Screening of Cashew Germplasm Accessions/Entries to Tea Mosquito Bug, Helopeltis antonii Sign.

摘要

In cashew (Anacardium occidentale L.), one of the reasons attributed to the drastic decline in production is the occurrence of tea mosquito bug (TMB), Helopeltis antonii Sign, which can cause yield reduction to the tune of 30-40% and in some situations 100% reduction in yield. Integrated pest management involving resistance and adopting spraying of insecticides is a good package to manage this pest. The varietal resistance will certainly reduce the complete dependency on chemical control. With this background screening of cashew accessions/entries to tea mosquito bug was taken up under AICRP on Cashew at Agricultural Research Station, Chintamani, Karnataka from November-April. During this period the activity of the pest was noticed. The accessions/entries evaluated are in multilocation trial-1992, multilocation trial-2002 and germplasm. The screening was based on 0-4 damage score rating technique developed by the Directorate Cashew Research, Puttur, Karnataka. The damage score for TMB infestation in MLT-1992 ranged from 0.82 to 3.01. The accession H-320 recorded lowest TMB infestation (0.82), whereas, the maximum percent damage was recorded in M-15/4 (3.01). In MLT-2002, the damage score was maximum in entry H-ll (2.60) and minimum in Chintamani-1(1.12). Among 104 germplasms, 40 accessions showed low occurrence, 18 accessions showed moderate occurrence and 46 accessions showed high occurrence of TMB. However, none of the yielding accessions/entries has shown resistant reactions to TMB infestation.