The global decline in crop production poses a significant threat to food security, particularly in the context of a growing human population. Among various environmental constraints on agriculture, biotic stress, particularly that caused by insect pests, remains a major reason for yield losses. Traditionally, synthetic pesticides have been used to manage insect infestations; however, their excessive and non-targeted application has raised serious concerns regarding environmental pollution, adverse health effects, and the accelerated development of pesticide-resistant pest populations. In this context, plant-derived biocactive 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 defence responses and synergising with other bioinsecticides. Despite their potential, research on flavonoid-based insect control remains limited, particularly in terms of their formulation, stability, and large-scale applicability. Further studies are needed to investigate their interactions with insect physiology, optimise 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. This review examines the potential role of flavonoids as biopesticides in pest management, highlighting the existing research gaps and prospects.
Focus on impoverished crops for sustainable food and nutritional security, especially sorghum, becomes increasingly important in the changing climate regime. Grain sorghum (Sorghum bicolor L.) is 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 (ALS) and Acetyl CoA Carboxylase (ACCase) inhibitors, has led to the development of herbicide-tolerant weeds. Developing herbicide-tolerant sorghum offers an effective strategy to manage weeds while enhancing crop productivity. Conventional approaches, such as utilising genetic diversity from wild relatives, germplasm screening, and induced mutagenesis, have successfully identified and transferred tolerant traits to cultivated sorghum varieties. These methods have produced hybrids tolerant to Acetolactate Synthase and Acetyl CoA Carboxylase inhibitors, providing new options for weed management. Commercially released herbicide-tolerant sorghum production systems include InzenTM (2016, USA), iGrowth® (2020, Argentina), and Double TeamTM (2021, USA), which benefit sorghum producers 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 tolerance. Advances in gene-editing technologies, such as Clustered Regularly Interspaced Short Palindromic Repeats, have enabled precise modifications to sorghum's genome, further enhancing the development of herbicide-tolerant varieties. Researchers worldwide are focusing on developing tolerance to 4-hydroxyphenyl pyruvate dioxygenase (HPPD), protoporphyrinogen oxidase (PPO)- inhibiting herbicides, Auxinic inhibitors, and Very Long Chain Fatty Acids Synthase (VLCFA) inhibitors, and this development needs to be accelerated. This review highlights the conventional and biotechnological approaches in developing herbicide-tolerant sorghum, underscoring the importance of integrating these strategies for sustainable sorghum cultivation and improved global food security.
The green peach aphid Myzus persicae (Sulzer) (Hemiptera: Aphididae) is an essential pest of pepper (Capsi-cum annuum L.). This study was conducted in 2015-2016. In this study, we collected data using 1 linear and 6 non-linear temperature-dependent development models, development parameters, and a life table of M. persicae at 6 different temperatures (18 degrees C, 22 degrees C, 25 degrees C, 28 degrees C, 30 degrees C, and 32 degrees C) on pepper. The development threshold temperature was 3.9 degrees C, and the thermal constant was 174.0 degree/day. The minimum, optimum, and maximum growth temperatures were calculated as 14.27 degrees C, 27.5 degrees C, and 35.5 degrees C, respectively. The shortest growth period of M. persicae was found to be 8.14 days at 28 degrees C. The raw data obtained at the end of the study were analysed according to the age-stage, two-sex life table method. The highest intrinsic rate of increase (r) and the highest finite rate of increase (A) were 0.25 d-1 and 1.28 d-1 at 25 degrees C, respectively. The highest net reproductive rate (RO) was 61.64 nymphs/female at 22 degrees C, and the highest mean generation time (T) was 20.92 days at 18 degrees C. According to the models applied, the optimum temperature for pest development is 27.5 degrees C, but the intrinsic rate of increase (r) calculated from the life table parameters was statistically higher in the 22 degrees C and 25 degrees C test groups. In this study, we investigated the effect of temperature on the pest's growth and development. Based on the observations, the temperatures at which the plants were not negatively affected and the insect's activity was limited, were determined from the reproduction, development, and life table parameters obtained under different temperatures in this study. This information may help effectively control pests without using, or minimise the use of, pesticides and emphasise the temperature factor, especially in places such as greenhouses where controlled climatic conditions are provided.
In the spring of 2022, small, regular, brownish spots of parenchymatous galls on leaves of oleander plants were observed on Nerium oleander L. cv. Emile Sahut. Bacterial isolates were obtained from diseased samples. The 16S rRNA sequence analysis and concatenated data set of housekeeping genes gltA, gyrB, rpoB, and rpoD showed that the obtained isolates are most closely related to Pseudomonas savastanoi pv. nerii. Pathogenicity tests on N. oleander L. (cv. Emile Sahut) plants confirmed the pathogenicity of the isolates. The study constitutes the first report of bacterial leaf galls caused by P. savastanoi pv. nerii in Poland.
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 & micro;M CuCl2 or 200 & micro;M ZnCl2 for 24 h) before 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 immobilising 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 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.
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 an Efficient-Net-B3 pre-trained model, which, in our related studies, performed better than re-implemented Inception V3 models. The CNN was trained on 90% of the images (2 880) for training and 10% (320) for validation, with data augmentation 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 a mean absolute error (MAE) of 0.715, indicating moderate 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 optimisation and strategic dissemination efforts will enhance its adoption among farmers.
Downy mildew of sunflower is caused by the oomycete Plasmopara halstedii (Farl.) Berl. et de Toni. 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 could help farmers and researchers control the disease. The most reasonable explanation for pathogen spread appears to be the genetic variability of P. halstedii. To develop an effective control strategy, we conducted a preliminary test in the central part of the peninsula (Marche Region) to gather data on this variability.
Anthracnose is one of the most destructive diseases that limits pepper production and quality worldwide. In this study, the causal agent of anthracnose in red chilli pepper in Southern Vietnam was collected and identified based on morphological characteristics and multilocus sequence regions (ITS, fl-tubulin, GPDH, ACT). The antifungal activity of Bacillus amyloliquefaciens and Pseudomonas fluorescens was evaluated in vitro and in vivo under greenhouse conditions. The results revealed that the morphological analysis categorised the Colletotrichum isolates into three species: C. acutatum, C. gloeosporioides, and C. scovillei. Sequence analysis of the four genes confirmed that C. scovillei was the causal agent of anthracnose in chilli pepper in Southern Vietnam. 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%. The consortium of B. amyloliquefaciens CC-LD2.4, P. fluorescens CC-FN1.1, and P fluorescens O-BT1.2 achieved 84.4% control efficacy at 7 days after inoculation (DAI), which declined to 68.5% at 14 DAI and 41.7% at 21 DAI, at the flowering stage, and achieved 100% control efficacy at the fruiting stage. B. amyloliquefaciens CC-LD2.4 showed very high chitinase, protease, and cellulase activities (halo diameter of 26.7 mm, 22.7 mm, 21.5 mm), whereas P. fluorescens CC-FN1.1 was very high in protease and cellulase (14.3 mm, 12.4 mm) but weak in chitinase (5.1 mm), and P fluorescens O-BT1.2 exhibited overall lower activities (3.4-9.9 mm). There is still considerable room to optimise bacterial consortia to develop bio-fungicides that meet the requirements for an alternative or advanced solution for controlling anthracnose in red chilli peppers in sustainable agriculture.
A long-term experiment in the maise-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, T3 - stale seedbed + hoeing, T5 - stale seedbed + mulch, T6 - raised stale seedbed + mulch, T4 - mulch 5 t per ha, T7 - intercropping fenugreek in rabiseason and soybeans in kharifseason, T8 - crop rotation (soybean, mustard, and maise-peas alternately), T9 - in-tensive cropping (additional crops of mustard in the fall and buckwheat in the summer), and T10 - chemical check (pen-dimethalin in rabi season and atrazine in kharifseason). A randomised complete block design with three replications was used to assess the weed flora, consisting of eight weed species during kharif 2020, fourteen during kharif 2021, and thirteen during the rabi seasons 2019-2020 and 2020-2021. The weed species composition 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, as indicated by diversity and phytosociological studies. 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 ma-tured in April and September. Crop rotation followed by Raised stale seedbed (RSSB) + hoeing + earthing resulted in a much greater yield; however, in the second year, the chemical check was comparable to this treatment. Additionally, crop rotation increased profitability over time
Methods used to control insect pests 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 the aqueous extracts of the whole plant Dittrichia viscosa (commonly known as false yellowhead), the aqueous extract ratio of D. viscosa, and the bio-adjuvant Silene fuscata (1:1), as well as the synthetic pesticides Thiamethoxam/Lambda-cyhalothrin. Abundance, fecundity, demographic parameters, and biochemical parameters (lipid-glucidic biomarkers) of the winter phenotype of the black poplar leaf aphid Chaitophorus leucomelas were considered variables to assess the effectiveness of different approaches. The results show a strong effect of the aqueous extracts of D. viscosa (A.E. Plant) on abundance, with pronounced insecticidal activity from the aqueous extract ratio (A.E. Ratio) (P < 0.05). The lipid and carbohydrate energy of sexuparae undergo significant changes depending on the products used, with a disturbing effect of the synthetic product compared to aqueous extracts (P < 0.05). Fecundity shows a remarkable disturbance under the action of the active ingredient compared to the extracts. The results confirm that the products applied cause a disturbance in the growth rate (rm) and net reproductive rate (R0) of sexuparae, with the chemical treatment having the strongest effect (P < 0.05). The full dose of the active ingredient causes remarkable disturbances in the multiplication rate (lambda) 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.
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, conducted from April to September 2024, included a systematic application and residue analysis using liquid chromatography-mass spectrometry (LC-MS). The results showed that azadirachtin degraded rapidly, with residual levels in leaves, green fruits, and mature fruits falling below the detection threshold (0.01 mg/kg) after 8-10 days following treatment. The statistical analysis revealed strong time-dependent residue dissipation, with little systemic buildup in fruit tissues. The findings suggest that azadirachtin is a viable, environmentally friendly alternative to synthetic pesticides, aligning with food safety requirements and customer preferences for pesticide residue-free fruit. Future research should investigate the ecological factors that affect degradation rates to optimise its application in diverse agro-climatic conditions.
The wheat seed gall nematode Anguina tritici is a scientifically interesting nematode due to its aerial parasitic behaviour 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 at IARI, New Delhi, India, to examine the effects of early and late sowing dates on the life cycle of the wheat seed gall nematode using 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 : 1.00 to 1.48 : 1.00. After GDD and cGDD (cumulative growing degree days) calculation, we found that the 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 wheat plant growth and development. 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.
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 from the four families: Cicadellidae, Aphrophoridae, Delphacidae and Membracidae were collected in different geographical regions of Poland. Real-time PCR with primers for rimM gene 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 bacterium's presence in these insects.
The avocado (Persea americana Mill.) is a high value fruit crop in Indonesia. This exotic commodity is affected by dieback disease, an unrecorded disease in the country that threatens the production. The objectives of the present study were to characterise the pathogen and culturable non-pathogenic fungi associated with the dieback disease of avocado plants. Fungal isolates were collected from branches of avocados showing dieback symptom in the Standard and Instrument Tropical Fruit Applied Institute (SITFAI) experimental orchards during 2022-2023. A total of 17 fungal isolates selected from 73 fungal isolates isolated from three location were characterised morphologically, molecularly, phylogenetically, and by pathogenicity tests. The fungal isolates were tested for their pathogenicity to the local variety of avocado with two stages and three replications. The identification of the fungal species was conducted on the morphological characteristics and molecular analysis obtained from the internal transcribed spacer (ITS), the 28S region of the ribosomal DNA, and translation elongation factor 1 (TEF1). The results revealed that the artificial inoculation of Avo7 and Avo3.2 isolates, identified as Lasiodiplodia theobromae, caused necrosis and wilt symptoms on the avocado seedlings. Several fungal species from the Botryosphaeriaceae, Eurotiomycetes, and Sordariomycetes groups were found alongside the pathogen responsible for causing the dieback symptoms in the avocados. The most frequently isolated genera were fast growing, Botryosphaeriaceae (58.9%), followed by Penicillium spp. (20.5%), Pestalotiopsis spp. (15.1%) and Colletotrichum spp. (5.4%). The information in this article should be used as new insights about the incidence of dieback disease caused by L. theobromae and proper management strategies against dieback disease on avocado need to be developed.
Allelopathic plants release phytotoxic compounds that contribute to their invasiveness by suppressing nearby species. However, it remains unclear which exact mode of action (MOA) underlies the allelopathy. This study explores the allelopathic mechanisms of Turnera subulata on the recipient indicator plant choy sum using a metabolomics approach. Briefly, T. subulata leaf aqueous extracts (LAEs) at different concentrations (0.0, 0.1, 1.0, 10.0, 50.0, and 100.0 mg/mL) were sprayed at 100 mL/m2 on choy sum seedlings at the two to three leaf stage. After 21 days, the Soil Plant Analysis Development (SPAD) values and photosynthetic pigments of the exposed choy sum were measured, and their metabolites were subjected to a gas chromatography-mass spectrometer (GC-MS) analysis. The results revealed a 25% decrease in the SPAD, a reduction of 65% (chl a) and 71% (chl b), and a 45% reduction in the stomatal length at 100 mg/mL. A total of 15 significant metabolites (P < 0.05) with variables important for the projection score exceeding 1 (VIP > 1) were selected as the important biomarkers. These metabolites were identified as amino acids, carbohydrates, and fatty acids. The findings reveal the allelopathic potential of T. subulata and provide insights into the response of choy sum in response to the allelopathic activity of T. subulata LAEs.
