| Abstrakt: |
Based on a field study in a tropical region of China, the effects of dry-period irrigation and fertiliser application on seed quality, leaf, whole-plant, and reproductive (flower and seed) traits of Plukenetia volubilis L. plants were examined. The results showed that leaf photosynthetic capacity and stomatal conductance, measured in the middle and at the end of the dry season, were significantly improved by irrigation, but not by fertilisation. Dry-season irrigation increased adaxial stomatal density, fine-root volume, leaf area index, total biomass, and fruit biomass during that season, but decreased water-use efficiency. Plants grown under natural drought conditions had lower numbers of female flowers, male flowers, and fruit per plant, and a higher percentage of fruit abortion at the end of the dry season compared to plants which had been well-watered. Although the effects of irrigation and fertilisation, applied during the dry season, on leaf traits and on the numbers of reproductive organs were not apparent in the wet season, pods that had initiated in the dry season were more likely to abort in the wet season, reducing yields at a late stage. Both irrigation and fertilisation increased the protein content of seeds collected at the end of the dry season, but they did not significantly affect the oil content or fatty acid profile of seeds. We conclude that dry-season irrigation can enhance plant growth, affecting overall yields in that year and possibly in subsequent years. However, irrigation and fertilisation did not seem to affect seed quality directly. [ABSTRACT FROM AUTHOR] |
