Efficacy of endophytic (Metarhizium brunneum) strain 6c1 in the control of oldworld Bollworm (Helicoverpa armigera) in okra

Abstract

Metarhizium brunneum strain 6c1 was evaluated for its capability to colonize okra plant with toothpick inoculation method. The results reflected the ability of Mb-6c1 to colonize the whole plant tissue. Different parameters such as pupae success, area consumed, weight gain and faeces dry weight bioassay were conducted to test whether the colonization of Mb- 6c1 could affect the performance of bollworm by means of Toothpick. The results showed that the inoculation had a significant pupae success, in particular, a gradual reduction of number of pupations were 80%, 73%, 20%, 13% for the control, Tween80 0.01%, (1×107 conidia/ml) and (1×105 conidia/ml), respectively. Consumed leaf area was significantly influenced by the treatment (p less than 0.05) with a mean of 63.13±11.90cm2 and 54.65±10.32cm2 for the high CONC and low CONC treatments, respectively. Nevertheless, Mb-6c1 increased the root dry weight of okra plants and acts as plant growth regulation. Moreover, the study suggested that Mb-6c1 can potentially be used as biological control agents against leaves chewing pests.