Z. Petrova1*, Z. Zlatev2 1Dobrudzha Agricultural Institute, 9520 General Toshevo, Bulgaria 2Department of Plant Physiology, Faculty of Agronomy, Agricultural University, 12 Mendeleev, 4000 Plovdiv, Bulgaria Abstract. The aim of this investigation was to determine the effect of the dat

Z. Zlatev, V. Popov Abstract. The aim of this study was to investigate the effect of organic fertilization on photosynthesis of young tomato plants (Lycopersicon esculentum Mill.) – cv. Trapezica and cv. Yana. The field experiments were carried out at the experimental field of the Agr

K. Uzunova, Z. Zlatev Abstract. Laboratory experiments were conducted to study the effect of soil drought on photosynthesis of young cowpea plants (Vigna unguiculata L.) – cv. Lagoa and cv. 1183. Drought conditions were imposed on 2-week-old plants by withholding water for 10 days. It

Z. Zlatev Abstract. Laboratory experiments were conducted to study the effect of soil drought on leaf gas exchange and water relations of young sunflower plants (Helianthus annuus L.) – cv. Favorit and cv. Albena. Similar changes were established in the parameters tested. Significant

Z. Zlatev, T. Kolev Abstract. Changes of functional activity of the photosynthetic apparatus of four durum wheat cultivars under low positive temperature stress were studied. Parameters of chlorophyll fluorescence in dark-adapted and light-adapted leaves were analyzed, as well as leaf