E64

FAW is the key pest of sweet corn in southern Florida with larvae feeding successively in whorls, tassels, silks, and ears. Broadspectrum insecticides are sprayed frequently, especially after tassels have emerged, but more selective chemistries might provide as good or better control with less impact on non-target organisms. The trial was conducted at the Southwest Florida Research and Education Center in Immokalee Florida on 4 raised beds 32 inches wide and 400 ft long placed on 12 ft centers and covered with whiteface polyethylene mulch under which was placed a single drip tape irrigation line with 4 inch emitter spacing. Fertilizer (15-315) was mixed into the beds at 50 lbs N per acre and a 7-0-7 liquid fertilizer was applied through the drip tape using a Dosatron® during every irrigation cycle over the growing season for a total of 200 lbs N per crop. Corn was direct seeded 15-Sep at 10-inch spacing with three seeds per hole. Thirteen treatments were assigned in a RCB design across 4 replicates. Applications were made with a high clearance sprayer travelling at 2.3 mph equipped with ceramic Albuz ® “yellow” hollow cone tips each delivering 10 gpa at 180 psi. On 7,11 -Oct, one nozzle was placed overheard and one nozzle was located on each of the two vertical drops (3 nozzles total). On 14,18,21,25,27 – Oct an additional nozzle was placed on each drop (5 nozzles total). All other applications were done with two nozzles on each of the two drops (4 nozzles total) (Table 1). A significant phytotoxic effect (Table 4) causing stunted plants and dwarfed ears, was observed with the MBI-206 + Induce treatments. Induce was discontinued from these treatments starting 1 Nov since we had previously observed similar effects with this product. Both MBI-206 treatments were not applied after 15-Nov (Table 1). Ten plants from each plot designated for either rate of the MBI-206 + Induce, the Lannate/Warrior rotation and the untreated check were measured on 17 Nov. from the tip of the tassel to the top of the bed to evaluate the phytotoxic effect of the MBI-206 plus induce treatments. Counts and damage assessments were made on 12 plants per plot noting the number of FAW larvae in the top of the whorl (12, 20 -Oct), in the tassel (27-Oct) and in the silk (3, 10, 17-Nov). Damage assessments were based on a rating of 0-5: 0 = no damage, 1= <5%, 2 = 6-25%, 3=26-50%, 4 = 51-75%, 5>76%. On 23-Nov (20 plants) and 1-Dec (15 plants) the dominant ear on each plant harvested was evaluated by removing the husks and grading to 3 categories; no damage, minor tip damage and significant ear damage. MBI-206 at both rates was not harvested on 1-Dec due to the lack of ears caused by the phytotoxicity. Data were subjected to ANOVA and means separated using LSD (P = 0.05).