochia and 4 to 5 inch kochia, at 8.5 and 17 gpa, and with nonionic surfactant (NIS), petroleum oil (PO), and methylated seed oil (MSO) adjuvants. Research data indicates that the greatest kochia control is achieved when Reflex is applied at 0.75 to 1 pt/A, to small kochia, at high gallonage and with MSO type adjuvants. Greater than 93% kochia control was observed under these conditions. Kochia was nearly completely controlled when two split applications were made when Reflex was applied twice at 0.25 or
Studies were conducted with Reflex in dry bean near Wahpeton, ND. Reflex applied at 1 pt/A with an MSO type adjuvant gave greater than 92% common ragweed and common cocklebur control with less than 10% dry bean injury at 14 days after application (DAA). At 28 DAA no dry bean injury was observed. When Reflex was tank-mixed with Raptor, it nearly completely controlled foxtail, wild proso millet, common lambs-quarters, common ragweed, and common cocklebur with no dry bean injury.
Spartan was applied preplant incorporated (PPI) and preemergence (PRE) at 2,67, 3, 4, 4.5, 5.33, and 9 oz product/A near Hatton, ND to Remington pinto and Navigator navy bean types. According to label direction, the Spartan rate to be used for the sandy loam soil, 2.8% organic matter, and 7.9 soil pH is 3 oz product/A. The highest Spartan rate of 9 oz product/A would constitute a 3X rate. Spartan applied PPI caused no dry bean injury at any rate except the 9 oz/A rate. Only navy beans exhibited less than 25% at 14 DAA but no injury was observed at 28 DAA. Spartan applied PRE at rates of 5.33 oz/A or less caused no pinto and less than 8% navy bean injury. Spartan at 9 oz/A initially caused 20% and 33% pinto and navy bean injury, respectively, but was reduced to 9% for both bean types at 28