báo cáo internship MÔN BỆNH CÂY

PART 1: INTRODUCTION 1.1 Aims and objectives 1.1.1 General aims As a country with a tradition of agriculture, the agricultural sector occupies a high proportion of Vietnam's economic structure as well as labor structure Agriculture is highly regarded and promoted, especially in terms of providing food for people and animals In addition to food, agriculture provides a great number of commodities and other materials in other sectors, particularly the export orientation that helped Vietnam approach to the international scale However, producers must not only have to cultivate their crops carefully but also take measures to control pests in order to obtain high yield of crops Depending on the characteristics of pests and the nature of the crop, the severity of the damage varies In the most seriously damaged crop situation, the farmers will get loss season It was reported that crop losses caused by insects, diseases and weeds was 36.5% (of $1.5 billion in 2002, in the worldwide), and the losses of diseases accounted for 14.1%, approximately $220 million In Vietnam, the rice diseases such as rice blast and bacterial leaf blight occur every year In the Southern of Vietnam, the rice is being attacked by viral pathogens causing the grassy stunt and ragged stunt diseases It is said that 10% of the rice area is being infected (estimate ~ million tons) and if over 30%, Vietnam will have to import rice It can be seen from the data above that the losses caused by pests are very huge, especially by disease factor Therefore, that is the reason why need to understand statute and management of plant pests in general as well as plant diseases particularly The internship of “Plant pathology” course is necessary and highly appreciated for giving students opportunity to observe plant diseases in reality in the fields and access to crops and farmers to know more about plant diseases and difficulties of controlling them 1.1.2 Specific aims Besides the aims of improving and strengthening knowledge that I have learned in the class, the internship also highly broadened my knowledge base as well as helped to understand the reality situations of agricultural production in our country through field activities The internship helped me to acquire knowledge in depth on communication, time management, survey conduction, data collecting, data presentation, report writing, work in grassroots level with farmers, critical thinking and managerial works During the internship, I performed various duties like communication & documentation, transportation to the fields, helping farmer water the crops, taking photos of plant diseases Through these performances I gained crucial experience that has resulted in immeasurable impact in my aptitude in various fields I highly recommend that Plant Pathology Department should design more internship programs in courses related to Plant Pathology to give students more chances to get access to the reality, use or apply their knowledge learned in class into practical situations and sharpen their soft skills to expose them to various job challenges in the future 1.2 Objectives At the very outset of this internship, I formulated several learning goals which I hunted to achieve: - Observe the main and popular diseases in targeted crops: corn, cabbage and pomelo; - Collect the data to determine disease intensity (prevalence, disease incidence, disease severity); - Collect data, present and analyze them, take photos of diseases to write report; - How to adjust in local environment; - Use my achieved skills and knowledge; - Enhance my communication skills; - Understand the management methods of diseases of farmers and determine or suggest which method is good and suitable 1.3 Requirements Specific requirements required to achieve the above objectives: - Have knowledge base of plant disease as well as crop science specialist - Read the guideline for internship carefully before going to the fields - Prepare necessary tools carefully for conducting survey - Work diligently, actively learn new knowledge and investigate, collect data, as well - Respect the property of the farmer, ask for permission before going into the field or collecting samples, taking photos and be polite when interviewing farmers PART MATERIALS AND METHODS 2.1 Location and time - Xuan Quan – Van Giang – Hung Yen in three days: 18, 21, 24/ 11/ 2018 2.2 Materials - Notebook, pen, 4m length tape measure, smartphone to take photos 2.3 Crops - Corn, cabbage and pomelo 2.4 Methodology 2.4.1 Methods of doing survey in field - At Xuan Quan – Van Giang – Hung Yen province, I chose main crops, fields for each crop to conduct survey (each field >= 300m 2) - Use the document “QCVN 01-38: 2010 / BNNPTNT” to conduct survey for crops - Investigation on each crop field: each survey field points, each point is 1m2 randomly located on the diagonal of the survey area The survey site must be at least 1m from the bank (for corn, cabbage), row (for pomelo) On each survey site, depending on the type of crop, we have specific method to survey * Corn: Disease investigation on corn leaves: 10 random leaves / points (including young and old leaves), count infected leaves and rank according to levels * Pomelo: On the basis of the basic garden: each point conducts survey of plants, investigates the whole tree For leaf, bud and fruit-eating organisms or diseases: Scale Rate of infection (%) 1 - 10 > 10-20 > 20-40 > 40-80 > 80 * Cabbage: Disease (black tendon, rotten): minimum 10 plants / point Count and rank according to levels 2.4.2 Methods of interviewing farmers - Ask farmers some questions related to diseases such as: which disease is popular, serious? When crops infected? Where diseases appear? - Ask farmers about their disease management methods: by chemical, mechanical or biological methods? Evaluate which method is most effective by myself - Take note while farmers share information 2.4.3 Methods of processing and analyzing collected data - Some formula to determine disease intensity: Prevalence (%) = 100 The data, in percentage, should be assigned in levels: ++++ (>75%), +++ (≥50-75%), + + (≥25-50%) and + (≥1-25%) Incidence (%) = 100 Severity (%) = 100 Including : N1: Number of disease plants in level N3: Number of disease plants in level Nn: Number of disease plants in level n N: Total of surveyed plants is highest level in hierarchy - Use statistics to analyze the collected data (mainly descriptive statistics such as average, standard deviation, coefficient of variation) PART 3: RESEARCH RESULTS 3.1 Corn  All observed diseases of corn are summarized in table 3.1 Table 3.1 Diseases of corn in Xuan Quan in days: 18, 21, 24/11/2018 N o Disease Common rust Northern corn leaf blight Southern corn leaf blight 3.1.1 Common rust  Symptoms Pathogen Prevalence Puccinia maydis Exserohilum turcicum ++++ ++++ Bipolaris maydis ++++ - Symptoms of common rust often appear after silking - Small, round to elongate brown pustules form on both leaf surfaces and other above ground parts of the plant - As the pustules mature they become brown to black - If disease is severe, the leaves may yellow and die early  Results Table 3.2 Disease intensity of common rust of corn in Xuan Quan Field Time Incidence (%) Severity (%) 18/11 56 18,22 21/11 56 20 Field 24/11 64 20,44 Mean 58,67 19,55 18/11 68 23,11 21/11 68 25,78 Field 24/11 72 26,51 Mean 69,33 25,13 18/11 52 20,44 21/11 54 23,33 Field 24/11 64 26,22 Mean 56,67 23,33  Conclusion: From the table 3.2, it can be seen that both incidence and severity of corn common rust have upward trend in fields In field 3, incidence has the most considerable increase (from 52% up to 64%), for severity, field also has the most dramatic increase, in the last observation day, the severity of field reach up to 26,22% compared to 20,44% in the first day However, the biggest incidence and severity mean belongs to the field 2, 69, 33% and 25, 13% in respectively This infers that corn common rust affects the field most severely  Recommendation about management methods: - Genetic Resistance + DuPont Pioneer researchers screen hybrids and parent lines for resistance and provide ratings for customers + Growers should choose hybrids with a “5” or “6” rating in areas that frequently experience common rust - Scout corn to detect common rust early Monitor disease development, crop growth stage and weather forecast - Apply a foliar fungicide if: + Rust is spreading rapidly or likely to spread and yield may be affected + Disease exceeds threshold established by your state extension plant pathologist - Commonly used fungicides include Aproach, Headline, Headline SC, Headline AMP, PropiMax EC, Quadris, Quilt, Quilt Xcel, Stratego, - Disease is wind-borne and does not overwinter in U.S.; therefore, rotation and tillage are not effective  Disease cycle of corn common rust 3.1.2 Northern corn leaf blight  Symptoms - The tan lesions of northern corn leaf blight are slender and oblong tapering at the ends ranging in size between to inches - Lesions run parallel to the leaf margins beginning on the lower leaves and moving up the plant They may coalesce and cover the enter leaf - Spores are produced on the underside of the leaf below the lesions giving the appearance of a dusty green fuzz  Result: Table 3.3 Disease intensity of northern corn leaf blight in Xuan Quan Field Time Incidence (%) Severity (%) 18/11 52 16 21/11 52 18,67 Field 24/11 58 22 Mean 54 18,89 18/11 58 22 21/11 64 24,67 Field 24/11 70 24,44 Mean 64 23,7 18/11 48 16 21/11 52 18,66 Field 24/11 60 22,22 Mean 53,33 18,96  Conclusion: The table 3.3 show disease intensity of northern corn leaf blight through incidence and severity In general, there is a considerable rise in both incidence and severity of infected fields The field is infected most seriously with incidence 64% and 23, 7% for severity However, the infection of northern corn leaf blight in field is the fastest (incidence rise from 58% to 70%) and the most seriously because mean of severity in observation days is the largest (23, 7% compared to 18, 89% and 18, 96% in field 1, respectively)  Recommendations about management methods: - Crop rotation to reduce previous corn residues and disease inoculum - Tillage to help break down crop debris and reduce inoculum load - Fungicide application to reduce yield loss and improve harvestability - Consider hybrid susceptibility, previous crop, tillage, field history, application cost, corn price  Disease cycle of NCLB 3.1.3 Southern corn leaf blight  Symptoms - Lesions are generally: from 1/8 to 1/4 inch wide by 1/8 to inch long; tan in color; rectangular to oblong in shape; usually found on leaves variable, making identification more difficult than for other diseases - Lesion type may depend on hybrid genetics Lesions usually develop first on lower leaves and work up the plant  Result: Table 3.4 Disease intensity of Southern corn leaf blight in Xuan Quan Field Field Field Time 18/11 21/11 24/11 Mean 18/11 Incidence (%) 46 48 52 48,67 60 Severity (%) 13,56 13,78 18,67 15,34 19,56 Field 21/11 24/11 Mean 18/11 21/11 24/11 Mean 66 70 65,33 40 46 52 46 21,56 26,89 22,67 13,78 14,89 19,11 15,93  Conclusion: It can be seen from table 3.4 that the infection of fields increases and is more serious after 6-day observation While field witnesses the fastest rise for incidence (from 40% to 52%), the field is the highest incidence mean at 65, 33% For severity, field is leading infection due to highest mean of severity (22, 67%), far higher than the other fields (15, 34% for field and 15, 93% for field 3)  Recommendations about management methods - Genetic resistance + Hybrid ratings range from "3" to "7" on Pioneer's to scale (9 = resistant) + Growers in high-risk areas with a history of SLB occurrence in their fields should choose hybrids with a "6" or "7" rating for SLB resistance - Crop rotation to reduce corn residue level and help break disease cycle - Tillage to encourage breakdown of crop residue - Fungicide application + Scout corn to detect SLB early + Monitor disease development, crop growth stage, and weather forecast + Apply a foliar fungicide if disease is spreading rapidly or likely to spread and yield may be affected + Common fungicides include Headline, Quadris, Quilt, PropiMax EC, Stratego and Tilt  Disease cycle of Southern corn leaf blight 3.2 Pomelo - Survey time: times in days: 18/21/24 – 11 – 2018 Table 3.5 Information of surveyed pomelo fields Field Field Field Field Area 5400m2 4500m2 3000m2 Variety Dien pomelo Dien pomelo Da xanh pomelo Growth stage Basic construction period Basic construction period Basic construction period All observed diseases of each crop are summarized in table 3.5 Table 3.6 Diseases of pomelo at location Xuan Quan in days: 18, 21, 24/11/2018 No Disease Citrus canker  Pathogen Xanthomonas campestris Prevalance +++ Symptoms of citrus canker 10 On the leaves, the lesions appear first on the lower surface The lesions on the twigs and fruits are very similar to those of leaves, only difference is the somewhat dull yellowish colour of the lesions on the leaves is absent in those of twigs and fruits  Result: Rating scale of disease and symbols in table (*) Level 1: 5-25 infected leaf area (****) Level 7: >25-50 infected leaf area (*****) Level 9: >50 infected leaf area Table 3.7 Disease intensity of citrus canker in Xuan Quan Field Time Incidence (%) Severity (%) 18/11 29,08 4,08 21/11 29,08 4,54 Field 24/11 29,08 5,4 Mean 29,08 4,67** 18/11 46,1 18,95 21/11 53,23 21,90 Field 24/11 54,25 22,32 Mean 51,18 21,06*** 18/11 46,40 17,30 21/11 47,36 17,66 Field 24/11 51,23 19,1 Mean 48,33 18,02***  Conclusion: Field has lowest infected area with incidence mean at 29, 08% (stable) and severity mean at 4, 67% and belongs to average level of disease (1-5 infected leaf area) Field has far higher infected area than that of field Both field and belong to average level of disease (>5-25 infected leaf area)  Recommendations of management methods: The farmers in Xuan Quan are very active in spraying pesticides They choose the appropriate spraying time as before the young buds They 11 usually spray “green humat” fertilizer for leaf and sulfate copper against fruit damage Farmers also regular visit and remove severely diseased plants  Disease cycle of citrus canker 3.3 Cabbage Table 3.8 Information of surveyed cabbage fields Field Field Field Field Area 360m2 400m2 360m2 Variety “Bắp sen” “Hai bắp rưỡi” “Bắp sen” Growth stage Cabbage roll period Cabbage roll period Cabbage roll period 12 All observed diseases of each crop must be summarized in a table as following Table 3.9 Diseases of cabbage in Xuan Quan in days: 18, 21, 24/11/2018 No Disease Pathogen Black rot Xanthomonas campestris Bacterial soft Erwinia carotovora rot 3.3.1 Cabbage black rot  Prevalance ++ + Symptoms It is caused by a bacterium and cannot be treated by any current product Symptoms usually start at the leaf edges: conspicuous V-shaped, yellow lesions develop as the bacteria move further into the leaf If you snap the leaf just below one of these lesions, you will notice a blackening within the vein The disease is systemic and eventually spreads to most of the plant  Results: Rating scale of disease and symbols in table (*) (**) (***) (****) (*****) Level Level Level Level Level 1: 3: 5: 7: 9: 5-25 infected leaf area >25-50 infected leaf area >50 infected leaf area Table 3.10 Disease intensity of cabbage black rot in Xuan Quan Field Field Time 18/11 21/11 24/11 Mean Incidence (%) 6,00 6,60 7,4 6,67 Severity (%) 0,85 0,93 1,04 0,94* 13 Field Field 18/11 21/11 24/11 Mean 18/11 21/11 24/11 Mean 9,01 9,9 11,11 10 5,59 6,79 7,39 6,66 0,98 1,08 1,21 1,09** 6,39 7,27 8,15 7,34***  Conclusion: Cabbage black rot disease occupies very small infection in field and (with disease level only belongs to and level), whereas cabbages in field are infected more seriously with highest severity (at 7, 34%) and has disease level  Methods of management: - Farmers use development stimulation chemical for cabbage as picture below: - Many farmers spray copper-based products to prevent the disease or slow its spread - Ultimately, the most effective control measure is to plant resistant varieties because resistance to bacteria trying to invade the plant through the hydathodes is stronger - If you farm in an area where black rot is a greater hazard, avoid planting late-maturing varieties and widen the spacing - In addition, you can increase the gap between plants to allow a better movement of air and a slightly dryer microclimate This will also bring the crop to harvest earlier, which will help to further reduce the danger of black rot The heads can be harvested before the black rot spreads from the outer leaves to the head and cover leaves This can sometimes mean the difference between success and severe damage  Disease cycle of cabbage black rot 14 3.3.2 Bacterial soft rot of cabbage After three - time observation, I did not see any cabbages infected with bacterial soft rot in all three fields There exists some holes in which cabbages infected with bacterial soft rot are removed by farmers Because the number of removed cabbages are very small, only four bacterial soft rot cabbages in field and one, three infected cabbages in field 1,3 respectively Therefore, the severity of all fields is under 1% and disease level is Farmers usually check and remove the bacterial soft rot cabbage to prevent the spread to other cabbage plants in the field Recommendation of management methods:  Chemical control method - An effective control bacterial soft rot can be achieved through prevention because once infection occurs, it cannot be cured, but the bacteria can be prevented from spreading - Copper-based fungicides are recommended for use in preventing and suppressing the activity of the bacterial pathogen and they include greencop 500wp; trinity gold 452 wp; colonizer 440wp; biodistinction xtra 700cs  Non-chemical control methods - Set out plants in rows to allow good air drainage - Plant resistant cultivars - Use disease free and healthy planting materials - Cultivate carefully to minimize injuring plants - Control frequency and source of irrigation water - Avoid overhead irrigation to keep the foliage dry 15 - If soft rot is a serious, recurring problem in the garden, DO NOT grow susceptible crops in that area for a minimum of three years - Remove infected plants immediately and not compost - Practise rotations with disease non-host crops - Minimize any handling of soft-rotted plants, but if you must handle such plants e.g., to remove them from the garden, wash your hands afterwards with soap and water PART 4: CONCLUSION After short internship of course “Plant Pathology”, I realize that: - On maize in Xuan Quan, common rust, southern leaf blight and northern leaf blight cause serious damage in corn, particularly have significant effects on productivity and the quality of corn ears We need to combine chemical method with cultural and biological method and apply them in appropriate time to immediately prevent the inoculation and spread of disease - Pomelo is indicated to be infected with more diseases than only one citrus canker disease as I observed in all fields That is because farmers visit the field regularly and take protective measurements as soon as recognize the presence of diseases In addition, farmers also have pesticide – spraying schedule with such an appropriate period to prevent the disease inoculation of plant - There are a wide range of diseases on cabbages, including black rot and bacterial soft rot (considered to be two main diseases of cabbage) However, the farmers sprayed the pesticide to reduce the spread of diseases and manage the diseases quite well Therefore, the intensity of disease on cabbage is the lowest in three surveyed crops in Xuan Quan - The situation of disease on plant species is quite complicated Therefore, preventive measures need to be evaluated in many aspects, and there should be proper awareness about plant protection Local authorities should advise farmers not to abuse pesticide, need to follow "5 golden rules" and "4 correct" when using pesticides V REFERENCES Vu Trieu Man, 2007 “General plant pathology” textbook published by “NXB Nông nghiệp Hà Nội” Vu Trieu Man, 2007 “Specific plant pathology” textbook published by “NXB Nông nghiệp Hà Nội” The document “QCVN 01-38: 2010 / BNNPTNT” National Technical Regulations on surveilance method of plant pests 16 Some other websites 17 ...I highly recommend that Plant Pathology Department should design more internship programs in courses related to Plant Pathology to give students more chances to get access... to expose them to various job challenges in the future 1.2 Objectives At the very outset of this internship, I formulated several learning goals which I hunted to achieve: - Observe the main and... Have knowledge base of plant disease as well as crop science specialist - Read the guideline for internship carefully before going to the fields - Prepare necessary tools carefully for conducting