Enhancing crop yield with the use of N‐based fertilizers co‐applied with plant hormones or growth regulators

Abstract

Crop yield, vegetative or reproductive, depends on access to an adequate supply of essential mineral nutrients. At the same time, a crop plant's growth and development, and thus yield, also depend on in situ production of plant hormones. Thus optimizing mineral nutrition and providing supplemental hormones are two mechanisms for gaining appreciable yield increases. Optimizing the mineral nutrient supply is a common and accepted agricultural practice, but the co-application of nitrogen-based fertilizers with plant hormones or plant growth regulators is relatively uncommon. Our review discusses possible uses of plant hormones (gibberellins, auxins, cytokinins, abscisic acid and ethylene) and specific growth regulators (glycine betaine and polyamines) to enhance and optimize crop yield when co-applied with nitrogen-based fertilizers. We conclude that use of growth-active gibberellins, together with a nitrogen-based fertilizer, can result in appreciable and significant additive increases in shoot dry biomass of crops, including forage crops growing under low-temperature conditions. There may also be a potential for use of an auxin or cytokinin, together with a nitrogen-based fertilizer, for obtaining additive increases in dry shoot biomass and/or reproductive yield. Further research, though, is needed to determine the potential of co-application of nitrogen-based fertilizers with abscisic acid, ethylene and other growth regulators.

Plant Hormones under Challenging Environmental Factors

“…The effect of N defi ciency is probably the most studied nutrient limitation in plants because of the high signifi cance of N for the biosynthesis of multiple plant organic molecules. Thus, there is increased interest in researching the N-phytohormone interactions (Kiba et al 2011 ;Zaman et al 2015 ). Thus, there is increased interest in researching the N-phytohormone interactions (Kiba et al 2011 ;Zaman et al 2015 ).…”

“…There is a great interest in agriculture to use N-based fertilizers co-applied with phytohormones or other growth-promoting chemicals (Zaman et al 2015 ). A strong coordination has been proposed among ABA, auxin, and CKs in controlling the demand and acquisition of nitrogen in plants (Kiba et al 2011 ;Zaman et al 2015 ). A strong coordination has been proposed among ABA, auxin, and CKs in controlling the demand and acquisition of nitrogen in plants (Kiba et al 2011 ;Zaman et al 2015 ).…”

“…Phytohormones play a crucial role in regulation of plant growth, development, nutrient, and source/sink allocations Kurepin et al 2013a ;Hüner et al 2014 ;Zaman et al 2015 ). They are signaling molecules that control many physiological and biochemical processes, affecting various plant physiological processes including seed dormancy and germination Park et al 2015 ).…”

Evaluating the use of plant hormones and biostimulators in forage pastures to enhance shoot dry biomass production by perennial ryegrass (Lolium perenneL.)

“…However, there are environmental concerns associated with the overuse of urea for increasing perennial ryegrass shoot biomass growth . Therefore, there is a renewed interest in identifying naturally occurring plant growth‐promotive compounds which can enhance shoot biomass growth of perennial ryegrass plants, and thus potentially reduce the overuse of urea …”

Response of Elite Kenyan Finger Millet (<i>Eleusine coracana, </i>L. Gaertn) Genotypes to Ethrel Application

“…Genetic improvement has been limited by the difficulties associated with hybridization, particularly emasculation [7]. Cereal crop performance can be optimized through the development of hybrids, application of fertilizer and/or growth regulators [8], among other management practices. Although hybrid seed production technology has been successful in several allogamous cereal crops (maize, sorghum), the results have not been replicated in autogamous cereal crops such as wheat, rice [9] and finger millet.…”