Identification and codification of phenological stages of the karonda (Carissa carandas L.) according to the BBCH scale

Abstract

Karonda is a nutritive and medicinally important wild fruit crop cultivated mainly in Asian countries. The plant and its produce are widely used in the Indian tribe’s medicine, Ayurveda, Unani, and Homoeopathic system of medicines. However, its phenological stages have not yet been defined systematically. In this study, the important phenological growth stages of karonda occurring during an annual growth cycle were identified and described using a three- digits extended BBCH (Biologische Bundesantalt, Bundessortenamt und Chemische Industrie) scale. A total of 38 secondary growth stages encompassing the 7 principal growth stages were identified and described as per the BBCH scale. The seven principal growth stages identified include three vegetative stages (bud, leaf and shoot development), two flowering stages (inflorescence emergence and flower development) and two fruiting stages (fruit development and maturity). Besides, the physicochemical changes occurring during fruit development and maturity stages were studied. The fruit weight, total soluble solids and iron content increased gradually during fruit development stages starting from 701 stage and reaching maximum at the 819 stage. Further, the important insect pests were documented from 010 to 819 stages. The insect pests such as defoliator and shoot webber cum borer were belonging to the Sphingidae and Tortricidae families respectively, were most commonly observed. The detailed description of phenological stages based on BBCH scale, information of physicochemical changes and insect pests generated in this study will help for scientific cultivation of karonda especially in scheduling crop production and crop protection practices. Besides, the developed BBCH scale can be a useful tool for characterization of germplasm in the gene banks and understanding the effect of climatic changes on karonda production.