EFFECT OF TITANIUM ON ASSIMILATION LEAF AREA AND CHLOROPHYLL CONTENT OF VERY EARLYMATURING POTATO CULTIVARS
Background. Titanium applied via roots or leaves stimulates plant growth. Titanium exerts a favourable effect on plant growth only at low concentration, while at higher concentrations it may exhibit toxic effects. Determining the optimal doses and dates of titanium application are very important in the optimisation of early potato production.
Material and methods. The effect of dose (0.2 dm3·ha-1 or 0.4 dm3·ha-1) and date (leaf development stage – BBCH 14-16, tuber formation stage – BBCH 41-43, and at both leaf development stage and tuber formation stage) of a Tytanit® application (8.5 g Ti in 1 dm3) on the assimilation leaf area and chlorophyll content of very early-maturing potato cultivars was investigated. The field experiment was established as a split-block-split-plot design with a control object without Tytanit®. The assimilation leaf area was measured by the weight method and the chlorophyll content was estimated using a chlorophyll meter SPAD-502.
Results. Tytanit® caused an enlargement of the assimilation leaf area and an increase in chlorophyll content in leaves, particularly under stress conditions. Under thermal and moisture conditions unfavourable for the growth of very early-maturing potato cultivars, a Tytanit® dose of 0.4 dm3·ha-1 stimulated the growth of leaves more strongly than a dose of 0.2 dm3·ha-1. The plants produced a greater assimilation leaf area when Tytanit® was only applied once, in the leaf development stage (BBCH 14-16) or in the tuber formation stage (BBCH 41-43). A double Tytanit® application resulted in a reduction in the assimilation leaf area compared with a single treatment. Following Tytanit® application, the leaf area index (LAI) averaged 4.13 and was higher by 0.42 compared with the cultivation without growth stimulant, while the specific leaf area (SLA) averaged 3.290 m2·kg-1 and was higher by 0.129 m2·kg-1 than in the cultivation without growth stimulant. The SLA was the highest when Tytanit® was only applied once in the tuber formation stage (BBCH 41-43). The dose and date of Tytanit® application slightly affected the leaf greenness index (SPAD).
Conclusion. The present study demonstrated the stimulating effects of titanium ions (Tytanit®) on the assimilation leaf area and chlorophyll biosynthesis in leaves of very-early maturing potato cultivars under stress conditions.