W artykule przedstawiono rzeczywisty i optymalny okres mlecznego użytkowania krów rasy polskiej holsztyno-fryzyjskiej, odmiany czarno-białej. Rzeczywisty okres użytkowania mlecznego krów wynosił około 3 laktacji, natomiast optymalny powinien wynosić od 5 do 8 laktacji. Główną przyczyną krótszego okresu użytkowania krów był wysoki poziom brakowania, który przekraczał 30%. Spowodowany był głównie jałowością (około 60-procentową), chorobami układu rozrodczego i wymion.
The aim of the study was to determine the effect of the length of the fodder galega utilization period on species composition and number of fungi isolated from rhizosphere, rhizoplane and from seeds. Fodder galega plants used for the research were cultivated for the following time length: I – 18–19-years, II – 8–9-years, III – 4–5-years, IV – 3–4-years. Analyses were conducted in 2009–2010. In total 953 colonies of fungi were isolated from roots including 476 colonies in 2009 and 477 in 2010. Cylindrocarpon destructans was the most frequently isolated species (18.5%) in the first year of the study, whereas Trichoderma koningii – was the most often isolated fungus in the second year (26.7%). More than 3.000 isolates representing 43 species were isolated from soil. Penicillium spp., T. viride and T. koningii were the most frequently isolated fungi in both years of the study. The highest number of fungi was isolated from roots and from soil in combinations with short period of fodder galega utilization. Ten species of fungi were identified on seeds. Alternaria alternata, Aureobasidium pullulans, Epicoccum purpurascens, Cladosporium herbarum, Stemphylium botryorum, T. koningii and Penicillium spp. were the most often isolated fungi.
The effect of sowing method, row spacing and length of utilization time of perennial ryegrass plantation on disease occurrence were studied. Plants sown in the autumn were significantly healthier than plants in other two treatments in most cases. There was not observed any effect of row spacing on disease occurrence on perennial ryegrass except for leaf spots during the summer estimation. Perennial ryegrass infection with pathogens usually increased in consecutive years of utilization.