Potential of Trichoderma Isolates to Control Plant Pathogen, Leaf Rust on Different Commercial Wheat Varieties/Genotypes

Abstract

The efficiency in the treatment of leaf rust of wheat was examined for the plant leaf extracts of neem and Moringa at varied concentrations of 50, 100, and 150 ml correspondingly. All treatments decreased fungal growth in vitro by greater than 90%. The germination of spores was decreased by 91.99% in the presence of neem leaf extract at 150 ml concentration. The percentage of pustules/leaf was reduced by foliar spray of the same treatments on seedlings of the wheat plant. The wheat plants show the greatest response against the pathogen of leaf rust by plant extract second foliar application on the fourth day of infection. Spray application of 150 ml, 100 mL of neem leaf extracts, and 150 ml of Moringa leaf extracts at wheat seedlings and rust development completely prevented four days after leaf rust inoculation. The application of treatments of all extracts on wheat plants at the mature stage significantly reduced the disease (ACI, average infection coefficient) and increased the efficacy of plant extract application as compared with control but neem 150 ml treatment was most effective in all. There was a higher increase of the chlorophyll and phenol content in wheat plants.

1. Introduction

Wheat (Triticum astivum L.) is an important crop that is grown for years to fulfill the requirements of human hunger. The demand for staple crops increases due to the increase in the world population. In Pakistan, the demand for its product increases therefore growing on a large scale at the government and small agricultural land farmer’s level. The tetraploidy and hexaploidy wheat is mostly grown in Asia at 99 million HA (hectares), and overall world production is approximately 215 million HA [1]. In Pakistan, India, and China, the total production is 62 million hectares [2]. In Pakistan, only the wheat sown in an 8.80-million-hectare area produces about 25.09 million tons [3].

The rust fungus gives great loss to the production of wheat all over the world where wheat is grown. Only in Asia does it affect about 43–63% of the growing region if susceptible varieties were grown [4].

2. Background study

In this chapter, a brief review of research work is given in a manner to highlight the contemporary status of findings in leaf rust.

Wheat rust was divided into three types: Of the most common wheat rust is leaf rust caused by Puccinia triticiana due to its distribution ability. It has usually fewer losses than the other two types of wheat rust, but the frequent virulence behavior of wheat leaf rust makes it interested to researchers due to its high annual losses. The kernel weight reduction was the major cause of yield loss. The surveillance shows that the rust pathogen has resistance to wheat varieties due to mutation or some migrated genes of rust evolved from other areas. In CIMMYT wheat, the rust pathogen has slow virulence rather than other yielding wheat varieties [5]. It shows that the rust pathogen was resistant against high yielding and low wheat cultivars, disease complexity, and some measures available in practice for control.

2.1 Leaf rust epidemic

In an epidemic situation of leaf rust Puccinia graminaea for the wheat susceptible variety, there was a 90% loss in yield. The inoculum that was used against wheat was taken from Research Institute Murree, Pakistan. The fungus was sprayed with five-nozzle sprayer, which was present as a suspension of uredospore [6]. There were about 192 wheat varieties from which the resistibility of wheat genotype was greater in number than the susceptible one. A total of 64 wheat genotypes show resistance, while susceptibility was not shown by any of the genotypes. But some algal species exist in wheat genotypes.

The study purpose of the wheat rust disease damage both qualitatively and quantitatively if the susceptible varieties of wheat line/genotype can be managed by the resistant line development. They evaluate the 30 lines against yellow and leaf rust where they do artificial inoculation and some lines were observed under natural conditions to assess the disease severity [7]. By using cobb’s scale method, they observe different rating scales of virulence on the 16 genotypes under a natural condition in comparison with the artificially inoculate rust in wheat lines. The genotypes also show different virulency against leaf rust and yellow rust. The data show that among 30 wheat lines that were inoculated artificially, the resistant and moderately resistant varieties/lines were six in number, while the line/varieties showing MRMS response were 13 and few of the lines showed susceptibility and moderately susceptible. But in natural conditions except from two lines/varieties, others were resistant against leaf and stripe rust. The resistant varieties can be a managed way to manage the leaf and stripe rust so breeders can have a stance on developing resistant varieties.

The surveillance in Pakistan from 2016 to 2018 of leaf rust affects the yield of wheat. A 3-year study design contains 95 districts from which 1202 fields were observed to check the spatial and temporal vigilance of disease severity of leaf rust distributed in the Sindh and Punjab provision of Pakistan. The results of 3-year disease incidence showed the most prevalence of disease in 2017 than in 2016 and 2018. The most affected province is where 60% disease severity occurred in 20% region, while Punjab has only 5% region where south Punjab was most affected and in Khyber-Pakhtunkhwa and Azad Kashmir only 1% disease occurred [8]. Some varieties that show susceptibility were Sehar, Inqlab-91, Shafaqand Morocco.

For the surveillance of rust virulence and disease incidence, their assessment characters are evaluated through the survey of trap plot. The survey is helpful in the seed system, plant breeding, and disease-protecting strategies. Many activities were done at the national level for rust pathogen control but at the global level, the strategies of rust surveillance work very slowly. To make rust surveillance effective at the global level, the Global Cereal Rust Monitoring System GCRMS was recognized to cope with the reinforced problem [9]. The system was a web-based monitoring protocol that will be helpful in testing, disease management, rust virulency, and all the factors that were interrelated for the cause of rust pathogen posing threat to wheat. It also includes surveillance data that will be compared to check the rust pathogen virulency at the global level.

2.2 Susceptibility of commercial wheat varieties

Two-season research was done by Muhammad et al. [10]. During the wheat-growing seasons of 2010–2011 and 2011–2012, 325 genotypes of bread wheat (Triticum aestivum L.) were tested for leaf rust resistance against specific pathotypes in the field. In the 2010–2011 growing season, 225 wheat cultivars exhibited no response to leaf rust, 12 genotypes were resistive to leaf rust response, 20 varieties/genotypes showed relatively resistance, 40 wheat lines were moderately susceptible, and 15 were MRMS and 13 genotypes indicated vulnerable response. In total, 233 wheat genotypes did not show any response, 8 genotypes were resistant, 14 genotypes were moderate resistance, 40 wheat lines were moderately susceptible, 8 genotypes were moderately resistant to moderately susceptible, and 22 genotypes were the susceptible response of wheat to leaf rust during the 2011–2012 wheat season. Slow-rusting genotypes had low AUDPC values, whereas high-rusting lines had high AUDPC values. The spread of leaf rust has been strongly impacted by epidemiological variables. Rust responses of different wheat genotypes had shown a strong correlation with environmental factors. Leaf rust reactions were linked to temperature attributes such as maximum and minimum temperature levels, rainfall, and relative humidity. It was also shown that some genotypes responded differently throughout the two crop seasons, which might be due to differences in environmental variables.

How much the severity of the leaf rust disease impacts photosynthetic and grain output in wheat. This was accomplished by calculating the photosynthetic rate, disease severity, chlorophyll content, and wheat reduction in six wheat cultivars grown in uncontrolled and fungicide-treated environments [11]. The mean disease severity level of leaf rust was the greatest on Faisalabad-08 and Galaxy-13 among six wheat varieties/lines such as Faisalabad-08, Galaxy-13, Lasani-08, Millat-11, and two wheat lines NW-3-3341-7 and NW-1-8183-8, although grain yields of wheat were also greater in Millat-11, Galaxy-13, and FSD-08. Fungicide dramatically decreased rust infections and increased chlorophyll concentration and photosynthetic rate, leading to considerably greater production in treated plots. Wheat cultivars FSD-08 and Galaxy-13 were determined to be highly resistant to rust illnesses based on leaf rust severity and yield component assessments. When treated with a rust fungicide, NW-3-3341-7 showed the cheapest and best ratio result. Rust disease drastically reduced grain output, according to the study. When host immunity is combined with little fungicide treatment, the negative effects of leaf rust were reduced and net yields were maximized.

The plants were infected with Puccinia recondita f.sp.tritici in natural conditions. Among 197 advanced wheat lines/varieties, based on a measure of disease severity, 89 lines/varieties of leaf rust were clear of any symptoms and 43 lines/varieties showed resistance, 32 MS, 10 mildly susceptible 16, and 7 were susceptible and highly susceptible, respectively, with extremely sensitive in the early planted plots. In late potted plants, 74 were healthy, 28 were immune, 31 were moderately resistant, 8 were moderately resistant, 17 were sensitive, and 39 were moderately sensitive. Either in early sown or late sown nurseries, there were no signs of yellow rust. Most lines/species planted lately exhibited considerably higher rust rates than the comparable genotypes planted earlier. Commercially produced wheat cultivars such as Bahawalpur 97, Inqilab-91, Kohistan-97, MH-97, and Iqbal-99 exhibited no leaf rust signs, suggesting disease resistance. In the early and late sown wheat plants, 89 and 74 lines/varieties were devoid of any disease signs or insect attack, respectively, suggesting their high genetic possibility for improved pest and diseases-resistant breeding [12].

The natural conditions were conducive to the establishment of the wheat leaf rust disease. Out of 150 lines/cultivars tested for brown/leaf rust, 29 lines/cultivars were immune, 57 types exhibited resistance, and the rest were vulnerable [13]. The area under the disease progress curves (AUDPCs) estimates of all types were determined. According to the virulency formula investigated, 57 types of leaf rust were resistant and 49 variations were susceptible to leaf rust fungus. Environmental variables have a significant impact on the progression of wheat leaf rust infections. There was also a relationship between disease severity and environmental factors. Many varieties/lines logically responded to environmental variables. Temperature, humidity levels, wind velocity, and rainfall were found to have a substantial impact on illness severity. Even though pathogenicity incidence did not affect the leaf rust virulence. The occurrence of virulence for them is concerning in situations where the genetic foundation of resistance in currently farmed varieties was stumpy.

The most cultivated varieties were Morocco, Pak-81, Fsd-85, Lylpur-73, Inqlab-91, Fsd-83, and WL-711. From 1991 to 1992 to 2000–2001, these varieties were consistently cultivated in a rust trial. Infection was achieved using both natural inoculum and artificial inoculum of the leaf rust Puccinia recondita f.sp. tritici. From the development of the first symptoms until the morphological development of the crop, leaf rust diagnostic evaluations premised on Peterson’s scale were collected [14]. A local weather station captured weather parameters such as weekly air temp, humidity levels, and precipitation. Leaf rust prediction models were developed using regression analysis for weather parameters as the independent variable and leaf rust severity as the dependent variable. Leaf rust developed in 10 seasons of wheat at different periods between January and April in different periods. All other environmental factors, except for rainfall, exhibited a significant association with illness severity. Based on 10 years of data, linear regression analysis revealed that the lowest temperature and night-time humidity levels were significant. Except for 1995–1997, the lowest temperature correctly predicted leaf rust in another 8 years.

2.3 Some historic bioagents used for controlling leaf rust

Eight plant extracts were used for the biocontrol of leaf rust and compared the efficacy of these plant extracts, that is, neem, white cedar, clove, garlic, garden quinine, Brazilian pepper, black cumin, and anthi mandhaari. By using foliar spray and in vitro evaluation, the spore germination was inhibited in both conditions [15]. In all used plant leaf extract, neem showed a significant result (98.99%) such as fungicide, while other plants extract shows efficacy lower than that of neem. The other method used by them is soaking the seeds in 2 ml/L of plant extract, which inhibits the spore/pustules per leaf by 36.82%. When the soaking method was compared with a foliar spray that reduced the spore’s production or pustule per leaf by 100% after 4 days of inoculation, these plants give a maximum result with positive control of Sumi fungicide against the wheat leaf rust pathogen. The most effective extract was neem, clove, and garden quinine. ACI, the average coefficient of infection, shows that at a mature stage of the plant, the foliar spray is more effective than other methods. The foliar spray of the extract also affected test weight, 1000 kernel weight, and grain yield production with one or two sprays after certain days of application. It was a way forward to lessen the use of fungicide and increase the use of plant extract.

Some biological agents against Bipolaris orzyae cause rice brown spot disease; its casing agent is a fungus Cochliobolus miyabeanus. They used plant extracts, antagonistic organisms, and oil cake. Two plants extracts out of eight plants that extract Nerium oleander inhibit 77.4% growth and 8 of 0.3% spores germinate Pithecolobium dulshows showing inhibition and spore germination 75.1 and 80%, respectively. These plant extracts were more effective against the Bipolaris oryzae, while the oil cake of Azadirachta indica inhibition percentage was 80.18% and the percentage of spore germination was 81.13%. The cake extracts of mahua and castors were also effective against the pathogen. The antagonistic organism Trichoderma viride showed 62.92% inhibition, and Trichoderma harzianum and Trichoderma reesei were also effective against the growth of mycelium and spore germination [16]. Under field conditions and glasshouse experiment, N. oleander, neem cake extract, and the specie Trichoderma viride were effective in controlling the Bipolars oryzae when sprayed two times in 15 day of intervals after the appearance of disease in rice plants.

There are three different domains to control leaf rust because the importance of wheat in the world cannot be ignored. The rust species Puccinia recondita gives a harsh response to wheat yield. The in vitro use of non-systemic fungicides gave such evaluation of pustules/uredospore reduction at different concentrations of 1000 ppm and 500 ppm, which reduce the spore production by 83.33 and 72.31%, respectively, and an average response was 54.85% by mancozeb and 40.89% by chlorothalonil [17]. The response of systemic fungicide to the inhibition percentage of uredospores was 86.03% by propiconazole, of which the highest systemic fungicide was followed by the fungicide hexaconazole with 77.40% and penconazole with 72.29%. While 20 plant extracts with different parts were used for the maximum reduction of uredospores by the bulb of garlic extract at 59.78% and onion bulb extract reduction with 57.70, the rhizome of ginger gives 54.81% reduction of spores.

The extracts of the different plants are affected to control the leaf rust of wheat. The plants used for biocontrol are Lawsonia Inermis, Melia azedarach, Acalypha wilkesiana, Punica granatum, and Lantana camara. The method of application is before the arrival of disease in wheat plants in two wheat seasons 2016–2018. These plants show the same result as the fungicide used to control wheat leaf rust [18]. It reduces the ACI coefficient of infection while with ACI of non-treated wheat plants. The most effective plant extract was L. camara giving 88.88% efficiencies equivalent to the fungicide diniconazole followed by Lawsonia Inermis, M. azedarach, A. wilkesiana, and P. granatum, respectively. These plant extracts not only reduce the disease severity but also increase the yield parameters, phenols, chlorophyll content, and the peroxidase and oxidase activity of wheat plants.

In the agricultural field of research, a study was undertaken to assess the allelopathic effects of leaf extracts of daylight neem leaves on wheat production and its constituents. With the treatment of 0, 50, and 100% liquid leaf extract of neem, grain yield, and several yield attributes of wheat, such as the number of viable tillers, grain/spike, 1000-grain weight, and spike length, no meaningful either promotive or negative impact was seen [19]. The leaf extracts of neem, on the other hand, did not affect wheat yield and yield contributing. The use of a natural weedicide (leaf extracts extract of neem) showed no negative impact on wheat quality.

For evaluating the genetic resistance of wheat lines of 45 genotypes/lines against rust, the lines were inoculated at the booting stage with an aqueous inoculum of wheat. It was a field study in Nepal where the results showed different pathogenicity ratios with high variation of wheat varieties [20]. The surveys of 66 production fields where the old varieties are observed have more disease severity rather than the new and resistant varieties. The prevalence of disease on wheat genotype revealed that leaf rust and yellow rust have a high level of prevalence. Leaf rust has more prevalence than yellow rust but low severity, while yellow rust has high a concern with disease severity. The management of disease and farmer literacy about rust makes the varieties more virulent against disease.

Seed priming using leaf extract and compounds has long been utilized to boost agricultural plant development, but the pathways are still unknown. The goal of this study was to figure out how different seed priming methods in greenhouse wheat work. Hydropriming, moringa aqueous extracts priming, and CaCl₂ priming were the seed priming methods utilized. The results revealed that all the seed priming treatments were more efficient than the control at enhancing wheat germinating and seed germination. However, Moringa was shown to be the most effective technique, followed by CaCl₂. The activation of increasing antioxidant and enhanced chlorophyll, soluble phenolics content, and ascorbic acid were all factors in this respect. The findings support the idea that seed priming with Moringa is cost effective and may be utilized to promote wheat development in greenhouses. Moringa oleifera leaf extract applied on wheat (T. aestivum L.) leaves had various results in grain production and yield parameters such as biomass of plant, number of ears, tillers, and 1000 seed weight. A treated field comparing various M. oleifera concentrations showed a 19% increase in crop yields at a 10% concentration, but still, no yield potential improvements with higher M. oleifera concentrations. Based on the year and data analysis plan, drier field experiments with Moringa doses of 5% and 10% revealed no impact on improvements in crop production. Variations in phytohormone content such as auxin, gibberellins, abscisic acid, jasmonic acid, and salicylic acid are caused by abiotic and biotic stresses before leaf harvest for the disparities in yield component responses. It was discovered that GA4 very probably interaction with auxin is the most important growth promoter. The hormone levels of Moringa are shown to vary significantly on an annual basis, which may have an impact on the biostimulant’s prospective application in agriculture.

2.4 Potential of Trichoderma harzianum

Wheat (T. aestivum L.) is one of the most important crops for humans worldwide. Stripe rust disease, caused by Puccinia striiformis f. sp. tritici, is the most devastating disease, posing a huge danger to wheat production across wide areas, causing significant yield and grain quality losses [21]. This investigation was carried out to evaluate the agents, namely Trichoderma harzianum, T. viridi, Chaetomium globosum, Saccharomyces cerevisiae, Bacillus subtilis, and B. chitinosporus. Under field condition, greenhouse effect, and lab condition, the used biocontrol reduces the coefficient of infection (ACI) of stripe rust Puccinia striiformis f. sp. tritici. It is recommended to use a biocontrol agent for plant pathogens.

The biocontrol of wheat stem rust in vitro is by using Arbuscular Mycorrhiza fungi and a combination of two species of Trichoderma harzianum and Trichoderma viride with single use also on the Puccinia graminis f.sp.tritici spores. The identification of both species of Trichoderma was done by using a system of GC-MS. The results observed under a scanning electron microscope indicate that when using the Trichoderma species suspension in combination, they were more effective in inhibiting the uredospores than other application methods. The application of bioagents under field condition not only reduces the disease but also increases the phenol content, the peroxidase enzyme activity, yield, and growth parameters [22].

The plant extract of A. indica, bioagent Trichoderma harzianum T-2 fungicide Iprodione is against the Alternaria brassica causing Alternaria disease radish blight. The inoculation spray of A. brassica spore concentration of 5 × 105/ml is on the flowering stage of the Radish field. The bioagent used for treatment purposes was used as a soil amendment in the concentration of 5 × 105 spores ml as a foliar spray after 3 days of spore inoculation, while for seed treatment the concentration was 3 g/Kg. At the flowering stage, the neem leaf extract was applied in the concentration of 10%, and to compare it with fungicide, they applied 200 ppm of Iprodione at 10 days with the four-time application. The results of the three treatments showed that the T8, T7, and T6 were the most effective on disease severity and increase the growth and germination of radish plants [23]. The yield for seed increases due to the nutrient availability by enhancing growth-promoting factors enhanced by the application of treatments.

When compared with the control, all 13 treatments enhanced yield and 1000-grain weight to a larger extent. Fungicide used to has a good effect. Moreover, the leaf extract of neem, Trichoderma harzianum, and the Panchgavya were the most efficient treatments for wheat leaf rust in various groups. The yield of fungicides sprayed areas was considerably higher than the control plots, showing that leaf rust had a major impact on yield. In comparison with other procedures, the 1000-kernel weight was beneficial in the abovementioned treated plots [24].

The adoption of resistant varieties is the most cost-effective and efficient means of controlling Puccinia triticina Eriks’ called leaf rust of wheat. Generally, assessment for rust resistance in wheat cultivars was done in a greenhouse experimental trial and under the natural condition of the field at the seedling stage and mature plants. For this purpose, the varieties were affected by ecological variables that restrict the number of races that may be examined at the same time. In their work, a detached leaf test was used to screen wheat lines for leaf rust resistance. Two senescence compounds that suppress benzimidazole and kinetin were introduced to 5% water-agar as treatments in various doses and combinations [25]. Three leaf rust races were used to verify the chosen medium in 20 wheat genotypes. The media for a treatment having a proportion of 30 mg/L benzamide and 10 mg/L kinetin were injected with the help of a sprayer showing the prominent results in slowing aging and therefore boosting sporulation. There was a positive association (r = 0.9) between the disease types measured by the detached leaf test and the entire seedling test. For detached leaf 0.24 and entire seedling, tests showed 0.3 standard errors. The minimal standard error support uniformity of illness reaction assessment across the tests performed.

The most dangerous disease affecting wheat plants is leaf rust produced by Puccinia triticina f.sp. tritici. Bioagents such as B. subtilis, Bacillus pumilus, Bacillus chitinospours, Trichoderma harzianum, and Trichoderma viride were tested to manage leaf rust. During two wheat-growing seasons, 2016/17 and 2017/18, the bioagents were sprayed pre and post P. triticina infection for 24 hours. Our findings revealed that B. subtilis was the most effective treatment, second by T. viride, with substantial increases in disease incubation and latent durations, but also an increase in 1000 kernel weight (g) and production (kg). In the contrast, a substantial reduction in the number, length and breadth of spores, the final rust severity percentage, and AUDPC. Furthermore, the treatments increased catalase activity (CAT) and peroxidase (POX), although electrolyte leakage was reduced when compared with the control. The relevance of FRS percentage as a suitable indicator for both the research effects of alternative bioagents in controlling leaf rust was demonstrated by a correlation test [26]. The use of bioagents as a source of disease control is harmless for the environment and the disease produces fungicide-resistant forms.

Under field circumstances, field trials were undertaken on two sowing dates to examine the feasibility of using bioagents to reduce the severity of foliar diseases such as Septoria leaf blotch, powdery mildew, and stem rust. Trichoderma harzianum, B. subtilis, Azospirillum brasilense, Pseudomonas fluorescens, and plant shield were tested. When compared with the control group, all therapies lowered the severity of the disease. In general, Giza 171 cv. had the least severe disease, followed by Misr 1 and Gemmiza 12. Furthermore, genotypes seeded sown earlier in November showed less disease severity than many of those sown late in December. Wheat grains sprayed with T. harzianum and B. subtilis had the greatest impact on the incidence of all diseases, followed by some of the other treatments. Therefore, such sprayed treatments also have the potential to reduce wheat leaf pathogens as a healthy alternative to synthetic treatment with no adverse health effects or environmental pollution [27].

Many environmental factors were the primary hurdles to attaining the maximum productivity possible in the grain yield. Economic losses due to biotic stressors were predicted to be 26–29% in the region. However, physiological processes have a greater negative impact on crop production that accounts for around 70% of the reduction in yield globally. Pesticides and fertilizers are commonly proven as an efficient control mechanism for wheat crop pests and diseases; however, the build-up of synthetic chemicals inside the soil, plant materials, and fungicide-treated kernels harms human and environmental life [27]. Trichoderma is commercially significant as a biocontrol agent, potentially replacing agrochemicals in the fight against biological and chemical stress.

Various methods such as (B. subtilis, Bacillus chitinosporus, and yeast extract), benzothiadiazole (BTH), salicylic acid, and oxalic acid, as well as the fungicide propiconazole, were developed to optimize the resistance, physiological characters of the wheat variety, and yield production in the vulnerable conditions. Wheat varieties (Gemmiza-7) especially in contrast to the high resistance wheat variety. In vitro, all treatments reduced fungal growth, disease severity percentage, and the quantity of uredia as compared with the vulnerable cultivar’s control infection. In susceptible wheat cultivars treated with bio-agents, salicylic acid, BTH, and oxalic acid treatments, antioxidant enzyme activities catalase, peroxidase, and polyphenol oxidase were significantly increased when compared with the control treatment. In the susceptible-infected cultivar, the concentration of chlorophyll was significantly reduced. The percentage of electrolyte leakage in susceptible treated cultivars was significantly lower than in susceptible infected untreated cultivars [28]. As a result, the treatments were able to boost chlorophyll concentration while also improving yield components such as grain weight 1000 per grain and grain weight in 10 spikes.

The research was carried out during two consecutive fall seasons in 2012/2014 at the El-Kassasein Experimental Farm, Hort. Res. Station, Ismailia Governorate, Egypt. The effect of three different nitrogen fertilizer sources was as follows: namely ammonium sulfate (20.5% N) at 390.2 kg/fed. (fed. = 0.42 ha.), botanical compost at 6.667 tons/fed., and chicken manure at 2.787 tons/fed. (each equaling 80 kg N/fed.), and five biological control (Trichoderma harzianum, Trichoderma viride, the mixture of Trichoderma harzianum + Trichoderma). When compared with Xera cultivar, Paulista cv. provided the maximum dry weight of shoots per plant and final yield. The use of chicken manure enhanced the dry mass of shoots and the overall yield of snap beans. Foliar treatment of a Trichoderma harzianum + Trichoderma viride combination improved the number of leaves and branches per plant, the dry weight of shoots per plant, pod length, and overall yield. Fertilizer application Paulista cv. with chicken manure and foliar application of Trichoderma harzianum + Trichoderma viride improved the number of leaves and branches per plant, plant height, dry weight of branches, leaves, and shoots per plant, pod length, and total yield [29]. When compared with Paulista plants, Xera cv. plants had the lowest rating for rust disease severity. Botanical compost application resulted in the lowest rust disease incidence and severity of snap bean plants, followed by chicken manure treatment, and ammonium sulfate at 390.2 kg/fed resulted in the highest results. In comparison with the control, foliar spray of biocontrol agents to snap bean plants reduced the incidence and severity of rust disease on the leaves. The combination of Trichoderma harzianum and Trichoderma viride reduced rust disease incidence, while Trichoderma harzianum reduced rust disease severity.

Plant diseases are one of the most significant restrictions to crop production and productivity, both in terms of quality and quantity. The use of pesticides remains the primary strategy for mitigating agricultural disease threats. However, because of environmental issues, human health problems, and other risks connected with the use of chemicals, the use of bioagents to reduce the disease-causing activities of plant pathogens is gaining popularity. Biocontrol is the intentional use of living organisms, either transferred or indigenous, other than disease-resistant host plants, to decrease the activities or populations of one or more plant diseases. Beneficial organisms, their genes, and/or products, such as metabolites, are used in biological control to lessen the detrimental impacts of plant diseases and stimulate positive plant responses [30]. A variety of commercial products based on diverse fungal and bacterial antagonists have been recognized at both national and international levels in this direction. These commercial products include Biocon, Biogaurd, Ecofit, FStop, Soilgaurd, and others that include Trichoderma sp. as an active ingredient, as well as Mycostop, Rhizopus Subilex, and others that contain various Bacillus species as active ingredients. Biological control can achieve disease suppression in a variety of methods, including antibiosis.

3. Conclusion

Puccinia triticiana, an obligate parasite, is the cause of wheat leaf rust. Rust is one of the most destructive cereal pathogens and coexisted that developed during grain cultivation. The growth of leaf rust affected and statistically substantial connection with environmental factors were shown in urst responses of various genotypes. Average temperature, maximum temperature, lowest, precipitation, and relative humidity were associated with rust processes. A foliar spray was the most efficient in decreasing leaf rust (ACI) infection and the neem extract at the mature plant stage. This study found several resistant types that may be used for the wheat reproduction programs of various research institutions in Pakistan that contribute to the production of resistance to leaf rust in wheat. The eco-friendly measures used in this study were effective in future research for extracting the secondary substance playing role in controlling leaf rust.

Acknowledgments

We also acknowledge (Lal Hussain Akhtar Director, Regional Agriculture Research Institute, Bahawalpur) for providing their pearls of knowledge with us throughout this research, as well as the reviewers for their contributions.

Conflict of interest

There is no “conflict of interest.”