Carrot pests and diseases
New viruses threaten carrot crops
Well established viruses affecting carrot crops are: Carrot Motley Dwarf (CMD) complex and Parsnip Yellow Fleck Virus (PYFV). Recent discoveries include: Carrot Yellow Leaf Virus (CYLV) and Carrot Torrado Virus (CaTV). Foliar symptoms are similar for many of the carrot viruses and can cause seedling death and severe plant stunting when crops are at an early stage. Typically leaves become yellow and reddish in colour. The main vector responsible for the transmission of these viruses is the Willow-Carrot aphid. Other possible vectors may include Peach Potato aphid and Parsnip aphid.
Monitoring crops for pests
Monitor crops closely when Rothamsted suction trap data indicates emergence of target aphids, using yellow water traps. Use in-field sticky traps to help monitor carrot fly activity and pest pressure.
Stay alert for downy mildew
Downy mildew can be a devastating disease in the absence of a robust fungicide programme. Early, forward crops and warm weather conditions are conducive for downy mildew development. Start fungicides early – when crops reach 4 to 5 leaves. Use crop growth stage rather than date for starting applications. Keep intervals tight, 7 days is ideal for protecting new growth. Including a range of active ingredients with different modes of action ensures cleaner crops.