Late Blight
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Late blight is a mould illness affecting tomato leaves, stems, and fruit. It develops in cool, moist climate and spreads quickly. Late blight is attributable to the oomycete Phytophthora infestans, which isn’t a real fungus however nonetheless causes devastation because it did through the Irish potato famine within the 1840s. Should you suspect you could have late blight, contact your native extension service for particular identification as a result of there are lots of strains of late blight.
Signs: Greasy-looking, irregularly formed darkish brown blotches with green-gray edges seem on leaves. A hoop of white mould develops across the spots, particularly in moist climate. The spots finally flip dry and papery. Blackened areas could seem on the stems. The fruit additionally develops massive, irregularly formed, greasy grey spots and may flip mushy from a secondary bacterial an infection.
Administration: Copper sprays provide some management. The fungicide Serenade works finest as a deterrent moderately than a treatment. Late blight can overwinter in soil, tomato particles, and seeds, even in colder areas. Take away all particles. Rotate crops to forestall infections the next 12 months.
Prevention: Rotate crops annually, plant blight-resistant varieties, promote air circulation between vegetation by spacing them out correctly and pruning leaves that contact.