Enhancing Grain Yield and Nitrogen Accumulation in Wheat Plants Grown under a Mediterranean Arid Environment by Foliar Spray with Papain-Released Whey Peptides

Abstract

Due to their beneficial, stimulating impact on plant growth, productivity, and alleviating environmental stresses, protein hydrolysates have recently received increasing attention as a possible substitute. This investigation aimed to explore the effects of foliar application of papain-produced whey protein hydrolysates (WPH) on the yield attributes and nitrogen use efficiency (NUE) of soft wheat. Wheat plants were cultivated under a Mediterranean arid environment and received four soil nitrogen (N) fertilization levels with ammonium nitrate (145, 185, 215, and 250 kg N ha−1) and compared to control treatment and urea foliar application. WPH increased grain yield, yield attributes, and N accumulation in wheat plants. Partial productivity factors of applied nitrogen, as NUE indicators under relatively steady-state cropping systems, were also enhanced by WPH compared to control treatment. WPH significantly improved flag leaf area, spike number m−2, and grain yield compared to urea foliar application. Increasing the soil N fertilization level from 145 up to 215 kg N ha−1 was accompanied by significant increases in all yield traits and N accumulation measurements, except for the partial factor productivity of applied N, which decreased. A strong positive association was detected among grain and straw yields, their attributes, and total N uptake. Results highlighted the efficacy of WPH in increasing wheat yield and NUE.

Comparative Efficacy of Foliar Plus Soil Application of Urea versus Conventional Application Methods for Enhanced Growth, Yield, Agronomic Efficiency, and Economic Benefits in Rice

“…13 The application of urea at three equal splits facilitated higher vegetative growth and hence attained the maximum plant height in aromatic rice. 15,16 Nitrogen is an essential constituent of chlorophyll and well-supplied nitrogen which enhanced the crop growth vigorously, 30 and both soil and foliar application of N significantly increased the plant height over soil-applied N in rice 17,20 and wheat. 26 Number of Effective Tillers hill −1 .…”

“…The increment of grain weight at a higher nitrogen rate might be primarily due to an increase in the chlorophyll content of leaves, which leads to a higher photosynthetic rate, and ultimately plenty of photosynthates available during grain development. 30 Foliar application of urea at the later growth stages of the crop might have increased the availability of nitrogen to the crop, which probably has favored the enhanced accumulation of photosynthates (TDM; Table 1) in the grains. These results are in line with Gholami et al, 21 who reported a significant increase in 1000-grain weight with the foliar application of nutrients.…”

“…Three splits of N at transplanting (50%), tillering (25%), and panicle initiation stages (25%) gave a higher plant height than two equal splits at the transplanting and tillering stages or one time at transplanting . The application of urea at three equal splits facilitated higher vegetative growth and hence attained the maximum plant height in aromatic rice. , Nitrogen is an essential constituent of chlorophyll and well-supplied nitrogen which enhanced the crop growth vigorously, and both soil and foliar application of N significantly increased the plant height over soil-applied N in rice , and wheat …”

“…The 1000-grain weight increased up to the soil and foliar (N 80% ) application of N (T 8 ) over the control and thereafter decreased with 100% soil (T 9 ) and 110% soil (100%) and foliar (10%) application of N (T 10 ). The increment of grain weight at a higher nitrogen rate might be primarily due to an increase in the chlorophyll content of leaves, which leads to a higher photosynthetic rate, and ultimately plenty of photosynthates available during grain development . Foliar application of urea at the later growth stages of the crop might have increased the availability of nitrogen to the crop, which probably has favored the enhanced accumulation of photosynthates (TDM; Table ) in the grains.…”

Morpho-Anatomical, Physiological, and Mineral Composition Responses Induced by a Vegetal-Based Biostimulant at Three Rates of Foliar Application in Greenhouse Lettuce

“…Plant biostimulants (BP) are neither fertilizers nor pesticides and do not have a direct effect on parasites and pathogens [ 2 ]. BP are able to improve the nutritional status of plants due to synergistic and/or additive effects dealing with an enhancement of NUE [ 3 , 4 , 5 , 6 , 7 , 8 ], higher soil organic matter mineralization by microorganisms [ 9 , 10 , 11 , 12 , 13 ], improved nutrients’ mobility and solubility [ 2 , 14 , 15 , 16 , 17 , 18 ], changes of root architecture and spatial configuration in the soil to better access to nutrients and water [ 19 , 20 , 21 , 22 , 23 , 24 ], up-regulation of transporters and enzymes to increase nutrients uptake and assimilation [ 25 , 26 , 27 , 28 , 29 , 30 ]. Among PB, plant-derived protein hydrolysate (PH), mixtures of polypeptides, oligopeptides, and amino acids, produced through partial hydrolysis of agri-food residues, can be an eco-friendly strategy to ensure development of the agricultural sector [ 31 , 32 , 33 ].…”