Potato crops undergo four clearly identifiable phenological phases:
1. Planting to emergence
2. Emergence to tuberization initiation
3. Tuberization initiation to tuber filling
4. Tuber filling to maturity
Each of these phases has specific environmental and nutritional requirements to achieve the growth objectives of the different organs of the plant; taking into account that usually more than one organ is developing at the same time and competing for the photoassimilates produced by the plant. This way, there is a balance between the vegetative and generative growth of the potato crop.
A vegetative balance privileges the development of stems and the foliar area, while a generative balance favours the production and filling of tubers. Nutritionally, the N: K ratio determines the vegetative and generative growth balances. A high N: K ratio promotes vegetative growth, while a low N: K ratio stimulates generative growth.