DISTRIBUTION OF FUSARIUM OXYSPORUM AND FUSARIUM OXYSPORUM F.SP. DIANTHI INOCULUM IN CARNATION GREENHOUSES*
The number of propagules of Fusarium oxysporum (F.o.) in soils was determined at the end of a carnation growing season at three soil depths, 0–20, 20–40 and 40–60 cm, by plating soil suspension on agar medium. The proportion of Fusarium oxysporum f.sp. dianthi (F.o.d.) in the total F.o. population was estimated by inoculating the susceptible carnation cv. Fantasia with spore suspensions (106/ml) from each of 25–50 F.o. randomly selected colonies. In ten greenhouses the total count of F.o. propagules in the entire soil profile of 0–60 cm was 330–6567/g soil, and of F.o.d. propagules - 32–1771/g soil. The highest population of propagules of both F.o. and F.o.d. was always found in the top (20 cm) soil layer. The 20–40 cm soil layer contained more propagules than the 40–60 cm layer, but this trend was not consistent in all greenhouses tested. Propagules of F.o. were detected in all soil samples tested, whereas F.o.d. was found only in two-thirds of them. The correlation coefficient calculated between the populations of the two fungi was low. For this reason, it was not possible to predict F.o.d. from F.o. population.
Reuven, M., Nitzani, Y., Szmulewich, Y., Ben-Yephet, Y. and Mor, Y. (1992). DISTRIBUTION OF FUSARIUM OXYSPORUM AND FUSARIUM OXYSPORUM F.SP. DIANTHI INOCULUM IN CARNATION GREENHOUSES*. Acta Hortic. 307, 51-56