Siika PAVLOVA, Vesselin DOCHEV
Abstract. During the period 2005–2007 at the experimental fields of IASS “Obraztsov chiflik” a provocative fiеld experiment was conducted with simulated drought of 20 varieties winter common wheat. The varieties were cultivated under conditions of moisture providing (control) and simulated drought during the most critical phase of ontogenetic development–flowering–formation of reproductive organs via shelter construction. Resistance to soil and atmospheric drought was investigated also and the vigor of seeds via electrical conductivity of seed membranes–conductormetric. The results of the investigation showed specific features, as depending on the simulated drought, so – on the meteorological variations during ontogenesis. The stress soil and atmospheric moisture during the spring vegetation decreased the resistance to heat of the varieties Todora, Enola and Ludogorie. Under conditions of soil and atmospheric drought the same varieties showed high resistance to heat, also and the varieties Prelom, Kristi, Pobeda, Pryaspa, Preslav. The vigor of seeds decreased as under conditions of stress water providing, so under conditions of soil and atmospheric drought. Increasing the strength of the stressor–soil and atmospheric drought, the vigor of seeds suddenly decreased.
Keywords: wheat, drought resistance, resistance to heat