Studies on Bio-efficacy and Persistence of Residue of CPPU in Grapes

Use of PGRs has been a usual practice in fruit crops, especially for the production of export quality grapes since long. The use of CPPU and GA3 are quite general in different parts of the world to improve fruit set and prevent pre-harvest drop respectively. An investigation entitled "Studies on bioefficacy, phytotoxicity, residue, persistence and dissipation of N-[2-chloro-4-pyridinyl]-N-phenylurea (CPPU) in grapes" was carried out to study efficacy, biochemical changes, gas exchange parameters, post harvest quality, phytotoxicity as well as dissipation and persistence of residue in Tas-A-Ganesh (Vitis vinifera L.) grapes at the experimental vineyard of ICAR-National Research Centre for Grapes, located in the city of Pune (latitude 18.32°N, longitude 73.51°E) for three years (2011-12, 2012-13 and 2013-14) under good agricultural practices (GAP) of grape cultivation. The dissipation rates and terminal residue of CPPU in the grape field were studied to evaluate dose specific PHI and consumer safety as per recently changed MRL (0.01 mg/kg) of CPPU.