Journal of Phytopathology and Pest Management (Al-Azhar University)
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Biological activity of certain natural products against Varroa destructor (Acari:Varroidae) and their selectivity against Apis mellifera (Hymenoptera: Apidae)
Get PDFThe ectoparasitic mite, Varroa destructor (Anderson and Trueman) is considered one of the most serious pests of beehives, causing tremendous damage to honey bees, Apis mellifera L. and great economic loses to the beekeeping industry. Efficacy of six natural plant products (Pomegranate, Garlic, Marjoram, Harmal, Black cumin, Ambrosia) was evaluated against varroa mite and Apis mellifera 2018 season. The tested materials were applied in different methods of application: spray method, dusting and fumigation methods. Results showed that fumigation was more efficient than spraying while treatment as dusting of the powder of these materials recorded the lowest efficacy. Treatment with Pomegranate fumigation resulted the highest efficacy against Varroa mite followed by Garlic and Marjoram (94.6, 89.8 and 89.8 % reduction for adult infestation) and 85.6, 86.1 and 82.4% for brood infestation. Spraying with extract of Harmal showed the highest efficacy against Varroa mite (91.88%) followed by Pomegranate (91.06%), Black cumin 89.11% and Garlic 88.82 % reduction for adult infestation. Among the tested plant products used as dusting the infested bee colonies, powder of Marjoram, Harmal, Black cumin and Garlic recorded the highest efficacy against Varroa mite infested adult (94.67, 94.67, 94.42 and 93.15 Reduction %). All products haven’t any effect against Apis mellifera and colonies treated with these materials gave a significant high honey productivity compared with control. Results indicated that using plant products in controlling Varroa mite through IPM program seem to be the ideal way for controlling this mite; hence these materials are available, safety to environment, selective to bees, easy in application and economically cheap
Effect of chemical inducers on plant resistance to Meloidogyne spp in tomato plants under greenhouse conditions
Get PDFThe effect of certain chemical inducers such as jasmonic acid (JA), salicylic acid (SA),  B-amino-n-butyric acid (BABA), acibenzolar-s-methyl (Actigard) and Potassium chloride (KCl) with concentration of 100 ppm on tomato plant resistance to Meloidogyne spp. was studied under greenhouse conditions. The experiment was conducted by spraying all chemical inducers on tomato plants (20 ml / plant) growing in pots 30 cm - diam. Two days after application 1000 eggs of nematode were inoculated on the root of plant roots. Nematodes and plant parameters were recorded two months post inoculation. Jasmonic acid (JA), acibenzolar-s-methyl (Actigard), salicylic acid (SA) and B-amino-n- butyric acid (BABA) reduced the numbers of eggs with 72.27, 54.9, 82.94 and 78.4%, respectively compared to inoculated untreated plants. Potassium chloride (KCl) had no significant effect (4.8%) in reduction % of total eggs numbers. Also, the compounds jasmonic acid (JA), SA, Actigard and (BABA) decreased number of root galls. The reduction values were 52.58, 41.43, 42.85 and 54.73%, respectively as compared to the untreated control inoculated. Results concluded that foliar application of Jasmonic acid (JA), (Actigard) and B- aminobutric acid (BABA) activate resistance in tomato plants to Meloidogyne spp. Therefore, they may be considered as good elements, especially in successful release of some schemes of integrated management of nematodes
Impact of weather factors and certain insecticides on the population density of cotton whitefly, Bemisia tabaci (Genn.) (Homoptera: Aleyrodidae)
Get PDFField experiments were conducted to study the impact of weather factors and certain insecticides on the population of cotton whitefly, Bemisia tabaci (Genn.) (Homoptera: Aleyrodidae) under cotton field conditions during 2013 and 2014 seasons. The cotton whitefly population started with average number of 0.83 and 0.33 insects/ plant in the 4th and the 2nd weeks of April and progressively increased throughout May and June during both seasons. The peak population of cotton whitefly reached 3.12 and 2.53 insects/ plant in average the 4th week of May and the 1st week of June. The results revealed that the relative humidity showed high significant negative correlation with the whitefly population, whereas, the maximum and minimum temperatures showed non-significant positive correlation. The foliar application of selected insecticides on the cotton whitefly under field conditions showed that all treatments caused significant reduction to whitefly population at 1, 7, 15 and 21 days after treatment as compared to the control. Thiamethoxam, malathion, and pirimicarb showed non- significant differences between them; and gave high efficiency reduction in whitefly population, as compared to acetamiprid, imidacloprid and dinotefuran. Thiamethoxam induced a maximum reduction in whitefly population with an average reduction of 80.72%. Malathion and pirimicarb showed similar effect with an average reduction of 50.23 to 46.82%. In contrast acetamiprid and dinotefuran showed intermediate results and were statistically similar in their efficiency with an average reduction of 20.08 and 38.88% during 2013 season. During 2014 season, imidacloprid and thiamethoxam caused the highest population reduction with an average 70.43 and 60.63%, whereas, acetamiprid and dinotefuran showed intermediate effect and were statistically similar in their efficiency with an average reduction of 44.78 and 45.48%. Results of this study indicated that the foliar application of neonicotinoid insecticides were highly effective against cotton whitefly, followed by pirimicarb and malathion in cotton fields
Efficacy of certain fungicide alternatives for controlling sugar beet powdery mildew
Get PDFIn order to study the importance of selection of suitable sugar beet cultivars for growing in Upper Egypt, ten sugar beet cultivars were tested for their susceptibility to Erysiphe betae, the causal fungus of powdery mildew Among them, Sirona (453 AUPMPC; the Area Under Powdery Mildew Progress Curve) was significantly the most resistant cultivar to powdery mildew disease while, FD.0807 (1484 AUPMPC) was the most susceptible one. Field experiment was conducted to evaluate five plant extracts, three chemical antioxidants and four microelement compounds for their efficacy in controlling E. betae. Results confirmed that all tested treatments caused significant reduction in AUPMPC values when sugar beet plants were sprayed with these tested compounds and the increasing of the concentration increased resistance of sugar beet plants against powdery mildew disease. Among the tested plant extracts, the highest protection (69.9% & 66.9%) on both cultivars Sirona and FD.0807 respectively was achieved by 30% of basil extract followed by 30% of garlic extract (53% & 60.4%) while, the least protection (33.9% & 52.8%) was obtained by 10% of black cumin seed extract. Concerning the tested inducers, the highest protection (56.7% & 70.6%) was achieved by 300 ppm of salicylic acid followed by 200 ppm of salicylic acid (51% & 63.7%), while, 100 ppm of ascorbic acid gave the least protection (2.2% & 34.1%). On the other hand, 40 ppm of cupric sulfate achieved the best percentage of protection (72% &78.7%) whereas, the least protection (8%) was obtained by 10 ppm of zinc sulfate on Sirona cultivar and the least protection (43.6%) was obtained by 10 ppm of magnesium sulfate on FD.0807 cultivar. The best comparative treatment was the tested fungicide Bellis® 38% WG (89.5% &90% protection). Usage of plant extracts, antioxidants and micro elements are well recommended as fungicide alternatives for controlling the disease in parallel with their safe influence on human health due to reduction of the accumulated chemical hazards in the plant tissues
Monitoring the fluctuations of certain piercin sucking pests infesting cucumber plants at Sohag governorate, Egypt
Get PDFThe population fluctuations of five piercingsucking pests; melon aphid, Aphis gossypii (Glover); cotton whitefly, Bemisia tabaci (Genn.); potato leafhopper, Empoasca decipiens (Paoli); onion thrips, Thrips tabaci (Lind.) and two-spotted spider mite, Tetranychus urticae (Koch) were investigated on Hail cucumber variety during autumn and spring plantation from 2014 to 2016 seasons. As a result in autumn plantation, population of aphid and whitefly had one peak during 2014 and 2015 seasons , meanwhile, thrips population recorded three peaks in the same seasons. Otherwise, in spring plantationin 2015 and 2016 seasons, the populations of aphid and thrips recorded three peaks and one peak, respectively. In the meantime, the whitefly’s population showed three and two peaks, respectively. Leafhopper was the lowest sucking insect attacked cucumber during the two plantations throughout 2014, 2015 and 2016 growing seasons. The two-spotted spider mite only observed on spring plantation 2015 and 2016 and recorded one peak through the growing seasons. It could be concluded that planting date is effective on population fluctuations of piercing sucking pest and can be avoided by planting in late planting date
Antifungal activity of different size controlled stable silver nanoparticles biosynthesized by the endophytic fungus Aspergillus terreus
Get PDFSilver nanoparticles (AgNPs) synthesized by using the aqueous extract of the endophytic fungus Aspergillus terreus F37 (KX024595) as reducing agent is reported here. The reaction medium employed in the synthesis process was optimized under a narrow range of pH and temperature to attain better yield, controlled size, and more stable of AgNPs. Further, the microbially synthesized AgNPs were studied through UV-vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) spectroscopy analyses. The obtained results indicated the formation of high crystalline spherical AgNPs with an average diameter of 45.2±0.5 nm at room temperature (22 ºC). Quantitative analyses indicated that reduction of the Ag+ precursor was promoted at elevated pH due to increased activity of biomolecules in the fungal extract. As a result, the size of the AgNPs decreased with increased pH of the reactions. The optimum conditions for maximum production of small control sized AgNPs (12± 0.5 nm) were pH (10) and temperature (100 ºC). The outcomes of the antifungal activity of different controlled sized AgNPs showed their efficiently to inhibit the mycelial growth of the pathogenic fungus Alternaria solani, the causal agent of tomato early blight disease and reduced their viability in a pH and temperature dependent manner. These findings revealed that the fine tuning of the reaction synthesis parameters, will increase the chance to obtain desired well shaped and small sized AgNPs with potent antifungal activities, may have important applications as new bio-fungicides in controlling various plant diseases caused by fungi
Application of date palm leaves compost and plant growth promoting rhizobacteria for controlling faba bean root rot disease in New Valley, Egypt
Get PDFThis study was designed to investigate the effect of date palm leaves compost (DPLC) individually and/or in combined with plant growth promoting rhizobacteria (PGPR) for controlling faba bean root rot disease caused by Rhizoctonia solani and Fusarium solani under greenhouse and field conditions. The obtained data indicate that DPLC at different concentrations significantly decreased root rot incidence either under artificial infection in pot or natural infection in field as well as increased growth and yield parameters during growing season 2013-2014. Date palm leaves compost at 8 ton/ feddan (feddan = 1.038 acres) recorded the highest protection against root rot disease and gave the highest increased of plant growth and yield parameters. On the other hand, PGPR viz. Bacillus megaterium, B. cereus and Pseudomonas fluorescens individually or mixed significantly decreased root rot incidence under greenhouse and field conditions. The mixed of PGPR strains significantly suppressed the diseases more than used alone of them. Plant growth promoting rhizobacteria increased efficacy of DPLC for controlling root rot disease in faba bean more than the applied of DPLC or PGPR alone under greenhouse and field conditions during both tested seasons as well as increased of nodulations, growth and yield parameters. The application mixed of PGPR strains and DPLC at 8 ton/feddan recorded the highest reduction of root rot incidence and increase of nodulations, growth and yield parameters during both growing seasons. Â
Biological control of damping-off and root rot of fenugreek
Get PDFEight Trichoderma and nine bacterial isolates which isolated from rhizospher and nodules of fenugreek plants. Also four isolates of rhizobacteria (PGPR) namely Basillus subtilis (B.s), Basillus polymyxa (B.p), Basillus megaterium (B.m) and Pseudomonas fluorescens (P.f ) were tested in vitro for thir ability against Fusarium solani, Rhizoctonia solani and Macrophomina phaseolina which caused damping-off and root rot of fenugreek plants.The results showed that Trichoderma isolate number (T3) gave the highest reduction on maycelial growth of three pathogenic fungi followed by isolate number (T2) which adentified as Trichoderma harzianum and Trichoderma hamatum, respectively. Pseudomonas fluorescens followed by Basillus polymyxa , Rhizobium sp. isolate (Rh3), Basillus subtilis and Basillus megaterium gave highly antagonistic effect was clear against the tested fungi as will as used in greenhous experiment. A pot experiment was carried out under greenhouse conditions. Results showed that Treated seed of fenugreek caltivar (Giza 2 cv.) with Rhizobacteria and or treated soil with T. harzianum and T. hamatum reduced pre and post damping-off and root rot diseases of fenugreek and increased survival plant compared with the control. Trichoderma harzianum followed by Rhizobium sp. isolate (Rh3) gave the best reduction in these respects
Laboratory host selection and development of immature Drosophila suzukii (Diptera: Drosophilidae) on fruits and artificial diets
Get PDFThe spotted-wing drosophila (SWD), Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), is an important pest of thin-skinned fruits including blueberries, raspberries, strawberries, and cherry. In this study, six fruit hosts were chosen (raspberries, blackberries, strawberries, blueberries, green grapes and red grapes) and used as fruit and artificial diets to evaluate oviposition selection by D. suzukii females in free choice assays and no-choice assays. Also, development and performance of progeny until adult emergence was determined. Overall, D. suzukii females preferred to lay eggs on raspberries rather than green grapes in both tested fruit and artificial diet. Also, larvae that developed in raspberries developed 2-4 days faster than those in red grapes and green grapes, in both no-choice and choice assays for tested fruit and artificial diets. No significant differences were found among tested fruits in both free choice assays for pupal duration. Furthermore, adults complete of the development time 3 days earlier in raspberries rather than green grapes in both choice and no-choice assays for both tested fruit and artificial diets. Results also showed that strawberries, raspberries and blackberries had similar and high proportion of pupal survivorship than green grapes in choice and no-choice assays on tested fruits. Proportion of adults was greater in raspberries than green grapes in both fruits and artificial diets. No significant differences were found among fruits and among artificial diets in proportion of males and females in choice and no-choice assays. It could be concluded that raspberries were more favorable and comfortable host for D. suzukii oviposition and progeny development and performance
Isoquercitrin and Baccharis spicata (Lam.) Baillon (Asteraceae) inflorescence extract as potential biocontrol agents against coleopteran rice weevil
Get PDFSitophilus oryzae L. causes significant damage during storage of agricultural products. The use of synthetic pesticides renders effective results in the short term, but has also caused pest resistance and environmental pollution. Integrated pest management programs promote the development of new pesticides from natural resources, such as those derived from plants. The objective of this work was to evaluate the insecticide activity of Baccharis spicata (Lam.) Baillon extracts and their major phenolic compounds as reduced-risk alternative substances against coleopteran rice weevil. The inflorescence methanol extract was toxic against rice weevil. Three phenolic compounds were identified in this extract by HPLC UV/DAD. Isoquercitrin showed a good toxic activity againt S. oryzae. The inflorescence methanol extract and isoquercitrin inhibited the cellulase activity on cellulose agar plate assay method, with these results and additional studies it will be possible to elucidate a mechanism of action. These findings will provide opportunities and challenges to search new botanical insecticides to control pest in stored grains