Varietal evaluation of sapota for resistance to Oriental fruit fly, Bactrocera dorsalis (Hendel)

Field and laboratory experiments were conducted during 2010–2011 at Fruit Research Station, Navsari Agricultural University, Gandevi, Gujarat, India to investigate the reaction of sapota varieties for their resistance/susceptibility to fruit fly, Bactrocera dorsalis. The genotypes viz., PKM -1, PKM-2, DHS-1, DHS-2, Bhuripatti, Pilipatti and Singapore were categorized as least susceptible to B. dorsalis. However, Zumakhiya, CO-2 and Kirthibarthi were found to be moderately susceptible. Likewise Kalipatti, Cricket Ball, Paria Collection, Murabba and Mohangoote werere corded as highly susceptible to B. dorsalis. Studies on effect of chemical constituents of all 15 sapota germplasm collections against fruit fly infestation revealed that the fruit fly infestation had significant positive correlation with total soluble solids (TSS) and total sugars whereas, it had negative correlation with acidity. Physical characters viz., fruit shape and skin pulp ratio had no significant impact on fruit fly incidence. Sapota germplasms with thin fruit skin were susceptible to fruit fly damage as compared to those with thick fruit skin.