Blight - Early and Late
Early blight and late blight are two very different diseases of tomato and potato crops. Early blight requires high humidity and mild to warm temperatures, whereas late blight is favoured by cool, moist and overcast conditions.
Early blight starts on the bottom leaves and causes brown lesions with concentric rings. It can lead to defoliation of plants. Late blight favours the new growth and starts with watersoaked lesions turning into dark blotches with white fluffy growth on the underside of leaves. The disease can progress to completely destroy plants within two weeks under favourable weather conditions.