Main symptoms

On salads produced in autumn and winter, interveinal jaundice is observed which is almost identical to that caused by the ( beet pseudo-yellows virus Beet pseudo-yellows virus , BPYV). This symptom first appears on a few low leaves. It should be noted that only the part of the leaf blade exposed to light presents this discoloration and that the veins remain green (figure 1). Subsequently, the yellowing spreads to all the leaves of the skirt and some intermediate leaves (figure 2). Old leaves thicken slightly and become brittle when pinched. Younger leaves show no symptoms (Figure 3).

As with most other viral infections, the severity of the damage depends on the precocity of the infection. If the seedlings are virus-infected from the nursery, yellows will affect many leaves at harvest, and in addition, the salads will turn out to be small in size. It is quite obvious that, under these conditions, their market value will be reduced after trimming; in some cases, they will even be unmarketable.

Symptoms caused by BPYV on other affected species are comparable to those seen on lettuce.