EFFECTS OF INCREASING SOIL CALCIUM APPLICATION ON GROWTH AND UPTAKE OF CALCIUM, PHOSPHORUS, ZINC AND BORON IN DURUM WHEAT (Triticum durum L.)

摘要

Calcium has an antagonistic relationship with other nutrients which influence significantly yield and quality of crops plants. These nutrient elements are phosphorus (P), zinc (Zn) and boron (B) which were investigated in the current study and they have positive effects on yield and quality of crop plants. Of these nutrient elements, phosphorus (P), zinc (Zn2+) and boron (BI-) are especially important for their positive effects on plants, which was the subject of the present study. In this study, the effects of a range of soil Ca2+ applications (0, 50, 100 and 200 mg kg(-1) soil) on shoot dry weight, shoot Ca2+, P, Zn2+ and B+ concentrations were determined in five durum wheat cultivars (Ege-88, Kiziltan-91, C1251, Fuatbey-2000 and Zenit). The results showed that shoot dry weight increased by soil Ca2+ application of up to 100 mg kg(-1), and 200 mg Ca2+ kg(-1) soil application reduced shoot dry weight to the level of 100 mg Ca2+ kg(-1) soil. Shoot Ca2+ concentrations also increased by soil Ca2+ applications, and at all levels. Compared to nill soil Ca2+ application, there was almost a three-fold increase in shoot Ca2+ concentration at the rate of 200 mg Ca2+ kg(-1) soil. In contrast, increasing soil Ca2+ supply reduced shoot P, Zn2+ and B+ concentrations significantly. These reductive effects of soil Ca2+ application were the largest on shoot B+ concentration. B+ was also the only nutrient for which there was a genotype x soil Ca2+ application interaction with some cultivars having deficient levels of B+ at the highest soil Ca2+ application (200 mg kg(-1)). The results demonstrate that increased soil Ca2+ content reduced P, Zn2+ and B+ nutrition of durum wheats significantly, thus resulting in lower yields. The results also show that durum cultivars differed in their sensitivity to increased Ca2+ application and potential nutritional disorders that result from it. Screening of a large number of cultivars/accessions for their responses to increased Ca2+ application, and subsequent identification of those with lower sensitivity could be useful for breeding programs that aim to maximise crop yields in soils with high Ca2+ content.