Growth and productivity of potato as influenced by cultivar and reproductive growth: I. Stomatal conductance, rate of transpiration, net photosynthesis, and dry matter production and allocation

Abstract

The effect of cultivar and reproductive growth on leaf gas exchange, water relations, dry matter production and allocation in potato was the subject of investigation. Debudded, flowering and fruiting plants of cultivars Al-624, Al-436, CIP-388453-3(A) and CIP-388453-3(B) were evaluated under field condition of a sub-humid tropical highland of Ethiopia during 2003. Cultivars exhibited differences with respect to leaf stomatal conductance, rate of transpiration and net photosynthesis rate. Cultivars Al-624 and CIP-388453-3(A) showed higher stomatal conductance and rate of leaf transpiration than CIP-388453-3(B) and Al-436. CIP-388453-3(A) exhibited higher net photosynthesis than Al-624 while Al-436 is intermediate. Fruiting plants had higher leaf stomatal conductance and higher rate of leaf transpiration and net photosynthesis. Fruit development promoted early plant maturity and without affecting total dry matter production it reduced the amount partitioned to the leaves, stems, and tubers. The experiment demonstrated that cultivar and fruit development influence on water relations, rate of net photosynthesis and source–sink interactions in the potato.