A rapid tissue testing methodology for optimum potassium fertilization of potato grown under subtropical short-day conditions

Abstract

Field experiments were conducted at the Central Potato Research Station, Jalandhar (Punjab) during 1989–90 and 1990–91 on a sandy loam soil (Typic Ustochrept) to develop a tissue testing methodology for determining the optimum dose of K to be applied as a side dressing at the time of earthing up, based on leaf tissue analysis. The sixteen treatments consisted of all combinations of four levels of K applied as basal at planting and as side dressing at the time of earthing-up (30 days after planting (DAP) in two potato cultivars, Kufri Jyoti and Kufri Chandramukhi. The combined application of basal and side dressed K was superior in increasing tuber yield of potato compared to their individual application. The concentration of K in leaf blade or petiole at the early stages (29–40 DAP) was more related to basal K than to basal+ side dressed K, while at the later stages (40–60 DAP) it was more related to basal+side dressed K than to basal K. This suggests the need to apply both basal as well as side-dressed K to maintain a high K concentration in the leaf tissues throughout the crop growth cycle.