Evaluation of chinese potato (Plectranthus rotundifolius) germplasms under coconut-based cropping system in Tamil Nadu

Coconut (Cocos nucifera L.), a key plantation crop in India, contributes significantly to the national economy. Despite high productivity, coconut farmers face challenges including fragmented landholdings and biotic stress, necessitating the adoption of intercropping systems to improve land use efficiency and profitability. Intercropping shade-tolerant tuber crops like Chinese potato (Plectranthus rotundifolius), particularly in the underutilized interspaces of coconut plantations, offers multiple agronomic and economic benefits. An experiment was conducted during the 2024-25 kharif season in Theni district, Tamil Nadu, to evaluate the performance of 40 Chinese potato germplasms under an 8-year-old coconut plantation. The study followed a randomized block design with three replications. Data on growth and yield parameters such as number of branches, days to flowering, tuber dimensions, tuber count and fresh tuber weight were recorded and statistically analyzed. Germplasm PKM-CP-2 exhibited superior performance in tuber length, width, number and yield (333.8 g plant-1), followed by PKM-CP-10, PKM-CP-4 and PKM-CP-8. In contrast, PKM-CP-23 consistently showed the lowest performance across several traits. The results suggest substantial genotypic variation among germplasms, with certain accessions demonstrating promising yield potential for intercropping systems. The study highlights the viability of integrating Chinese potato as a high-value secondary crop in coconut plantations, providing enhanced income opportunities for smallholder farmers and optimizing resource utilization. Further exploration of high-performing germplasms could support commercialization and diversification in coconut-based farming systems.