Nitrogen deficiency (N)
Nitrogen deficiencies will result in stunted plants and pale-yellow discoloration, which will initially show on older leaves.
Treatment: Foliar fertilisation with nitrogenous fertilisers containing a moderate but relatively effective dose of nitrogen. Spring fertilisation with mineral fertiliser either on naked soil or between vines. An advisable preventive strategy is to maintain and to improve the soil’s organic substance. This is supported by an appropriate green cover, reutilisation of pruning waste and applications of soil conditioners/organic fertilisers, in addition to conducting a soil analysis.