PATAT’UP: Towards a Low-Input Potato

Potato cultivation in Wallonia holds economic and cultural significance, but its heavy reliance on inputs poses risks at environmental, health, and economic levels. The Patat’Up project aims to address these challenges by identifying and integrating levers to create low-input production systems. The use of late blight-resistant varieties is one of the chosen levers to reduce the high fungicide use. The objective of the 2023 trial was to determine the possibilities of delaying fungicide interventions, according to the variety’s resistance, without affecting yield. The trial investigated four different varieties with four modalities: untreated modality; control modality with full treatments based on a warning monitoring system of late blight; and two delayed modalities where the first treatment was postponed by 2 or 4 applications. Results showed that delaying treatments is not possible for sensitive varieties (Fontane and Agria) in the 2023 context with high late blight pressure. Delaying the first intervention for these varieties induces foliage destruction from 25 to 100% and yield reduction from 7 to 25 t/ha compared to the control. With the use of mid-resistant variety (Louisa), delaying only 2 applications is possible. Extending the delay to 4 applications induces significant foliage destruction and a yield loss of 10 t/ha compared to the control. For the resistant variety (Acoustic), both delayed treatments resulted in similar yields to the control with no or few symptoms of foliage destruction. The use of a resistant variety enabled savings of 66% to 84% of active ingredients.