Sugarbeet Insect Pests Control, 1989

Granular insecticide treatments were applied at planting time to 2 separate flood-irrigated fields located in Carbon County in eastern Mont. Each field was planted on 'Monohy 149' on 20 Apr. The fields were 3-yr stands of alfalfa. Granular insecticides were applied as a 5 inch band on top of the row through a ground-driven Gandy applicator and lightly incorporated with a drag chain. Treatments were replicated 3 times in a randomized complete block. Individual replicates were 6 rows (22-inch row spacing) × 100 ft. Stand counts were made by counting the number of plants in 3 ft of row in 10 locations in each replicate. Feeding damage by PFB was assessed by removing 30 seedling plants from each replicate and rating each seedling as injured (presence of feeding scars) or uninjured. SBRM damage was determined for each treatment by removing 10 beets/replicate. Beets were rated using the following scale: 0, no damage; 1, 1-4 small scars of pinhead size; 2, 5-10 pinhead-size scars or 3 large scars; 3, more than 3 large scars; 4, 4 large scars to one-quarter of the root surface covered with scars; 5, one-quarter to one-half root surface covered with scars; 6, one-half to threequarters root area blackened by scars; 7, more than three-quarters root surface blackened.