Influence of calcium on yield and quality aspects of potatoes (Solanum tuberosum L.)

[摘要] ENGLISH ABSTRACT: The potato (Solanum tuberosum L.) is an adaptable crop, and modern varieties make its cultivation feasible in numerous parts of the world. The high production potential of the potato ensures that it has the potential to contribute significantly to the world's food requirements. Correct fertilisation is an important factor in potato production to obtain maximum yields and high quality tubers. Calcium (Ca) is an essential plant element and plays a significant role in the potato plant by maintaining cell membrane and cell wall structure. Recent studies have indicated that tissue Ca level is linked to the quality of various fruit and vegetable products. In the case of potatoes a reduction in tuber internal defects and an improvement in storability can be expected with an increase in tuber Ca. The mechanism of Ca uptake by the potato plant and translocation of Ca within the plant however inhibits the uptake of Ca into the tuber. Thus the present study aims to evaluate the methods to improve Ca tuber content and tuber quality aspects.Potato seedlings of four cultivars (Mondial, Sifra, Lanoma and Innovator) were used in a tunnel where different concentrations of Ca (1.1, 3.2, 6.6 and 9.8 meq Ca L-1) were applied. Tuber mass, shoot fresh mass and shoot dry mass was affected by the Ca application levels and also differed between the cultivars. Mondial, a popular South African cultivar, performed best in terms of tuber yield. Application of 3.2 meq L-1 Ca through drip irrigation was most beneficial to yield parameters (tuber yield, shoot fresh mass and harvest index). To study the Influence of different calcium application levels on potato plants under low temperature growing conditions, potato seedlings of cultivars Destiny and Lanorma, were transplanted into 3 m3 bins containing three different soils (sandy, sandy loam and loam) during the winter season. Three calcium application rates (1.1, 3.2 and 6.6 meq Ca L-1) were applied through drip irrigation. The interaction between Ca application levels and cultivars significantly influenced tuber mass, shoot fresh and dry mass. The influence of Ca as a foliar application on the growth, yield and quality aspects of potatoes was also investigated. Two cultivars (Lady Rosetta and Mondial) were used in a trial where different concentrations of Ca were applied as foliar application or soil drench, during tuber bulking and maturation. None of the parameters measured; tuber fresh mass, tuber number, specific gravity, percentage dry mass or chemical composition was significantly influenced by either the foliar application or soil drench calcium applications. It appears that supplemental Ca applied at these rates and time of plant development has no added benefit on yield or quality aspects of potato tubers.Calcium fertilisation can positively affect both yield and tuber quality but the rate and method of application are of utmost importance. Cultivars also respond differently to Ca application and producers should bear this in mind.

[发布机构] Stellenbosch University