Evaluation Of Mung Bean (Vigna Radiata) Varieties For Resistance To Bruchid (Callosobruchus Spp) Infestation Using The “No Choice Test"

Abstract

Mung beans (Vigna radiata) commonly known as green grams, are an important legume crop cultivated for food and as a source of income. Mung bean seeds are highly susceptible to infestation by bruchids (Callosobruchus spp), which can cause significant post-harvest losses, hence impacting on the global food security. Bruchid infestation control remains a priority, and overreliance on chemical pesticides contributes to environmental concerns due to the potential harm to non-target species such as soil and water quality. Investigating natural resistance mechanisms in mung beans can contribute to sustainable and eco-friendly pest management practices. This study aimed at identifying mung bean varieties resistant to storage bruchids using the 'No Choice' test by determining the seed damage. Twenty-three mung bean varieties, both wild and local, were obtained from KALRO Katumani and evaluated against pulse beetle (Callosobruchus maculatus) under laboratory conditions. Fifty seeds of each test sample were placed in separate petri dishes. Five male and female pairs of 0–24-hour-old adults of the beetle were released into each petri dish, covered to prevent insect escape and allow air circulation. The observations were made after 72 hours on oviposition preference by determining the number of eggs laid and percentage seed damage by counting the seeds with one or more holes from the total. The mung bean variety V100-35226 exhibited the highest resistance to bruchid infestations, with minimal seed damage. Other varieties with slight resistance included AMVU-1612, AMVU-1601, AMVU-1603, and V100-1802. The results highlighted significant differences in resistance levels among the mung bean varieties, indicating that some varieties possess natural resistance mechanisms to bruchid infestation