Phosphorus efficient potato cultivars for Nilgiris

摘要

Field experiments were conducted at Central Potato Research Station, Muthorai, the Nilgiris, Tamil Nadu for three years with seven potato cultivars under four levels of phosphorus application to evaluate their phosphorus use efficiency. Cultivars Kufri Neelima and Kufri Swarna were found more P efficient because of their higher relative biomass production, tuber yield efficiency index, harvest index, agronomic use efficiency (AUE) and P uptake efficiency. These two cultivars produced higher tuber yields under no P and at P max of standard variety. The cultivars Kufri Girdhari, Kufri Jyoti and Kufri Himalini proved P responsive as they responded well to its application and produced very low yields under no P application. Higher root biomass in these two efficient cultivars could be the reason behind their higher P use efficiency in comparison to other cultivars. The two P efficient potato cultivars also happened to be resistant to potato cyst nematode, which are very common and serious problem in Nilgiris. The mechanism to have resistance against PCN, whose cysts emerge only in the presence of root exudates of susceptible potato cultivars, could also have benefitted those cultivars to show more efficiency in native P utilization. Further investigations are required to find out the exact mechanism of P efficiency in these two PCN resistant cultivars.