Strawberry plants, although easy to grow and relatively hassle free when done properly, are susceptible to some diseases which hamper or destroy the crop if left unchecked. In this article, the diseases that affect strawberry plants above ground will be discussed, the signs that indicate each disease and ways to remedy the situation will be discussed.
Strawberries are affected by a few different leaf spot diseases. Leaf spot forms purple or red spots on foliage, these develop dead centers with time. The disease is not really harmful to the plants, except that it occurs on the fruit. Known as black seed disease, it forms black spots on the strawberries. These do not render the fruit bad and can be cut out and the fruit eaten, but commercially it destroys the crop’s value as consumers do not want to buy the berries if they have the black spots on them.
There are a number of other leaf spots, leaf blights, and leaf scorches, but these can be kept in control through proper cultural practices. They generally do not harm the fruit unless there is a severe outbreak. Good practices that are important are to have good drainage, good air circulation, and removal of dead plant material in fall and again in spring to prevent disease from overwintering. If the disease is a major problem, resistant varieties may also be purchased.
Botrytis can affect strawberries, and it can destroy the fruit. Botrytis thrives in wet conditions, and can get out of hand on cool, cloudy or rainy days, especially if air circulation is poor. Adapt a raised row, hill, or spaced row method to improve circulation and clean any diseased material to curb botrytis.
Leather rot also affects fruit. It appears on immature fruit as dark areas, and when the fruit ripens it appears bleached and faded in color where it is infected. When the fruit is eaten, it tastes sour and rotten. Like most strawberry diseases, good drainage and air flow reduce spread and make conditions harsh for the disease. A good mulch, such as pine needles or straw, will keep fruit off the ground and reduce the spread of leather rot.
Anthracnose forms lesions on the fruit. They are brown and circular in shape, and sometimes exhibit pink spore formations. Anthracnose likes warm, wet humid weather. Destroy plant debris to reduce overwintering and increase circulation and drainage to reduce the disease.
These are the major above-ground diseases of strawberries. They can sound overwhelming and discouraging, but basic cultural practices should discourage the ability of diseases to flourish in most years. By providing good drainage and air circulation, most of these diseases can be averted. However, knowing the signs of the disease can allow one to respond and rectify the situation.