K.dubey
- 1. Khushboo Dubey Dept of Plant Pathology TMU,Moradabad MANAGING FOLIAR DISEASES
- 2. What is the nature of these fungi? • Fungi with the common name ‘mildew’ are numerous, and they attack many vegetable and cucurbit species. • Each of the fungi has different life cycles and preferred hosts. • Downy mildews and powdery mildews behave very differently and thrive under different conditions. • Downy mildews prefer cool and wet weather for infection and are favoured by free moisture (dew or moisture from rain or irrigation) on leaves. • Powdery mildews like warm and dry weather and are inhibited by free moisture on leaves. Mildew fungi survive in infected plant material (weeds, commercial crops or seeds), and each has specific or preferred hosts.
- 3. Downy Mildews • High humidity andmild temperatures favour downy mildew, but not all hosts are equally susceptible. • Resistant and tolerant varietiesof cucurbits and some Brassica species exist but clean transplants are essential to give all crops a good start • Direct sun and good ventilation help reduce disease threat even in the most susceptible varieties.
- 4. Powdery Mildews • The fungi grow best at 20-25°C and the first symptoms appear in spring. • The symptoms include powdery patches on most above-ground surfaces, especially on leaves. • In some crops, such as capsicums and tomato, the patches on the upper leaf surfaces are yellow rather than white.
- 5. White Blister • White blister requires 3-4 hours of free moisture in mild (6-24°C) temperatures for spores to germinate and infect leaves or heads of developing cauliflower and broccoli plants. • These conditions occur frequently in greenhouses and in fields during spring and summer mornings.
- 6. How can I protect my vegetable crops • Check all incoming seedlings and isolate them from your production areas. • spores spread from infected plant material, make sure the cropping area is free of plant debris,volunteer hosts and weeds. • In strip cropping, promptly remove and destroy all infected crop debris as soon as harvesting is completed. • Planting tolerant varieties whenever possible. Very few vegetables have resistance to the mildews. White blister may develop on some broccoli and cauliflower varieties, but most cabbages are tolerant or resistant
- 7. what can I do? • Sulphur is the most widely used fungicide for powdery mildew control and despite resistance development being unlikely, sulphur is not suitable for use on all crops, especially during hot weather. • Copper may be effective on some downy mildew infections, but on cucurbits the active constituents dimethomorph and metalaxyl are very effective if applied at the onset of the disease
- 9. controlling the foliar fungi • Managing the Mildews control in vegetables are those of growers who have integrated the planting of resistant or tolerant varieties, strict farm sanitation, excellent weed control, monitoring for early symptoms on older leaves and specific cultural actions- irrigation (and humidity) timing, nutrition levels, and sometimes crop-free periods.
- 10. Managing White Blister • The impact of white blister on some susceptible crops has been greatly reduced by strategies that integrate irrigation timing and resistant varieties.
- 11. Conclusion • foliar diseases are welldeveloped and have allowed progressive vegetable growers to reduce their dependence on chemicals while improving their produce quality, and reducing their costs and the threat of chemical residues and chemical resistance.
- 12. THANK YOU