Red tamarillos (Cyphomandra betacea): Post-harvest control of fungal decay with hot water and imazalil dips

Abstract

A hot water dip at 50 D C for 8 min effectively controlled quiescent infections in red tamarillos (Cyphomandra betacea (Cav.) SendL) caused by Colletotrichum gloeosporioides (Penz.) Arx and C. acutatum Simmonds. This dip reduced the percentage of fruit with body lesions without significantly increasing peduncle necrosis. Fungi colonising damaged peduncle tissue were controlled using an imazalil dip (1 min at 15 -20DC) at 250 mg active ingredient/litre. The method of imazalil application (in hot water, as a separate cold water dip, or in wax) did not affect its efficacy. Imazalil residues in skin, pulp, and whole fruit were lowest when the fungicide was applied as a separate cold water dip. Storage disorders were significantly reduced using the hot water/imazalil dip, allowing 7 days shelf-life at 20 D C after 8 weeks cool storage at 3.5°C.

Control of Postharvest Diseases of Fruit by Heat and Fungicides: Efficacy, Residue Levels, and Residue Persistence. A Review

“…Arx and Colletotrichum acutatum Simmonds over 8 weeks of storage at 3.5 °C plus 1 week at 20 °C. In addition, water dip treatments at 50 °C followed by IMZ at 750 mg/L, in wax or water mixture at ambient temperature, were equally effective in controlling stem-end lesions and calyx mycelium and necrosis, although IMZ residues in the wax mixture were higher than in the water mixture (1.2 versus 0.5 mg/kg) …”

“…In addition, water dip treatments at 50 °C followed by IMZ at 750 mg/L, in wax or water mixture at ambient temperature, were equally effective in controlling stem-end lesions and calyx mycelium and necrosis, although IMZ residues in the wax mixture were higher than in the water mixture (1.2 versus 0.5 mg/kg). 23 IMZ residue levels in lemons following dip treatments were closely correlated with the rate of fungicide applied. 24 After application of IMZ at concentrations ranging from 250 to 1500 mg/L IMZ at 50 °C, its residues were ca.…”

“…its effectiveness was found to be similar in water or wax. 23 Dip treatments for 10 min in water at 50 °C followed by a 1 min dip in water or wax mixtures containing IMZ at 250, 500, or 750 mg/L at ambient temperature were equally effective in controlling stem-end lesions caused by Colletotrichum gloeosporioides (Penz.) Arx and Colletotrichum acutatum Simmonds over 8 weeks of storage at 3.5 °C plus 1 week at 20 °C.…”

Combined Effects of Fungicides and Thermotherapy on Post-Harvest Quality of Horticultural Commodities

“…In tamarillos, Imazalil was effective against Collectotricum gleosporioides or C. acutatum both in water and in wax if fungicide application followed a hot dip treatment in water at 50 °C for 10 minutes (Yearsley et al, 1987).…”

Tamarillo (Cyphomandra betacea): Effect of field-applied fungicides and post-harvest fungicide dips on storage rots of fruit

“…This technique was not considered commercially acceptable and further investigations of post-harvest treatments have concentrated on the use of cold water dips. A prochloraz + imazalil dip (20°C for 1 min) has been effective in reducing tamarillo storage rots (Yearsley et al 1987).…”