The effect of foliar fertilizers in enhancing the resistance of broccoli plants against the cabbage looper, Trichoplusia ni (Hubner)

The experiment was conducted in the fields of the College of Agricultural Engineering Sciences, University of Baghdad, Al-Jadriya, during 2023-2024 to study the role of foliar application in the improvement of broccoli resistance against the Trichoplusia ni. The experiment was designed using a completely randomized block design. The foliar fertilizers Agro-K Amino, FoliaStim Ultra and Agro- A. + FoliaStim U. showed significant effect on the infestation by cabbage looper, Trichoplusia ni on broccoli plants. Use of foliar fertilizer of Agro- A. + FoliaStim U exerted the most significant effect than Agro-K Amino and FoliaStim Ultra. Infestation reached 9.94 holes per leaf in control but in treatments that sprayed with Agro-K Amino, FoliaStim Ultra and Agro-A. + FoliaStim U. recorded 4.95, 3.80 and 3.14 holes per leaf on 11/12/2023, respectively. The highest percentage of leaf infestation was 69.78% in control treatment, while it decreased to 33.48, 28.74 and 20.82% for the different treatments, respectively, on 11/12/2023. The treatments also led to a reduction in the percentage of infestation severity and an increase in plant yield. FoliaStim U fertilizers increased the resistance in broccoli plants, (Brassica oleracea var. italica) against the cabbage looper and reduced its damage