Pakistan Journal of Phytopathology

LINEAR REGRESSION-BASED MODELING OF THE RELATIONSHIP BETWEEN LEAF RUST SEVERITY AND YIELD ATTRIBUTES ON WHEAT

yasir Ali

Wheat (Triticum aestivum L.) production is globally threatened by leaf rust, a destructive disease caused by Puccinia triticina that severely compromises grain yield and quality. This study was conducted over two consecutive growing seasons (2023–2025) in Layyah, Pakistan, to quantify the relationship between disease severity and yield attrition using a susceptible cultivar, Sehar-06. Various levels of disease pressure were established through strategic fungicide application schedules, and epidemiological stress was measured using the area under disease progress curve (AUDPC). Results from linear regression analysis revealed a profound negative correlation between AUDPC and both grain yield (R² = 91.6% – 92.7%) and 1,000-grain weight (R² = 92.1% – 96.7%). Pooled data confirmed that AUDPC is a robust predictor of avoidable yield loss (AYL), accounting for approximately 94% of the variance in preventable grain loss. These findings demonstrate that monitoring AUDPC values provides a reliable diagnostic framework for estimating the economic impact of leaf rust and optimizing the timing of fungicidal interventions to mitigate significant yield gaps.

Impact of Potassium Chloride on the Germination dynamics of Oryza sativa L.

Aiko Ali

Rice (Oryza sativa L.) is a fundamental dietary staple for over half of the world’s population, with various environmental stresses such as salinity posing challenges to its cultivation and yield. This study aimed to investigate the effect of different concentrations of potassium chloride (KCl) solutions on the germination rate of Oryza sativa L. seeds. Brown rice grains were placed for germination under varying KCl concentrations (0, 0.001, 0.005, 0.01, 0.05, 0.1, and 0.5 M) and allowed to grow for five days. Analysis using Pearson’s product-moment correlations revealed a negative relationship between KCl levels and seed germination rates (r = -0.8841, p < 0.05). Notably, germination rates significantly dropped beyond 0.001 M KCl concentrations, indicating potential chemical toxicity affecting germination. The high chloride (Cl^-) content from KCl can induce salinity stress, while excessive potassium ions (K⁺) can inhibit plant growth. Additionally, the presence of mold on some seeds may have further impeded successful germination, as mold infestation weakens plants and can lead to their failure to thrive.

In Vitro Evaluation of Plant Extracts and Fungicides against Penicillium digitatum Causing Green Mold of Citrus

Rafia Ameen Fatima

Citrus is an economically important crop cultivated in more than 130 countries worldwide. However, postharvest diseases, particularly green mold caused by Penicillium digitatum, cause significant losses during storage, marketing, and transportation. Although synthetic fungicides such as thiabendazole and fludioxonil are widely used, repeated applications have led to the emergence of resistant strains and raised concerns about chemical residues. Therefore, safer and more sustainable alternatives are required.

This study evaluated the in vitro antifungal activity of selected plant-derived essential oils (Cinnamon, Clove, and Neem) and commercial fungicides (Profile and Isotonic) against P.digitatum. The pathogen was isolated from naturally infected citrus fruits and characterized morphologically and microscopically. Antifungal activity was assessed on potato dextrose agar (PDA), and data were analyzed statistically using SPSS.

Results showed that fungicides were highly effective, with a mean mycelial growth of 5.72 mm (isotonic) and 7.42 mm (Profile) compared to 32.89 mm in the control. Among essential oils, cinnamon oil exhibited the strongest inhibition (4.97 mm), followed by neem and clove oil. This study concludes that essential oils, particularly cinnamon oil, can reduce reliance on chemical fungicides. Combining plant oils with lower concentrations of fungicides may provide a sustainable approach to controlling citrus green mold while minimizing chemical residues and environmental impact.

First Report on the Occurrence and Morpho-Molecular Identification of Fusarium Solani Causing Wilt Disease in Blackgram (Vigna Mungo L.) In the Punjab Region of Pakistan

Fayqa Shamim — 2025-12-30

In July and August 2023 and 2024, typical wilt-disease symptoms were seen in several blackgram accessions/genotypes at Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad, Pakistan. Therefore, the present research was carried out to characterize the pathogen(s) linked with wilt-disease in blackgram using morphological and molecular approaches. Based on morpho-cultural characteristics (such as colony colour, growth-habit, number, shape and conidia and chlamydospores) and molecular identification using genus specific primer for Fusarium spp. and Fusarium solani, the associated pathogen was identified as F. solani from 42% samples. Pathogenicity test of fungus F. solani was proved on a susceptible accession “38272” planted in paper-cups under glasshouse conditions and in earthen pots under a glasshouse. Blackgram has been grown for a long time; however, this is the new report of F. solani causing wilt-disease in blackgram worldwide. These findings highlight the need to implement effective disease management strategies to reduce future economic losses caused by F. solani in blackgram-growing areas.

Comparison of Aggressiveness of Four fusarium spp. That cause Head blight on Bread wheat, Durum wheat and Barley

Nachaat Sakr — 2025-12-30

Fusarium head blight (FHB) is a significant disease affecting wheat and barley and is caused by several Fusarium species. However, contradictory data is available about their comparative pathogenicity on small grain cereals. Also, little research have compared the pathogenicity of individual Fusarium isolates on different plant parts (heads vs. detached leaves, detached heads, and coleoptiles) on cereals. This study aimed to assess the comparative pathogenicity of four Fusarium species at the earliest and latest growth stages under artificial infection with eight bread wheat, durum wheat and barley cultivars with diverse quantitative resistance levels. Four Fusarium species (F. culmorum, F. verticillioides, F. solani, and F. equiesti) were identified using an aggressive index involving nine pathogenic components generated under in vitro, growth chamber and field conditions to explore the relationships among Fusarium fungi and cereal plants. All the 16 tested FHB isolates and species were found to be pathogenic and induced typical FHB symptoms on small plant parts and adult heads. High level of variation in aggressiveness was observed among isolates within the species tested. Nevertheless, there was a similar comparative pathogenicity among the four tested Fusarium species when testing on the head and small plant parts tests. The origin of FHB pathogens may play a crucial role in this pathogenic similarity. This study suggests that screening for resistance to FHB requires the use of aggressive isolates or a mixture of several isolates. In addition, it indicates a lack of adaptation of these four tested Fusarium species. Our data clarifies for the first time the nature of comparative pathogenicity of diverse FHB species on durum wheat. It will provide critical information for cereal breeders to develop and improve FHB-resistant cultivars.

Phytochemical Profiling and Antifungal Activity of Aqueous Persea americana Leaf Extracts Against Alternaria alternata Causing Tomato Leaf Blight: In Vitro and In Vivo Assessment

Mohammed Kara

Tomato (Solanum lycopersicum L.) production is often threatened by early blight caused by Alternaria alternata, a destructive fungus responsible for substantial yield and quality losses. To promote safer and more sustainable disease control, this study evaluated the antifungal activity of aqueous leaf extracts from avocado (Persea americana Mill.) through complementary in vitro and in vivo assays. Four extract concentrations (12.5–100 mg mL⁻¹) were tested for their effects on mycelial growth inhibition. The 100 mg mL⁻¹ concentration achieved an inhibition rate of 82.36%, comparable to that of a commercial fungicide. Greenhouse experiments further demonstrated both protective and curative effects on tomato foliage, with no phytotoxic symptoms observed. LC–MS/MS analysis identified phenolic acids primarily coumarinic (83.9%), salicylic (9.3%), and gallic (4.1%) acids as the dominant constituents, accompanied by minor flavonoids that likely contributed to antifungal activity. These findings indicate that P. americana leaf extract represents a promising bio-based alternative for managing A. alternata, supporting the development of environmentally sustainable strategies for tomato cultivation.

Keywords: Solanum lycopersicum; Alternaria alternata; Persea americana; antifungal activity; phenolic compounds; LC–MS/MS

New Records of Three Pratylenchus Species from Pakistan

Namra Inam — 2025-12-30

Plant-parasitic nematode of the genus Pratylenchus pose a significant threat to global agriculture by seriously reducing yields across numerous crops. During, a recent survey conducted in Karachi, Pakistan, several plant parasitic nematode (PPN) species from root and soil samples. Among these, nematodes from the genus Pratylenchus were frequently encountered. The study showed several notable findings: three species of Pratylenchus acuticaudatus Braasch & Decker, 1988, P. ekrami Bajaj & Bhatti, 1984, and P. mulchandi Nandakumar & Khera, 1970 are reported as new records of Pakistan. Additionally, Pratylenchus wescolagricus Corbett, 1983 was found in the rhizosphere of coconut (Cocos nucifera), representing a new host record for this species in the country.

Basal Stem Rot of Oil Palm in Southern region of Côte d’Ivoire Pathogen Identification.

Cisse abraham Ismael Abraham

Purpose: Basal stem rot (BSR) of oil palm, caused by Ganoderma species, poses a growing threat to oil palm production in Côte d’Ivoire. This study aimed to identify the Ganoderma species responsible for BSR and to assess their pathogenicity on oil palm seedlings.

Research Method: Sporophores were collected from symptomatic oil palms and used for fungal isolation. Molecular identification was performed using ITS region sequencing. Pathogenicity tests were conducted on three-month-old pre-nursery seedlings by root dipping in mycelial suspensions, and disease severity was evaluated through external symptoms and a severity index.

Findings and Values: Three isolates, GN13, GN6, and GN19, were identified as Ganoderma zonatum through phylogenetic analysis. All isolates induced typical BSR symptoms consistent with field observations, with incidence rates of 68%, 69.77%, and 83.32%, respectively. Among them, GN6 was the most virulent. This work provides the first evidence of Ganoderma zonatum as the causal agent of basal stem rot in oil palms in southern Côte d’Ivoire, offering new insights for regional disease management strategies.

the Battling the Invisible Threats: Abiotic and Biotic Stresses Challenging Global Wheat Security.

Muhammad Siddique Samoo

Wheat (Triticum aestivum L.) covers nearly 215 million hectares globally, with about 44% grown in Asia. China, India, and Pakistan together account for roughly 62 million hectares, while Sindh province in Pakistan contributes around 350,000 hectares. Despite this vast cultivation, wheat productivity remains highly vulnerable to a range of biotic and abiotic stresses that threaten global and regional food security.Among biotic stresses, stem (black) rust—caused by Puccinia graminis f. sp. tritici—is the most destructive. The emergence of the virulent Ug99 race, capable of overcoming the widely used Sr31 resistance gene, has placed nearly 90% of global wheat cultivars at risk. The rapid evolution and spread of this pathogen demonstrate the significant susceptibility of current germplasm, including wheat grown in Pakistan.Wheat is simultaneously exposed to major abiotic stresses, particularly salinity, heat, and heavy metal toxicity (Cd, Pb, As). Salinity disrupts ion balance and water uptake, heat stress shortens grain filling and reduces photosynthetic efficiency, while heavy metals induce oxidative stress and impair metabolic pathways. These stresses, individually and in combination, severely restrict growth, physiology, and yield potential, especially in arid and semi-arid wheat-growing environments.This review highlights the global and regional importance of wheat and critically examines the impact of both abiotic and biotic stresses—specifically salinity, heat, heavy metals, and stem rustemphasizing their growing significance under changing climatic and environmental conditions.

Identification of diseases affecting Sesamum indicum L. in the province of Mayo-Kebbi/East (Chad).

Madjerembé Dapsia Abdoul

The study conducted in the province of Mayo-Kebbi/East (Chad) aims to characterize the impact of fungal diseases on four local sesame accessions (Sesamum indicum L.), namely Pach, Hum, S4, and Goy. Using a randomized block experimental design across nine agroecological sites, fungal pathogens were identified by visual diagnosis and isolation in the laboratory on PDA medium. The main diseases observed were charcoal rot (Macrophomina phaseolina), cercosporiosis (Cercospora sp.), alternariosis (Alternaria sp.), fusariosis (Fusarium sp.), aspergillosis (Aspergillus sp.), and Penicillium sp. rot, with a few cases of powdery mildew (Podosphaera sp.). Statistical analyses reveal significant variability in incidence and severity depending on accessions and local agroclimatic conditions. The Pach accession is the most susceptible, while Goy and S4 show better tolerance. These results highlight the need for integrated pest management and varietal selection adapted to the Sahelian context.

Keywords: Sesame, Fungal diseases, Incidence and severity, and Mayo-Kebbi/East (Chad).

A laboratory based assessment of various fungicides effectiveness against post-harvest botrytis cinerea

nimra Nill Nill

Grape (Vitis vinifera L.) is the most widely cultivated plant worldwide. Grapes are characterized by their high nutrient content, strong antioxidant and protecting effects on human health. Grapes are essential not only for wine production but also for fresh consumption. Botrytis cinerea is the main fungus prevalent worldwide. The main objective of this study is to evaluate suitable fungicides and potential biological control agents against botrytis cinerea that cause gray mold. Symptoms are brown, water-soaked lesions on berries, and covering the fruit and berry Shriveling. Disease samples will be collected from Sargodha district. The research will involve isolating and culturing Botrytis cinerea from infected samples, subsequently, a range of fungicides commonly used in post-harvest diseases management will be tested at various concentrations. Isolation of Botrytis cinerea will be done on PDA. The data on radial growth on each plate will be measured after 5, 10, 15 and 20 days. The efficacy of fungicides against the Botrytis cinerea will be measured by putting a plug of pathogen and fungicides corresponding to each other and growth inhibition will be measured with the same interval as above. The results of this study will provide valuable information on the effectiveness of different fungicides against Botrytis cinerea.

Evolution of different fungicides against post-harvest losses caused by Alternaria alternata in apple under laboratory conditions

Muqaddas MH Hashmi

Apples (Malus × domestica Borkh.) are economically significant fruits due to their nutritional and bioactive properties, including essential nutrients like dietary fibers, vitamins, and antioxidants apple is available throughout the year. Alternaria alternata is common fungal pathogen that causes significant postharvest losses in various fruits and vegetables. The main objective of this study is to check the invitro efficacy of fungicides against Alternria alternata that cause fruit rot. Fruit symptoms are often limited to tiny, dark, corky lesions, but when the skin is affected, they can grow into huge, black, and rotting lesions. The research will involve isolating and culturing Alternaria alternata from infected samples, subsequently, a range of fungicides commonly used in post-harvest diseases management will be tested at various concentrations. Isolation will be performed on Potato Dextrose Agar (PDA). The fungicides inhibitory effects on fugal growth will be assessed under the laboratory conditions using poison food technique. The efficacy of fungicides against the Alternria alternata will be measured by putting a plug of pathogen and fungicides corresponding to each other and growth inhibition will be measured with the same interval as above. The results of this study will provide valuable information on the effectiveness of different fungicides against Alternria alternata.

Exploring Plant-Based and Microbial Strategies for the Sustainable Management of Aspergillus flavus Infecting Maize Crops

Brian Gagosh Nayyar

Maize (Zea mays) is a key global crop and serves as an essential nutritional resource for both humans and livestock. However, its yield has been significantly affected by fungal infections, particularly those caused by Aspergillus flavus. A. flavus produces mycotoxins, especially aflatoxins, which are extremely toxic and carcinogenic and contaminate crops, including maize. The main objective of this study is to assess the antifungal efficacy of plant extracts and microbial antagonists against A. flavus through both in vitro and in vivo approaches. In in vitro studies, the effectiveness of plant extracts appeared to be in this sequence: Anagallis arvensis > Cannabis sativa > Convolvulus arvensis, while the fungal strains were placed in order as: Trichoderma harzianum > Aspergillus oryzae. Whereas, in in vivo trials, the antifungal strength of chosen plants and fungi followed this order: Cannabis sativa > Convolvulus arvensis > Anagallis arvensis and Trichoderma harzianum > Aspergillus oryzae. These findings provided useful new insights into how biocontrol agents can reduce Aspergillus flavus infection, maintain environmental sustainability, and improve crop quality, while offering a viable alternative to chemical pesticides in maize production. Overall, the fungus Trichoderma harzianum proved to be the most effective antagonist across both in vitro and in vivo conditions. Among the plant-based treatments, Cannabis sativa was the most effective under in vivo conditions, whereas Anagallis arvensis showed its strength mainly in the controlled environment of in vitro trials.

First Report on the Occurrence and Morpho-Molecular Identification of Fusarium Solani Causing Wilt Disease in Blackgram (Vigna Mungo L.) In the Punjab Region of Pakistan

Fayqa Shamim — 2025-12-30

Biological Control of Fusarium Wilt of Cucumber under in-vitro condition and in High Tunnels

Muhammad Waris — 2025-12-30

Cucumber is an important vegetable being affected by Fusarium wilt disease, caused by Fusarium oxysporum f. sp. cucumerinum (FOC), which is a soil borne disease, that transmits through soil and water and it is one of the most destructive diseases of cucumber plants under high plastic tunnel conditions worldwide including Balochistan, Pakistan. The current study was conducted to evaluate the efficacy of four biocontrol agents such as Trichoderma harzianum, T. hamatum, T. viride, and Paecilomyces sp., using a dual culture assay under in vitro and naturally infested tunnel conditions in Balochistan in a Completely Randomized Design with four replications. The results under in vitro revealed that all the biocontrol agents significantly inhibited the radial growth of FOC as compared to control. The highest inhibition was demonstrated by T. harzianum (77%), followed by Paecilomyces sp. (75%), T. hamatum (72%), and T. viride (70%). Based on in vitro findings, three most effective agents such as T. harzianum, T. hamatum, and Paecilomyces sp. were further evaluated under high plastic tunnel conditions using soil drench method. The results under tunnel revealed that T. harzianum and T. hamatum demonstrated the highest effectiveness, reducing the disease incidence (13.2% and 17.0%), plant mortality (10.2% and 21.3%), and root infection (13.97% and 18.00%) compared to the untreated plants, moreover, with respect to the growth parameters, the both bioagents considerably enhanced the shoot and root growth, leading to increase the fresh and dry biomass of the plants. It was concluded from the findings of current study that the T. harzianum and T. hamatum could be effective biological agents for managing the Fusarium wilt of cucumber in high tunnels.

Evaluation Of Native Bacterial Antagonist Against Fusarium Subacianum In Potatoes

Muhammad Ataullah — 2025-12-30

This study investigated the prevalence and impact of Fusarium dry rot, a significant postharvest disease of potatoes. The objectives of this research were to determine the primary Fusarium species causing dry rot in potato markets and to assess the antagonistic potential of selected bacterial biocontrol agents against the dominant pathogen. Market surveys revealed significant disease losses, with Islamabad exhibiting the highest incidence (17.2-19%). Fusarium species, particularly F. subacianum (62.50%), F. oxysporum (57.50%), and F. solani (56.25%), were identified as the primary pathogens. Pathogenicity tests confirmed the virulence of these isolates, with F. oxysporum (45 mm) demonstrating the highest aggressiveness. To explore biological control options, three bacterial strains (Pseudomonas fluorescens, Bacillus velezensis, and Bacillus subtilis) were evaluated for their in vitro and in planta antagonistic activity against F. subacianum. Their efficacy was assessed through in vitro dual-culture assays and in planta experiments on potato tubers using both preventive and curative application methods. B. velezensis exhibited the strongest in vitro inhibition of fungal growth (74.91%) and demonstrated the most effective disease control in both preventive (14.28%) and curative (16.82%) applications on potato tubers. The demonstrated efficacy of B. velezensis underscores its potential as a sustainable biocontrol tool, offering a viable strategy to reduce postharvest losses and minimize reliance on synthetic fungicides in potato storage systems.

Advancing Agricultural Sustainability through Rhizosphere Fungi: A Review of Metagenomic Approaches and Applications

Tutik Kuswinanti

Rhizosphere fungi play a crucial role in agricultural sustainability by contributing to nutrient cycling, soil health, and plant resilience. This review examines their potential in sustainable agriculture, with a focus on metagenomic approaches to elucidate their diversity and function. Metagenomics enables comprehensive studies of microbial communities from environmental samples, providing insights into the genetic diversity and functional potential of rhizosphere fungi. Recent metagenomic studies have revealed numerous unknown fungal species and their genes in the rhizosphere, offering opportunities for developing sustainable agricultural strategies. These studies have identified key metabolic pathways and functional genes involved in plant-microbe interactions, including nutrient acquisition, disease resistance, and stress tolerance. The knowledge from metagenomic analyses can be used to enhance crop productivity, improve soil health, and mitigate environmental stressors on agricultural systems. This review discusses the challenges of metagenomic approaches, including technical constraints and ecological complexity. Future perspectives highlight emerging technologies like single-cell genomics, metatranscriptomics, and machine learning to advance understanding of rhizosphere fungal communities. The integration of fungal data into precision agriculture systems and development of fungal-based biofertilizers shows promise for sustainable practices. This review emphasizes the importance of collaboration, policy support, and farmer engagement in translating research into practical applications for sustainable agriculture.

Regional and Solvent-dependent Variation in Antioxidant and Antifungal activities of Eucalyptus sideroxylon subspecies Extracts Targeting A. Alternata and B. Cinerea

Nada A. Turki — 2025-12-30

This study provides the first comparative evaluation of methanolic and ethanolic leaf extracts from red- and white-flowered Eucalyptus sideroxylon subspecies collected from four Algerian regions, focusing on regional and solvent-dependent variation in their phytochemical composition, antioxidant capacity, and antifungal potential. Total phenolic, flavonoid, and condensed tannin contents were quantified using spectrophotometric colorimetric methods. Antioxidant activity was determined by the DPPH radical-scavenging assay, while antifungal efficacy was evaluated in vitro using the agar well diffusion method against Botrytis cinerea and Alternaria alternata. Results revealed significant variability in phytochemical content and biological activities depending on both subspecies and geographic origin. The highest total phenol content was observed in Boughezoul region (458.71 mg GAE/g) for white-flowered in methanolic extracts, while in ethanolic extracts, the highest value was recorded in Miliana (305.22 mg GAE/g for red-flowered). Condensed tannin peaked in Boughezoul (702.16 mg CE/g in white-flowered), and flavonoid content was highest in Medea's red-flowered samples. Methanolic extracts of the white-flowered subspecies showed the strongest antioxidant activity, particularly in Médéa (IC₅₀ = 0.0929 mg/ml). The white-flowered ethanolic extract from Médéa showed the highest antifungal activity, with inhibition zones of 21.5 ± 0.2 mm against A. alternata and 17.0 ± 0.3 mm against B. cinerea, exceeding Nystatin’s effect. The white-flowered methanolic extract from Boumerdes also exhibited notable antifungal activity (19.0 ± 0.5 mm and 15.0 ± 0.5 mm, respectively), likely reflecting environmental influences on metabolite accumulation. These findings support the use of white-flowered Eucalyptus sideroxylon extracts as a sustainable, natural biofungicide for integrated crop protection.

Epidemiological Studies of Citrus Scab Disease in Different Growing Areas of District Sargodha

Muhammad A. Zeshan — 2026-01-03

Citrus scab is a destructive disease that deteriorates the quality of the produce and makes it unfit for marketing and export. It also reduces fruit yield considerably. This study was planned to assess the role of epidemiological factors in the development of citrus scab disease in major citrus growing areas of Sargodha (Punjab-Pakistan). A prominent growing region (Silanwali Tehsil) was selected for survey of citrus orchards. Data on disease intensity irrigation sources and cultural practices was recorded with. The results indicated that orchards that were irrigated with canal water and that had weeds, dense canopies, and intercrops were highly infected with scab pathogens. There was a very strong relationship between disease incidence and severity; similarly, disease intensity increased with rise in temperature, relative humidity and wind speed. The study concludes that integrated management options with controlled irrigation and cultural practices are vital for sustainable, climate-resilient control of citrus scab.

Comparison of Aggressiveness of Four fusarium spp. That cause Head blight on Bread wheat, Durum wheat and Barley

Nachaat Sakr — 2025-12-30