The plant of Strawberries
The strawberry is a fruit characterized by an excellent aroma and a sweet taste.
The strawberry, a member of the rose family, is a perennial stolonifera plant, consisting of a short stem, called peduncle or crown, on which grow sprouts and three long oval leaflets, serrated and arranged to form a small rose of leaves. The root system is shallow and it extends on a limited volume of soil, in fact, 90 % of roots are located in the first 15 cm of soil. At the axilla of leaves grow corymbs, consisting in 3-8 white flowers, which usually are self-fertile hermaphrodites; in case of flowers, the female varieties of strawberries need pollinators. The edible part of strawberries is the false fruit, resulting from the development of the receptacles, once fertilization occurred. The true fruits of strawberries are achenes, dry indehiscent fruits that remain attached to the fleshy false fruit. However, as we intend and eat strawberries, the fruit of the plant of strawberries is the edible part, characterized by a surface, covered with many yellow and brown small dots.
Although strawberries are cultivated from plains up to 1,000 meters above sea level, they require specific environmental conditions: best areas are those with a temperate climate, with short summers, characterized by hot periods, and winters cold enough. Strong summer solar heat, can in fact cause leaves to fall in advance, diebacks, dark and small misshaped fruits, with low consistency. During flowering, the plant of strawberries needs warm and uniform temperatures, while extreme changes in temperature between day and night and precipitations, contribute to hinder it.
For this reason, strawberries prefer loose, pH neutral or sub-acid soil, with a medium texture, fresh but well drained, with a depth exceeding 50 cm and rich in organic matter. Strawberries do not like heavy, asphyxiated, very calcarous and saline soils, with stagnant water, because in this case fruits become susceptible to gray mold.
The resistance to disease has become a more and more important aspect of the production of strawberries, as a result of climate change and events that have affected various areas cultivated with strawberries. In 2005, in fact, methyl bromide for fumigation of agricultural lands in industrialized countries, was abolished: to solve this problem, several researches have been started to find an alternative solution that will have a low environmental impact, among which there is the genetical improvements of strawberries, thanks to the identification of genotypes that show tolerance to diseases of the roots.
The most dangerous insects for strawberries, are aphides, which, because of the production of honeydew, cause sooty molt, rolling and curling of leaves and fruits, cutworms and othiorhyncus. To oppose pests, chemical intervention is suggested only if their presence in the field has crossed the threshold of damage, taking into account natural predators. Main fungi for the plant of strawberries are gray mold, powdery mildew or mildew, root rots, which occur in case of continuous cropping, anthracnose, brown rot and pitting.