Effect of treatment with Trichoderma harzianum Rifai formulated in invert emulsion on postharvest decay of apple blue mold
Y. A. Batta
International Journal of Food Microbiology, Volume 96, Issue 3, 15 November 2004, Pages 281-288
2004
บทคัดย่อ
Conidia of Trichoderma harzianum were formulated in invert emulsion (water-in-oil type) at a concentration of 6.0×107 conidia/ml of the formulation. Treatments with conidia in the formulated emulsion and conidia in sterile distilled water were conducted to assess the effect on Penicillium expansum Link inoculated on applefruits.Comparisons were made with control treatments of an uninoculated emulsion and uninoculated distilled water. The T. harzianum-containing emulsion significantly (P£0.05) reduced the decay-lesion diameter compared to the T. harzianum-containing water or the uninoculated emulsion or distilled water controls (17.5, 25.7, 34.0, and 34.2 mm, respectively). Significant differences (P£0.05) were also obtained between means of percent reduction in decay-lesion diameter relative to sterile distilled water control in the treatments with formulated and nonformulated conidia and control with uninoculated invert emulsion (48.8%, 24.8%, and 0.6%, respectively). Mean time period needed for sporulation of P. expansum was significantly (P£0.05) increased when the treatments with formulated T. harzianum conidia were applied in comparison with the other types of treatments (14.2 versus 12.2, 9.0, and 8.8 days, respectively, for the other treatments). However, no significant differences (P£0.05) were obtained in means of decay-lesion diameter or in means of time period needed for sporulation of P. expansum in the control treatments (uninoculated invert emulsion versus sterile distilled water). This indicates that the effect of the formulation ingredients on decay-lesion development of P. expansum or its sporulation was not significant. A significant (P£0.05) long period of protection from P. expansum infection (up to 2 months) was also obtained when unwounded applefruitswere dipped for 30-s period in formulated T. harzianum conidia before being inoculated by P. expansum compared to the woundedfruits.This indicates the importance of the latter type of treatment in protecting applefruitsfrom blue mold infection for long time atpostharveststage without refrigeration.