The assesment of drought resistance of species and cultivars of perennial grasses | Daudzgadīgo stiebrzāļu sugu un šķirņu sausumizturības vērtējums
2019
Berzins, P., Latvia University of Life Sciences and Technologies, Skriveri, Skriveri Municipality (Latvia). Research Inst. of Agronomy | Rancane, S., Latvia University of Life Sciences and Technologies, Skriveri, Skriveri Municipality (Latvia). Research Inst. of Agronomy | Stesele, V., Latvia University of Life Sciences and Technologies, Skriveri, Skriveri Municipality (Latvia). Research Inst. of Agronomy | Jansons, A., Latvia University of Life Sciences and Technologies, Skriveri, Skriveri Municipality (Latvia). Research Inst. of Agronomy | Vezis, I., Latvia University of Life Sciences and Technologies, Skriveri, Skriveri Municipality (Latvia). Research Inst. of Agronomy
Latvia is increasingly affected by the climate change and it is important for grass breeders to follow these processes. 2018 was the driest year in the history of Latvian weather observations. In 2018 in general, the precipitation was by 30% lower, but in summer months it was even 2−3 times lower than the long-term average. It means that during the entire vegetation period there was an increased drought, which was combined with elevated air temperatures. While the previous 2017 was very rich in precipitation (in summer months it exceeded by more than 40%). The challenge of grass breeders is to develop varieties more resistant to these changes. This article summarizes data on dry matter yields (DMY), regrowth, winterhardiness, drought resistance and grass coverage in three ley years (2015−2017) of three field experiments in light to medium loamy sand soils for species: Lolium perenne L., Dactylis glomerata L., Festulolium, Phleum pratense L., Festuca pratensis Hudds, Festuca arundinacea Schreb. After the 1st cut in late May − early June some of species and varieties showed no signs of re-growth for a very long time. Regrowth was strongly affected by the species, variety and the ley year. Higher DMY was demonstrated by the swards of the 1st ley year. If in the rainy year of 2017 an average DMY was 7−8 t haE−1 , then in the dry year of 2018 it was only 2−5 t haE−1 or 30% − 60%. The assessment of the total DMY and regrowth capacity ranked the grass species in our experimet in the following descending droughtresistance sequence: F.arundinacea; → F.rubra; → D.glomerata; → Ph.pratense; → F.pratensis; → xFestulolium; → L.perenne. There were differences between varieties within each species.
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