I. Symptom recognition Tomato virus disease is mainly caused by tobacco mosaic virus (TMV), cucumber mosaic virus (CMV), tobacco leaf curl virus (TLCV), alfalfa mosaic virus (AMV) infection, etc. Leaf virus, cucumber mosaic virus, and tobacco leaf curl virus are the main seeds. Symptoms mainly include three types: mosaic type, leaf type, and strip type.
1. Mosaic shape: yellow-green interphase or deep and shallow spots appear on the leaves, the veins are transparent, and the leaves are slightly shrunken. The diseased plants are slightly shorter than the normal plants.
2, leaf type: yellow veins between the veins, the edge of the leaves are curved upwards, the leaflets are spherical or twisted into a spiral deformity, the whole plant atrophy, sometimes clumping, early disease, more can not flower results.
3. Stripe type: occurs on leaves, stems and fruits. The shape of the lesion varies from place to place, with brown-brown spots or moiré on the leaves; dark brown patches on the stems and on the fruit, and the discolored parts are only in the surface layer and do not penetrate into the stem or the inside of the fruit. These types of symptoms are often caused by the combined infection of tobacco mosaic virus or other one or two viruses, which are prone to occur under high temperature and strong light.
Second, the prevention and treatment methods 1, a reasonable rotation: the implementation of more than 3 years of vegetable field rotation, try to avoid continuous cropping with the Solanaceae crop.
2, the selection of disease-resistant, disease-resistant varieties: tomato virus pathogens, and strain differentiation, often mixed in the field, most of the varieties are only resistant to partial virus disease, there is no high antiviral disease varieties. After the autumn extension in the north, you can use Jiafen No. 2, No. 10, Xiaofeng No. 3, etc.
3, seed disinfection: seed before sowing first with water for 5 hours, then with 10% trisodium phosphate solution for 20 minutes, or first wash with soapy water, then soaked with 0.1% potassium permanganate solution for 10-15 minutes, Then wash with water; or treat the seeds under dry heat at 70 ° C for 2-3 days, then carry out germination or live broadcast.
4. Remove the diseased seedlings: After the emergence of the seedlings, the seedbeds should be cleaned regularly, and the seedlings with irregular leaf color, poor growth, and twisted leaves should be removed in time; for diseased plants with only individual leaf diseases, the diseased leaves should be cut off in time. This work should be carried out 3-4 times before planting. Also pay attention to the hands or tools during the cleaning process, do not touch the normal seedlings, to avoid infection.
5, the agricultural operation should be the first strain of the plant after the plant: the tomato will continue to appear after the planting of the plant, its performance is the mosaic, leaflets, line leaves, leaf rolling, dwarf and so on. Farming operations such as tipping, tying, snoring, bottoming, and fruit picking should be carried out according to the practice of the first strain of the plant to avoid the transmission of hands or tools. Conditional can also be used to wash hands and tools with soapy water or 10% aqueous solution of trisodium phosphate after completing a row of plant farming activities.
6, timely anti-mite: seedling period is covered with silver-gray film or shade net to repel aphids. After planting, the silver-gray plastic strips are drawn along the skeleton around the greenhouse, and the interval is about 10 cm. At any time in production, the occurrence of mites in the shed will be investigated, and once it occurs, timely prevention and control will reduce the chance of locust poisoning.
7, cultivation and disease prevention: timely sowing, cultivation of strong seedlings. A week or so of seedlings before planting, select healthy and disease-free seedling transplants. Organic fertilizer should be fully decomposed, and appropriate application of phosphorus and potassium fertilizer. Take half-high ridge cultivation and timely water supply. When the fruit is red, it should be harvested as early as possible to coordinate the contradiction between reproductive growth and vegetative growth of tomato, enhance the disease resistance of the plant, and achieve the purpose of disease prevention and yield increase.
8. Biological control: (1) Attenuated vaccine N14 is mainly used to control viral diseases caused by tobacco mosaic virus (TMV) infection, and has certain immune protection. Usage: When 1-2 slices of true leaf seedlings of tomato, wash the roots of the soil, immerse the roots in 100 times of N14 for 30 minutes, or gently rub the cotyledons with 100 times of N14. Wipe inoculation; 7-9 needles can be tied to the head of the chopsticks to take N10 100 times liquid lightly inoculated leaves; N14 can also be diluted 50 times with toxic water, according to 4 kg / square meter The pressure is sprayed inoculated with 2-3 true leaves of tomato; it can also be added with 0.5 g of 400-600 mesh silicon carbide with 100 times of N14, shaken and inoculated with a high pressure gun. (2) The satellite virus S52 is used to control viral diseases caused by cucumber mosaic virus (CMV) infection, and its use method is the same as the attenuated vaccine N14. If S52 and N14 are mixed in equal amounts, the control effect is better.
9. Spray control at the beginning of the disease. In the early stage of the disease (5-6 leaf stage), the spray protection was started. The agent was 3.85% virus Becker WP500 times solution for foliar spray. The drug was sprayed once every 7 days, and sprayed 3 times continuously to prevent and cure tomato virus disease. The curative effect can reach 75-80%; it can also be sprayed with 1.5% phytopathogenic 800 times solution or 20% virus A500 times solution. The method of use is the same as before, the control effect on viral diseases can reach about 70%, and 5% bacteria can be used. Water-repellent agent 400 times liquid or potassium permanganate 1000 times liquid, in addition to spraying 50-100 mg / kg of production and 1% superphosphate as root dressing, can improve disease resistance.
Article source: "Agricultural Technology Service"
Steel Grating is also called steel grate, steel grate mesh or metal grid mesh. It is made by stainless or mild steel of certain sizes through the processing of grooving, lock-pressure, welding, finishing and other treatment. Galvanized steel grating is the mostly used one due to its economic cost and good property.
Material: Mild Steel (Low carbon steel) / Stainless steel
Steel grating types:
There are three kinds of steel gratings distinguished by different bearing bar types.
The respective of features are as follows:
Plain: the most widely used gratings, available for flooring sidewalk, all kinds of ditch cover, Stair Tread, etc.
Serrated: best non-skid property & safety compared with plain grating.
I-shape: lighter, Not substantially weaken the case of load capacity more economical and practical comparing with plain grating.
Steel grating standards:
|
Standards |
Steel Grating Standard |
Steel Material Standard |
HDG Coating Standard |
|
China |
YB/T4001.1-2007 |
GB700-88 |
GB/T13912-92 |
|
USA |
ANSI/NAAMM(MBG531-88) |
ASTM-A36 |
ASTM-A123 |
|
UK |
BS4592-1987 |
BS4360(43A) |
BS729 |
|
Australia |
ASl 657-1992 |
AS3679 |
ASl650 |
Common Specifications with charting:
|
Parameters |
Data |
|
Bear Bar Type |
Flat Bar, I-Bar, Serrated Bar, etc.. |
|
Bearing Bar Size |
20x5mm, 25x3mm, 35x5mm, 40x5mm, 50x5mm, 60x5mm, etc.. |
|
Bearing Bar Spacing |
20mm, 25mm, 30mm, 33mm, 40mm, 43mm or multiplier. |
|
Cross Bar Type |
Twisted Steel Rod, Flat Bar |
|
Cross Bar Size |
3mm, 4mm, 5mm ,6mm or thicker |
|
Cross Bar Spacing |
50mm or 100mm |
|
Bearing Bar Length |
Customerized from 1000mm to 6000mm or more |
|
Cross Bar Length |
Under 1200mm |
|
Material Grade |
Mild Steel(Q235B), Stainless Steel 304 or 316, etc. |
|
Treatment Available |
Hot dipped Galvanized, Anodized, Polished and Powder Coated |
Application: Steel grating can be widely used in petrochemical, water plants, sewage treatment plants,
municipal engineering, environmental engineering and other fields of platforms, walkways, steel grating bridge , ditch cover, covers, ladders, fences and railings etc.
Steel Grating
Welded Steel Grating,Galvanized Steel Grating,Heavy Duty Grating,Electro Forged Grating
Anping Enzar Metal Products Co.,Ltd. , http://www.enzarmetal.com