BEAN

BEAN

To the Phaseolus genus, part of the large leguminous family, belong numerous species of cultivated beans. An important characteristic of the leguminous family consists in their capability of fixating atmospheric nitrogen through symbiosis with bacteria living in their roots. In Europe, prior to the discovery of America, a legume similar to the bean was known, belonging to the Vigna genus, and commonly called cowpea for its characteristic black spot on the skin next to the juncture between the seed and the pod. What we now know as beans, have been imported from Central and South America during the Post-Colombian era. Since then, its cultivation has spread throughout the old continent. Beans are cultivated to harvest their seeds, both fresh and dry (to shell), or for the consumption of the still green pod (snap beans). Of all the varieties today, there are both dwarf beans (variety with a limited growth) and climbing varieties (unlimited growth).
Beans, as well as other legumes, have a great nutritional value as they are extremely rich in protein, which in some cases may surpass 20% of the bean's actual weight. In addition, they contain 40% carbohydrates and numerous mineral salts. The energetic value of 100 grams of beans is 291 Kcal.

CULTIVATION

The bean is a plant with relatively high thermal requirements that, in our climates, can be grown during the spring and summer. Optimal temperature for growth should not fall below 15 ° C at night and 24 ° C during the day. Under these conditions, the plant's development is very fast and, in 30 days for snap beans and 40 for shell beans, one can begin harvesting starting from the plant. Since beans are legumes, their fertilization may do without nitrogenous fertilizers, but must be provided with sufficient doses of phosphorus and potassium. For a production of 1 to 2 kg / sqm of seeds, the recommended dose is 2 kg / sqm of compost, 30 g / sqm of potassium sulphate, and an equal amount of triple superphosphate. The distance between transplantation depends on the variety: dwarf beans can be transplanted in double rows 60 cm apart between the double rows, 20 cm apart between each row, and 5 cm on the row. The climbing variety must always be placed in double rows, with a distance between the double rows of 80-100 cm, 20 cm between rows, and 10 cm between plants in the row. For climbing varieties, it is necessary to provide nets or poles to support the branches. In any case, the supports must be at least 1.50 m high and must be sufficiently strong.

ADVERSITIES

Parasites that attack the bean primarily affect the aerial part. Leaves, flowers, and fruits may be attacked by aphids and the white butterfly. These insects can be eliminated by spraying natural pyrethroids or by throwing insect predators. The attacks of the red spider mite are also dangerous, and can be distinguished by the fine cobweb woven on the vegetative apex and below the leaves. These can be eliminated by introducing the predatory mite Phytoseiulus persimilis. Finally, with regard to fungal parasites, there are anthracosis, rust, and botrytis; important in these cases are preventive treatments with copper and the maintenance of good environmental conditions.