Fungi occurring on narcissus plantation in annual and biennial cropping

摘要

The foliage and bulb healthiness and fungi occurring on four narcissus cultivars (Dutch Master, Fortissimo, Gigantic Star and Tahiti) grown in two subsequent years on the commercial plantation near PuLawy, were investigated in 2009-2010. Among fungalisolates obtained from foliage, species Botrytis narcissicola dominated. The share of the pathogen isolates increased in the second year of cropping, ranged from 92 to 100% of all obtained isolates at the end of flowering. The mean disease index values for the above-ground plant parts of investigated cultivars ranged from 0.75 to 2.75 at the beginning of flowering and from 2.0 to 3.5 at the end of flowering. The species Fusarium oxysporum was more frequently isolated from the diseased bulbs of narcissiin the second year of cropping. The mean disease index values of bulbs ranged from 7.0 to 17.5 in the first year and 7.5 to 20.75 in the second year of cropping. The most infected cultivar was Tahiti. The obtained results indicated the necessity of digging up the bulbs every year and rotation of cropping place to reduce possible risk of smoulder and Fusarium rot in the secound year of subsequent cropping.