Integrated Disease Management Research Articles

An updated review of Alternaria blight of pigeonpea (Cajanus cajan (L.) Mill sp.)

Pigeonpea (Cajanus cajan (L.) Mill sp.) is an important food legume grown in semi-arid tropical and sub-tropical farming systems under diverse agroecological environments. Alternaria blight (Alternaria tenuissima (Kunze ex Pers.) Wiltshire) is a minor disease when the pigeonpea is sown in June-July but becomes the most serious disease in crops that are sown in mid-September in north-eastern India. Alternaria blight disease has been reported from 13.67 to 49.33% disease intensity in different climatic conditions. This disease is found on leaves, stems, and pods, and dark spots on the leaves and pods reduce the photosynthesis capacity and immature ripening, reducing the amount of quality seeds. The recurrence of the disease depends upon weather conditions, genotypes, age of plants, and virulence of the pathogen, and crop growing areas prioritized the research for developing an extensive range of Alternaria blight. Earlier workers on pathological, physiological, and biochemical characteristics of pathogen the nature of the infection process, and the genetic basis of the pathogen in variability could not clearly be reported. It is required to investigate Alternaria blight including signs, symptoms, biology, status, epidemiology, pathogenic, biochemical, and genetic variability, refinement of the resistance screening techniques, and develop integrated disease management technology of the pathogen to understand the change of disease scenario in the context of climate change. Available information on pathogen symptomatology, status, variability, source of resistance, different management options, and genetic basis of resistance have been updated and discussed with the identification of future research priorities.

Elicitation of native bio protective microbial agents associated systemic defense responses and plant growth promotion against bacterial stalk rot pathogen in sorghum (Sorghum bicolor)

Dickeya dadantii is the causal agent of bacterial stalk rot and one of the most destructive and widespread diseases of the sorghum in the world. Here, we explored microbe-based approaches for managing this destructive pathogen, intending to provide alternatives for integrated disease management. The objective of the research was to decipher the effect of antagonistic microbes on systemic defense enzymes, histochemical changes, plant growth attributes, reduction in disease severity, and interaction of these antagonistic microbes with host. Trichoderma, Pseudomonas, and Bacillus isolates were collected from rhizospheric soil and characterized using morphological and molecular tools. ITS and 16S rRNA sequences were analyzed to determine the molecular characterization of all antagonist microbes, and they were identified as T. asperellum, T. viride, T. harzianum, B. subtilis, and P. flourescens. These isolates were evaluated for antibacterial properties against D. dadantii under in vitro conditions and showed the higher inhibition in a dual culture method. Further, the effects of seed bio-priming and soil application of these isolates were tested under glasshouse and field conditions. T. viride outperformed the other isolates, significantly enhancing the plant growth parameters and induced resistance to Dickeya dadantii (BSR). T. viride showed a significantly higher accumulation of defensive enzymes, viz. PAL (1.02), PO (1.70), PPO (1.25), CAT (1.11), and TPC (0.91) at 48 h after pathogen challenge, as compared to the control. Histochemical tests confirmed lignification and callose deposition in the cell walls of the treated plants. Antagonist microbes were further evaluated under field conditions against D. dadantii infection. Compared to the control, there is a significant enhancement of plant growth parameters and yield with a simultaneous decrease in disease severity in T. viride treated plants. Results showed that the potential benefits of T. viride could not only effectively induce resistance in plants, enhance plant growth, increase yield, and suppress pathogen infection but also reduce the use of hazardous pesticides. As a result of correlation, PCA and heat map analyses indicated that T. viride is interconnected to determine the crop ability to sustain its growth under pathogen stress.

Assessing the Baseline Sensitivity of Predominant Soil-Borne Pathogens against Carbendazim

Fungicide resistance is reducing the effectiveness of fungicides in controlling plant diseases, leading to increase crop losses and the need for alternative control strategies. Addressing this issue requires careful fungicide use and the development of new management approaches. The main objective of present study was to determine the baseline sensitivity and development of fungicide resistance in predominant soil-borne pathogens against carbendazim at various concentrations. It was observed that the EC50 of Fusarium oxysporum and Macrophomina phaseolina was 9.970 and 16.294 µg ml-1, respectively. The baseline sensitivity of both fungi was determined based on the inhibition percentage at which the pathogen showed sensitivity. Repeated transfer of these cultures at same concentrations for some generations showed the progressive decline in growth inhibition across generations resulting in the development of fungicide resistance. These studies have demonstrated that overreliance on certain fungicides can lead to the development of resistant fungal strains, compromising the efficacy of disease management. This emphasizes alternative use of fungicides with different mode of action or following integrated disease management strategies to mitigate fungicide resistance and sustainably protect crops.

Survey on Fungicide Usage Patterns and Farmer’s Willingness to Adopt Disease Management Practices in Cucurbits

The rising use of fungicides in cucurbits are significant issue, there are insufficient data to support the various factors influencing fungicide usage pattern. In this survey, a structured questionnaire and sequential exploratory mixed design was used to gather information about marginal scale (<5 acre) cucurbits farmers along with their perception on fungicide and their knowledge towards adopting integrated disease management. Cucurbits downy mildew and powdery mildew poses major diseases and shows severe yield loss upto 42% and 34%, respectively. The results revealed that most of the farmers heavily relied on fungicide (55.71%) for management, although they were aware of the negative impacts of fungicides on human health and the environment (67.14%). In this Dimethomorp (18.57%) and Metalaxyl + Mancozeb (17.14%) was mostly used. During a cropping season, farmers (38.57%) was used fungicide frequently for 8-9 times and also adhered to less pre-harvest intervals. In this study, a data on farmers following indiscriminate and frequent use of chemical fungicide which led to disease resurgence, resistance, also encouraged to follow integrated disease management strategy and adoption to preventive measures based on forewarning advisory.

Management of Sclerotinia rot of rapeseed-mustard through integrated pest management

In vitro studies revealed maximum mycelial growth inhibition (98.5%) of Sclerotinia sclerotiorum byTrichoderma koningii isolate JMA-11 followed by DMA-8 (90.4%). Extract of Vitex negundo and Melia azedarachshowed 100 per cent and 98.3 per cent inhibition ofmycelial growth of S. sclerotiorum at 5% concentration followed by 96.7 per cent and 91.7 per cent growth inhibition at 2.5% concentration, respectively. At 1% concentration, 57.6 per cent growth inhibition of the pathogen was shown by Melia azedarach followed by 55.6 per cent inhibition with Vitex negundo. Fifty nine genotypes of rapeseed-mustard screened under artificial field conditions showed lack of the resistance to S. sclerotiorum. However, ten genotypes viz., NRCG-104, NRC-DR-603, HC-0213, HC-0212, HC-9603, HC-9605, BCRS-17, Pusa Swarnim, Kiran, and PBC-9221 belonging to Brassica carinata were found to be moderately susceptible. In the integrated disease management, a combination of row spacing 45 cm, 2-3 lower leaf removal at 80 and 100 days after sowing and one spray of companion (0.2%) was found to be best treatment in reducing the disease incidence of Sclerotinia rot in Brassica napus.

Integrated Disease Management (IDM) Modules against Karnal Bunt (Tilletia indica) of Wheat

Wheat (Triticum aestivum L.) belonging to family “Gramineae” and genus “Triticum”, is one of the world’s most widely cultivated food grain crop, due to its wider adaptability to different agro-climatic and soil conditions. Karnal bunt (Tilletia indica) is an important wheat disease with implications for wheat grain quality and inflicts changes in chemical composition of infected grains. IDM modules evaluated under pot and field condition revealed that all the thirteen modules were significantly effective and observed lower disease incidence of karnal bunt. Module M11 andM8 recorded nil (0.00%) disease incidence in both condition. The maximum incidence was recorded (0.425%) and (0.81%) in M12 followed by M5 (0.395%) and (0.68%) whereas minimum incidence was observed in M9 (0.002%) and (0.05%) under pot and field respectively. However, in the field maximum yield (44.65 q/ha) and test weight (36.04 g) was recorded in module M11, followed by (44.30q/ha) and (35.91g) in M8, while, minimum yield (40.35q/ha) and test weight (35.30g) was observed in M12.

Estimating the Health and Economic Impact of Improved Management in Prevalent Chronic Obstructive Pulmonary Disease Populations in England, Germany, Canada, and Japan: A Modelling Study.

COPD is a leading cause of morbidity and mortality globally. Management is complex and costly. Although international quality standards for diagnosis and management exist, opportunities remain to improve outcomes, especially in reducing avoidable hospitalisations. To estimate the potential health and economic impact of improved adherence to guideline-recommended care for prevalent, on-treatment COPD populations in four high-income settings. A disease simulation model was developed to evaluate the impact of theoretical improvements to COPD management, comparing outcomes for usual care and policy scenarios for interventions that reduce avoidable hospitalisations: 1) increased attendance (50% vs 31-38%) of early follow-up review after severe exacerbation hospitalisation; 2) increased access (30% vs 5-10%) to an integrated disease management (IDM) programme that provides guideline adherent care. For cohorts of 100,000 patients, Policy 1 yielded additional life years (England: 523; Germany: 759; Canada: 1316; Japan: 512) and lifetime cost savings (-£2.89 million; -€6.58 million; -$40.08 million; -¥735.58 million). For Policy 2, additional life years (2299; 3619; 3656) and higher lifetime total costs (£38.15 million; €35.58 million; ¥1091.53 million) were estimated in England, Germany and Japan, and additional life years (4299) and cost savings (-$20.52 million) in Canada. Scenarios found that the cost impact depended on the modelled intervention effect size. Interventions that reduce avoidable hospitalisations are estimated to improve survival and may generate cost savings. This study provides evidence on the theoretical impact of policies to improve COPD care and highlights priority areas for further research to support evidence-based policy decisions.

Mathematical Model for Spread and Control of Cocoa Black Pod Disease

Black pod disease is a major threat to cocoa production worldwide. A mathematical model for the spread of cacao black pod disease is presented in this article. The model takes into account several variables that influence the spread of the disease. A set of differential equations that are numerically solved using Runge-Kutta method embedded in MATLAB software are used to simulate the dynamics of disease transmission which form the basis of the model. Utilizing information from the literature and ecological observations from cocoa fields in West Africa, where black pod disease poses a serious threat to the production of cocoa, the model was verified. The model's outcomes highlight the significance of early detection and rapid intervention in mitigating the severity of cocoa black pod disease outbreaks. Moreover, it emphasizes the importance of adopting integrated disease management approaches that consider fungicide administration and removal of infected pods. The usefulness of mathematical modeling as a tool for understanding and managing cocoa black pod disease is illustrated by this study.

In-vitro Compatibility Assessment of Trichoderma harzianum with Chemical Fungicides and Botanical Extracts

The threats of devastating soil-borne disease, limited availability of its management strategies, development of fungicide-resistant strains, outbreaks of new diseases, and growing concerns regarding nature and the environment have compelled us to use integrated disease management (IDM) strategies with appropriate biocontrol agents. Trichoderma, free-living fungi, are successful antagonists with promising biocontrol potentials and can be used with chemicals and botanicals in the IDM approach to control various plant pathogenic fungi. So, the present experiment was conducted to evaluate the compatibility of Trichoderma harzianum with chemical fungicides and botanicals in in-vitro using a poisoned food technique. The experiment was conducted in a completely randomized design with three replications for each treatment at the central laboratory of the Institute of Agriculture and Animal Science, Lamjung, Nepal, and data were taken at different time intervals and analyzed. For fungicides, the maximum compatibility was found in Copper oxychloride at 100 ppm, and the highest inhibition (100%) was observed in Carbendazim + Mancozeb, Carbendazim, and Hexaconazole even in lower concentration (100 ppm). For botanicals, Azadirachta indica and Zingiber officinale enhanced T. harzianum, and the highest compatibility was observed at 10% leaves extract of Azadirachta indica with a growth inhibition percentage of -5.43% (Day 5). Aqueous extracts of tested botanicals were found compatible with T. harzianum, except for the Acorus calamus, Artemisia vulgaris, and Allium sativum. In IDM practice, compatible fungicides and botanicals at recommended doses can be used with T. harzianum.

Artificially applied late-terminal drought stress in the field differentially affects Ramularia leaf spot disease in winter barley

Ramularia leaf spot disease (RLS) is one of the most dominating fungal diseases in barley. The disease typically appears late in the season after flowering and results in a rapid loss of photosynthetic leaf area. A recent decline in fungicide efficacy and a lack of RLS-resistant cultivars hamper effective control. Global warming will provoke increasing droughts which influence host plant physiology and probably affect outbreak and severity of RLS. Relatively little is known about genetic resistance to RLS in winter barley and about the influence of various weather conditions and climate change on RLS pathogenesis. Hence, we evaluated severity of RLS on 15 winter barley genotypes under persistent late-terminal drought stress or controlled irrigation, respectively, in a field rainout shelter. Over three consecutive years, we observed reproducible differences in quantitative RLS field resistance of the used cultivars and variable suppression of RLS under drought. Our results support a function of drought in suppression of RLS in winter barley, but also reveal strong year effects even under semi-controlled rainout shelter conditions. Data may be relevant for genotype selection in breeding programmes for RLS resistance and for farmers in the frame of integrated disease management under a changing climate.Graphical abstract

Activity of volatiles induced by microbes and natural plants stifled the growth of Pythium aphanidermatum - the damping off in Tomato

BackgroundVolatilomes from natural plants and microbes imparts diverse antifungal properties to suppress the growth of plant pathogens and therefore can be a suitable alternative of chemical fungicides. The present experiment was to study effect of volatiles produced by natural plants and microbes on the fungal growth of Pythium aphanidermatum, which is a tomato seedling pathogen.ResultsIsolate of P. aphanidermatum, causing damping off in tomato were isolated and incubated at 25 ± 2 °C. The isolate was tested for the anti-oomycetes activities of volatiles in vitro. The volatiles produced by the leaves of Mentha spicata and Cymbopogon citratus showed the maximum inhibitory effect of 45.56 and 24.70 percent, respectively on the mycelial growth of P. aphanidermatum, whereas, the pathogen was not inhibited on exposure to the volatiles of macro-basidiomycetes fungi. The volatiles of T. asperellum showed the maximum inhibitory effect of 69.26 percent against P. aphanidermatum. The study also included the identification of Volatile Organic Compounds (VOCs) involved in the suppression of pathogens by Headspace Gas Chromatography Mass Spectrometry (HS GCMS). The results revealed the production of carvone by the leaves of M. spicata; citronellol and geraniol by C. citratus; isopentyl alcohol and limonene by T. asperellum with increased peak area percentage and these compounds possessed antifungal properties. The vaporous action of isopentyl alcohol completely suppressed the mycelial growth of P. aphanidermatum, which is highly correlated to the T. asperellum extract on pathogenic growth. While the compounds, carvone, and citronellol showed the maximum inhibitory effect of 89.02 and 85.49 percent, respectively when used at 500 ppm and also altered the sporulation behavior of P. aphanidermatum.ConclusionResults showed that volatiles of M. spicata and T. asperellum have anti-oomycetes action on pathogenic growth leading to a distortion of sporulation of P. aphanidermatum. High antifungal properties make VOCs suitable for incorporation as a new integrated plant disease management programs.

In vitro Compatibility of Trichoderma and Bacillus biocontrol agents with Different Fungicides

Biocontrol agents are beneficial for plant and soil health and are effective in controlling many plant diseases. These biocontrol agents in combination with fungicides at reduced doses can be more effective than using alone. Keeping this in view, an in vitro study was carried out to test the compatibility of commonly used fungicides viz., captan 50 WP, thiram 75% DS, tebuconazole 5.36% FS, carboxin 37.5% + thiram 37.5% DS, prochloraz 24.4% + tebuconazole 12.1% w/w EW and thiophanate methyl 450 g/l + pyraclostrobin 50 g/l with two fungal (Trichoderma asperellum and T.viride) and three bacterial biocontrol agents (Bacillus subtilis S4KB5, B. subtilis S8KB2 and B. subtilis B3). All the five fungicides were found to be compatible with all the biocontrol agents at 100ppm and 250ppm. All the fungicides except thiram, showed complete inhibition of T. asperellum at 1500ppm and 2000ppm and with T. viride, 100 per cent inhibition is shown by all the fungicides at 1500ppm and 2000ppm except carboxin + thiram. With biocontrol isolates, B. subtilis S4KB5, B. subtilis S8KB2 and B. subtilis B3, highest inhibition zone were recorded by prochloraz + tebuconazole (2000ppm), tebuconazole (2000ppm) and thiophanate methyl + pyraclostrobin (2000ppm). Present findings suggest that compatible fungicides can be used with biocontrol agents in an integrated disease management practices for the control of seed and soil borne pathogens.

A review on detailed understanding and recent advances on Colletotrichum capsici causing anthracnose of chilli.

Chilli is one of the most significant spice crops cultivated with numerous culinary, medicinal, and industrial applications. Colletotrichum have a wide host range causing anthracnose disease in various crops whereas in chili anthracnose caused by Colletotrichum capsici is the major constraint in chili production. Under severe environmental conditions, the symptoms appear all over the plant including fruit which lead to complete crop damage. The particular disease has a huge economic impact on yield reduction and also debars the export criteria due to the less quality of chili crop. Management of the disease is difficult under field conditions and majority of the management strategies are highly dependent on the use of chemicals. Solely rely on chemicals is harmful to environmental and human health so integrated disease management approach can help to manage the disease at the initial stage. Detection and identification of pathogen play a major role in pathogen management. Early identification and detection of the pathogen based on conventional and molecular methods are very important to reduce yield loss under field conditions. The current review consists of a detailed understanding of the pathogen, identification, detection and diagnosis, and the most recent research updates.

Determination of Phytophthora Species Causing Root and Crown Rot on Tomatoes Grown in Antalya Province and Reactions of Some Tomato Genotypes against Phytophthora nicotianae

Antalya province is the main center of vegetable production in Türkiye. Tomato comes first in terms of crops cultivated under greenhouse. Phytophthora species causing root and crown rot are among the factors negatively affecting tomato yield and quality. This research aimed to determine the prevalence of root and crown rot of tomatoes grown in Antalya province and to identify Phytophthora species causing disease. During surveys performed in 170 tomato greenhouses, plant and soil samples were taken from the areas where root and crown rot, stem blight, and drying symptoms were observed. Disease prevalence and incidence in the investigated greenhouses were 25.88% and 4.87%, respectively. Phytophthora symptoms were not observed in the greenhouses in Demre and Kepez districts, while the highest disease prevalence was found in Elmalı district with 75%. Eighty of 84 Phytophthora isolates were identified as P. nicotianae and four as P. capsici, according to their cultural, morphological and molecular characterisation. Virulence of 18 selected isolates were determined by using stem inoculation technique and all isolates caused lesions with different lengths on tomato stems. The reactions of 22 tomato genotypes in the gene pool of BATEM against P. nicotianae were also investigated and the genotype DT-15 was found as the most susceptible genotype with the largest lesions, while A-286 was the most resistant genotype. This study formed the basis for further studies on tomato breeding and integrated disease management.

Yellow Mosaic Virus (YMV) in Green Gram: Impacts, Management, and Future Perspectives

Yellow mosaic virus (YMV) is a destructive viral pathogen that affects green gram (Vigna radiata) crops, leading to significant yield losses and economic repercussions. This review paper provides a comprehensive analysis of the impacts of YMV on green gram cultivation, explores the current management strategies employed to combat the disease, and discusses future perspectives for effective YMV control and prevention. YMV is primarily transmitted through whiteflies and infects green gram plants at various stages of growth, causing severe symptoms such as leaf yellowing, stunted growth, and mosaic patterns. These symptoms ultimately lead to reduced crop yield and quality. The virus poses a major threat to green gram production globally, demanding urgent attention and effective management practices. Various management approaches have been employed to mitigate the impact of YMV. Cultural practices, including proper field sanitation, weed control, and crop rotation, play a vital role in disease management. Insecticide application, use of yellow sticky traps, and whitefly population monitoring are important components of integrated pest management strategies aimed at reducing virus transmission. Additionally, the development and deployment of resistant cultivars through conventional breeding and biotechnological approaches have shown promise in minimizing YMV infection and its associated losses. Despite these efforts, YMV continues to pose significant challenges to green gram production, necessitating further research and innovative approaches. Future perspectives for YMV management involve the integration of advanced technologies such as molecular diagnostics, genome editing, and RNA interference to enhance disease resistance in green gram varieties. Additionally, promoting awareness among farmers about YMV symptoms, preventive measures, and adoption of integrated disease management strategies will contribute to sustainable green gram production. In conclusion, YMV represents a major threat to green gram cultivation, affecting crop productivity and economic sustainability. This review emphasizes the need for concerted efforts to develop comprehensive YMV management strategies. By combining conventional and modern techniques, effective disease control measures can be implemented to mitigate the impact of YMV and secure the future of green gram production.

Management of Fungal Diseases of Temperate Rice in the Kashmir Valley, India

Over half of the world's population is fed by rice. It is consumed as a staple food by many countries worldwide. It is affected by a number of diseases among which fungal diseases contribute to its significant loss. Kashmir Valley located in the North Western Himalayan region of India is known for various coarse varieties of rice for their taste and elite class. However, the diseases cause a serious problem for the local farmers as well as the people who also consume rice as their staple food. One of the best remedies for disease management is the adoption of integrated disease management strategies, which include the use of resistant varieties, cultural practices, and judicious use of fungicides. In this review, we present the major fungal diseases affecting rice in Kashmir Valley and their management using Integrated Plant Disease Management (IDM).

Publisher Correction: Integrated disease management of Fusarium wilt (Fusarium oxysporum f. sp. ciceris) of chickpea

Publisher Correction: Integrated disease management of Fusarium wilt (Fusarium oxysporum f. sp. ciceris) of chickpea

Biological Control of Fungal Phytopathogens with Trichoderma harzianum and Its Fungicidal Compatibility

Excessive synthetic fungicide use reduces soil's antagonistic population, allowing soil-borne plant pathogens to cause significant global losses. Despite high fungicide application, plant diseases persist, harming the ecosystem. Trichoderma spp, an eco-friendly plant symbiont, can serve as an alternative biocontrol agent. This study evaluated Trichoderma harzianum's antagonistic effect against fungal pathogens and its compatibility with fungicides under in-vitro using a Completely Randomized Design with four replications per treatment. Trichoderma harzianum showed high antagonistic activity for Alternaria brassicicola (70.35%), Fusarium solani (70.82%), Helminthosporium sorokinana (66.55%), Rhizoctonia solani (78.58%), Sclerotium rolfsii (92.53%). Among the tested fungicides, Copper oxychloride and Mancoxeb at 400 ppm showed maximum compatibility with growth inhibition percent (GIP) of 2.41% and 7.91%, respectively, after 60 hours of incubation. Fungicides viz., Carbendazim, Hexaconazole, and Carbendazim+Mancozeb at all concentrations aren't compatible with 100% GIP throughout the experiment, and for Metalaxyl+Mancozeb, high growth inhibition percent was observed ranging from 42.77% to 78.40% making it incompatible. In integrated disease management, compatible fungicides at recommended doses can be used in combination with T. harzianum.

Effect of Integrated Disease Management (IDM) Practices on Disease Severity and Incidence of Common Scab of Potato

Effect of Integrated Disease Management (IDM) Practices on Disease Severity and Incidence of Common Scab of Potato

Biological control in relation to Integrated Disease Management

Biological control in relation to Integrated Disease Management