EFFECT OF BORON AND CALCIUM SPRAYS ON PHOTOSYNTHETIC PIGMENTS, TOTAL PHENOLS AND FLAVONOID CONTENT OF SWEET CHERRY (PRUNUS AVIUM L.)

Abstract

The aim of our study was to establish the effect of a three-year-long boron and calcium treatment on some phytochemical compounds of sweet cherry (Prunus avium L.) leaves and fruits. In our trial we used eight-year-old cultivar 'Germersdorfi 3' grafted on Prunus mahaleb rootstock. The boron treatment was applied by spraying disodium-octaborat-tetrahydrat, while calcium was supplied as a calcium nitrate spray. Photosynthetic pigments and total phenol content of sweet cherry leaves and total anthocyanin, flavonoid and phenol contents of sweet cherry fruits were measured, respectively. Boron sprays at blooming time had a positive effect on photosynthetic pigment contents of sweet cherry leaves, on contrary to two times spraying, which reduced their content. Total carotenoids responded similarly to boron spraying: single treatment increased their mass, two-times spraying had a negative effect on the total carotenoid content of the leaves, respectively. Every calcium treatment increased the chlorophyll a and chlorophyll b content. The mass of carotenoids were also in close connection with calcium sprays. It is to be noted that time and frequency of application influenced the mass of both photosynthetic pigments. Effect of boron and calcium sprays on total phenol content was significant. After the double boron treatment, quantity of total phenol content was just ninth of the control leaves. Boron and calcium sprays decreased the total phenol, anthocyanin and flavonoids content in sweet cherry fruits, respectively. However, boron treatment was more effective than calcium sprayings. Conclusion of boron and calcium spraying was significant in most cases of our trial.