How to grow pea
How to grow pea
The cultivation of pea is very variable depending on the countries and the destination of the products. The dried peas are traditionally cultivated in a number of Third World countries where they constitute a subsistence crop, practiced in the cold season or in altitude, especially in East Africa (Ethiopia, Uganda, Kenya). In industrialized countries (Europe, Canada, United States) it is essentially a mechanized crop mainly devoted to animal feed, to the canning and freezing industry, but also to professional horticulture for the fresh market. Peas are often present in family gardens. The reproduction of the pea occurs only by seed. In the Mediterranean, the pea is sown either at the end of winter or at the beginning of spring, or in autumn, in regions where frosts are not too fearsome, or farther north using cold-resistant varieties (winter varieties). The pea is in fact an annual plant without dormancy, which can be sown without the need for vernalization. The winter varieties allow you to gain in harvesting and yield. For preserved peas, sown in spring, the seeds are staggered in order to distribute the workload of the machines. The plant has a vegetative cycle of about 140 days for the spring varieties, being able to go down to 90 days for the ultra-early varieties and 240 days for the winter varieties.
Several thousand different cultivars are known in the world. The European catalog of species and varieties authorized for cultivation (updated in September 2008) includes 1390 varieties, of which 514 for forage peas and 776 for horticultural peas. Thirty-two varieties of peas were obtained induced mutagenesis, a technique that allowed in particular to create the cultivars of the type afila, with leaflets transformed into tendrils. Fourteen varieties were obtained by irradiation with X-rays or gamma and the others by cross-breeding.
Among the horticultural peas, there are varieties with smooth or rough seeds (more sugary); this character is one of those used by Gregor Mendel in his studies on the hereditary transmission of the characters (see below), as well as the color of the seeds (yellow or green). The selection of varieties is also based on the precocity of the cycle, and on the presence or absence of the parchment pod. Then there are dwarf varieties and climbing varieties, which require a guardian.
Peas are plants that are very sensitive to frosts and to bending stalks (except for varieties with stalks), to soil degradation, as well as to various deficiencies in minerals.
The old farmers report that the wild pea was once grown as “medical grass” to fertilize the fields left to rest, or as fodder for livestock; the dried seeds were an excellent birdseed for poultry and other birds, such as pigeons; in times of food shortages or economic hardship, the dried seeds, cooked in soup, were also used for human food.
The fodder pea is traditionally grown in association with a cereal (rye, triticale or oats), which acts as a guardian. The cereal / legume association is fairly balanced in terms of nutrition.
The fodder pea is traditionally grown in association with a cereal (rye, triticale or oats), which acts as a guardian. The cereal / legume association is fairly balanced in terms of nutrition.
Peas, like other fast-growing legumes such as vetches or grass peas, can be grown as green manure, to enrich the soil with nitrogen and improve its structure.
Peas can be attacked by different fungal, bacterial or viral agents. The main diseases of economic importance are represented by: seed rot due to different fungi of the genus Pythium; radical necrosis, due, among other things, to Fusarium solani and to Aphanomyces spp .; cryptogamic diseases of the vegetative apparatus such as the peronospora of the pea (Peronospora pisi), the gray mold (Botrytis cinerea), the mal white of the pea (Erysiphe pisi), the sclerotinia of the soya (Sclerotinia sclerotiorum), the rust of the pea (Uromyces pisi ) and anthracnose (Colletrichum pisi); various viral diseases, including the pea yellowish of the pea, due to the PYVX virus (Pea Top Yellow Virus – Luteoviridae) and the common pea mosaic, due to PCMV virus (Pea Common Mosaic Virus – Potyviridae).
Numerous pest insects attack pea crops in their different stages; among these we mention the sitona del pisello (Sitona lineatus) which is a small curculionide beetle that devours the leaves by making semicircular notches on the edge and whose larvae feed on the roots, weakening the plants. The pea weevil (Bruchus pisorum) is a small beetle that attacks the pods in formation and completes its development inside the mature and dry seeds, escaping through a circular hole. It can be attacked by a chrysomelidae native to South America (Zabrotes subfasciatus), whose larva is known as “tropical pea caterpillar”, which reproduces in the dried seeds of various legume species. The cecidomia of the pea (Contarinia pisi) which is a diptera that causes the formation of galls on the flowers, causing it to fall, should be considered. The larvae of the pea torch (Cydia nigricana, Tortricidae) that voraciously attack the seeds create particular damages. The peas are also susceptible to attacks by caterpillars of different species of lepidoptera of the family Noctuidae that feed on their leaves including: Pottery pisi, Lacanobia oleracea, Autographa gamma, Mythimna unipuncta. Then we recall the green pea aphid (Acyrthosiphon pisum) which damages leaves and stipules and is also the vector of various viral diseases, the pea thrip (Frankliniella robusta) and the thrips of cereals (Thrips angusticeps) are tiny insects (size of 1 mm) that attack flowers and pods and whose larvae develop inside the pods. They cause drying and stunting of plant growth. Finally, in Mediterranean regions, pea crops can be parasitized by plants of the Orobanche genus, and in particular by Orobanche crenata, which attaches itself to the roots of the host plant.