Efeito de tratamentos fitossanitários na produção de cultivares de batateira (Solanum tuberosum L.) no planalto do Huambo (Angola)

Trials in complete casual blocks subdivided in the time to compare the behaviour of 3 imported seed-potato cultivars – ‘Diamant’, ‘Romano’, ‘Picasso’ – and 3 regional cultivars – ‘Tchigembo’, ‘Kanjangala’, ‘Boa nova regional’ –, planted in two dates on rain season (October and February) and in a third date (June), in dry season, with irrigation. The trials were repeated in three locals of the Huambo country – Bailundo, Chianga e Calenga – with 50 km of distance. In all seasons and cultivars were applied, or not, pesticides, the fungicide (mancozeb + metalaxil-M) during the two first seasons, to control the potato blight (Phytophthora infestans) and the insecticide (lambda-cihalotrine) on the third season to control the aphids (Myzus persicae). The number and weight of the total and commercial value tubers (O > 25 mm), the incidence and severity of the late blight and aphids and the potato vegetative period were evaluated.