Performance of AM fungi in peat substrates in greenhouse and field studies

The impacts of peat on mycorrhizal traits has been studied in several field and greenhouse experiments at MTT Agrifood Research Finland In the field experiments, AMF traits were affected by cropping systems and preceding crops but also by peat amendment. Peat had a negative impact on mycorrhizal effectiveness and AMF spore numbers, but did not affect species frequency or the Shannon-Wiener diversity index

Hög skördepotential hos jordgubbe i ekologisk odling beror på markens biologiska egenskaper

Ett långliggande fältförsök med olika odlingssystem utnyttjades för jämförelse av skördepotentialen hos jordgubbe i konventionell respektive ekologisk odling. Skördepotentialen var högre på de ekologiskt odlade försöksytorna och kunde höjas ännu med genom tillförsel av torv

Arbuscular mycorrhiza as part of sustainable agriculture

Here we present some results from two studies of mycorrhizal functioning in conventional vs. organic agriculture and also of the impact of various standing crops

Uudet tekniikat käyttöön avomaalla

Avomaan vihannesviljely kamppailee monien kannattavuutta nakertavien ongelmien puristuksessa. Viljelytekniikoiden kehittäminen on haastavaa, sillä hintojen vertailu osoitti viime kesänäkin, että esimerkiksi kerä- ja kukkakaali oli elokuussa Suomessa jopa halvempaa kuin Hollannin suurissa huutokauppahalleissa. AVIKE-hankkeen päätösseminaarissa 31.8. Hyvinkäällä etsittiin keinoja avomaan vihannestuotannon kilpailukyvyn parantamiseen.vo

Damping-off of sugar beet in Finland: III Effect of temperature and disease forecasting

The effect of temperature on the severity of damping-off of sugar beet was studied under controlled conditions. The disease incidence increased with increasing temperature. When the time up to emergence in a finesand soil was characterized by low temperatures (8°C night, 15°C day), a period of 14—21 days immediately after emergence caused a strong increase in disease incidence. In peat soil, even 7 days was enough to initiate such an increase. In neither of the soils used did three days of high post-emergence temperature cause any marked disease increase. When the pre-emergence period was characterized by high temperatures (15°C night, 25°C day) the disease was at a high level and in the very fine sand soil could not be lowered by lower temperatures. In the peat soil, however, a constant, low postemergence temperature significantly inhibited the development of the disease. The possibilities of damping-off forecasting by comparing the disease incidence in pot experiments to damping-off in the field seemed rather limited. When the temperature is taken into account, a negative prognosis may be possible. The basis of such a prognosis is the determination of the inoculum potential of the soil

The effect of vesicular-arbuscular mycorrhizal inoculation on the growth and root colonization of ten strawberry cultivars

Ten strawberry cultivars, four early maturing, three late maturing and three “special” cultivars, were inoculated with six strains of vesicular-arbuscular mycorrhizal (VAM) fungi in a pot experiment. Growth effects and colonization of the VAM fungi were studied. Three strains, Glomus macrocarpum V3, G. mosseae Rothamsted and G. sp. V4, were highly efficient, causing significant growth increases in most cultivars. ’Jonsok’ showed the highest mycorrhizal dependency index, 648, and ’Ostara’ the lowest, 269, for the mean response of all six fungi. The fungal strains which increased shoot growth the most also increased the runner plant formation the most. Early cultivars showed higher colonization percentages than late maturing cultivars. Sporulation of the introduced VAM fungi was on average more abundant in early and special cultivars than in late cultivars. Root colonization and strawberry shoot dry weight correlated significantly in most cultivars, but the correlation between colonization and runner formation was generally poor

Occurrence and pathogenicity of Pythium spp. in seedling roots of winter rye

Seedlings of winter rye collected from yellowing patches during October to November 1985—1987 showed oospores of Pythium species in apparently healthy as well as in discolored roots. Examination of 1550 root pieces of rye on CMA yielded fungi belonging to 35 genera. The most commonly isolated ones were Fusarium spp, Penicillium spp, Mucor spp, Mortierella spp. and Cladosporium spp. Pythium spp. were isolated from 35 root pieces on CMA. Identified species were P. splendens, P. irregulare, P. dissimile, a species resembling P. aristosporum and a species resembling P. ultimum. In in vitro and in vivo, tests on the cereals winter rye, spring wheat, oats and barley the pathogenicity of some Pythium isolates varied from high (P. splendens, P. irregulare) to moderate (P. irregulare, P. dissimile) and low (a species resembling P. ultimum)

The effect of growth substrate and fertilizer on the growth and vesicular-arbuscular mycorrhizal infection of three hosts

The effect of growth substrate in combination with two compound fertilizers or bone meal on the vesicular-arbuscular mycorrhizal (VAM) infection and growth of micropropagated strawberry (Fragaria x ananassa Duch.) and arctic bramble (Rubus arcticus L.), as well as maize (Zea mays L.) was studied in pot experiments. With all test plants, sand fertilized with bone meal was superior to the richer peat-based substrates in initiating rapid VA mycorrhizal infection and sporulation of the VAM fungi used. A fertilizing regime yielding plants of a sufficient size, which at the same time are mycorrhizal, is suggested

Diversity and abundance of arbuscular mycorrhizal fungi associated with acacia trees from different land use sysetms in Ethiopia

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Genetic and management adaptation of field bean (Vicia faba L.) in Finland

The investigation of field bean adaptation in Finnish climatic conditions was carried out at the University of Helsinki in 1976—77. The main objectives were to study the effects of seeding time and population density on the quantity and quality of the yield and the vegetative features in the development of two different types of field bean varieties. Field bean yielded 4061 kg/ha in 1976. In 1977only 2042kg/ha was harvested due to the lack of light during the grain filling period and the presense of plant diseases. Delayed seeding lowered yields in both years. Maximum yield was obtained with the seed rate of 240 kg/ha. Two weeks delay in the seeding speeded up flowering by two days. Temperature sum in degree days from seeding to emergence was 140—170°C, from seeding to flowering 618—637°C and from seeding to maturity 1670—1890°C. LAI was 5.7 for early variety and 4.3 for late variety at the time of pod setting representing very effective situation for CGR. Number and distribution of internodes, pods and seeds were primarily influenced by population density and secondly by the differences between varieties