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Studies on parsnip canker
Author(s) -
CHAN A. G.
Publication year - 1963
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.1963.tb03689.x
Subject(s) - biology , spore , canker , horticulture , botany , petri dish , peat , agronomy , ecology , genetics
SUMMARY In Petri‐dish trappings in parsnip crops during the wet seasons of 1958 and 1960, ballistospores of Itersonilia pastinacae were first obtained in August and increased in number to a peak in October or November. In the dry seasons of 1959 and 1961 the spores were much fewer and appeared later. There was a diurnal periodicity in the numbers of spores trapped, the maximum concentration occurring around dawn and the minimum during the afternoon. The fungus occurred to only a small extent in the air over bare ground. The numbers of ballistospores of I. perplexans were lower than those of I. pastinacae , but showed somewhat similar seasonal and diurnal fluctuations. I. pastinacae was isolated from parsnip leaves either at the same time as, or shortly after, the earliest trappings from the air. Attempts to prevent the ballistospores of I. pastinacae reaching the roots, by raising ridges of soil or peat over them or by defoliating the plants, resulted in reductions in black canker on the roots.