Control of Southern Armyworm Spodoptera Eridania in Staked Tomato, 1995

Greenhouse raised seedlings of “Neptune” tomato were planted 27 Sep 18 inches apart into twelve fertilized and sub-irrigated beds, 32” wide and 240 ft long. Beds were fumigated with a 67/339 mixture of methyl bromide and chloropicrin at a rate of 220 lb. acre, covered with white-sided polyethylene-mulch, and divided into 10 plots ca 24 ft long and 3 rows wide. A RCB design was used to assign treatments into 4 replications. Kocide 101 and Maneb 80 WP were sprayed weekly with alternating combinations of Maneb 80 WP at 1 lb/acre plus Kocide 101 at 3 lb/acre and Bravo 720 at 1.5 pt/acre for disease control. Six treatment applications were applied weekly with a high-clearance sprayer using a hydraulic pump operating at 200 psi. The sprayer was equipped with 2 drop nozzles per row, each configured with 3 yellow Albuz nozzles on 14 Nov. for a delivery rate of 76 gpa, increasing to 4 nozzles to deliver 103 gpa for the remaining applications Latron CS-7 was tank-mixed at 16 pz/100 gallon spray for all treatments. Foliar damage and larval counts were made weekly from the south side of 18 plants per plot by randomly selecting 3 pairs of plants between the 4 center stakes of each row, moving to the next pair of plants if any in the first six were atypical. Foliar damage was evaluated visually using a Horsfall type rating scale where 1 = no apparent damage, 2 = 0-1% leaf area removed, 3 = 2-5%. 4 = 6-10%, 5 = 11-30%, and 6 = >30% leaf area removed. The numbers of larvae (SAW and an occasional beet armyworm) were recorded by size (small, medium, large) and species per plant. A precount of 160 plants on 13 Nov showed 55% to have an average foliar damage of less than 1% and average number of larvae to be 4 small, 1.4 medium and 0.23 large per plant. Fruit was harvested from 24 plants per plot and marketable fruit was graded on a commercial table with weights and numbers recorded. Unmarketable fruit was counted and weighed. Value of harvest was calculated on a $5, 7, 9, 12 market for small, medium, large and extra-large fruit, respectively.