H. Nedeva*, R. Ivanova, H. Yancheva
Crop Science Department, Faculty of Agronomy, Agricultural University, 12 Mendeleev, 4000 Plovdiv, Bulgaria
(Manuscript received 20 May 2016; accepted for publication 6 June 2016)
Abstract. The aim of the study was to establish the amount of plastid pigments and some physiological parameters related to photosynthetic processes in two triticale cultivars, grown for biomass under different nitrogen fertilization rates and harvesting stages in the region of Southern Bulgaria. The research was carried out in the field of Crop Science Department at the Agricultural University, Plovdiv, during the period 2013 – 2015. The experiment was set after the block method with four replications, and 20m2 for each experimental plot. Two triticale cultivars – Musala and Attila grown for green biomass at different fertilizer rates (N , N , N , N , N ) have been tested. The two cultivars are harvested in heading formation and milk maturity stages. The physiological parameters – 0 120 160 200 240 intensity of transpiration, photosynthesis rate and the amount of plastid pigments (Chlorophyll A, Chlorophyll B, Carotene) have been observed at different cultivars and harvesting stages. In both tested cultivars in heading stage the transpiration intensity was higher when rates of N were used, while in milk 200 maturity stage the highest values were in variant with N . The photosynthesis rate at both cultivars in heading stage was increased with increase of the 240 nitrogen rate. In the stage of milk maturity the values of some indices decreased in both cultivars. The lowest content of plastid pigments in leaves of Musala cultivar was received in the control variant. It was observed that the increase of the nitrogen rate leads to increasing the pigments content. The highest content of pigments in Attila cultivar was received when N was applied.