Turnip yellows virus

Turnip yellows virus (TuYV) is a significant plant pathogen belonging to the genus Polerovirus. This viral disease is primarily transmitted by aphids, most notably the green peach aphid (Myzus persicae), in a persistent manner. It remains one of the most economically damaging viruses affecting various agricultural crops globally.

The primary hosts of this virus are members of the Brassicaceae family. It poses a severe threat to oilseed rape (canola), cabbage, broccoli, cauliflower, and various mustard crops. Additionally, the virus survives in numerous wild weed species, which act as critical reservoirs for the pathogen during periods when the main crops are not in the field.

Infected plants typically exhibit chlorosis, which starts at the leaf margins and progresses inward between the leaf veins. This yellowing may sometimes be accompanied by a reddish or purplish discoloration due to the accumulation of anthocyanins. The overall plant growth is stunted, and in cases of early infection, the yield potential is drastically reduced due to smaller and fewer seeds per pod.

The spread of TuYV is heavily influenced by environmental conditions that favor aphid proliferation. Warm, dry autumns are particularly conducive to the migration of aphid populations into newly emerged seedling crops. Once the virus enters the plant, it travels through the phloem, causing systemic infection that persists throughout the plant's life cycle.

Economic losses caused by this virus can range from moderate to severe, depending on the timing of the initial infection. Control measures are focused on vector management:

• implementing early-season insecticidal treatments;
• selecting virus-resistant or tolerant crop varieties;
• managing wild cruciferous weeds surrounding agricultural fields;
• monitoring aphid flight activity;
• ensuring vigorous crop growth through balanced fertilization.