Browsing by Subject "fungisidi"

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  • Ohralahti, Kalle (Helsingfors universitet, 2013)
    Barley is the most cultivated cereal in acreage in Finland. Barley has many plant diseases that cause yield reductions like net blotch, scald and mildew. The weather conditions and the disease resistance of the cultivar are affecting the appearance of the plant diseases. Plant diseases can be controlled by certified seed, seed treatment, crop rotation, fungicide treatment and by cultivating resistant cultivars. Net blotch causes reduction in green leaf area, thousand grain weight and thereby it reduces yield. The aim of this study was to study what is the yield response of barley to fungicide treatment when cultivars are either susceptible or tolerant to net blotch. The data of this study was based on The profitability of plant protection -trial series. The field trials were conducted at three locations in Finland during 2006–2009. The cultivars in the trials were divided based on their net blotch resistance to susceptible and tolerant groups. Fungicide treatment was made with Acanto Prima as a single treatment at the flag leaf stage. Tolerant and susceptible groups differed significantly in the amount of the net blotch. Fungicide treatment decreased the appearance of net blotch more in the susceptible group although the amount of net blotch was significantly less in the tolerant group. In the tolerant group the disease level was low even before the fungicide treatment. The conclusions of this study were, that tolerant cultivar group had better yield, but susceptible cultivar group had better yield response to the fungicide treatment. The yield response was in average 400 kg/ha in the susceptible and about 200 kg/ha in the resistant cultivar group. The yield response was due to the higher thousand grain weight. The yield security of disease resistant cultivar is better also in higher disease pressure. Resistant cultivar is one way to reduce the usage of plant protection products in IPM farming. Breeding of resistant cultivars is needed because the plant diseases are altering in their disease infection capability.
  • Klingberg, Ninni (Helsingfors universitet, 2012)
    Fungi are the major causal agents of several plant diseases. Fungicides are regularly used in forest tree nurseries to protect and eradicate fungal pathogens. However, the use of fungicides can create problems such as the alteration of natural fungal communities in the upper and lower part of the seedling, and fungicide resistance. These factors may lead to new disease problems in the nursery. Excessive use of fungicides is harmful to environment and might prevent the emergence of novel beneficial fungal species. Some foliar endo- and epimycota are known to suppress fungal diseases and protect the host from herbivoria and abiotic stress. The aim of this study was to investigate if routinely used fungicide (Tilt 250 EC propiconazole as an active ingredient) against Scleroderris canker (Gremmeniella abietina) has side-effects on the non-target foliar mycobiota as well as on the height growth of Scots pine (Pinus sylvestris) seedlings in a Finnish forest nursery. The experiment was conducted in a Finnish forest tree nursery during one growing period. Altogether 100 needles were sampled which resulted in a total of 186 fungal endophytic isolates, and 40 needles sampled resulted in a total of 86 epiphytic isolates. Endophytic isolates were further analysed and assigned to 37 operational taxonomic units (OTUs). Phoma spp. were the most frequently isolated OTUs in both treatments. There were no statistically significant differences between mycota isolated from fungicide treated and control seedlings (except between epiphytes in September), however there were quantitative and qualitative differences which was mainly seen in the higher number of exclusive fungi in control seedlings. There were no statistically significant differences between the growth of fungicide treated and control seedlings but fungicide treated seedlings grew faster at the end of the growing season. These results suggests that fungicide treatment has side-effects on the non-target foliar mycobiota and the growth of Scots pine seedlings.