Waleed.pptx
- 1. Mango Diseases in Pakistan By: Hafiz M. Waleed Hassan Roll# 12 (M-B)
- 2. Anthracnose & Die Back Reference Book: Diseases of Fruit Crops By R.S. Singh Pg#161
- 3. Casual Organism Colletotrichum gloeosporioides Penz. Anamorph of the Ascomycetous fungi Glomerella cingulata (Ston.) Spould and Shrenk, is a widely distributed funga causing leaf spot and anthracnose on citrus, sugarcane, etc. In addition to C. gloeosporioides, many other fungi are reported to be associated with die-back leaf blight, and fruit rot symptoms on mango.
- 4. Economic Importance Association with leaf spots, blossom blight is a widespread disease has major economic importance in areas where mango is grown commercially. reported from many countries including Pakistan, India, Philippines, Indonesia, Trinidad, Peru, Hawaii and Portugal. occurs on all parts of the tree but is most common on flowers and flower stalks. Young and mature fruits are also infected. If early infection of fruits takes place they fall off. Infected ripe fruits are blemished hence fetch a low price in the market. In storage the anthracnose leads to postharvest storage rot.
- 5. Symptomology The leaf spot and twig anthracnose is characterized by leaf spots, wither-tip and blossom blight. Young leaves are most susceptible Numerous oval or irregular, brown to black spots appear on the leaf blade restricting further growth of the leaf Under humid conditions these spots increase rapidly and form irregular, necrotic areas Sometimes, the dead parts of the blade separate and fall down. Badly affected leaves may also shed. In wet and warm weather, acervuli of the fungus develop as pink bodies on the dead and infected parts. Later, these fungus structures turn black. In blossom blight, minute, brown to black lesions appear on floral parts and floral stalks. Affected flowers in the panicle dry and shed. This causes significant loss to fruit setting
- 7. Epidemology Conidial production in acervuli is favored by temperatures of 10°-30°C and a relative humidity of 95-97%. The fungus does not grow at a relative humidity less than 95%. Thus, humid and misty conditions, temperatures of 24°-32°C, especially at the time of development of shoots, flowers and fruits, are considered most favorable for infection
- 8. Disease Cycle Diseased twigs, leaves and dried fruits on the tree and on the orchard floor are a prolific source of perenation of the fungus and fresh infections. The pathogen can survive as leaf spots on the tree throughout the year On the fruits, infections take place from the start of the blossoming until fruits are more than half grown. Infection pegs from the aspersoria enter the fruit through pores in the skin but the infection remains latent and the fungus grows only to a limited extent in the epidermal layers of the fruit. Further growth of the fungus usually occurs during ripening of the fruit. Latent infection can occur through lenticels also. Aspersoria have an important role in epidemiology of anthracnose. Most of the aspersoria from germ tubes of conidia lodged on the fruit do not germinate immediately but remain firmly attached to the fruit skin as the latent stage of the pathogen. These latent aspresoria serve as inoculum that gives rise to anthracnose spots on ripe fruits.
- 9. Management Tree and general orchard sanitation Vigorous growth of trees should be maintained by proper fertilization Pruning and Destruction of Diseased Branches 4 to 5 Sprays of Fungicides Use of resistant variety
- 10. Powdery Mildew Reference Books: Diseases of Fruit Crops By R.S. Singh Pg#147
- 11. Casual Organism Oidium Mangifera (Acrosporum Mangifera)
- 12. Economic Importance The affected flowers and fruits drop Prevent the fruit set. Reduce yield upto 90%
- 13. Symptomology White superficial powdery fungal growth on Leaves stalk of panicles flowers and young fruits.
- 14. Epidemiology Fungus is favored by Cloudy weather and Heavy mist Disease is more severe during cool, DRY weather. minimum, optimum and maximum temperature for germination are 9º,22ºand 30º- 32º Conidia grow well in temperature 9º-32º.
- 15. Disease Cycle Fungus survives as mycelium Conidia on the tree branches and also on other annual and perennial hosts. In favorable weather conidia formed on, the mycelium are dispersed by wind and spread the disease. The optimum temperature for germination of conidia is 22°C, maximum 32°C and minimum 9°C. The conidia are quickly destroyed in dry weather and under strong sunlight. Generally, cold nights, light rains or foggy weather at the time of flowering favor initiation of the disease. the disease destroys mango panicles during the second half of March when average minimum temperatures are around 15°-17°C and the relative humidity 65-85 %. High wind velocity favours spread of powdery mildew.
- 16. Management Spray of fungicides (Sulphur based fungicides) removal and burning of affected leaves, blossoms, twigs Use of resistant or Best variety
- 17. Mango Malformation Reference Books: Diseases of Fruit Crops By R.S. Singh Pg#161
- 19. Economic Importance 1st Recognized in 1891 by Maries Also known as Bunchy top Serious threat to the mango growing areas Complex Nature
- 20. Symptomology Bunchy Top of seedling Vegetative Malformation Floral Malformation
- 21. Epidemiology 60% diseased pedicles in Feb – March While same plant has 4.5% malformation in June Severe when temp. lies b/w 10-15ºC Observed more in Young Plants About 91% in 4-8 Years old Plants
- 22. Disease Cycle Natural Spread Aerial Flights Fusarium Spores Disease is sporadic in Nature Propagation & Distribution of diseased Plants. May Cause wide distribution of the Disease.
- 23. Management Tree Management Variety Selection Spray of Fungicide
- 24. Stem End Rot Reference Books: Diseases of Fruit Crops By R.S. Singh Pg#157
- 25. Casual Organism Caused by several fungi but the following is most common Lasiodiplodia theobromae Diplodia natalensis
- 26. Symptomology The skin of the fruit around the pedicel becomes dark green and water-soaked and then turns into a brown black circular lesion, surrounded by lighter margin. This lesion may bear pycnidia of the fungus.
- 27. Economic Importance most destructive postharvest diseases affect tropical and sub-tropical fruits The fungus can attack mango leaves, twigs and flowers
- 28. Disease Cycle Lasiodiplodia theobromae is often considered a disease agent of stressed or weakened plants. It has a wide host range that includes fruit trees as well as certain field crops and causes leaf spots, cankers, root rot, fruit rot and seed decay on different hosts The fungus survives on the trees in cankers or in the bark or dead twigs and also through pycnidia On fallen diseased plant parts Lasiodiplodia theobromae invades mango pedicel through wounds and in mature green and ripe fruits, the invasion can occur without quiescence These fungi are present in soil on the orchard floor.
- 29. Management Spray of Fungicides Fruit should be Harvested with minimum 10mm Stalk Fruits placed in cellophane bags immediately after harvest Proper Handling can minimize the disease
- 30. Sudden Death Reference Books: Diseases of Fruits & Vegetables Volume 1 By S.A.M.H Naqvi Pg#525
- 31. Casual Organism Lasiodiplodia theobromae
- 32. Economic Importance Very Destructive Disease in Pakistan This syndrome is a complex problem This is the result of a particular mix of fungi resulting in Die back, root rot, tip dieback, gummosis and dying of trees Collapse of mango plants occurs within a couple of days because of its quick decline. This disease has 100% mortality.
- 33. Symptomology First sign of the disease is the oozing of the bark development of cankers on the trunk Rotting and blackening of the bark The splitting of the trunk, and the drying and curling of twigs and branches. Finally, the leaves are shed from the tree. Collapse of mango plants occurs within a couple of days because of its quick decline. This disease has 100% mortality.
- 35. Epidemiology: Artificial inoculation experiments have shown that establishment of fungus requires at least 48 hrs at temperature 20-32°C and relative humidity of about 80-85%.
- 36. Disease cycle The disease can remain in dead trees for a long time, and enters the tree via cuts and injuries made by unclean equipment, bark beetles and other mango tree bark feeding insects.
- 37. Management Keeping trees healthy and avoiding water stress will help to prevent the trees from succumbing to the disease Regular monitoring of orchards is important in identifying the problem at an early stage Application of Bordeaux mixture twice a year helps to reduce the fungal inoculums (sources) on the tree The diseased trees should be removed and burnt Control bark beetles or caterpillar borers by applying bifenthrin (e.g. Talstar) First spray during the last week of February Second spray before the onset of monsoon rains Third spray after the rainy season
- 38. Any Question
- 39. Thank You