描述:In order to discover efficient, low toxicity and environmentally friendly pesticide lead compounds, the inhibitory effects of five sterol biosynthesis inhibitors (SBIs) antifungal drugs (econazole, fluconazole, voriconazole, ketoconazole and miconazole) against seven plant pathogens were determined by mycelial growth rate method. After the preliminarily screening, effective fungicides were further tested in greenhouse and in field. The results showed that voriconazole had the highest fungicidal activities against the seven plant pathogens, and its EC50 values were lower than 0.349 mg/L. Miconazole exhibited potent fungicidal activities against Fusahum graminearum, Alternaria kikuchiana, Fusarium oxysporum and Glomerella cingulata. Econazole showed strong fungicidal activities against A. kikuchiana and F. oxysporum, ketoconazole displayed excellent fungicidal activities against Magnaporthe oryzae. Both their EC50 value were higher than that of difenoconazole against the corresponding plant pathogens. In greenhouse, voriconazole and fluconazole showed excellent inhibitory effects against wheat powdery mildew with the control efficiencies of 98.26% and 89.11%, respectively, at the dosage of 37.5 mg/L, which were higher than that of the commercial fungicide triadimenol. At the dosage of 150 mg/L, econazole showed strong inhibitory effect against rice sheath blight with the control efficiency of 86.14%. In the field trial, the control efficiency of fluconazole against wheat stripe rust was 98.42%, and the control efficacy of econazole against rice sheath blight was 75.21% at the dose of 240 g a.i./hm2. Fluconazole, voriconazole and econazole exhibited potent fungicidal activities against the tested plant pathogens, which can be used as lead compounds for agricultural fungicides.
描述:In order to clarify the insecticide resistance status in the field populations of the small brown planthopper (Laodelphax striatellus (Fallén)) from Henan Province, the resistances to 12 commonly used insecticides in seven field populations of L. striatellus collected from Xinxiang, Puyang, Kaifeng, Zhumadian, and Xinyang in Henan Province of China during 2020 to 2021 were detected by rice seedling dipping method. The results showed that the field populations of L. striatellus have developed medium-level resistance to buprofezin (resistance ratio, RR=14.9-91.1). Furthermore, the field populations produced low to medium-level resistance to pymetrozine (RR=6.91-16.7) and chlorpyrifos (RR=8.48-70.0) and were susceptible to medium-level resistance to triazophos (RR=1.29-11.1). In addition, all field populations of L. striatellus were susceptible or low-level resistance to thiamethoxam (RR=0.95-5.19) and lambda-cyhalothrin (RR=3.31-7.24), and relatively susceptible to imidacloprid (RR=0.89-3.92), acetamiprid (RR=1.11-2.33), nitenpyram (RR=0.16-0.64), dinotefuran (RR=1.87- 3.86), isoprocarb (RR=0.47-1.37) and flonicamid (RR=1.63-4.33), respectively. The results shed light on the sustainable control of L. striatellus field population and scientific use of insecticides in Henan Province.
描述:Flupyradifurone is a new neonicotinoid insecticide developed by Bayer CropScience. In order to explore the application prospects of flupyradifurone on rice planthopper, the resistance of ten field populations of Nilaparvata lugens from seven provinces in China and eight field populations of Sogatella furcifera from five provinces in China to flupyradifurone were evaluated using the riceseedling dip method. The results showed that the populations of N. lugens in those ten areas showed low to moderate resistance [resistance ratio (RR)=6.1−17.4], among which the populations from Nanchang in Jiangxi, Xinyang in Henan, Liuan in Anhui, and Hangzhou in Zhejiang exhibited moderate resistance (RR=10.1−17.4). In contrast, all field populations of S. furcifera were relatively sensitive to flupyradifurone (RR=1.1−3.6) except the population (RR=6.3) in Xiaogan. This study investigated the cuRRent resistance status of field populations of N. lugens and S. furcifera to flupyradifurone, and provids a theoretical basis for the scientific application of flupyradifurone in the control of rice planthopper.
描述:Penoxsulam is a new acetolactate synthase inhibitor (ALS) herbicide developed by Dow AgroSciences. In order to explore the sensitivity of Echinochloa spp. to penoxsulam on rice field, whole-plant bioassay experiments were conducted to evaluate the resistance level of 70 field populations of Echinochloa spp. from main rice production in seven provinces of China. The results showed that 50.0% of the 70 populations had evolved high resistance, 47.1% of the populations was moderate resistance, and only 2.9% of the populations exhibited low resistance. None populations were sensitive to penoxsulam. More than 60% of the populations had evolved high resistance from Hubei, Anhui, Ningxia and Heilongjiang Province. The populations of high level resistance was more than 25% in other three province. More than 60% of the population with moderate level resistance were from Hunan, Jiangxi and Jiangsu Province, and the populations of 20.0%-40.0% were also with moderate level resistance in others 4 provinces. The 10.0% and 12.5% of population were with low level resistance in Hubei and Heilongjiang Province, while other 5 provinces had no low level resistant populations. This work investigated the evaluation and monitoring of the field resistance of populations of Echinochloa spp. to penoxsulam, which provided a theoretical basis for the scientific application of penoxsulam to control Echinochloa spp. in the main rice cultivation area.
描述:On the basis of briefly describing the research progress of humic acid in agriculture in recent years and the preparation principle of humic acid fertilizer, the research progress of field trials of humic acid green low ・ carb on fertilizer is summarized ・ Introduced that humic acid has greatly improved the utilization rate of chemical fertilizers, that is, reducing the loss of fertilizer nutrients and promoting the absorption of nutrients・ The rational application of different types of humic acid fertilizers is conducive to impro・ ving crop yield and quality, for example, humic acid phosphate fertilizer treatment increases corn grain yield by 4.5% to 13.6%; the addition of humate ammonium can increase oil sunflower yield by 23・ 98%; the application of humic acid compound fertilizer increased tomato yield by 16. 4% and cucumber yield by 10. 9%; the add让ion of active humic acid compound fertilizer increased the soluble sugar content of sweet potato by 20. 45% and the soluble protein content by 41. 86%, so the economic benefit was also improved.
描述:To study the new materials for the control of Nilaparvata lugens, sodium alginate and peptone were used as water phase, rosin + sodium alginate film was prepared by adding oil phase composed of rape oil and rosin, and optimizing the ratio of oil phase to water phase. The physicochemical properties and performance indexes such as pH value, viscosity, solid content, film formation time and resistance to rain water erosion were determined, and the indoor inhibition activity and field control efficacy of rosin + sodium alginate film on Nilaparvata lugens were determined by rice straw spray method. The results showed that when the mass fraction of sodium alginate, peptone, rosin and rapeseed oil was 3%, 8%, 12.5% and 10%, respectively, the drawing degree, viscosity and ductility of rosin + sodium alginate film reached the optimal value, showing weak acidity, the pH value was between 6.34 and 6.91, the viscosity was 108 -114 Pa.s, and the solid content was 38.62%. Indoor inhibition activity showed that after being treated with 50 times diluted film for 3 days, the body weight of Nilaparvata lugens decreased significantly, the weight loss rate was as high as 92.78%, and the corrected mortality rate was only 20%. After being treated with 100 times diluted film for 7 d, the corrected mortality of Nilaparvata lugens was 59.26%. The results of field control experiment showed that the control efficacy of 50 times diluted film on Nilaparvata lugens was similar to that of 20% isoprocarb EC diluted 1 500 times, and the control efficacy on Nilaparvata lugens after 7 days were 64.21% and 64.04%, respectively. This study shows that rosin + sodium alginate film has a good control efficacy on Nilaparvata lugens and has potential application value, which provides a new idea for the control of diseases and insect pests in the field.
描述:In order to determine the best fertilization amount and fertilization formula of Momordica charantia in Haikou city, the “2+X” field experiment of fertilization effect was carried out on the laterite soil of Dongshan Town, Haikou City in 2019. The results showed that the yield increase effect was obvious and the yield increase rate up to 12.7%. The yield of the optimized fertilization area was 1628.8 kg/667m2, which was 183.3 kg/667m2 higher than that of the conventional fertilization area. The order of the yield from high to low was optimized fertilization area > conventional fertilization area > 130% optimized nitrogen area > 70% optimized nitrogen area > no nitrogen area. The quadratic equation of nitrogen application rate and yield was established by Excel. The optimal N application rate was 15.91 kg/667m2, and the best economic yield was 1532.28 kg/667m2. The results showed that the optimized fertilization scheme was feasible in summer cultivation of M. charantia.
描述:In order to identify the pathogenicspecies of edible roses leaf spot diseases in Guizhou Botanical Garden andHuishui County, Guizhou Province, China, the samples of leaf spot diseases werecollected. By using single spore isolation method and pathogenicitydetermination, combined with morphological analysis combined with ITS, GADPH, ACT, CHS-1 gens, the taxonomic statusof its pathogenic bacteria was determined. On this basis, through platedilution and plate confrontation method, combined with physiological andbiochemical experiments and 16SrRNA and gyrA gens, screening and identification ofantagonistic bacteria on edible rose, then combined with the mycelial growthrate method to screen the chemical agents with better control effect on roseleaf spot, commercial microbial preparation Lvkangwei, Myclobutanil 12% EC + Dithane65% WP, Oxadixyl mancozeb 64% WP and GUHS97 were used for field control effectexperiments. The results showed that: 1) The pathogen causing leaf black spotwas confirmed to be Marssinina rosae, and the pathogen causinganthracnose was confirmed to be Colletotrichum boninense; 2) In thisstudy, a strain GUHS97 was screened from the healthy rose leaves in the heavilyinfected field and was identified as Bacillus amyloliquefaciens; 3)Indoor toxicity test showed that 9 fungicides had a certain inhibitory effecton C. boninense. Theinhibition effects of zhongshengmycin 3% WP, difenoconazole 10% WDG,pyraclostrobin 25% SC and metalaxyl∙fludioxonil 62.5% SC were higher with theEC50 values of 0.8440 mg∙L−1、1.3854 mg∙L−1、1.8667 mg∙L−1 and 3.5945 mg∙L−1,respectively, followed by ningnanmycin 8% AS and bromothalonil 25% EC, with theEC50 values of 18.9624 mg∙L−1 and 25.4813 mg∙L−1,respectively. Pyraclostrobin 25% SC and bromothalonil 25% EC at the mixtureratio of 1:7, 1:8 and 1:10 showed obvious synergistic effect; 4) Furthermore,GUHS97 exhibited 59.12% control over leaf spot in field experiments and wasmore effective than other treatments including fungicide application. Overall,these results provide a scientific basis for the identification of edible roseleaf diseases and their control.