The most common disease is powdery mildew, which develops during warm, humid conditions. Early symptoms can be found from late December on but it is best controlled by prevention rather than cure. However, a number of fungicides are available to control this disease. Root diseases such as fusarium are a serious threat to mini-pumpkins. There is no control and sterilising the soil prior to sowing is a last option but is very expensive.
Plants can suddenly wilt and die when infected with fusarium.
Older plants show stunting with a progressive leaf yellowing from the base to the runners when infected and eventually they too will die. Infection can be recognised by inspecting the vein tissue for browning of the water-conducting tissues. Viruses can be a problem, and when plants are infected at an early stage they may become stunted. Leaves have a yellow and green mottled appearance. No control is possible and presently there are no resistant or tolerant cultivars.