Plants require sufficient amounts of the essential plant nutrients to ensure normal growth and production. Any deficiencies may result in abnormal growth, but especially in lower tuber yield and quality. A deficiency in any of the essential plant nutrients can usually be noticed as visual symptoms on the leaves or foliage. It  is important to note that leaf symptoms may also occur as a result of reasons other than nutrient deficiencies (e.g.  herbicide damage). It is advisable to take leaf samples from plants that show any symptoms and have it analysed to  confirm any possible nutrient deficiencies. This will confirm whether the levels of essential nutrients are within critical  limits for potatoes. Leaf deficiency symptoms may occur due to too low levels of a specific nutrient, or as a result of imbalances between  elements in the soil. Plants may also experience deficiencies due to abnormally low or high soil pH levels, which may  induce deficiencies due to reduced availability of nutrients to plants. The most common deficiency symptoms on  potatoes are discussed below. Macro nutrients Nitrogen (N) Phosphorus (P) Potassium (K) Magnesium (Mg) Calcium (Ca) Sulphur (S) Micro nutrients Micro nutrient deficiencies in potatoes often occur as induced deficiencies, rather than low nutrient levels in the soil.  This typically occurs as a result of nutrient imbalances in the soil, or when the soil pH levels fall outside the range for  optimal plant growth.  Boron (B) Copper (Cu) Iron (Fe) Manganese (Mn)  Molybdenum (Mo) Zinc (Zn) Acknowledgements Deficiency symptom photos were taken by Burger Cillié and edited by Niel Cillié. Ca and Zn photos were supplied by Yarra. Fe photos supplied by Piet Brink. ARC-Roodeplaat (Niederwieser, 2003; Denner & Venter, 2011) Literature sources Bennet, W.F. (ed.), 1993. Nutrient deficiencies and toxicities in plants. APS Press. Minnesota, USA. Misstofvereniging van Suid-Afrika (MVSA), 2003. Bemestingshandleiding. MVSA. Lynnwoodrif, Pretoria, Suid-Afrika. Reuter, D.J. & Robinson, J.B. (eds.), 1997. Plant analysis and interpretation manual. CSIRO publishing. Collingwood. Australia. Silva J. A. & Uchida, R. (eds.), 2000. Plant Nutrient Management in Hawaii's Soils. Approaches for Tropical and Subtropical Agriculture. College of Tropical Agriculture and Human Resources, University of Hawaii, Manoa, USA. Westermann, D.T., 1993. Fertility management. In: Rowe, R.C. (Ed). Potato Health management. Ohio State University. APS Press. Minnesota, USA.
Nutrient Deficiencies
Martin Steyn and Hennie du Plessis