ТОП 10 на сайтеПриготовление дезинфицирующих растворов различной концентрации
Техника нижней прямой подачи мяча.
Франко-прусская война (причины и последствия)
Организация работы процедурного кабинета
Смысловое и механическое запоминание, их место и роль в усвоении знаний
Коммуникативные барьеры и пути их преодоления
Обработка изделий медицинского назначения многократного применения
Образцы текста публицистического стиля
Четыре типа изменения баланса
Задачи с ответами для Всероссийской олимпиады по праву
ЗНАЕТЕ ЛИ ВЫ?
Влияние общества на человека
Приготовление дезинфицирующих растворов различной концентрации
Практические работы по географии для 6 класса
Организация работы процедурного кабинета
Изменения в неживой природе осенью
Уборка процедурного кабинета
Сольфеджио. Все правила по сольфеджио
Балочные системы. Определение реакций опор и моментов защемления
Life cycle of chinch bug and control.
Life Cycle: Chinch bugs1 spend the winter as adults2 in partially protected areas (under shrubs or around foundations of houses). As the weather warms in the spring, adults move into open areas, where females begin laying eggs. Fifteen to 20 eggs per day are deposited for two to three weeks. The eggs hatch in one to two weeks, and the nymphs3 begin to suck the juices from host plants. It takes 30-90 days to reach adulthood. There are two generations per year, with a partial third generation in unusually warm summers. There is considerable overlap of generations, and all stages can be found during the summer.
Control: In many instances, chemical control of chinch bugs is not necessary. Studies in Michigan have demonstrated that lawns which receive adequate amounts of water throughout the summer (preferably weekly deep waterings) are able to tolerate relatively high populations of chinch bugs without sustaining damage. In addition, many lawns have natural populations of predators.
1chinch bug- клоп-черепашка
1. Rotations2 with other than root crops should be employed as the size of the garden permits. This way the buildup of aggressive scab strains3 can be avoided
3. Plant resistant varieties4. If scab has been a problem before, test one of the following varieties under local conditions to determine whether it is suitable.
4. In a garden where irrigation is available, scab can be reduced by keeping the soil reasonably wet for several weeks while the young tubers are beginning to form.
6. One of the best methods for combating scab is the use of acid producing fertilizers, especially those that contain liberal amounts of sulfate of ammonia.
7. Test the pH of the soil and apply elemental sulfur to lower the soil pH to 5.2.
1scab organism- организмы, вызывающие заболевание паршой
3aggressive scab strains-агрессивные штаммы парши
4resistant varieties-устойчивые сорта
Barley is best adapted to well-drained, fertile, loam soils1. It generally produces low yields2 on sandy soils. Moderately fertile soils favor a rapid growth, but barley grown on soils high in nitrogen often produces low grain yields3.
It is grown in rotation with other crops, particularly after cultivated row crops such as corn, soybeans, beans, potatoes or sugar beets. Sometimes barley follows other small grains. Fertilizers sometimes are applied to barley that follows another cereal crop.
2low yields-низкий урожай
3grain yields-урожай зерновых
Plants consist essentially of three main parts. Below ground is the rooting system1, which serves as an anchorage to attach the plant firmly to the soil, and which is able to absorb water, and water solutions of plant nutrients from the soil.
Above ground are the stems and leaves2, which are the green part of the plant. The stems are, in most cases, rigid and capable of keeping the plant erect, and the leaves are arranged on the stems in a manner that exposes them to sunlight, from which they absorb energy for the manufacture of materials for plant growth.
The third essential structure in a plant is the flower3, which contains the parts associated with reproduction and which is responsible for seed formation.
The rooting system remains in darkness below the surface of the soil. In many rooting systems,
There is a central root, sometimes known as the tap root, from which a number of side roots develop as branches, and the side roots end in a large number of fine rootlets with fine root hairs,
Which absorb water and water solutions of plant nutrients from the soil. Through a series of hollow vessels the substances absorbed by the root hairs reach the base of the stem. Another series of vessels in the stem is available for the passage of these materials to the leaves and flowers
1rooting system- корневая система
2stems and leaves-стебли и листья
The Penicillium expansum type of blue mold1 has been the form most frequently reported, but a number of other less common species, which are also usually less aggressive, have been encountered. The positive identification of the different species2 that cause blue mold is only possible by means of laboratory cultures and microscopic examination, and even then positive determination is difficult because of the very slight differences encountered among species. All of the blue molds are primarily wound parasites, most frequently gaining entrance through fresh mechanical injuries3 such as stem punctures, bruises4 and insect injuries, finger-nail scratches by pickers, necrotic tissues5 of diverse origin or through normal stems or open calyx canals6. Sometimes infections may occur through lenticels, especially when they are damaged by cracking after a sudden abundant supply of water following a period of dryness, or after bruising late in the storage season when fruit have been weakened by ripening and aging.
1blue mold- голубая плесень
2different species-различные сорта
3mechanical injuries-механические повреждения
4bruises- повреждение (растений , фруктов)
5necrotic tissues-некротические (отмирающие) ткани
6calyx canals-каналы чашечки
Varieties. Seed selection.
The names of the original varieties1 from which strains have been selected are not known, but all South Australian celery 2is generally called South Australian Long White. Individual growers select their own strains. These mature over a period of time and comprise approximately 50 per cent early, 40 per cent mid-season and 10 per cent late strains.
As the crop is being cut, a number of well-shaped, true-to-type and vigorous plants are selected and left standing for seed bearers. When cutting has finished, these selected plants are lifted and planted together. Care is taken to plant the different strains some distance from each other to prevent crosspollination. As the seed heads grow, the plants have to be supported. They are regularly sprayed to reduce septoria leaf spot infection.
When the seed has matured, about January or February, it is threshed, cleaned, spread out to dry and then stored in air tight containers until required. Seed matures too late for use in the following year's crop, and two year's supply is usually kept on hand. Septoria leaf spot is one of the principal diseases affecting celery. It is commonly carried on the seed, and an early infection often starts from sowing infected seed.
Последнее изменение этой страницы: 2016-12-12; Нарушение авторского права страницы
infopedia.su Все материалы представленные на сайте исключительно с целью ознакомления читателями и не преследуют коммерческих целей или нарушение авторских прав. Обратная связь - 126.96.36.199 (0.009 с.)