Plant Protection Science - In Press
Isolation and characterization of pathogenic and endophytic fungi associated with avocado plants showing dieback symptoms in IndonesiaOriginal Paper
Riska Amril, Tri Budiyanti, Jumjunidang Jumjunidang, Sri Hadiati, Raden Heru Praptana, Mizu Istianto, Nurmansyah Nurmansyah, Herwita Idris
Avocado (Persea americana Mill) is a high value fruit crop in Indonesia. This exotic commodity is affected by dieback disease, an unrecorded disease that threatens production. The objectives of the present study were to characterize the pathogen and endophytic fungi associated with dieback disease of avocado plants. Fungal isolates were collected from branches of avocado showing dieback symptom in Standard and Instrument Tropical Fruit Applied Institute (SITFAI) experimental orchards during 2022–2023. A total of 17 fungal isolates selected from 73 fungal isolates recovered from three location were characterized morphologically, molecularly, phylogenetically, and by pathogenicity tests. Identification of fungal species were done on morphological characteristic and molecular analysis obtained from internal transcribed spacer (ITS), 28S region of ribosomal DNA, and trans elongation factor 1 (TEF1). The fungal isolates were tested for their pathogenicity to avocado local variety test with two stages. First step was mechanical inoculation of all the fungal isolates with one avocado seedling and three slashed stems as replication. Second step was mechanical inoculation of four selected isolates (the isolate caused necrosis symptom to avocado seedling) to avocado local variety seedling with three seedlings and three slashed stems as replications. The result revealed that fungal species such as Neofusicoccum parvum, Colletotrichum tropicale, C. fruticola, Neopestalotiopsis sp. Pestalotiopsis sp., Pseudofusicoccum ardesiacum, Nigrospora sphaerica, Nemania bipapillata, Neoroussoella leucaenae, Penicillium citrinum, Lasiodiplodia theobromae, L. krabiensis, Lasiodiplodia sp. were obtained from avocado plant showing dieback symptom. The most frequently genus isolated were fast growing, Botryspaeriaceae (58,9%), followed by Penicilium spp. (20.5%), Pestalotiopsis spp. (15.1%) and Colletotrichum spp. (5.4%). Artificial inoculation of a L. theobromae isolate induced necrosis symptom on local avocado seedling.
Life table and development parameters of green peach aphid [Myzus persicae (Sulzer) (Hemiptera: Aphididae)] at six different temperatures on pepper (Capsicum annuum L.)
Furkan Harun Bas
The green peach aphid Myzus persicae (Sulzer) (Hemiptera: Aphididae) is an essential pest of pepper (Capsicum annuum L.). In this study, we collected data, using 1 linear and 6 non-linear temperature-dependent development models, development parameters, and life table of M. persicae at 6 different temperatures (18°C, 22°C, 25°C, 28°C, 30°C and 32°C), on pepper. The development threshold temperature was 3.9°C and the thermal constant was 174. 0 degrees/day. The minimum, optimum, and maximum growth temperatures were calculated as 14.27°C, 27.5°C, and 35.5°C, respectively. The shortest growth period of M. persicae was found to be 8.14 days at 28°C. The raw data obtained at the end of the study were analyzed according to the age-stage, two-sex life table method. The highest intrinsic rate of increase (r) and the highest finite rate of increase (λ) were 0.25 d-1 and 1.28 d-1 at 25°C, respectively, the highest net reproductive rate (R0) was 61.64 nymph/female at 22°C and the highest mean generation time (T) was 20.92 days at 18°C. According to the models applied, the optimum temperature at which the pest develops is 27.5°C, but the intrinsic rate of increase (r) calculated according to the life table parameters was statistically higher in the 22°C and 25°C test groups. In this study, we investigated the effect of temperature on the growth and development of the pest. As a result of the observations, the temperatures at which the plants were not negatively affected and the activity of the insect was limited were determined according to the reproduction, development, and life table parameters obtained as a result of different temperatures in this study. This information may help to effectively control without using or minimizing the use of pesticides and emphasize the temperature factor, especially in places such as greenhouses where controlled climatic conditions are provided.
Azadirachtin as a sustainable tool for zero pesticide residue production: Residue dissipation in open-field tomato productionOriginal Paper
Tahseen Chikte, Michal Kumšta, Václav Psota, Tomáš Kopta
The growing demand for vegetables free from pesticide residues has fuelled the search for sustainable pest management solutions. This study assessed the efficacy of azadirachtin, a neem-derived biopesticide, in achieving no detectable pesticide residues in tomato production under open-field conditions. The experiment from April to September 2024 included systematic application and residue analysis with Liquid chromatography-mass spectrometry (LC-MS). The results showed that azadirachtin degraded rapidly, with residual levels in leaves, green fruits, and matured fruits falling below detection thresholds (0.01 mg. kg-1) after 8-10 days following treatment. The statistical analysis revealed strong time-dependent residue dissipation, with little systemic buildup in fruit tissues. The findings indicate that azadirachtin is a feasible, environmentally friendly alternative to synthetic pesticides, consistent with food safety requirements and customer preferences for pesticide residue-free fruit. Future research should examine ecological factors affecting degradation rates to optimize its application in diverse agro-climatic conditions.
Secondary Metabolites from Lactiplantibacillus plantarum and Lacticaseibacillus paracasei Inhibited Growth of Ralstonia syzygii subsp. celebesensis (RSC), Causal Pathogen of Banana Blood DiseaseOriginal Paper
MICHELL KAH VEN SAM
Banana blood disease is a banana wilt disease caused by Ralstonia syzygii subsp. celebesensis (RSC) has significantly threatens banana plantations particularly in Indonesia and Malaysia. Yet, the current control methods are inadequate to mitigate the disease. Biological control agents (BCAs) offer a promising solution by utilizing beneficial microorganisms that are against pathogens. Among BCAs, lactic acid bacteria (LAB) have gained increasing attention in agriculture due to their ability to produce a variety of antimicrobial compounds. This study investigates the antimicrobial substances produced by Lactiplantibacillus plantarum and Lacticaseibacillus paracasei against RSC using cell-free supernatants (CFS) and liquid-liquid extraction (LLE). The inhibitory effect of the LAB extracts against RSC were evaluated using agar well diffusion method. Liquid chromatography mass spectrometry analysis confirmed the bioactive metabolites with potential antibacterial activity against RSC are monoglucosyl-enterobactin, (6Z,9Z,12Z)-octadecatrienoic acid, 2-(hydroxymethyl)-3-(acetamidomethylene)succinate from CFS-L. plantarum, canavanine, norspermidine, and 4-guanidinobutanamide in CFS-L. paracasei, sinapinic acid, lecanoric acid and D-glucono-1,5-lactone in LLE-L. plantarum and lithocholic acid, orotic acid, and sterculic acid in LLE-L. paracasei. Scanning electron microscope has shown the disruption and the damaging of the RSC cells in the treatment of LAB. These findings highlight the potential of L. plantarum and L. paracasei metabolites for biocontrol applications.
Flavonoids as bio-insecticides: Harnessing plant metabolites as a biochemical shield against insectsReview
Thamaraikannan Sivakumar, Sunilkumar Devanathan, Parthasarathi Ganesan, Kavithamani Duraisamy, Murugan Marimuthu, Vellaikumar Sampathrajan, Karthikeyan Adhimoolam, Senthil Natesan
The global decline in crop production threatens food security, particularly as the human population grows. Among the many environmental challenges affecting agriculture, biotic stress caused by insect pests is a major factor in yield reduction. Traditionally, synthetic pesticides have been used to manage insect infestations; however, their excessive and indiscriminate application raises serious concerns regarding environmental pollution, human health risks, and the development of pesticide-resistant pest populations. In response, natural plant-derived compounds, particularly flavonoids, have emerged as promising bioinsecticides due to their potent insecticidal properties. Flavonoids, a diverse group of secondary metabolites found abundantly in plants, exhibit strong insecticidal activity by disrupting insect digestion, interfering with nutrient absorption, and inhibiting growth and metamorphosis. These bioactive compounds act through multiple mechanisms, reducing the likelihood of resistance development while offering an eco-friendly alternative to conventional chemical pesticides. Additionally, flavonoids contribute to integrated pest management strategies by enhancing plant defense responses and synergizing with other bioinsecticides. Despite their potential, research on flavonoid-based insect control remains limited, particularly regarding their formulation, stability, and large-scale applicability. More studies are needed to explore their interactions with insect physiology, optimize delivery methods, and assess their environmental impact. Advancing flavonoid-based bioinsecticides can contribute significantly to sustainable pest management in modern agriculture, reducing dependence on synthetic pesticides while preserving ecosystem balance.
Characterization of Colletotrichum species associated with anthracnose disease in chili pepper in the South of Vietnam and control effective of consortium Bacillus amyloliquefaciens and Pseudomonas fluorescensOriginal Paper
Vo Ha, Huynh Thuong Vuong, Huynh Thanh Hung, Tran Bao Thang
Anthracnose is one of the most destructive diseases that limit pepper production and quality worldwide, as well as in Vietnam. In this study, the causal agent of anthracnose in chili plants in Southern Vietnam, was isolated from the disease sample, identified through a combination of morphological characteristics and multilocus sequence gene regions (ITS, β-tubulin, GPDH, ACT). The antifungal activity of Bacillus amyloliquefaciens and Pseudomonas fluorescens was evaluated in vitro and in vivo under greenhouse conditions. Additionally, the enzyme activity of the bacterial isolates was investigated. The results revealed that the morphological analysis categorized the Colletotrichum isolates into three species: C. acutatum, C. gloeosporioides, and C. scovillei. Sequence analysis of the four genes involving ITS, β-tubulin, GPDH, ACT confirmed all of the fungi were C. scovillei. B. amyloliquefaciens and P. fluorescens bacteria demonstrated antifungal activity against C. scovillei in vitro, with mycelial growth inhibition rates ranging from 20.79% to 78.69%. Under greenhouse conditions, the bacterial consortium of B. amyloliquefaciens CC-LĐ2.4, P. fluorescens CC-FN1.1 and O-BT1.2 significantly reduced disease severity and incidence, performing comparably to chemical and biological products. In addition, B. amyloliquefaciens CC-LĐ2.4, P. fluorescens CC-FN1.1 and O-BT1.2 had chitinase, glucanase, and protease enzyme activity, showing potential for use in sustainable agriculture to manage anthracnose and other plant diseases. Efforts are ongoing to develop biofungicides from these bacteria and investigate efficacy under field conditions.
A Green Approach: Effects of organic weed control on weed diversity and phenology
Sarwan Kumar, S. S. Rana, Gaytri Hetta, Navjot Rana, Graciela Dolores Avila-Quezada, Ahmed Z. Dewidar, Mohamed A. Mattar
A long-term experiment in the maize-pea cropping system was conducted in Palampur from October 2019 to September 2021 as part of the All India Coordinated Research Project on Weed Management (AICRP-WM). Ten methods for managing weeds. namely, T1-hoeing, T2-raised stale seedbed + hoeing, T2-stale seed bed + hoeing, T5-stale seed bed + mulch, T6-raised stale seed bed + mulch, T4-mulch 5t ha-1, T7: Intercropping fenugreek in rabi season and soybeans in kharif season . A randomized complete block design with three replications was used to assess T8-crop rotation (soybean, mustard, and maize-peas alternately), T9-intensive cropping (additional crops of mustard in the fall and buckwheat in the summer), and T10-chemical check (pendimethalin in rabi season and atrazine in kharif season). The weed flora consisted of eight weed species during kharif 2020, fourteen during kharif 2021, and thirteen during rabi season 2019–20 and 2020–21. The species composition of weeds changed significantly in the second year compared to the first. In contrast to the chemical check, the organic weed control treatments showed a variety of weed flora, according to diversity and phytosociological study. Long periods of germination/emergence, blooming, and fruiting were found in phenological research. Rabi weeds appeared between October and January and between May and August. They flowered and produced fruits or seeds in March and September, respectively, and matured in April and September. Crop rotation followed by Raised stale seed bed (RSSB)+ hoeing + earthing up resulted in a much greater yield; however, in the second year, chemical check was comparable to this treatment. Additionally, crop rotation increased profitability over time.
Bionomics of wheat seed gall nematode Anguina triticiOriginal Paper
Manish Kumar, Matiyar Rahaman Khan, Ajay Singh Sindhu, Arti Kumari, Swathi Karthika, Bharat Gawade, Ashish Kumar Singh, Vishal Singh Somvanshi, Anil Sirohi
The wheat seed gall nematode Anguina tritici is a scientifically interesting nematode due to its aerial parasitic behavior, and ability to survive for years under desiccated conditions in seed galls. However, Anguina’s life cycle and its correlation with host-plant growth and environment are poorly understood. Here, we conducted a microplot study in IARI, New Delhi, India to examine the effects of early and late sowing dates of wheat on the life cycle of the wheat seed gall nematode by using the growing degree days (GDD). The study confirmed the presence of juvenile stages in the soft, undifferentiated floral mass and the upper one-third part of the stem. During the early stage of floral differentiation, the plant ovary develops into milky grains, while the galls (false ovules) become fully green. An increase in size and gonad cell development was observed when nematode J2s entered the floral tissue. The count of adult females in galls marginally surpasses that of adult males, and the female:male ratio ranged from 1.46:1 to 1.48:1. After GDD and cGDD (cumulative growing degree day) calculation we found that nematode completed its life cycle in 90 to 140 days, depending on the wheat sowing dates and change in temperature. The study also showed that nematode development was in-sync with the growth and development of wheat plants. The information developed from the study such as the cumulative GDD and it’s correlation with Anguina’s life cycle, presence of nematode in stem, flower and gall, it’s migration from collar to flower, presence of various stages of nematode in different plant tissues, and it’s undergoing the anhydrobiotic process in seed galls may be used to determine the best time to intervene and manage nematode infestations.
New data on pathotype distribution of Plasmopara halstedii in one of the most important Italian areas dedicated to sunflower cultivationShort Communication
Andrea Del Gatto, Mauro Dal Pra', Ilaria Alberti
Downy mildew of sunflower is caused by the oomycete Plasmopara halstedii Novot. Italy has seen an increase in mildew infections in parallel with the spread of the crop. In the present situation there is a substantial lack of information that can help farmers and researchers in the control of the disease. The most relevant one seems to be the pathogenetic variability of P. halstedii. To overcome the problem, we conducted a preliminary test to collect the first data about this variability.
From Images to Insights: Using Convolutional Neural Network to Improve Powdery Mildew Severity Detection in MungbeanOriginal Paper
Pitchakon Papan, Witsarut Chueakhunthod, Chanwit Kaewkasi, Wanploy Jinagool, Akkawat Tharapreuksapong, Teerayoot Girdthai, Kanlayanee Sawangsalee, Piyada Alisha Tantasawat
Abstract: To efficiently identify powdery mildew (PM) severity in mungbean leaves, we developed a Convolutional Neural Network (CNN) approach and validated its effectiveness against human evaluation. We fine-tuned a pre-trained model of EfficientNet-B3, which in our related studies proved to perform better than re-implemented Inception V3 models. The CNN was trained with 90% of the images for training (2880) and 10% for validation (320), wherein data augmentation techniques were applied using Python and TensorFlow. The model obtained 82.10% and 73.03% as training and validation accuracies after 14 epochs, respectively. Further analysis with an additional 15 datasets revealed PM disease indices ranging from 2.03 (resistance) to 6.45 (high susceptibility). The concordance between AI-predicted and human-assessed PM severity was 74.4% (adjusted R2: 72.4%), with an average root mean squared error (RMSE) of 0.854 and mean absolute error (MAE) of 0.715, indicating a moderate level of predictive error. Comparison of our developed AI-based application prototype on smartphones with expert evaluations yielded a strong correlation (r = 0.992**, R2 = 0.984), suggesting that this tool can effectively estimate PM severity across mungbean cultivars. The application shows considerable promise, and further optimization and strategic dissemination efforts will enhance its adoption among farmers.
Role of the Arabidopsis AT2g21490 dehydrin gene in enhancing tolerance to copper and zinc stress in transgenic tobacco plants.Original Paper
Eva Boszorádová, Mária Švecová, Peter Nemeček, Petra Ranušová, Milan Karas, Jana Moravčíková
We studied the role of the Arabidopsis AT2g21490 (DH2) histidine-rich dehydrin gene in plant responses to copper and zinc stress. Transgenic plants overexpressing the DH2 gene were generated via Agrobacterium-mediated transformation. Progeny from both transgenic and non-transgenic (control) plants were cultivated hydroponically and subjected to short-term stress (100 µM CuCl2 or 200 µM ZnCl2 for 24 hours) prior to analysis. The differences observed between transgenic and non-transgenic plants in the expression of phytochelatin synthase (NtPCS) and certain metal transporters (NtMTP1A, NtMTP1B, NtHMA_A, and NtHMA_B) suggest that the DH2 gene plays a role in immobilizing excess copper, primarily in the roots, thereby mitigating its harmful effects on the aerial parts of the plant. The overexpression of the DH2 gene influenced the levels of both enzymatic (NtAPX, NtSOD, NtCAT) and nonenzymatic antioxidants, particularly by increasing the levels of polyphenolic compounds such as chlorogenic acid by at least 12-fold and rutin by at least 3-fold. The contribution of the DH2 gene to zinc stress tolerance appears to be less significant.
An investigation of the presence of Xylella fastidiosa in Cicadomorpha specimens collected in different habitats in PolandOriginal Paper
hab. Monika Kałużna, dr hab. Grażyna Soika, Wojciech Warabieda
A quarantine organism, the bacterium Xylella fastidiosa (Xf) is a xylem-inhabiting, vector-transmitted, Gram-negative, and very slow-growing bacterium in the Lysobacteraceae (earlier Xanthomonadaceae) family. The spreading of X. fastidiosa over long distances occurs mainly via import/export human-mediated transportation of mainly latently or symptomatically infected plant material. Short-distance distribution is usually by xylem sap-feeding insects. Until now, the presence of X. fastidiosa has not been reported or studied in Poland. During our study, over 500 individuals of insects from the four families: Cicadellidae, Aphrophoridae, Delphacidae and Membracidae were collected in different geographical regions of Poland. The use of real-time PCR with a TaqMan probe and nested PCR to detect X. fastidiosa, using DNA extracted directly from selected insects known as potential vectors of X. fastidiosa, did not confirm the presence of the bacterium in them.
Attenuating strategies of the insecticidal effect and life history traits of Chaitophorus leucomelas (Koch, 1854) (Insecta: Aphididae): Case of the aqueous extracts of Asteraceae dittrichia viscosa and a synthetic product of the Neonicotinoids /Pyrethroids familyOriginal Paper
Fatma Zohra TCHAKER, Zahr-Eddine DJAZOULI, İsmail KARACA
Methods used to control natural enemies; insects in particular, have been mainly chemical. Given the irritations associated with the use of pesticides, a search for alternatives is required, particularly through the use of plant extracts. The present study focused on comparing the insecticidal power of aqueous extracts of Dittrichia viscosa in combination with a bio-adjuvant Silene fuscata and a synthetic pesticide Thiamethoxam/ Lambda-cyhalothrin on the abundance, biochemical life traits and demographic parameters of the winter phenotype of Chaitophorus leucomelas. Two extracts were prepared through the maceration process: aqueous extracts of the whole plant D. viscosa and aqueous extract ratio of D. viscosa and S. fuscata (1:1). As for the chemical product, two concentrations were used: the prescribed dose (4 mL/L) and half of that dose (2 mL/L). Abundance, fecundity, demographic parameters, as well as the energy balance (lipid-glucidic biomarkers) of C. leucomelas were considered variables to assess the effectiveness of different approaches. The results show a strong effect of the aqueous extracts of D. viscosa on the abundance, with a well pronounced insecticidal activity under the effect of the aqueous extract ratio. Lipid and carbohydrate energy biomarkers of sexuparae undergo strong changes depending on the products used, with a very significant disturbing action of the synthetic product compared to aqueous extracts. The fecundity shows a remarkable disturbance under the action of the active ingredient compared to aqueous extracts. The results also confirm that the products applied cause a disturbance in the growth rate (rm) and reproduction (R0) of C. leucomelas females, with the chemical treatment having the strongest effect. The full dose of the active ingredient causes remarkable disturbances on the multiplication rate (λ) and the mean generation time (T) of the sexuparae compared to the other applied molecules. Some stability is reported for the doubling time (DT) of treated females compared to the control ones. Overall, the extracts induce a significant toxic effect with a minor disruptive impact on the biochemical life traits and demographic parameters of the pest, compared to the synthetic product.
HERBICIDE RESISTANT GRAIN SORGHUM:OPPORTUNITIES AND CHALLENGESReview
G RAGHAVI, S Lakshmi Narayanan, M Gunasekaran, M Raveendran, M Sudha, A Senthil, S Manoharan
Focus on impoverished crops for sustainable food and nutritional security, especially sorghum, becomes increasingly important in the changing climate regime. Sorghum (Sorghum bicolor L.), a vital cereal crop that could endure an array of biotic and abiotic stresses and is well-suited to arid ecological zones. Sorghum productivity is hindered by intense competition with weeds. However, conventional herbicide use, particularly Acetolactate synthase and Acetyl CoA Carboxylase inhibitors, has led to the development of herbicide-resistant weeds. Developing herbicide-resistant sorghum offers an effective strategy to manage weeds while enhancing crop productivity. Conventional approaches, such as utilizing genetic diversity from wild relatives, germplasm screening, and induced mutagenesis, have successfully identified and transferred resistance traits to cultivated sorghum varieties. These methods have produced hybrids resistant to Acetolactate Synthase and Acetyl CoA Carboxylase inhibitors, providing new options for weed management. Commercially released herbicide resistant sorghum include Inzen, iGrowth, Double Team benefits sorghum farmers globally in many countries. Additionally, molecular mapping techniques, including quantitative trait loci mapping and marker-assisted selection, are critical for identifying genes responsible for herbicide resistance. Advances in gene-editing technologies, such as Clustered Regularly Short Palindromic Repeats, have enabled precise modifications in sorghum’s genome, further enhancing the development of herbicide resistance. Researchers worldwide are concentrating in developing resistance to 4-hydroxyphenyl pyruvate dioxygenase, protoporphyrinogen oxidase inhibiting herbicides, growth regulator inhibitors and seedling inhibitors and needs to be accelerated. This review highlights the conventional and biotechnological approaches in developing herbicide-resistant sorghum, underscoring the importance of integrating these strategies for sustainable sorghum cultivation and improved global food security.