Control of melonworm on cantaloupe with foliar applied insecticides 2023

Melonworm can be a destructive pest in cantaloupe and may defoliate plants, destroy flowers, and attack fruit by chewing on the rind, whereas the Pickleworm can bore directly into the young fruit and reduce yield. This experiment was conducted at the Southwest Florida Research and Education Center in Immokalee Florida. The crop was planted on 2 raised beds 440 ft long and 32 inches wide on 12 ft centers. Beds were covered with white on black polyethylene mulch. Cantaloupe was direct seeded on 28 Sep into punched holes 24 inches apart. Four treatments plus an untreated check were assigned in a randomized complete block design (RCBD) with 4 replicated plots of 15 plants each separated by 5-ft buffer space. Foliar treatments were made with a Black & Decker 20 Volt Battery operated backpack sprayer (Model 190657) equipped with a low volume fan nozzle by making 4 passes at normal walking speed ensuring the length of the vine was treated and delivering the equivalent of 50 gpa (Table 1). All sprays included Dyne-amic a nonionic surfactant at a 0.13% v:v ratio.

On 22 Nov, 10 young developing fruit were inspected for damage and the presence of larva, and on 8 and 14 Dec, all ripe fruit from all 15 plants per plot were removed and evaluated for damage and qualitative and quantitative assessment on fruit. Evaluation included surface and internal melonworm feeding damage. Marketable and culled fruit were separated on each harvest date, and data for marketable fruit were then analyzed for treatment effect. Data were subjected to ANOVA, and means were separated using LSD pending a significant (P = 0.05) F value.

On 22 Nov, fruit from all treated plots showed less damage caused by melonworm when compared to the untreated check. No damage was observed in the fruit sampled from the Coragen treatment, which was only statistically significant from the fruit in the Intrepid treatment (Table 2). There was no significant difference in fruit damage in plots treated with Exirel, Avaunt eVo, and Intrepid (Table 2).

The total numbers of fruit collected from the harvest dates were combined for the analysis (Table 3). The number and weight of cantaloupe increased in all treatments compared to the untreated control. The number of fruit with internal damage was significantly lower in all treatments than the untreated check, while only Coragen and Exirel reduced surface damage on the rind.

No phytotoxicity was observed. The experiment was supported by industry gifts of pesticide and research funding.