Photosynthetic Efficiency in Sweet Potato (Ipomoea batatas) under Different Nitrogen Fertilization Regimes

摘要

The photosynthetic activity of sweet potato leaves was determined under field experiment during 2015–2017 in ?yznów (49°49′ N, 21°50′ E), using split-plot design in three replicates. The experiment included doses of nitrogen (0, 50, 100, 150 kg N . ha -1 ) and three sweet potato varieties (Beauregard, Carmen Rubin, and White Triumph). The aim was to establish the interactive effect on the physiological activity of sweet potato leaves ordered in the following way: environmental conditions > years x varieties > varieties > years x fertilisation > fertilisation x varieties > fertilisation > years x varieties x fertilisation. Genetic features of the studied varieties had a significant influence on physiological indicators, as: minimum fluorescence efficiency (F o ); maximum fluorescence efficiency (F m ); maximum photochemical efficiency of photosystem II (F v /F m ) PSII efficiency on the light (F v’ /F m’ ) and the actual photochemical efficiency of PSII (Y). Nitrogen fertilisation decreased in the maximum photochemical efficiency of PSII (F v /F m ) which, affected the actual photochemical efficiency of PSII related to the electron transport efficiency (Y). The interaction of variety x fertilisation had the greatest influence on determining the minimum value of chlorophyll fluorescence, whereas the interaction of years x variety x fertilisation, had strong influence on the non-photochemical fluorescence quenching of chlorophyll (qN).