V. Maneva*, D. Atanasova, T. Nedelcheva, M. Stoyanova, V. Stoyanova
Institute of Agriculture, 8400 Karnobat, Bulgaria
Abstract. In the period of 2012 – 2014, on the experimental field of the Institute of Agriculture in Karnobat, Bulgaria, was conducted a field trial of various sowing and fertilization rates of einkorn. There were four sowing variants: 100% − optimal sowing rate, accepted as control (420 seeds/m2), 125% (525 seeds/m2), 150% (630 seeds/m2) and 175% (735 seeds/m2). The fertilization rates were also four: unfertilized control − N0, N40, N80 and N120 kg/ha. All the trial variants were investigated for insects, diseases and weeds. The highest einkorn yield was obtained after increasing the sowing rate by 50% above the optimal, followed by 25%. The differences in yield after the various fertilization rates were insignificant, which supported the view that it is not necessary to fertilize einkorn. There is greater lodging of einkorn when the fertilization rate is increased. During the studied period no diseases were found on einkorn. As for the pests, there was found the harmful effect of three types of cereal flies − Phorbia securis T., Chlorops pumilionis Bjerk. and Oscinella frit L. and the cicada Philaenus spumarius. The highest density of 6.5 nb/m2 for the cereal flies was established for the optimal sowing rate and the unfertilized variant, probably due to the sparser crops. During the einkorn spring vegetation period, the cicada Philaenus spumarius was found in its highest density for the optimal sowing rate, probably due to the sparser crops and in the variant with N80 fertilization. The least attacked variants were 175% and N120, due to the greater crop density. With the increase of sowing rate of einkorn the weed density and fresh mass were reduced. The increasing rates of nitrogen fertilization increased the competitiveness of einkorn, which led to reducing the weed density, but the fresh mass per weed plant increased proportionally with increasing the fertilization rates. The weeds in all the trial variants had low density, below the economic threshold of harmfulness.