Authors:S. Bencze, K. Balla, B. Varga, and O. Veisz
A long-term experiment was started in 2005 in the Agricultural Research Institute to monitor the effects of extreme climatic events on the grain yield, quality and disease resistance of cereals. The yield was poor in 2007 due to the long dry period from autumn till spring, while it was high in 2006 and 2008 when there was more precipitation. The grain quality was the highest in 2007, however, despite the extreme weather events. Fungicide treatment generally resulted in higher yield potential and better grain quality in every year.
Authors:B. Varga, K. Balla, S. Bencze, and O. Veisz
The unfavourable effects of climate change were studied in terms of changes in the stress tolerance of cereals. The yield and physiological parameters of two winter wheat genotypes (Mv Mambó, Mv Regiment) were analysed in the phytotron after water was completely withheld for 7 or 14 days in three phenophases. The plants were raised in climate chambers, one adjusted to ambient CO2 concentration and the other to a higher level (750 μmol mol−1). The aim of the present work was to determine the correlations between the duration of water withholding and the phenological, physiological and yield parameters of winter wheat. It was hoped to identify how elevated CO2 levels affected the stress sensitivity of plants and whether they contributed to counteracting the damaging effects of drought. In both varieties, the grain mass decreased to the greatest extent when water was withheld at first node appearance (5.9–71.3%). A longer period of drought at first node appearance and grain filling only reduced the grain number and mass in the case of enhanced CO2. The yield and physiological parameters of Mv Regiment, however, deteriorated substantially as a result of water deficiency, though this variety was better able to utilise surplus CO2, giving outstanding results at elevated CO2 level.
Authors:S. Bencze, I. Keresztényi, B. Varga, B. Kőszegi, K. Balla, A. Gémesné-Juhász, and O. Veisz
The effect of CO2 enrichment on the rate of photosynthesis and the water use efficiency (WUE) of young pepper and tomato plants was studied in the phytotron. A CO2 level of 1000 ppm significantly increased the net assimilation rate in the upper foliage, while the increase was even more considerable in the lower layers of the canopy, with values of up to 100%. The 1500 ppm CO2 level caused a further substantial increase in CO2 assimilation and at least doubled (in tomato) or tripled (in pepper) the water use efficiency on a leaf area basis compared to the ambient values. Although the response in terms of photosynthesis and WUE was not variety-specific, there were differences between the pepper hybrids in the biomass components, exceeding 100% for the total biomass at the 1500 ppm CO2 level. In tomato, however, there was no significant variation in the total biomass of the three hybrids investigated in this early phase of development at either CO2 level.