Plant Protection
The purpose of this study was to clarify the population dynamics of Aphis rumicis and Menochilus sexmaculata on Rumex dapibus herba, and the effects of Aphis rumicis on the growth, development and fecundity of the dominant natural enemy, Menochilus sexmaculata. In this study, the Rumex dapibus herba was used as the host plant of A. rumicis, and the population dynamics of aphid and ladybeetle were investigated every 6 days by using the five-point sampling method. Ladybeetle was fed with aphid, and the developmental duration, survival rate and oviposition of adults were recorded. The results showed that: (1) the maximum population density of A. rumicis appeared in late July, which was 35.29 individuals/plant, and the maximum population density of M. sexmaculata in the field survey of leaf-eating grass planting base during the same period was 6 days later than that of A. rumicis, and the maximum population density was 1.60 individuals/plant. (2) During the whole development of the laboratory population, the survival rates of the egg stage, the 1-4 instar larval stage, and the pupal stage (pre-pupal stage) were 93.3%, 87.5%, 96.0%, 97.9%, 100%, and 100%, respectively, and the overall survival rate from eggs to the completion of one generation was 66.7%. The development period from egg to pupal was (2.49± 0.07) d, (2.75±0.07) d, (2.38±0.01) d, (2.40±0.07) d, (2.05±0.03) d, (5.62±0.10) d, and the pre-oviposition period was (2.52±0.10) d. (3) The net reproduction rate R0=108.27>1, the intrinsic growth rate r=0.18>0, and the weekly growth rate λ=1.20>1, showing an increasing trend. Average generational duration = 25.95 d. The above indicators showed that the population of ladybeetle was increasing, which proved that Rumex dapibus herba was also a good food source for A. rumicis, and A. rumicis could be used to rear M. sexmaculata.
This study aims to screen biocontrol strains against Fusarium graminearum species complex in order to provide new biocontrol resources for the sustainable management of fusarium head blight. A high-efficiency biocontrol strain was isolated from non-agricultural soil samples collected in Badong County, Enshi, Hubei Province, using the dilution plate method with Fusarium graminearum as the indicator strain. The inhibitory effects of the isolate Glarea lozoyensis fermentation broth on mycelial growth and spore germination of F. graminearum were assessed,as well as its degradation rates on deoxynivalenol (DON) and zearalenone (ZEN) in vitro. The strain was identified through morphological characteristics and 18S rRNA gene sequence analysis. Further experiments were conducted to assess control efficacy in field plots. The results showed that a 10-fold dilution of its fermentation broth inhibited F. graminearum mycelial growth and spore germination by 91.98% and 100%, respectively, and achieved 100% degradation rates for DON and ZEN. Morphological characteristics and 18S rRNA gene analysis identified as Glarea lozoyensis (GL), designated GL-P1. Field trial results demonstrated that the fermentation broth of GL-P1 achieved a 71.36% control efficacy against Fusarium head blight, comparable to the fungicide tebuconazole. The above study indicates that Glarea lozoyensis P1 is a biocontrol isolate with promising field efficacy against Fusarium head blight, showing potential for further application and development.
In order to explore the effect and application technology of slightly acidic hypochlorite water (SAHW) in strawberry disease control, the fungal inhibition tests (inhibitory effect on the spore germination) was used in this paper to study the antifungal activity of SAHW against the two disease pathogens (Fusarium oxysporum and Botrytis cinerea). Illumina Miseq sequencing technology was also used to analyze the fungal community structure and diversity of the strawberry rhizosphere soil during the planting, early blooming and full-fruiting stages of strawberry before and after SAHW treatment. The results showed that the germination rates of F. oxysporum and B. cinerea spores cultured in the 25 mg/kg SAHW treatment group were both lower than 10%, while the germination rate of the control group cultured by purified water was close to 100%. A total of 15 phyla, 45 classes, 96 orders, 220 families and 405 genera were identified by Illumina Miseq sequencing. Among them, Ascomycota, Mortierellomycota and Basidiomycota were the dominant fungi. At the genus classification level, the relative abundance of Aspergillus (2.21%-53.54%) and Trichocladium (4.76%-26.54%) was relatively high. The relative abundance of the phytopathogenic fungus Aspergillus reached the highest value during the flowering stage and then showed a decreasing trend in the treatment groups. In addition, Penicillium, Fusarium and Colletotrichum gradually accumulated in the strawberry rhizosphere soil treated with purified water and reached the highest level during the fruiting period, but remained at a low level in the strawberry rhizosphere soil treated with SAHW. This study preliminarily revealed the antifungal effect of SAHW and its impact on the diversity of strawberry rhizosphere fungi, providing a scientific basis for comprehensive prevention and control of strawberry diseases.
In order to clarify the mechanism of herbicidal activity of strain HY-021 on Chenopodium album L., electron microscope scanning technology was used to observe the process of infestation of C. album leaves by the strain after inoculation, and changes in the activity content of C. album plants after inoculation were determined using physiological index assay. The results showed that the mycelium of the HY-021 strain invaded leaf tissues through stomata, parasitized, proliferated and produced spores, which gradually destroyed the tissue. Concurrently, leaf surfaces began to show chlorosis and developed disease spots, ultimately leading to plant death due to an inability to perform photosynthesis. Following inoculation of C. album plants with the HY-021 strain, the content of MDA inside the plant bodies gradually increased, while the activities of enzymes such as SOD, CAT, and POD showed trend of increasing and then decreasing after inoculation. It showed that the strain had multiple effects on the plant physiological mechanisms and defense enzymes, and caused a wide range of metabolic changes in the plant after inoculation. The overall content of soluble proteins was higher than the control, indicating that soluble protein content increased following infection by the strain, which enhanced the plant's resistance capabilities.
To clarify the effects of rubber varieties on the development and reproduction of Parasaissetia nigra, the developmental duration, survival rate, and fecundity of P. nigra were investigated on seven rubber tree varieties (‘IAN873’, ‘Reyan 7-33-97’, ‘PR107’, ‘Reyan 7-20-59’, ‘Yunyan 77-4’, ‘GT1’ and ‘RRIM600’) in a cage experiment under field condition. Additionally, population life tables of P. nigra on these rubber tree varieties were constructed, respectively. The results showed that developmental duration of P. nigra was the longest on ‘RRIM600’ (99.1 d) and the shortest on ‘PR107’ (74.3 d). Notable mortalities of first-instar nymphs were found in all seven rubber tree varieties, with the survival rates ranging from 27.9% to 59.0%. For a whole generation of P. nigra, the survival rates on seven rubber tree varieties in decreasing order were ‘PR107’> ‘Yunyan 77-4’> ‘Reyan 7-33-97’> ‘Reyan 7-20-59’> ‘IAN873’> ‘RRIM600’> ‘GT1’. The longest oviposition period (64.4 d) and adult longevity (94.4 d) of P. nigra were observed on rubber tree variety ‘Reyan 7-33-97’. The highest fecundity was recorded also on ‘Reyan 7-33-97’ (727.0 eggs), followed by ‘PR107’ (526.2 eggs), whereas the lowest fecundity was found on ‘RRIM600’ (303.5 eggs). The population trend index of P. nigra on seven rubber tree varieties in decreasing order were ‘PR107’> ‘Reyan 7-33-97’> ‘Yunyan 77-4’> ‘GT1’> ‘Reyan 7-20-59’> ‘IAN873’> ‘RRIM600’. Therefore, ‘PR107’ and ‘Reyan 7-33-97’ were identified as the suitable hosts for P. nigra, whereas ‘GT1’ and ‘RRIM600’ were considered as unsuitable hosts.
The pathogen and symptoms of rice spike rot disease were introduced. The occurrence regularity of rice spike rot disease was expounded from the occurrence conditions and epidemic regularity of the disease. The agricultural control measures of rice spike rot disease were introduced from the aspects of cultivation management, fungus source accumulation and selection of resistant varieties. The control effects of different pesticides on rice spike rot disease were also introduced. It is suggested that the control of rice spike rot disease should be based on agricultural control measures, including scientific cultivation, timely elimination of fungal sources and selection of disease-resistant varieties, and the chemical control should be included at the opportune moment. The occurrence and damage of spike rot disease were expected to be effectively controlled to a certain extent while ensuring the safety of grain production.
To screen out the better agents for controlling the eggs and larvae of Tuta absoluta, the leaf-dipping method was employed to assess the indoor toxicity of 11 agents, as well as the synergistic effects of mixtures of biopesticides and chemical pesticides. The findings revealed the following toxicity rankings of different agents on the eggs of T. absoluta in the laboratory: emamectin benzoate> abamectin> spinetoram> indoxacarb> rotenone> matrine> beta-cypermethrin·emamectin benzoate> azadirachtin> Metarhizium anisopliae CQMa421> Bacillus thuringiensis> Beauveria bassiana ZJU435. Regarding the toxicity to the larvae of T. absoluta, the ranking was: emamectin benzoate> abamectin> spinetoram> matrine> rotenone> beta-cypermethrin·emamectin benzoate> indoxacarb> azadirachtin> Metarhizium anisopliae CQMa421> Beauveria bassiana ZJU435> Bacillus thuringiensis. Metarhizium anisopliae CQMa421, Beauveria bassiana ZJU435, and Bacillus thuringiensis were each blended with emamectin benzoate, spinetoram, and indoxacarb at active-ingredient ratios of 1:9, 3:7, 5:5, 7:3, and 9:1 to evaluate the synergistic effects on the eggs of T. absoluta. When Metarhizium anisopliae CQMa421and indoxacarb were combined at an active-ingredient ratio of 9:1, the co-toxicity coefficient reached its peak at 204.90, demonstrating the most pronounced synergistic effect. The tests indicated that emamectin benzoate, avermectin, and spinetoram exerted high toxicity on both the eggs and larvae of T. absoluta. The mixtures of Metarhizium anisopliae CQMa421, Beauveria bassiana ZJU435, and Bacillus thuringiensis with emamectin benzoate, spinetoram, and indoxacarb manifested synergistic effects, thereby enhancing the control of T. absoluta and reducing the reliance on chemical pesticides.
To determine the control effect of cyromazine, chlorantraniliprole and spinetoram on Drosophila suzukii larvae, the fruit damaged by D. suzukii was collected and the experiment was carried out by means of insecticide spray. The mortality rate of D. suzukii larvae was calculated on day 1, 2, 3, 4 and 5 after medication. The mortality rates of D. suzukii larvae after 5 days of treatment with 3000, 2500 and 2000 times cyromazine spray were 53.72%, 56.47% and 58.48%, respectively. After 5 days of treatment with 5000, 4500 and 4000 chlorantraniliprole spray, the mortality rates of D. suzukii larvae were 51.49%, 54.85% and 58.42%, respectively. After 5 days of treatment with 2500, 2000 and 1500 times spinetoram spray, the mortality rates of D. suzukii larvae were 41.38%, 43.30% and 49.74%, respectively. Cyromazine and chlorantraniliprole have certain control effect on D. suzukii larvae.
Spartina alterniflora, as an alien invasive plant, has spread rapidly in the Yellow River Delta region, threatened native species, and damaged ecosystem health. This paper analyzes the invasion footprint of Spartina alterniflora in the Yellow River Delta by using remote sensing satellite image analysis techniques. It was found that after Spartina alterniflora completed colonization (before 2004), it quickly occupied the invaded habitat and rapidly spread (2004—2014). Although human intervention had suppressed the invasion speed of Spartina alterniflora and reduced the invasion area in the past decade (2014—2024), it still had the potential to make a comeback and reinvade. Therefore, we further classify and summarize the hypotheses of different stages of Spartina alterniflora invasion, compare various control measures, the prospect of scientific exploration of microbiological control of Spartina alterniflora in the future is proposed. The aim of this study is to provide a new way to prevent and control Spartina alterniflora invasion in the future.
In order to explore the alleviating effect of exogenous ascorbic acid on the toxicity of beet seedlings under atrazine stress and the degradation mechanism of atrazine, using beet 'KWS1197' seeds as experimental materials, pot experiments combined with instrumental analysis were conducted to determine the effects of different concentrations of ascorbic acid on physiological and biochemical indexes of beet under atrazine stress, as well as the pesticide residues and degradation mechanisms in the soil. The results showed that atrazine stress inhibited the growth of beet seedlings, after spraying ascorbic acid, the toxicity of beet seedlings under atrazine stress was alleviated. Spraying 1mmol/L ascorbic acid had the most significant effect. The dry weight of the above-ground part and the underground part was 2.54 times and 3.43 times that of atrazine treatment group (AT treatment group). Chlorophyll content was increased by 42.5%. MDA content and electrolyte permeability were 53.57% and 65.01% of those in AT treatment group. SOD, POD and CAT enzyme activities were reduced by 60.5%, 61.3% and 51.1%, compared with AT treatment group. Spraying ascorbic acid can reduce the residual amount of atrazine in soil, and the higher the concentration, the more obvious the degradation effect. Four degradation products were found, and four possible degradation pathways of atrazine were further speculated. Ascorbic acid can improve the adverse effects of atrazine on the growth of beet seedlings, and the effect is significant at 1 mmol/L. This study provides a reliable reference for the degradation of atrazine.
In order to clarify the effects of rearing with different volume-density combinations on the developmental duration, survival rate, and weight of pupae and adults of the ten-spotted ladybird beetles, under conditions of 25℃, relative humidity of 60% to 80%, and a light cycle of 10 L:14 D, three containers (A: 1000 mL; B: 1500 mL; C: 2000 mL) and 3 densities (15 heads; 20 heads; 25 heads), feeding, recording and analyzing the development period, survival rate, pupal and adult weight of each insect of M. dilatata. The results showed that the survival curve of M. dilatata showed an "S" downward trend with the growth of instar, and the development duration of each treatment was C3>C1>A1=C2>A3>A2=B2>B1>B3, and the average development time of group B was the shortest. The survival rate of the 1st and 2nd instar larval stage and pupal stage of each treatment was lower, and the pupation rate and adult rate of B2 treatment were 76.67% and 73.33%, which were higher than those of the other treatments. The weight of each treatment at pupal stage from high to low was A1>C2>C3>B1>A3>C1>B3>A2>B2, and the weight of adults from high to low was B1>B3>B2>C2>C3>C1>A2>A3>A1. In summary, the best feeding container for M. dilatata should be B2 treatment, that is, 1500 mL feeding density of 20 heads/box is the best. This study provides a theoretical basis for the efficient breeding of larvae of M. dilatata.
The article provides references for the prevention and management of Myospalax fontanieri, this study summarizes and analyzes the research progress regarding the ecological characteristics, damage traits, outbreak causes, and control methods of Myospalax fontanieri. Based on the current state of research and existing issues, it is proposed to strengthen and improve the population monitoring and damage assessment of Myospalax fontanieri. Additionally, the study encourages exploring an integrated pest management system centered on ecologically prioritized and environmentally friendly control technologies and products, to effectively regulate the population of Myospalax fontanieri and to protect the stability of agricultural production and the ecological environment.
In order to clarify the species, biological characteristics, and the control agents of the pathogen of apple scab in Yuexi County, the pathogen was identified and analyzed based on the molecular biology and morphological characteristics, and the biological characteristics of pathogen were studied in different culture medium, pH, carbon source and nitrogen source. The field control effects of 5 common fungicides were studied. The results showed that the pathogen causing apple scab in Yuexi County was identified as Venturia inaequalis. The optimum culture medium was wheat bran agar medium, the optimum pH was 7-8, the optimum carbon source was glucose, and the optimum nitrogen source was peptone. The field control results showed that the five fungicides could effectively control apple scab, and the control effect of 20% pydiflumetofen was the best, with the control effect was 89.54%. The order of the control effect was 20% pydiflumetofen SC> 20% pydiflumetofen·difenoconazole SC> 40% flusilazole EC> 50% kresoxim-methyl WG> 36% thiophanate-methyl SC. The above results showed that 20% pydiflumetofen, 20% pydiflumetofen·difenoconazole and 40% fluosilazole can be applied as reference pesticides for controlling V. inaequalis in field.
Utilizing bibliometric software CiteSpace, a visual exploration was undertaken on 143 relevant publications regarding Arboridia kakogawana in the CNKI database spanning from 1987 to 2024. The analysis encompassed annual publication trends, authorship patterns, institutional affiliations, and prevalent keywords. The objective was to offer insights for future research directions within the A. kakogawana domain. The results indicated that the annual publication of research related to A. kakogawana from 1999 to 2016 was relatively high, with a total of 127 publications and an average of 7 articles per year. There was no widely connected author cooperation network in this field, and most scholars were independent of each other and lack of cooperation and connection. The cooperative relationships among research institutions were not close, presenting an independent distribution status. Over time, the research focus had shifted from the biological characteristics of A. kakogawana to physical control and management. In conclusion, future investigations on A. kakogawana should prioritize interdisciplinary convergence, leverage existing scientific and technological resources, and intensify studies in transcriptomics, predictive habitat suitability assessments, and physicochemical control methodologies.
This study comprehensively reviews the recent research on bacterial degradation of pesticide residues both domestically and internationally, enumerates the common bacteria for degrading pesticide residues in soybeans, conducts an in-depth analysis of the pathways and mechanisms of bacterial degradation of common pesticide residues in soybeans, and deliberates on the impacts of pesticide structure, the intrinsic mechanism of bacteria, and environmental factors on the bacterial degradation of pesticide residues in soybeans. In light of the issues such as soil and crop pollution caused by excessive pesticide use, which adversely affect human health and the ecological environment, the degradation function of bacteria on pesticides can be utilized for improvement, thereby enhancing crop yield and facilitating sustainable agricultural development. It is proposed that the further exploration of bacterial species capable of degrading pesticide residues in soybeans and the strategy of combining bacterial strains in the future should be pursued, with the aim of enhancing soybean yield and quality, reducing the harm of pesticide residues to human health, and providing a reference for ecological protection.
In order to further understand the herbicide resistance of barnyard grass [Echinochloa crus-galli (L.) P. Beauv.] in Jiangsu rice field, the seeds of barnyard grass populations were collected from rice fields in Jiangsu Province from 2019 to 2022, and the resistance of barnyard grass species to metamifop, cyhalofop-butyl, penoxsulam and quinclorac was determined by stem and leaf spray method. The suspected resistant populations of 100 collected barnyard grass populations were screened by differential dose method, and then the resistance index of these suspected resistant populations to the corresponding herbicides was determined by the series concentration of different herbicides. The results showed that there were 10 populations with low resistance, 8 populations with medium resistance and 1 population with high resistance to metamifop; there were 5 populations with low and medium resistance to cyhalofop-butyl; there were 3, 9 and 1 with low, medium and high resistance to penoxsulam, respectively; there were 1, 7 and 1 with low, medium and high resistance to quinclorac, respectively. The tested barnyard grass populations in 13 prefectural level cities in Jiangsu Province, except Changzhou, all have resistant population distribution, and some populations show multiple resistances.
To investigate the antifungal activity of essential oils (EOs) derived from A. tatarinowii and A. argyi, as well as their principal components, we assessed the antifungal efficacy of both EOs against four pathogenic fungi using the Oxford Cup method. Additionally, EO constituents were analyzed through gas chromatography-mass spectrometry (GC-MS). Subsequently, the minimal inhibitory concentration (MIC) and fractional inhibitory concentration index (FICI) were determined through a 96-well plate assay. The results showed that both EOs at a concentration of 50 mg/mL exhibited significant inhibitory effects on Colletotrichum gloeosporioides, followed by Fusarium oxysporum and Fusarium solani. GC-MS analysis revealed that A. tatarinowii EO contained 34 compounds, with β-asarone and α-asarone identified as the primary constituents. In contrast, A. argyi EO comprised 98 compounds, among which caryophyllene, β-caryophyllene, eucalyptol, and myrtenal constituted a substantial proportion. Furthermore, the MIC of β-asarone and α-asarone were found to be comparable to that of hymexazol. When utilized in combination with hymexazol, the two EOs demonstrated an additive impact on Fusarium oxysporum in the pairwise combination experiment. Overall, the EOs and their main components from A. tatarinowii and A. argyi exhibited robust antifungal activity against four fungal pathogens, indicating potential for further research.
The aim of this study was to explore the sensitivity of black soldier fly larvae (Hermetia illucens) to imidacloprid, to understand the impact of pesticide residue on their growth, providing a theoretical basis for the large-scale rearing of black soldier flies. Using bioassay methods, we conducted imidacloprid toxicity tests on 5-day-old and 7-day-old black soldier fly larvae with four treatments of 0.1, 0.5, 1, and 2 mg/kg, and measured mortality rate and larval weight with DMSO and blank controls serving as references. The results showed that for 7-day-old larvae, the mortality rate after 7 days of exposure to concentrations ranging from 0.1 mg/kg to 2 mg/kg was between 3.3% and 17.3%. When the concentration was ≤0.5 mg/kg, imidacloprid significantly promoted the increase in the weight of black soldier flies. Under continuous exposure to feed containing imidacloprid, the treatment at 0.1 mg/kg resulted in a 16.4% increase in individual larval weight compared to the control group. After being switched to regular feed following 3 days of exposure to imidacloprid-containing feed, the individual larval weights in the 0.1 mg/kg and 0.5 mg/kg treatments were 26.2% and 21.4% higher than those in the control group, respectively. Low concentrations of imidacloprid have no obvious adverse effects on the growth of black soldier fly larvae and are able to promote an increase in their body weight, which provides a basis for further research into the stimulatory effects of black soldier flies.
In order to provide reference for rational fertilization and green disease prevention and control in flue-cured tobacco, the effects of boron and silicon nutrient elements on the diseases prevention and control and the physiological mechanism were discussed. The field experiment was conducted to study the effects of different boron and silicon application levels on the incidence of potato virus Y (PVY) disease and defense enzyme activity of flue-cured tobacco named ‘Yunyan 100’. The results showed that the application of boron and silicon reduced the incidence and disease index of PVY in flue-cured tobacco. Compared with the treatment of spraying water (CK), the incidence and disease index of PVY under 9.0 kg/hm2 boron+ 6.0 kg/hm2 silicon treatment decreased by 32.5% and 22%, respectively. Meanwhile, reasonable application of boron and silicon fertilizer significantly improved the defense enzymes activities of tobacco leaves, and the phenylalanine degradation enzyme activity and proline content were significantly increased by 121.4%-426.5% and 30.0%-74.3%, respectively. Correlation analysis showed that the incidence of PVY was significantly negatively correlated with proline content, while phenylalanine degradation enzyme activity was significantly positively correlated with proline content. The combined application of 9.0 kg/hm2 boron+ 6.0 kg/hm2 silicon could reduce the occurrence of diseases and induce the increase of defense enzyme activity.
Sugarcane pokkah boeng disease is a fungal disease caused by multiple species of Fusarium. In order to clarify the pathogen species of sugarcane pokkah boeng disease in Yunnan, thirty-three samples of sugarcane pokkah boeng disease were collected from Kaiyuan and Menglian in Yunnan, and strains FS1 and FS2 were isolated and purified, and their DNA was extracted; the primers of transcription elongation factor (EF-1α), tubulin gene (TUB2), polymerase gene (RPB2) were used for PCR amplification of the isolated strains. The result was that a clear and bright band consistent with the target band was obtained, and the products were sequenced and analyzed by BLAST on the NCBI website, the EF-1α, TUB2 and RPB2 sequences of strains FS1 and FS2 were compared with EF-1α (accession number: MK609907.1), TUB2 (accession number: MT011039.1) and RPB2 (accession number: MW238849.1) of Fusarium sacchari with 100% similarity and coverage. Phylogenetic trees of strains FS1 and FS2 were constructed by maximum likelihood method with MEGA6.0 software, and the results showed that FS1 and FS2 clustered on the same branch with F. sacchari. Therefore, based on the morphological characteristics of strains FS1 and FS2 and the results of molecular biological identification, the pathogen of sugarcane pokkah boeng disease was identified as F. sacchari. F. sacchari spores were inoculated with ‘Yunzhe 08-1609’, and the symptoms of leaf regression and leaf yellowing appeared on the 7th day of inoculation, the infected leaves were isolated and sequenced again. The sequence similarity and coverage between EF-1α of the isolated strain and EF-1α of F. sacchari (accession number: MK609907.1) were 100%. F. sacchari was shown to be the causal agent of sugarcane pokkah boeng disease in Kaiyuan and Menglian.
Plant Protection
