Foliar nutrition: Current state of knowledge and opportunities

Abstract

The effectiveness of foliar nutrition is affected by numerous endogenous (related to leaf anatomic structure) as well as exogenous (nutrient concentration, soil type, pH) and environmental factors. Simultaneous application of foliar nutrition with plant growth and development biostimulators enables the increase of crop yield and the improvement of its quality. A significant trend in functional food production is plant biofortification with mineral nutrients - mainly Ca, Mg, microelements, and biogenic trace elements. Foliar nutrition can be used as a method of increasing crop level of these elements. Citrus plants, despite its thick cuticle layer of leaves, respond relatively well to foliar nutrition due to a high number of stomata on the lower leaf surface accompanied by a greater amount of cuticle pores (easing nutrient absorption) than any other epidermal cells. Foliar application treatments, when properly planned and conducted, may stimulate the flowering, increase yield, and improve nutritional and postharvest quality of citrus fruits.