In recent years, the author has directed the management of local orchards in Gansu, Shaanxi, Shanxi, Henan and other places, and found that apple brown spot disease is widespread, and some places are still serious. In order to control apple brown spot disease in time, the author put forward control ideas, suggestions and control schemes according to his own understanding of early defoliation disease, for the reference of fruit farmers and friends in production.

1 Causes of Apple Brown Spot

1. 1 unclear or unclear in place.

As we all know, the main factors for the epidemic of brown spot disease are the existence of a large number of overwintering pathogenic bacteria in orchards, the centralized planting of apple varieties such as Red Fuji with low disease resistance, and the timely emergence of suitable environmental conditions for the disease. The serious problem in actual production is that many fruit farmers don't know enough about the harm of brown spot. Most fruit farmers have not been clear about winter and spring gardens for many years or have not been clear about their places. Some orchards plant grass between rows, which also brings inconvenience to cleaning the diseased leaves on the ground. In addition, the Apple market has been weak for many years and the price has been low. The extensive management of orchards has caused the phenomenon of fruit hanging in different years from time to time, which has also seriously affected the enthusiasm of fruit farmers. Because the garden is abandoned in winter and spring for cleaning, the overwintering base of pathogen in orchard is large. Lay a hidden danger for future disease outbreaks.

1.2 extensive management

At present, there are many people who have extensive orchard management. A considerable number of fruit farmers failed to fertilize in time last autumn, and the trees were not well nourished. In addition, some areas have frost in spring or hail in summer, so they lose confidence in management and give up management, resulting in weak trees and decreased resistance. When diseases occur, many fruit farmers only pay attention to spraying drugs blindly and neglect spraying nutritional supplements, which can not give full play to the dual functions of drugs and fertilizers.

1.3 Incorrect plastic trimming in continuous winter.

Too many branches are removed, cutting and sawing are not timely and not in place, and trees are not protected effectively in winter. Freezing injury is widespread, coupled with poor rot control, tree vigor is seriously weakened, and resistance is reduced.

1.4 management concept is biased

In Shaanxi, some fruit farmers only pay attention to big shaping and strong pruning by learning the four key technologies of apple production, ignoring the cultivation of strong trees through fertilization, and many people muddle along in production. In addition, the amount of flowers in 2004 and 2006 was too large. The psychology of cherishing fruit is serious. Too many fruits are left, and the nutrient supply of trees is insufficient, which leads to the decline of resistance and the occurrence of brown spot.

1.5 A considerable number of fruit farmers "as long as the fruit has no leaves"

It is believed that everything will be fine after bagging, and there is no need to spray drugs to control pests and diseases, showing the drug habit of "tightening before loosening, regardless of the middle term" The author investigated the main apple producing areas in Shaanxi and Gansu. By the beginning of August, most fruit farmers didn't use medicine until about 40 days after bagging, and some people didn't spray medicine for 60 days. Some fruit farmers stubbornly believe that high-grade pesticide products are used in the early stage, and there will be no problem if the spraying interval is longer. Some fruit farmers are lucky enough to think that some low-grade fungicides can be selected after bagging, which can not only reduce the cost, but also control the disease, and the result is not worth the candle. There are countless similar cases, which seriously delay the opportunity of prevention and control and cause irreparable losses.

1.6 The methods and skills of medication are not in place.

At present, many people employ "spray teams" to spray drugs in rural areas. A considerable number of "spraying teams" are "modern" equipment, and the spraying of drugs is not calculated by time, but by the amount of water sprayed. Most "blowout prevention teams" drilled the water outlet holes of the spray pieces with nails in advance, and the "sprayer" became a "fire brigade" as soon as it entered the orchard. When encountering an orchard with a high crown, the only way to spray it to the upper part of the crown is to adjust the nozzle. Often, a stream of water is sprayed in a straight line, so some people still feel that it is not "enjoyable" and it is not enough to spray the medicine on the tree. Standard anti-aircraft guns are not enough to shoot flies, and the effect of spraying drugs can be imagined. The investigation also found that many fruit farmers know little about pesticide preparation, do not know the dispensing order, rarely use secondary dilution method to dispense drugs, and often appear fire, precipitation, flocculation and other phenomena in the preparation process. Results Not only the drug effect was poor, but also the drug injury was easy to occur.

1.7 Ignoring ground control

The investigation found that when diseased spots appeared in orchards, more than 97% fruit farmers concentrated on spraying pesticides on trees, ignoring ground control, which led to continuous improvement of spraying pesticides on trees and repeated spread and infection of germs on fallen leaves on the ground. As a result, the "main force" in the upper part of the tree was defeated, and the "guerrillas" on the ground were rampant, and the awareness of re-administration was serious and it was impossible to prevent.

1.8 improper selection of chemicals

It is also important to choose chemicals to prevent brown spot disease. Traditional carbendazim, tuijunte, thiophanate-methyl, Nong Kang 120, polyoxin and compound mancozeb and thiram have poor control effects on brown spot. The concentration of mancozeb made in China is 600 times, while the dosage of thiophanate methyl imported is about 800 times. 43% Dashengfu, spray fulu and triazole fungicides with good control effect should be selected in production.

1.9 Ignore the application of meat tax pass

Many fruit farmers have confirmed in production practice that spraying soft water can significantly increase the adhesiveness, improve the efficacy and reduce the water consumption, thus greatly reducing the difficulty of pest control. However, some people think that pests and diseases were controlled in the early stage, and in order to reduce costs in the middle and late stage, the use of soft water pipes was abandoned. This is also the cause of brown spot disease.

2. Ideas and measures for controlling brown spot disease,

2. 1 Cultivate robust tree types to improve disease resistance.

Although brown spot disease is highly pathogenic and spreads quickly, preventing early defoliation is the premise to ensure the vigorous growth of trees and improve their disease resistance. Therefore, through scientific pruning, strengthening soil, fertilizer and water management, thinning flowers and fruits according to tree potential, age, yield and reasonable load, it is very important to maintain good ventilation and light transmission conditions in the orchard and promote the photosynthetic efficiency of fruit trees. , in order to maintain vigorous tree potential and prevent diseases. A large number of investigation results show that orchards with neat garden capacity, strong trees and comprehensive management, such as paying attention to applying base fertilizer in autumn, generally have fewer diseases, high yield and excellent fruits.

2.2 Do a good job in clearing the garden to reduce the occurrence of diseases.

Combined with the application of base fertilizer in autumn to clean up fallen leaves deeply, pruning and draining the dead leaves on the upper part of trees in winter, and spraying eradication agent in the whole garden in early spring to completely eliminate the overwintering bacteria source, so that sporadic fruit trees during the growth period can be treated in time. To prevent the spread and spread of the disease. These agricultural (agronomic) measures are the key to control the occurrence of diseases.

2.3 Application of amino acid fertilizer and trace element fertilizer

Orchards with apple brown spot disease during the growing period should be coated with high-quality amino acid stock solution and high-quality trace element fertilizer (such as Stokopp made in Spain) in time to promote fruit expansion. Enhance the tree potential. If it is a New Year tree or orchard, if necessary, spray 300-400 times of fruit friend amino acid +6000 times of Stokopp before and after flowering. And topdressing in the ground to improve the disease resistance of trees. Reduce the occurrence of diseases. This experience has been verified by the majority of fruit farmers in northwest China for many years.

2. 1 spraying scheme

Spraying 10- 15 days according to weather conditions from 5 to 7 days after flowering. Spray 1 time softened water 4000 times +43% Dashengfu SC or 42% Fulu SC 600-800 times+calcium lactate or calcium amino acid 400-600 times +Stokop 6000 times. At the initial stage of the disease, the whole garden should be sprayed with Burou Shuitong 4000 times +50% Geha suspension 1000- 1200 times or 70% nano-azide 800- 1000 times+calcium lactate or amino acids 400-600 times +Stokop 6000-8000 times. The interval is 7. Orchards with diseases or disease outbreaks in the middle and late stage. Spraying Bruiser 4000 times +25% Jinli, EC 5000 times or 70% Nano-Xin wettable powder 800 times +43% Dashengfu SC or 42% Spray Fulu SC 800 times (if necessary)+You Guo amino acid 300 times or Stokop 6000 times. The interval is 7- 10 days. Spray continuously for 3-4 times. At the onset, 43% Dashengfu Suspension Concentrate or 42% Spray Fulu Suspension Concentrate was added for 800 times, which has both therapeutic and protective effects, and the control effect is good.

2.5 Precautions for spraying drugs (1) When mixing drugs of various dosage forms, attention should be paid to the sequence between them. Unless otherwise specified, the conventional order is as follows: Roushuitong-water agent-suspending agent-thousand suspension-emulsion in water-water dispersible granule-dispersible granule-soluble powder-wettable powder-emulsifiable concentrate-foliar fertilizer. It is worth mentioning that the application of Roushuitong can not only optimize the water quality, but also improve the affinity of mixed pesticides. Fully improve the drug effect, at the same time make the liquid medicine fully adhere to the leaves, and completely sterilize. But also can greatly reduce the water consumption. In application, it should be emphasized that the water softener should be added to water first, and then other drugs should be prepared by secondary dilution method to ensure good efficacy.

(2) Pay attention to the selection of high-quality spraying equipment to ensure that the liquid medicine is even and thoughtful. It is strongly recommended that fruit farmers change the spraying tablets frequently when spraying drugs to ensure the atomization effect and improve the control effect. Put an end to disease recurrence.

(3) Spray each time: spray the trees and the ground at the same time, pay attention to fine spraying, even spraying and thoughtful spraying to protect the leaves. In orchards with unclear gardens or grass growing between rows, attention must be paid to spraying the trees and the ground at the same time from the time after flowering.

Expand Hunan citrus industry

Citrus industry in western Hunan should take the road of high-quality goods

After more than 20 years' efforts, ponkan industry in Xiangxi has become a regional dominant industry in China, with the planting area accounting for 1/4 of the whole country, and the per capita output value of ponkan 1.50 yuan. Further expanding and strengthening the citrus industry is of great significance to promoting the construction of a new socialist countryside in Quanzhou.

However, there are still many restrictive factors in Xiangxi citrus industry: the supply of seedlings is chaotic and the industrial layout is unscientific. Low level of training and management technology, lack of brand awareness and weak market development. To strengthen and improve the citrus industry in western Hunan, we must take the road of quality development.

Implement high-quality demonstration projects. Build a number of "demonstration villages" and "boutique villages" for the development of citrus industry in the main citrus producing areas with good industrial foundation and high enthusiasm of the masses. Effectively increase technical guidance for "demonstration villages" and "boutique villages". Realize the standardization of base construction, irrigation and fertilization, disease prevention and pest control, picking and preservation, packaging, storage and transportation, and ensure that the high-quality fruit rate reaches 70%. Strengthen technical training. Big; B Popularize practical technologies such as low-quality citrus products, formulated fertilization, water-saving irrigation, pest control, and "double-shearing" picking to ensure the average yield of 667 square meters 150 1) kg in the demonstration area. Strive to complete the task of changing 26,600 hectares of citrus products into low-grade products in 3-5 years: the task of building rainwater harvesting and water-saving irrigation facilities in industrial bases.

Implement brand marketing projects. Increase marketing and promotion efforts. Improve the market influence, make the annual "China Xiangxi Citrus Festival" unique, participate in all kinds of high-quality agricultural products exhibition and advertising, and expand the popularity of Xiangxi Citrus. Build 5-6 large-scale professional wholesale markets and a number of threshold citrus distribution centers in areas with convenient transportation. Create a number of export windows in large and medium-sized cities in China.

Mayang: Vigorously develop sugar orange industry

Mayang County, Hunan Province actively develops the industrialized production of citrus. Since 1984 widely planted sugar oranges in the county, by the end of 2005, the citrus planting area in the county had reached 1330 hectares with an annual output value of 4.5 billion yuan.

The development of Mayang sugar orange mainly began with the World Bank loan in 1980s, and in recent years. Due to insufficient investment, the progress of the citrus quality improvement project is slow, the construction of "boutique garden" and "demonstration area" of ice-sugar orange is still blank, there are still no leading enterprises in the ice-sugar orange industry, and the national marketing network has not yet been established. Citrus brand still stays in the provincial brand. Zhang Gantai, the county magistrate of Mayang County, pointed out that the development of citrus industry, as a "four hundred" project in Mayang County, lacks leading enterprises, and the production and sales are not organized, so it is difficult to win projects, and citrus sales cannot enter the big market. In the future, the county will take major measures to increase investment in the development of citrus industry year by year and actively take quality measures. Efforts should be made to improve the quality of citrus and increase investment in citrus industrialization and the construction of leading enterprises.

Southern Hunan: Navel orange FI-A is exported to Russia and Canada in the international market.

Xinning navel orange is one of the internationally competitive fruits of southern Hunan navel orange and one of the four major navel orange production bases in China. According to research and comparison, the quality of Xinning Liangfeng and Newhall navel oranges exceeds that of American "Sunkist". In recent years, Xinning County, Wugang County and Daoxian County have vigorously developed navel oranges. Xinning county has now reached the scale of 1.33 million hectares. In 2006, navel orange10.5 million tons was produced. It is understood that the southern Hunan navel orange belt produces about 200,000 tons of navel oranges every year.

Chen Youxiu, secretary of Xinning County Party Committee, said. The navel oranges in Xinning are of good quality and internationally competitive, but the most important thing is how to enter the international market. First of all, we should improve farmers' ability to participate in market competition. The county party committee and government take the lead in organizing the training of farmers, collecting and providing information on price trends, and guiding farmers to run the market. At present, there are nearly13 farmers selling navel oranges in the production area, and Xinning navel oranges have entered the international market through various channels. Prices are also rising. In Sanxing Village, Xinning County, a fruit sorting and packaging production line with an investment of 8 million yuan will be put into use soon. Navel oranges are cleaned, sorted and packaged according to international standards, and then exported for unified use. "Mountain" brand. At present, the wholesale price of 10 Jin navel orange has reached 55 yuan. Although there is still a big gap with the international price. But it is 80% higher than the wholesale price in previous years. At present, Xinning County is actively negotiating with Asian Fruit Industry, a London-listed company with an international sales network, and is preparing to sell Xiangnan navel orange directly to the international market.

Yongxing: developing sugar oranges and implementing the strategy of high quality and pollution-free

Recently, Yongxing County of Hunan Province was awarded the title of "Key County of High-quality Sugar Orange Base in China" by the National Fruit Circulation Association, becoming the only county in China to receive this honor.

In recent years. The county regards sugar orange as the leading industry of developing "one county, one product" and increasing farmers' income, formulates the development plan of sugar orange industry, and establishes three leading enterprises, including Yongxing Sugar Orange Co., Ltd., to speed up the industrialization of sugar orange. Driven by leading enterprises. Farmers' enthusiasm for developing sugar orange planting bases has been continuously improved. At present. The planting area of sugar oranges in the county reaches 5200 hectares, of which 1 1 large base exceeds 66.7 hectares; There are more than 7,000 growers and nearly 20,000 employees. The annual output of sugar oranges is more than 30,000 tons, and the output value exceeds 100 million yuan.

(According to Farmers Daily)