Morphological and Physiological Analysis of VRI-3 Cashew Plantations under Different Planting Density Systems

Abstract

Cashewnut (Anacardium occidentale L.) is an export-oriented plantation crop. The VRI-3 cashew plantation, utilizing a 7 x 7 m low-density (LD) system with approximately 200 plants ha-1, falls short of meeting the country's import and export demands. Consequently, a high-density planting (HDP) system was developed in Tamil Nadu to enhance India's cashew production. Further advancement through ultra-high-density planting (U-HDP) has proven effective, achieving a plant population of about 1250–1600 plants per hectare. In addition to the increased number of plants in the U-HDP approach, morphological characteristics such as tree height, trunk height, trunk girth, and canopy ground coverage were studied. The impact of these morphological changes resulting from an increased tree population on physiological parameters like Leaf Area Index (LAI) and light extinction coefficient (k) was also analysed. This analysis was carried out using the ‘Ceptometer’ model AccuPAR LP-80 device, aiming to determine how these changes might interfere with productivity and subsequently influence the cashew plantation's production capacity.