Influence of environmental conditions in a glasshouse on conidia of Botrytis cinerea and on post-harvest infection of rose flowers.
Kerssies, A.; Zessen, A. I. B. van; Frinking, H. D.;
European Journal of Plant Pathology Year: 1995 Vol: 101 Issue: 2 Pages: 201-216 Ref: 29 ref.
1995
บทคัดย่อ
Quantification and horizontal distribution of air-borne inoculum of B. cinerea in a rose crop was studied in a greenhouse of 300 m2 during 1991-92. Conidia of B. cinerea were caught in spore traps consisting of an agar medium selective for B. cinerea in Petri dishes placed within the crop at flower height 1 m above ground. Spore catches were counted as colonies after incubation. Lesions due to conidial infection were counted on petals of rose flowers, also after incubation. RH and temp. within the greenhouse and global radiation and windspeed outside were recorded during the experiments. The horizontal distribution of B. cinerea in a rose crop grown under glass was fairly uniform in both years. In 1991, no clear seasonal pattern in the number of colonies was found. In 1992, the number of colonies were high in Aug., Sep. and Oct. The number of lesions on rose flowers showed a distinct pattern in both years. In Aug., Sep. and Oct., many lesions were counted, whereas in the other months few lesions
appeared. In linear regression analysis, variation in numbers of colonies (spore catches) could not be explained by environmental factors recorded during the experiments. Linear regression accounted for 76 and 63% of the variation in the number of lesions on rose flowers in 1991 and 1992, in terms of RH (positively correlated), global radiation outside the greenhouse (negatively correlated) and numbers of colonies on spore traps (positively correlated). The results in the rose crop suggest that RH, global radiation and spore density in greenhouses are important variables in regulating the numbers of lesions during storage and transport. The numbers of spores in greenhouses are dependent on the production system. A greenhouse with a system resulting in wet dead tissue on the ground gave higher amounts of spores in the greenhouse air and through that high numbers of lesions on flowers. On roses outside the greenhouses high numbers of lesions were often counted, mostly during and after rain showers, as a resul
t of rain-deposition of spores onto the flowers.