Botrytis cinerea als parasiet van vlas

After some introductory words on flax, different forms of the parasite Botrytis cinerea Pers. ex Fr. were compared. Use of differences in production of organic acids as done by van Beyma Thoe Kingma were not a satisfactory distinction between formae lini of Botrytis. The M, Sc and Sp growth forms, few isolated interforms, B. bifurcata Miller and B. allii Munn. all produced significant amounts of citric acid; the amount depended on isolation, temperature, nutrient medium and amount of CaC0 3 in the medium. Although the species was polyphagous, where it grew as a parasite was related to its growth form.
Stages discussed of the disease in flax were the juvenile phase (caused by infected seed, spread through the soil to other plants), an intermediate phase (during accelerated growth of the flax, the stem base was attacked by spores of the juvenile phase), and the flowering phase (spores from elsewhere or from the interphase).

Other topics were: environmental influences encouraging grey mould during the phases; ways of treating flax seed, research on seed infection (comparison of the Ulster and filter-paper method); differences in infectivity with environment; and finally chemical disinfection of seed and its toxicity to the plant.