ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Detection and significance of symptomless latent infections of Monilinia fructicola in plums.

Northover, J.; Cerkauskas, R. F.;

Canadian Journal of Plant Pathology Year: 1994 Vol: 16 Issue: 1 Pages: 30-36 Ref: 28 ref.

1994

บทคัดย่อ

ABSTRACT :

Immature European plums with symptomless latent infections were detected in orchards in Niagara, Ontario, Canada, which showed evidence of blossom blight or brown rot (caused by M. fructicola) of immature fruits. Plums were surface-disinfested in 70% ethanol for 10 sec and in 0.5% NaOCl with 0.05% Tween 20 for 4 min, followed by a sterile water rinse. Fruits were dipped in paraquat (Pq) (6 g/litre) for 1 min followed by a 3 min sterile water rinse, or ethephon (Eth)(1.5 g/litre) for 4 min without a rinse. Treated plums were incubated in sterile containers at high humidity (>95%) at 25 deg C in light (L) or darkness (D). Fruits at the pit-hardening stage of development responded rapidly to the Pq-L treatment, with 80% of them developing brown rot after 5 d of incubation. The order of descending efficacy was: Pq-L, Pq-D, Eth-D, Eth-L, Check-D, Check-L. For Stanley and Bluefre plums at the fruit-colouration stage, latent infections responded similarly and their rate of development into brown rot le

sions with sporodochia was greater for a high incidence than for a low incidence of latent infection. The combined percentages of plums with brown rot at harvest and after postharvest incubation, were postively correlated with the percentages of immature fruits with symptomless latent infection (r=0.917, (P=0.01) and r=0.954 (P=0.001) for 7 and 14 d incubation, respectively). It is concluded that the earlier detection of latent infections would allow corrective measures to be taken preharvest or postharvest to reduce brown rot of mature plums.