تأثیر قارچ Trichoderma harzianum در مدیریت شب‌پره پشت الماسی Plutella xylostella (Lepidoptera: Plutellidae)

Biological control is a viable solution for effectively managing agricultural pests while minimizing the need for pesticides. Plutella xylostella L. (Lepidoptera: Plutellidae), often known as the diamond-back moth, is a significant pest of Cruciferae (Brassicaceae) that has developed resistance to chemical pesticides. Currently, management techniques for P. xylostella primarily depend on chemical insecticides, which can have negative effects on the pest, natural enemies, and the environment. Therefore, there is a need for eco-friendly alternative technology. By triggering the signaling pathways of plant hormones and defense chemicals such as amino acids, peroxidase, and phenolic compounds in damaged plants, Trichoderma spp. can induce systemic resistance in plants. The aim of the present study was to determine whether T. harzianum affected P. xylostella management in laboratory conditions. T. harzianum was prepared for this purpose from a collection preserved in the pathology department of Vali-e-Asr University, Rafsanjan, Kerman, Iran. The concentration of the suspension was found to be 107 ml for the fungi's application in soil. Three sections of cabbage root were injected with concentrations of 10 and 50 ml of Trichoderma suspension at 30-day intervals. P. xylostella larvae were placed on Brassica oleracea var. capitata leaves after the second inoculation. Treated pots were kept at 25±1 ̊ C, 60±10% humidity, and a photoperiod of 16L:8D h. A randomized complete block design was used for the experiment, with two treatments and three replications for each block. The injury level data were analyzed using the SPSS 26 statistical program. The one-way ANOVA method was used to compare means. The larval injury was daily investigated for 7 days after treatment. Ultimately, the scoring method developed by Hasan Khan Robin et al., 2017 was used to determine the injury levels. The results indicated that there was a significant difference in the injury level in the Trichoderma-treated plants compared to the control. The means of the injury levels (%) for T. harzianum and control were recorded at 25 and 52.78, respectively. The means comparison between treatments has shown that the highest and least injury levels were obtained with control and T. harzianum, respectively (p 0.05). Generally, the results of this research showed that applications of T. harzianum can be considered as a safe control method in an integrated pest management framework of P. xylostella.