DRY MATTER ACCUMULATION AND DISTRIBUTION IN POTATO GROWING WITH SUPERFICIAL AND SUBSUPERFICIAL DRIP FERTIGATION

Abstract

Under greenhouse conditions, an experiment on superficial and sub-superficial drip irrigation was established to assess dry matter distribution and accumulation in potato (Solanum tuberosum). The sub-superficial fertigation system consisted in burying a dripper at 20 cm depth. To apply a nutritive solution with nitrogen, phosphorus, and potassium both systems were automated. The variables measured were stalk, leaf, root and tuber dry biomass, aerial biomass, total biomass, harvest index and absolute growth rate (AGR) of each organ the Montserrat variety. Dry matter accumulation of the total biomass and the harvest index were significantly higher in the superficial fertigation system; on the other hand, leaf and root dry matter were statistically smaller with respect to sub-superficial fertigation system. Stalk, tuber and air biomass were statistically similar in both systems. The AGR for stalk, leaf, root, and aerial biomass in the sub-superficial fertigation were significantly higher than in the superficial fertigation system. The opposite ocurred for tuber and total dry biomass. The AGR of tubers was increased through time to accumulate dry matter, 72 days after emergency the AGR was higher with subsurface fertigation (10.29 g plant^-1) than with surface fertigation (7.84 g plant^-1), thus
indicaling that during the intermediate tuber period, dry matter accumulation was still ocurring.