The effect of temperature on graft union formation in mango (Mangifera indi
ca L.) was studied using light microscopy. Graft union was favoured at temp
eratures of 24 and 28 degrees C, but grafts failed to develop at 15 and 20
degrees C. At 38 degrees C, unions formed 20 days after grafting, but furth
er exposure to this temperature caused tissue injury and death of callus ce
lls.