GARDENING
AUGUST 6 -12, 2021 | PAJARO VALLEY MAGAZINE
Strawberry virus decline
16
RED BEAUTY Strawberries are easy to grow at home due to mild weather.
Multiple viruses can affect production By KATE RUSSELL
N
o, strawberries are not declining in our area. Quite the contrary. Many residents are learning just how easy it is to grow strawberries at home, thanks to our mild winters and sunny summers. Strawberry virus decline refers to a collection of viral diseases that may reduce or eliminate that delicious crop. Strawberry viral diseases are odd. If only one disease appears, you won’t see any symptoms and your strawberry plants will be fine, though fruit production may be somewhat reduced. The real problem occurs when a second or third virus infects your strawberry
plants. Suddenly, there’s a flurry of symptoms and little or no fruit production. This set of conditions is called strawberry virus decline. Most strawberry plants infected by a virus will be stunted; fruit and runner production will be reduced, and leaves may be deformed in some way. Learning to recognize the symptoms of these diseases, and following some simple preventive measures, can help keep your strawberry plants healthy and productive. Below is a list of the viruses that make up strawberry virus decline and their symptoms: • Strawberry crinkle virus causes smaller fruit, deformed and/ or streaked flower petals, and
crinkled leaves. Vein spotting may also be seen, as well as lesions on petioles (leaf stems) and stolons. Infected plants may appear top heavy. • Strawberry mild yellow edge virus causes older leaves to turn bright red, but leaves around the crown nearly always exhibit yellow margins or edges; hence the name. These yellowed areas eventually die and turn brown. Leaf cupping may also occur. • Strawberry mottle first appears on smaller-than-normal young leaves that may show yellow distorted areas. As the disease progresses, symptoms become more severe, with older leaves turning red. • Strawberry pallidosis also causes older leaves to turn red or purple. The roots of infected plants are brittle and show fewer rootlets. • Strawberry vein banding appears as broken bands of yellow in leaf veins. Infected leaves are significantly smaller than those of healthy plants. The two halves of infected leaves may be held closer together than is normal, and the margins are wavier than normal. Some crinkling of the leaf surface may also occur. As the leaf opens, the bands of yellow become somewhat more obvious. Symptoms appear more strongly in the second and third leaves, but are not likely in later growth. These diseases are all carried by aphids, except for pallidosis, which is carried by whiteflies. These are difficult pests to control, especially because the very insecticides and insecticidal soaps used to control the pests also harm beneficial pollinators. Prevent strawberry virus decline in your garden by installing certified disease-free plants, placing new plants in quarantine, and removing plants suspected of being infected. Kate Russell is a UCCE Master Gardener.
