Abstract:
A pot experiment was conducted to study the influence of NPK fertilization levels on
photosynthesis, soluble sugars content in source, phloem and sink organs and yield. The major
plant nutrients NPK are involved in numerous physiological processes and their deficiency can
reduce the yield of potato crop. This study aimed to investigate the response of two potato
cultivars to different NPK regimes during subsequent stages, namely reduced photosynthesis
capacity, disturbed sugars content and yield depression.
Our results showed that cultivar, NPK level and tuberization stage influence potato yield mainly
through affecting sugars accumulation and distribution via the photosynthetic efficiency.
Data clearly demonstrated that Spunta, mid-early cultivar, showed higher performance
concerning photosynthesis and yield under sufficient and deficient NPK fertilization levels.
Plants subjected to excess NPK doses recorded an early defoliation. Daifla, mid-late cultivar,
presented similar Fv/Fm for all treatments during different dates of measure, while performing
better regarding production parameters under excess NPK regimes.
Correlation test suggests that plant with high photosynthesis performance lead to low tuber yield
under all NPK levels. This unexpected result could be explained by the effect of high
temperature and long photoperiod which results in a decrease in tuber yield and an increase in
photosynthesis.
|
