Ecofriendly Response of Citrus Peels to Alternaria Leaf Spots of Tomato: Exclusive Role of Peel Phenolics

Citrus is an important agricultural commodity of Pakistan. All of its uses including food and beverage industries result into the waste of its peel, which may be a remarkable reservoir of plant defensive biochemicals including phenolics; and can be used to control various plant pathogens e.g. Alternaria alternata causing leaf spots of tomato. Present study concentrated upon phenolics recovery and evaluation of antifungal potential of phenolics isolated from peels of various citrus types i.e. Lemon, Kinno, Malta, Mossambi and Feutrell's early. Maximum phenolics were recovered from Mossambi (0.21%) with the decreasing trend towards Malta (0.19%) greater than Feutrell's early (0.14%) greater than Lemon (0.13%) greater than Kinno (0.06%). Mossambi contributed better control of A. alternata in comparison with Malta, while the growth inhibition was less in case of Lemon, Kinno and Feutrell's early. Spray of phenolics prior to infection provided protection from fungal pathogen with a maximum disease in case of 1% Mosambi. A decreased curative potential of phenolic acids prevailed in order: Mossambi greater than Malta greater than Feutrell's early greater than Kinno greater than and Lemon with the maximum individual percentage control of 73.4 greater than 59.7 greater than 54.7 greater than 45.5 greater than and15.3%; respectively. Such high antifungal potential of phenolics makes citrus peel an important source of pesticide. copyright 2014 Friends Science Publishers