Effects of Type of Wound, Species, and Humidity on Curing of Yam (Dioscorea alata L.) Tubers before Storage

Abstract

The first week after yam tubers were harvested, conditions of humidity, temperature, and treatment influenced the curing of wounds, the degree of fungus infection, and subsequent moisture loss and breakdown in storage. Certain kinds of wounds, including bruises and deep cuts, are difficult to heal and are not very much affected by treatments. On the other hand, superficial scrapes are best cured in dry air. Cut surfaces can best be cured by drying, but extensive drying causes cracking, which permits fungal infection. Although humid air reduces water loss, it also encourages the growth of fungi. Curing does not involve wound periderm formation, but suberization of wounded surfaces provides ample protection in some varieties. The principal needs of wounded yam tubers during the curing period are restriction of water loss and inhibition of fungal infection. These are contradictory and it may be that curing conditions must be selected as compromises between extremes.