Evaluating the physiological effect of strobilurin-based fungicide (Opera 183 g/L SE) against Sclerotium rolfsii and Aspergillus niger pathogens of Arachis hypogaea L.

Abstract

The present study was designed to investigate the effect of fungicide Opera 183?g/L SE on groundnut crop (either as seed or foliar treatment) to control damages and losses incurred especially by the soil borne pathogens Sclerotium rolfsii and Aspergillus niger. The results revealed that 0.15% Opera-treated seeds showed early germination, high percentage of germination, less mortality rate in S. rolfsii and A. niger-infested soil. Enhanced activities of defence-related enzymes, protein, carbohydrate and chlorophyll content up to 2–4 d were observed in Opera-treated plants as compared with untreated plants. Moreover, the application of Opera had a positive effect on yield up to 22%, green fodder at the time of harvest and no disease incidence. From the present study, it is recommended that application of Opera at 750?ml/hectare in the form of foliar treatment to groundnut plants could help in inducing resistance towards opportunistic pathogens and also could enhance the yield.     

Induction of peroxidase and polyphenol oxidase in Arachis hypogaea in response to treatment with Pseudomonas fluorescens and inoculation with Alternaria alternata

Abstract

The application of talc-formulation through seed, seed treatment plus foliar spray and foliar spray alone significantly reduced the leaf blight incidence both under greenhouse and field conditions. The groundnut plants treated with biocontrol agent and challenge inoculated with Alternaria alternata recorded significantly increased activity of Peroxidase isozyme (PO), Polyphenol oxidase isozymes (PPO) activity. Expression of PO2, PPO1 and PPO2 isoforms were found in all the plants treated with Pf1 while additional PO1, PPO3, PPO4 and PPO5 were observed in Pf1-treated plants followed by challenge inoculation with the pathogen.     

Plant Growth–Promoting Methylobacterium Induces Defense Responses in Groundnut (Arachis hypogaea L.) Compared with Rot Pathogens

This study, framed in two different phases, studied the plant-growth promotion and the induction of systemic resistance in groundnut by Methylobacterium. Seed imbibition with Methylobacterium sp. increased germination by 19.5% compared with controls. Combined inoculation of Methylobacterium sp. with Rhizobium sp. also significantly increased plant growth, nodulation, and yield attributes in groundnut compared with individual inoculation of Rhizobium sp. Methylobacterium sp. challenge-inoculated with Aspergillus niger/Sclerotium rolfsii in groundnut significantly enhanced germination percentage and seedling vigour and showed increased phenylalanine ammonia lyase (PAL), β-1,3-glucanase, and peroxidase (PO) activities. Under pot-culture conditions, in Methylobacterium sp. seed—treated groundnut plants challenge-inoculated with A. niger/S. rolfsii through foliar sprays on day 30, the activities of enzymes PO, PAL, and β-1,3-glucanase increased constantly from 24 to 72 hours, after which decreased activity was noted. Five isozymes of polyphenol oxidase and PO could be detected in Methylobacterium-treated plants challenged with A. niger/S. rolfsii. Induced systemic resistance activity in groundnut against rot pathogens in response to methylotrophic bacteria suggests the possibility that pink-pigmented facultative methylotrophic bacteria might be used as a means of biologic disease control.     

Jasmonic Acid-Mediated-Induced Resistance in Groundnut (Arachis hypogaea L.) Against Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae)

Jasmonic acid (JA) acts as a signal molecule to induce resistance in plants against herbivores and its levels are elevated in plants after wounding or insect damage. Groundnut is an important crop in many tropical and subtropical regions worldwide, but there is surprisingly little knowledge on its induced defenses against herbivores. The effect of JA as a spray on induced resistance in three groundnut genotypes, namely, ICGV 86699 (resistant), NCAc 343 (resistant), and TMV 2 (susceptible), against Helicoverpa armigera was studied. The activity of oxidative enzymes [peroxidase (POD) and polyphenol oxidase (PPO)] and the amounts of other host plant defense components [total phenols, hydrogen peroxide (H₂O₂), malondialdehyde (MDA), and protein content] were recorded at 24, 48, 72, and 96 h after pretreatment (1 day) with JA followed by infestation with H. armigera (PJA + HIN) and H. armigera infestation with simultaneous JA application (HIN + JA) to understand the consequences of induced resistance in groundnut. The plant damage, larval survival, and larval weights were also recorded. There was a significant increase in POD and PPO activities and in the amounts of total phenols, H₂O₂, MDA, and proteins in PJA + HIN- and JA + HIN-treated plants as compared to the plants treated with JA and infested with H. armigera individually and to untreated control plants. Among all the genotypes, the strongest induction of defense was observed in the ICGV 86699 genotype. It is concluded that pretreatment with JA and its application during low levels of insect infestation can increase the levels of host plant resistance against herbivorous insects and reduce the pest-associated losses in groundnut.     

Salicylic acid induced systemic resistant on peanut against Alternaria alternata

Abstract

The effect of Salicylic Acid (SA) in inducing resistance in groundnut plants against Alternaria alternata was investigated. Foliar application of SA at the concentration of 1 mM significantly reduced the leaf blight disease intensity and increased the pod yield under glasshouse conditions. Changes in the activities of phenylalanine ammonium lyase, chitinase β-1,3 glucanase and in phenolic content on groundnut after application of SA and inoculation with A. alternate were studied. In SA-treated leaves (plants) an increase in phenolic content was observed five days after challenge inoculation with A. alternata in groundnut plants pretreated with SA. There was a marked increase in chitinase and pathogen inoculation in SA-treated leaves. In chitinase, β-1,3 glucanase activities were observed in response to plants with an increase in SA treated leaves. Foliar applications of SA-induced in peroxidase and polyphenol oxidase activities were observed upon challenge inoculation with pathogen.     

Effect of jasmonic acid and salicylic acid induced resistance in groundnut on Helicoverpa armigera

Induced resistance in plants affects insect growth and development as a result of the up‐regulation of defence‐related secondary metabolites or enzyme‐binding proteins. In the present study, the effects of jasmonic acid (JA) and salicylic acid (SA) induced resistance in groundnut on Helicoverpa armigera (Hübner) are examined. Larval survival, larval weights and the activities of digestive enzymes (total serine protease and trypsin) and of detoxifying enzymes [glutathione S‐transferase (GST) and esterase (EST)] are studied in insects fed on four groundnut genotypes with moderate levels of resistance to H. armigera (ICGV 86699, ICGV 86031, ICG 2271 and ICG 1697) and a susceptible genotype (JL 24). The plants are pre‐ and/or simultaneously treated with JA and SA, and then infested with H. armigera, which are allowed to feed for 6 days. Significantly lower serine protease and trypsin activities are observed in H. armigera fed on plants treated with JA. Greater GST activity is recorded in insects fed on JA and SA treated plants, whereas EST activity is low in H. armigera larvae fed on plants treated with JA and SA. Serine proteases, trypsin and GST activities and larval weights (r = 0.74–0.95) and larval survival (r = 0.77–0.93) are positively correlated, whereas EST activity and larval weight (r = ?0.55) and larval survival (r = ?0.65) are negatively correlated. The results suggest that midgut digestive and detoxifying enzymes can be used as indicators of the adverse effects of constitutive and/or induced resistance in crop plants on the insect pests and the role of JA and SA in insect pest management.     

Silicon application promotes rice growth and negatively affects development of Spodoptera frugiperda (J. E. Smith)

Silicon (Si) has been reported to enhance plant resistance against biotic and abiotic stressors and also benefit plant growth. These effects are more pronounced in grass species, especially with soil‐applied Si. This study investigated the effects of Si application on rice resistance to Spodoptera frugiperda development and plant vegetative growth. Effects of Si on rice were assessed via soil and foliar applications and compared with untreated plants (control). Si was soil‐ and foliar‐applied as 1% silicic acid solution at a dosage equivalent to 1.4 t Si per ha. After application, leaf material was collected from Si‐treated and untreated plants and placed in Petri dishes with individual S. frugiperda neonate larvae, where development was followed to adult emergence and biological parameters recorded. Vegetative growth parameters recorded in rice plants were the height, chlorophyll content, fresh and dry weights of shoots, and shoot Si content. No effects of Si application were observed on the durations of larval and pupal stages, larval and pupal survival, and sex ratio of S. frugiperda. Insects fed leaves from Si‐treated plants exhibited lower leaf consumption, larval and pupal weights, longevity of males and females, number of eggs, and egg viability. The negative effects were correlated with higher rice Si content. Si application to rice increased plant height, chlorophyll content and dry weight. Our study demonstrates that foliar‐applied Si is as efficient as soil‐applied Si in negatively affecting S. frugiperda development and providing beneficial effects on rice plant growth.     

The effect of acetylsalicylic acid and oxalic acid on Myzus persicae and Aphidius colemani

Plants can respond to damage by pests with both induced direct defences and indirect defences by the attraction of their natural enemies. Foliar application of several plant-derived chemicals, such as salicylic acid and oxalic acid, can induce these defence mechanisms. The effect of acetylsalicylic acid and oxalic acid on the aphid Myzus persicae Sulzer (Homoptera: Aphididae) and its parasitoid Aphidius colemani Viereck (Hymenoptera: Aphidiidae) was investigated. Experiments were carried out with direct application of acetylsalicylic and oxalic acids on these insects, as well as choice and no-choice tests using foliar application of both chemicals on Brussels sprouts plants, Brassica oleracea var. gemmifera L. (Brassicaceae). Parasitoids were given a choice between treated and untreated plants for oviposition, and the effects of the chemicals on aphid and parasitoid development were determined. Although direct application of both chemicals increased aphid mortality, their foliar application did not induce resistance against aphids. The foliar application of such compounds, even in low concentration as shown in the choice tests, has the potential to induce indirect plant defences against aphids by encouraging aphid parasitisation. Although the direct application of both chemicals reduced parasitoid emergence from their hosts, the foliar application of acetylsalicylic acid and low concentrations of oxalic acid did not have a negative effect on parasitoid emergence ability. However, 10 m m oxalic acid reduced the number of emerged parasitoids in no-choice experiments. This study shows that foliar application of acetylsalicylic and oxalic acids has the potential to encourage aphid parasitisation, but care is needed as high concentrations of oxalic acid can have a negative effect on these beneficial organisms.     

Effects of jasmonate-induced defenses in tomato on the potato aphid, Macrosiphum euphorbiae

Jasmonates such as jasmonic acid (JA) are plant‐signaling compounds that trigger induced resistance (IR) to a broad range of arthropod herbivores. JA‐dependent defenses are known to reduce the growth and survivorship of many chewing insects, but their impact on piercing–sucking insects such as aphids has not been extensively investigated. In this study, induced resistance was activated in tomato (Lycopersicon esculentum Mill) (Solanaceae) using a foliar application of synthetic JA, and control plants were treated with carrier solution. The life parameters of individual potato aphids and their progeny (Macrosiphum euphorbiae Thomas) (Hemiptera: Aphididae) were evaluated on the unsprayed leaves of plants in order to access the systemic effects of the foliar treatments. IR significantly reduced the longevity and net reproduction of adult aphids, as well as the percentage of juveniles to survive to maturity. These results indicate that JA application induces systemic defenses in tomato that have a direct negative impact on aphid survivorship. This study also examined aphid honeydew excretion, in order to evaluate the potential influence of induced resistance on aphid feeding behavior. The average honeydew production per aphid was comparable on plants with or without JA treatment, indicating that JA‐dependent defenses did not deter feeding. This suggests that the observed effects of JA on aphid survivorship were due to antibiotic rather than antixenotic factors. In addition to studying the effects of JA treatment on a tomato cultivar that is susceptible to aphids, this study also examined the effects of exogenous application of JA on tomato plants that carry the aphid resistance gene, Mi‐1.2. JA application did not significantly enhance or inhibit aphid control on resistant tomato. These findings expand our understanding of the effects of JA‐dependent defenses on piercing–sucking insects, and of the potential interactions between induced resistance and R‐gene mediated aphid resistance in tomato.     

The modes of action of two benzimidazoles and thiophanate-methyl used for the control of Verticillium wilt of strawberry

Benomyl, thiabendazole and thiophanate-methyl were found to be fungistatic against Verticillium dahliae in vitro. All materials suppressed wilt symptoms on artificially inoculated strawberry plants when applied as a root dip, soil drench or a foliar application. Quantitative bioassays of the amount of toxic residues and fungal colonization in tissues of treated plants after root treatment revealed that these materials or their toxic breakdown products were readily translocated to crown and leaves: they suppressed the internal spread of the pathogen throughout the plant. After foliar application there was no marked basipetal movement of material within the plant: fungal colonization was greatly reduced in treated leaves, but the roots and crowns were colonized to a similar extent to those of untreated plants.     

Screening of As-Accumulating Plants Using a Foliar Application and A Native Accumulation of As

The discovery of novel accumulating plants is useful for efficient phytoremediation due to the demands of various conditions of impacted sites such as land use, soil properties, concentration of pollutants, and climate. In the present study, we investigated foliar application or a field with highly bioavailable arsenic (As) to screen As-accumulating plants. Plants grown in the downstream of a hot springs area were analyzed for native As accumulation and As foliar application, and the rhizosphere soils were collected. The water-soluble As in the rhizosphere soils had a high average, 144 μg/kg, whereas total As was similar to normal soil in Japan. Among 34 herbaceous plants and 17 woody plants, Chelidonium majus var. asiaticum accumulated a relatively high As level, 8.07 mg/kg DW (93.6% of As added), that was not revealed by native accumulation. In a further pot experiment, C. majus accumulated a moderately high As level (314 mg/kg DW) in the roots but not in the shoot (30.1 mg/kg DW), and exhibited a low transfer factor (TF = 0.096). Thus, a foliar application would be a simple and high-throughput method to screen plants that accumulate and tolerate As. C. majus would be useful as a tool for phytostabilization of As.     

The effect of foliar application of urea on the root fungi of wheat growing in soil artificially contaminated withFusarium spp.

Repeated treatment of overground parts of wheat with a solution of urea was reflected in an increased count of bacteria and a decreased count of fungi on the roots of plants grown in soil contaminated with the fungusFusarium spp., which is known to be noxious to plants. The occurrence of some fungal genera on the roots of plants growing in contaminated and uncontaminated soil after foliar application of urea was also changed. The roots of treated planted were found to contain more bacteria with a lytic effect and retarding the growth of the fungus used for the contamination. The favourable effect of foliar application of urea on wheat was reflected in an increased dry weight of plants even if growing in a soil contaminated withFusarium.     

Jasmonic acid-induced resistance to fall armyworm in soybeans: Variation among genotypes and tradeoffs with constitutive resistance

A negative correlation between constitutive and inducible resistance across plant populations is expected for a variety of reasons; however, empirical evidence for such trade-offs remain ambiguous, particularly for crop plants. The current study investigated the relationship between constitutive and inducible resistance in vegetative-stage soybeans (V5-V6) against larvae of the generalist defoliator, Spodoptera frugiperda. Eighteen soybean genotypes differing in their constitutive resistance to coleopteran or lepidopteran defoliators were used over four experiments. Exogenous jasmonic acid (JA, 2 mM) was used to induce plants. Constitutive resistance of each genotype was estimated by measuring weight gains, foliar consumption, and foliar conversion efficiency in short-term feeding assays on excised leaf disks of terminal trifoliate leaves of plants not treated with JA. JA was applied to plants immediately after removing leaf material for assays of constitutive resistance, and induced resistance was estimated 48 h after application of JA using leaf disks from the remaining leaf tissue of the same trifoliate used for measuring constitutive resistance. Larval weight gains before JA treatments revealed genotypic variability in constitutive resistance. . Overall, reductions in weight gain (28.7% to 76.7%), foliar consumption (3.7% - 65%) and conversion efficiency (10.9% - 42.2%) were found in JA treatments. Significant (P < 0.05) or marginally significant (P < 0.10) negative correlations between constitutive resistance (larval weight gains on non-induced plants) and induced resistance (differences in weight gains before and after induction) were found in all four experiments, suggesting tradeoff between the two modes of resistance does exist in soybean for this herbivore. Additional evidence for tradeoffs between constitutive and inducible resitance was also found in the analysis of consumption data. Comparisons of consumption and conversion efficiencies suggest that similar antibiotic and antixenotic factors are involved in constitutive and inducible resistance to fall armyworm in soybean.     

Induction of systemic acquired resistance in Zea mays L. by Aspergillus flavus and A. parasiticus derived elicitors

Host defence mechanisms can be elicited by using different elicitors produced from the pathogen/host. In this study, an effort has been made to study the effect of two fungal elicitors derived from Aspergillus flavus and A. parasiticus on induction of various defence-related enzymes in maize (Zea mays L.). Foliar application was done on 20-days-old maize plant with 10% A. flavus fungal culture filtrate (AFFCF) and A. parasiticus fungal culture filtrate (APFCF) as elicitors to trigger systemic acquired resistance (SAR). As a response of SAR, an increase in activities of phenylalanine ammonia lyase (PAL), peroxidase (POX), β-1,3-glucanase, nitrate reductase (NR) and nitrite reductase (NiR), total proteins were found highest on 4th day after treatment (DAT), whereas total carbohydrate and total chlorophyll on 2nd and 6th DAT, respectively, in comparison with the control plants. The SDS PAGE analysis revealed the induction of PR proteins, namely Chitinase (25, 29?kDa) and β-1,3-glucanase (33?kDa), in treated plants in comparison with untreated control plants. The treated plants showed enhanced growth and development as well as increase in yield. About 100% survival rate was found in maize seeds treated with AFFCF and APFCF and grown on respective fungal infested soil than control. The enhanced activities of defence enzymes and elevated protein, carbohydrate, chlorophyll content in treated maize plants suggest the induction of SAR against A. flavus and A. parasiticus by using the same fungal elicitors.     

The effect of etiolation and shading of stock plants on rhizogenesis in stem cuttings of <Emphasis Type="Italic">Cotinus coggygria</Emphasis>

In order to improve vegetative propagation of a difficult to root Cotinus coggygria the stock plants were subjected to: etiolation, shading and spraying with IBA, combined with the application of two commercially available rooting powders. The IBA treatment was more suitable for rooting of C. coggygria cuttings than the NAA application and it enhanced rhizogenesis regardless of the form of auxin application (foliar application to a stock plant or a rooting powder used directly on cuttings) and the amount of light provided to stock plants. Etiolation did not improve rhizogenesis in stem cuttings, however, reduction of light intensity by 50% and 96% of the ambient prior to harvest of cuttings affected rooting positively. Positive effects of shading can be ascribed to changes in shoot anatomy, i.e. a weaker sclerenchyma development. Synergistic effect of shading and foliar auxin application can result from the increase in leaf blade area and/or thinner lower epiderm. Enhanced rooting in cuttings from shoots grown out under reduced light intensity was accompanied by decrease in the contents of total soluble sugars, soluble proteins and free ABA and by increase in total chlorophyll, free amino acids, polyphenolic acids and free IAA contents.     

Effects of Stress Modifier Biostimulants on Vegetative Growth,Nutrients, and Antioxidants Contents of Garden Thyme (Thymus vulgaris L.) Under Water Deficit Conditions

The aim of this study is to investigate the effect of stress modulators on vegetative growth, antioxidants, and nutrient content of Thymus vulgaris L. under water deficit stress conditions. A factorial experiment was performed in the form of a randomized complete block design with 10 treatments and 3 replications in the 2019–2020 growing season. The factors were stress modulators at 5 levels (ZN: zinc nano-fertilizer, AA: amino acid, SW: seaweed, HA: humic acid and C: control) and irrigation regime at 2 levels [FIrr: full irrigation (100% field capacity) and DIrr: deficit irrigation (50% field capacity)]. The highest plant height, number of branches, and total dry weight of the garden thyme plant were observed in the foliar application of HA and SW under full irrigation conditions. Relative water content, chlorophyll a and b, and uptake of nutrients (N, P, and K) were reduced under water deficit stress, but the foliar application of stress modulators increased relative water content, chlorophyll content, and nutrient uptake of the garden thyme plant significantly compared with control. The water deficit increased proline content, total flavonoid, and phenol content in the garden thyme plant. So, the highest total flavonoid and phenol content was obtained from plants treated with HA, whereas proline content was higher in the control plants. Soluble sugars and essential oil increased significantly under water deficit stress conditions. The foliar application of HA compared to the control plant increased soluble sugars and essential oil in garden thymes. The activities of catalase, superoxide dismutase, and ascorbate peroxidase enzymes were improved in stress modulator treatments such as HA and SW compared to control plants under water deficit stress conditions. The plants of garden thymes showed a good response to stress modulator treatments under water stress conditions, and HA and SW treatments were found to be more effective.

     

Changes of microflora of wheat roots after foliar application of urea

Upper parts of wheat grown in containers with brown soil were four-times repeatedly treated with a solution of urea. The foliar application of urea resulted in a considerable increase of the number of bacteria in the roots and a decrease of the number of fungi. Seventeen and 13 genera of fungi could be detected in the rhizosphere of the treated plants, 3 and 5 weeks, respectively, after the application, whereas 23 and 16 genera could be identified in the rhizoplane of the treated plants. Fungi of the generaFusarium andPenicillium predominated in the root region. The foliar application of urea resulted in an increased relative occurrence of the genusFusarium and decreased relative representation of the genusPenicillium. Changes in the relative occurrence of other 18 genera of fungi present in small quantities on wheat roots could also be observed. The foliar application of urea affected not only numbers of fungi determined by the dilution plate method but also the occurrence of active hyphae.     

Induction of Systemic Acquired Resistance in Arachis hypogaea L. by Sclerotium rolfsii Derived Elicitors

Plants evolve a strategy to survive the attacks of potential pathogens by inducing the microbial signal molecules. In this study, plant defence responses were induced in four different varieties of Arachis hypogaea (J‐11, GG‐20, TG‐26 and TPG41) using the fungal components of Sclerotium rolfsii in the form of fungal culture filtrate (FCF) and mycelial cell wall (MCW), and the levels of defence‐related signal molecule salicylic acid (SA), marker enzymes such as peroxidase (POX), phenylalanine ammonia lyase (PAL), β‐1,3‐glucanase and lignin were determined. There was a substantial fold increase in POX, PAL, SA, β‐1,3‐glucanase and lignin content in FCF‐ and MCW‐treated plants of all varieties of groundnut when compared to that of control plants. The enzyme activities were much higher in FCF‐treated plants than in MCW‐treated plants. The increase in fold activity of enzymes and signal molecule varied between different varieties. These results indicate that the use of fungal components (FCF and MCW) had successfully induced systemic resistance in the four different varieties of groundnut plants against Sclerotium rolfsii.     

Colorado potato beetle control by application of the entomopathogenic nematode Heterorhabditis marelata and potato plant alkaloid manipulation

Control of the Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), with the entomopathogenic nematode Heterorhabditis marelata Liu and Berry (Nematoda: Heterorhabditidae) was examined in the laboratory and in potato fields in north central Oregon. This research tested the hypothesis that varying nitrogen fertilizer levels would affect foliar alkaloid levels, which would stress the host, and allow increased nematode reproduction and long‐term control of the CPB. Laboratory results indicated that nematodes tended to reproduce more readily in CPB fed on potato plants with high levels of fertilizer. Field trials tested CPB population responses to four treatments: application of nematodes vs. no nematodes, with application of low vs. high rates of nitrogen fertilizer. The higher nitrogen application rate increased field foliar levels of the alkaloids solanine by 35%, and chaconine by 41% over the season. Nematodes were applied twice during the season, causing a 50% reduction in adult CPB populations, and producing six times as many dead prepupae in nematode‐treated soil samples as in the untreated samples. However, no reproducing nematodes were found in the 303 dead prepupae and pupae collected from nematode‐treated plots. Nitrogen fertilizer levels, and their related alkaloid levels, did not affect nematode infection rates or reproduction in the field. Foliar alkaloid levels of plants from the growth chamber were 3–6‐fold as high as those in the field, which may explain the variation in nematode response to nitrogen applications to host plants of the CPB. Heterorhabditis marelata is effective for controlling CPB in the field, and does not have negative non‐target effects on one of the most common endemic CPB control agents, Myiopharus doryphorae (Riley) (Diptera: Tachinidae), but the low rate of nematode reproduction cannot be manipulated through alkaloid stress to the beetle. Until H. marelata can be mass‐produced in an inexpensive manner, it will not be a commercially viable control for CPB.     

Chlorosis correction and agronomic biofortification in field peas through foliar application of iron fertilizers under Fe deficiency

Effectiveness of different iron (Fe) foliar sprays for leaf chlorosis correction and grain Fe boosting was studied in field peas under Fe deficiency. No chlorophyll reduction was observed in Fe deficient plants treated with foliar sprays. EDDHA [ethylenediamine-N,N′-bis(2-hydroxyphenylacetic acid)] followed by FeSO₄ (73.7?mg/l Fe) treated at the start of flowering was most responsive in correcting chlorosis and increasing shoot dry biomass in peas. Inductively coupled plasma-atomic emission spectroscopy data showed significant increase of Fe in grains while treated with all foliar sprays at the time of grain filling in Fe-deficient plants. Among them, FeSO₄ (73.7?mg/l Fe) was the most efficient in biofortifying Fe in mature grain under Fe deficiency in peas. Results also pinpoint that flowering is a suitable time for applying foliar sprays to boost Fe in mature grains. Taken together, application of Fe foliar sprays facilitated both chlorosis correction and Fe boosting in peas and can be further used by breeders and farmers.