Hi, a number of my potato plants produced no potatoes or only a few pea sized ones this year. I have never had this problem before. Thanks.

Hi Kate, small potatoes can be caused by lack of water, insufficient fertiliser, poorly drained soils, very hot temperatures, lack of sunlight, or from planting too late in the season. Small pea sized potatoes can also be caused by the Potato psyllid, a small sucking insect that looks like a small cicada, it is a sap sucking insect that injects a bacterium into the plant when it feeds called liberibacter. There is no remedy if this happens, if the potatoes were infected by psyllid early in the season, it could be the reason for your small pea sized potatoes. Psyllid is a problem for plants in the Solanaceae family - potatoes, tomatoes, egg plant, capsicum and tamarillo. If you suspect it is psyllid, remove all plant material to prevent the psyllid overwintering in the soil and burn or dispose of in the rubbish, don't compost. Plant early maturing potato varieties, and cover later plantings with fine insect mesh to keep them at bay. Your local garden centre will be able to recommend a suitable spray to control psyllid, it can be active in warmer regions year round, slow in winter, and is a problem mostly in spring and summer. I have attached a fact sheet from Landcare Research here.  Lianne