The effects of soil and foliar fertilisation on zinc

The gap

Evidence profile

Sourced from the recommendations and stated research gap and abstract of the source papers, classified as general, drawn from work published between 2017 and 2026, spanning 3 journals.

Supporting evidence — 4 representative gaps

• Zinc-induced modulation of growth and stress biochemistry in mandarin orange (Citrus reticulata Blanco): A comprehensive study for delineating deficiency and toxicity threshold (2026) · Plant Science Today · doi

  RESEARCH PRIORITIES 95 95 96 96 97 99 99 100 100 100 101 101 101 101 101 101 101 101 102 102 102 102 103 103 103 103 104 104 104 104 106 106 106 106 108 108 110 113 114 116 117 120 121 121 122 123 124 124 125 125 126 127 127 129 132 135 ExECUTIVE SUMMARy Zinc is essential for the normal healthy growth and reproduction of plants, animals and humans and when the supply of plant-available zinc is inadequate, crop yields are reduced and the quality of crop products is frequently impaired. In plants, zinc plays a key role as a structural constituent or regulatory co-factor of a wide range of different enzymes and proteins in many important biochemical pathways and these are mainly concerned with: v carbohydrate metabolism, both in photosynthesis and in the conversion of sugars to starch, v protein metabolism, v auxin (growth regulator) metabolism, v pollen formation, v the maintenance of the integrity of biological membranes, v the resistance to infection by certain pathogens. When the supply of zinc to the plant is inadequate, one or more of the many important physiological functions of zinc is unable to operate normally and plant growth is adversely affected. The changes in plant physiological mechanisms brought about by a deficiency of zinc can result in the plant developing visible symptoms of stress which might include one or more of the following: stunting (reduced height), interveinal chlorosis (yellowing of the leaves between the veins), bronzing of chlorotic leaves, small and abnormally shaped leaves and/or stunting and rosetting of leaves (where the leaves form a whorl on shortened stems). These different types of symptoms vary with plant species and are usually only clearly displayed in severely deficient plants. In cases of marginal deficiency, plant yields can often be reduced by 20% or more without obvious visible symptoms. This is called ‘hidden’, ‘latent’ or ‘subclinical’ deficiency. Zinc-deficient soils causing hidden deficiency may remain undetected for many years unless soil or plant diagnostic tests are carried out, because there are no obvious signs of stress in the crops growing on them. However, a change to growing less zinc deficiencytolerant crop species or cultivars, or the adoption of more intensive farming methods may lead to the development of a more severe deficiency in the crop accompanied by visible symptoms which will bring the problem to the notice of the farmer. Losses of yield of 20% or more as a result of hidden zinc deficiency can have an economic impact on the farmer. In more intensive types of arable farming where expensive inputs of seed, fertilisers, agricultural chemicals and possibly irrigation water are involved, the failure of crops to realize their potential yield is a major loss of income to the farmer.

  generalrecommendationsevidence 5/5
  Keywords: zinc plant deficiency leaves crop symptoms growth plants reduced metabolism visible hidden farmer supply inadequate
• Assessing Zinc Requirement of Newly Developed Wheat Variety NWB-50 (2026) · Journal of Applied Research in Plant Sciences · doi

  Zinc deficiency is a significant problem in wheat production, particularly in arid and semiarid regions. There is a need to find the optimal zinc dose for improving wheat growth and yield.

  generalstated research gapevidence 5/5
  Keywords: zinc deficiency significant problem wheat production particularly arid
• Zinc-induced modulation of growth and stress biochemistry in mandarin orange (Citrus reticulata Blanco): A comprehensive study for delineating deficiency and toxicity threshold (2026) · Plant Science Today · doi

  The limited understanding of zinc's role in plant development. The need to identify critical biochemical and morphological markers for leaf zinc status.

  generalstated research gapevidence 5/5
  Keywords: limited understanding zinc role plant development need identify
• PROTOCOL: Agronomic biofortification strategies to increase grain zinc concentrations for improved nutritional quality of wheat, maize and rice: a systematic review (2017) · Campbell Systematic Reviews · doi

  However, the effects of soil and foliar fertilisation on zinc concentrations beyond basic plant nutrition and productivity remain not fully understood.

  generalabstractevidence 4/5
  Keywords: effects soil foliar fertilisation zinc concentrations beyond basic plant nutrition productivity remain fully understood

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