Journal of Phytopathology and Pest Management (Al-Azhar University)
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Reaction of certain tomato (Lycopersicon esculentum L.) cultivars to damping-off disease
Get PDFFive fungal isolates were isolated from infected tomato seedlings showing dampingoff which collected from several tomato nurseries of Assiut and New Valley Governorates, Egypt. These isolates were Rhizoctonia solani Kühn, Fusarium oxysporum f.sp. lycopersici Schlechtendahl, Fusarium semitectum Berk. & Rav., Setosphaeria rostrata Leonard and Alternaria alternata (Fries) Keisler. Also, six tomato cultivars and hybred, namely Castle Rock, Super marmande, Super Strain B, Enz 10F1, 0240F1 and Dream Hybrid were evaluated for their susceptibility to damping-off disease. All tested tomato cultivars were susceptible to damping-off disease, Castle Rock cv. showed the highest percentage of pre and post emergence damping-off disease severity followed by Super marmande and Super Strain B cvs. then Dream Hybrid and Enz 10F1 Hybrid. 0240 F1 Hybrid gave the lowest ones. Each tested tomato cultivars showed higher amount of total phenolic and total protein content in infected plants with the tested pathogenic fungal isolates than uninfected plants (control). The highest amount of total phenol and total protein was found in infected plant of tomato Enz 10F1cv. followed by 0240F1cv. while the lowest amount of total phenol and total protein were found in infected plant of castel Roke cv. then super marmande cv
Evaluation of some rodenticides and traps for controlling the Norway rat, Rattus norvegicus Berk., in poultry farms at Giza governorate, Egypt
Get PDFDifferent control methods (i.e. Zinc Phosphide 2% and 3%; Super Caid 0.005% and Live traps) against Rattus norvegicus Berk., evaluated by food consumption method in poultry farm (Bortos village -El Warraq area) at Giza Governorate during August and September 2016. The highest poison baits daily consumption were recorded when used Super Caid 0.005% (52.53 and 40.39 g/night) followed by Zinc phosphide 2% (0.23 and 1.93 g/night) and Zinc phosphide 3% (0.09 and 0.26 g/night) ) inside and outside building. The Super Caid 0.005% treatment gave high mortality numbers against R. norvegicus inside and outside the building. The pest mortality records increased from 3rd day until 6th day of treatment. Mortality records during treatment (inside building) were 7, 6, 6, 4 and 2 individuals in 7, 6, 5, 3 and 4 days, respectively. While mortality records during treatment (outside building) were 11 and 8 individuals in 6 and 7 days, respectively. The highest reduction of R. norvegicus when used Super Caid 0.005% were 79.98 and 46.04 % followed by Zinc phosphide 2% (51.85 and 36.51 %) and Zinc phosphide 3% (67.6 and 32.15 %) ) inside and outside building. While, when used live trap bait items inside building with attractants such as: tomato, lanshon, cucumber and falfel the reduction percentages in rat individuals were 78.41, 61.32, 92.43 and -65.1%, respectively. The analysis of variance and treatment means were significantly different between plain bait daily consumption pre-treatment of all transactions (Super Caid 0.005%, Zinc phosphide 2% and 3% inside and outside building and also live trap bait items)
On-farm leaf curl disease management of chilli (Capsicum annuum L.)
Get PDFChilli is an important vegetable and condiment used widely in Indian food preparations. Chilli leaf curl caused by chilli leaf curl virus transmitted by whiteflies is one of the major limiting factors in cultivation of the crop. Two different integrated disease management practices were compared with regular farmer conventional practices (sole reliance upon chemicals). Field experiments were conducted for the disease management of leaf curl in chilli including seed treatment with imidacloprid 17.8% at the rate 3 g kg-1 of seed, seedling treatment with imidacloprid 17.8% at the rate 0.3 ml l-1 of water for 30 minutes and destruction of infested plants and foliar sprays of imidacloprid at the rate 0.3 ml l-1 of water during two successive years i.e. 2012 and 2013. There was 41 to 74% protection, against disease incidence, observed over conventional practices based solely on use of chemicals. However, IDM practices fairly restricted the leaf curl index from 2.2 to 0.8 and an increased advantage 5.78 to 18.34% yield over farmers’ practice. Number of foliar sprays of insecticides was also reduced to a great extent from 10 to 4. Besides, highest benefit cost (B:C) ratio 3.66 to 3.74 was recorded under integrated disease management practices against 3.04 to 3.09 under farmers’ practice.Â
Evaluation of some fungitoxicants for controlling tomato early blight disease
Get PDFThree different fungitoxicants, i.e., Trichoderma harzianum, Bacillus subtilis and Roxil Plus WP50 fungicide, were investigated against tomato early blight disease caused by Alternaria solani fungus in vitro and in vivo. By using dual culture technique, the highest reduction percentage of A. solani growth was recorded with B. subtilis followed by Roxil treatments, while Roxil followed by T. harzianum treatments recorded highest reduction percentage of sporulation. Meanwhile, by using poisoned food technique the highest reduction percentage of A. solani growth was recorded with Roxil followed by B. subtilis treatments, while B. subtilis recorded highest reduction percentage of sporulation. Three fungitoxicants were investigated as foliar spray for their abilities for controlling early blight disease on naturally infected tomato plants under open field conditions. Roxil fungicide followed by B. subtilis treatments caused the highest significant reduction in disease incidence and disease severity percentage during the two successive growing seasons 2013/14 and 2014/15. Concerning to yield parameters, Roxil and T. harzianum treatments were significantly increased total yield weight and average weight of tomato fruit. Moreover, all tested treatments increased clearly total phenol content, peroxidase, polyphenoloxidase and chitinase activities, as well as, vitamince C contents as compared to control treatment
Influence of certain eco-physiological factors on predation efficiency of Gambusia affinis (Baird and Girard) on Culicine mosquito larvae
Get PDFThe effect of light, water temperature and pH on the predation efficiency of Gambusia affinis (Baird and Girard) on Culex pipiens L. (Diptera: Culicidae) mosquito larvae was studied under laboratory conditions. Significant predation rate was recorded in light than in darkness for both male and females, despite fish size. The temperature 30°C showed the most favorable degree for predation compared with 25 and 35°C. Also, the predatory efficiency of G. affinis on mosquito larvae was significant at pH 9 than on 7 and 12. The present results should be taken in consideration in biological control of mosquito larvae
Laboratory and field efficacy of certain fungicides against gummosis of citrus disease in Tunisia
Get PDFGummosis, caused by Oomycota, is a devastating disease for citrus production in Tunisia. Due to the limited strategies available for this disease management, the laboratory and field applications of some commercially fungicides were conducted.Using the mycelia growrh ratios, from the tested fungicides, metalaxyl, cymoxanil, propamocarb, and mancozeb are the most efficient fungicides ,with 94.75%, 94.62%, 91.13%, and 90.75% in reducing the mycelial growth of Oomycota pathogens, respectively. While azoxystrobin and fosetyl-Al have generated a moderate growth reduction, with 81.25% and 74.25%, respectively. The lowest fungicides effect was obtained with trifloxystrobin, thiophanate-methyl and chlorothalonil, with 38.87%, 36.25%, and 15.25%. In field experiments, metalaxyl and fosetyl-Al were applied as paint trunk and as foliar spray, against infection by Phytophthora nicotianae. The results showed that the metalaxyl was more efficiency in reducing the length lesion caused by P. nicotianae, than the fosetyl-Al. Furthermore, paint treatments revealed to be more effective in reducing lesion expansion than foliar spray treatments both in curative and in residual activity. Moreover, citrus clementine variety is the most susceptible to P. nicotianae infection, while the most tolerant is tangerine variety.Â
Biological control of fungal wilt of tomato by plant growth promoting rhizobacteria and Trichoderma harzianum
Get PDFThe efficacy of plant growth promoting bacteria i.e. (Bacillus subtilis, Bacillus polymyxa, Bacillus megaterium, Pseudomonas fluorescence, Azotobacter sp., Azospirillum sp. and the fungus Trichoderma harzianum were studied as bioagents for controlling Fusarium oxysporum f.sp. lycopersici and Verticillium dahliae the causing wilt disease of tomato. The results of antagonistic activity of the PGP bacteria against Fusarium oxysporum f.sp. lycopersici and Verticillium dahliae in vitro  exhibited higher variation in their abilities to reducing the growth rate of the pathogen and increasing the percentage of pathogen inhibition as compared with the control treatment. Also, the obtained results showed that Trichoderma harzianum I, Pseudomonas fluorescens and Bacillus subtilis gave the best results for controlling Verticillium dahliae and Fusarium oxysporum f.sp. lycopersici. Under greenhouse conditions, the inoculated tomato seedling with a mixture of (Azotobacter sp+ Azospirillum sp.+ B. megaterium var. phosphaticum + B. subtilis+ B. polymyxa +Pseudomonas fluorescence+ T. harzianum I showed the least percentage of infection as compared with the bioagent treatments individually.Â
The occurrence of apricot bacterial canker disease caused by Pseudomonas syringae pv. syringae in Saudi Arabia and factors affecting disease development
Get PDFBacterial canker of apricot (Prunus armeniaca L) has become a serious disease in many countries, including Saudi Arabia, but the causal agent in Saudi Arabia has not yet been sufficiently characterized. In the present study, bacterial strains were isolated from apricot fruits, showing bacterial canker symptoms, grown in Abha region, Saudi Arabia. Based on physiological, biochemical, and genetic characteristics, the pure bacterial cultures were identified as Pseudomonas syringae pv. syringae (Pss). The pathogenicity assays on P. armeniaca cv canino fruits developed canker symptoms that were similar to those observed on apricot fruits in Abha region. The 16S rDNA sequences were 99.9% identical to those of the Pss strains available in GenBank. Analysis of variances indicated that the temperature and inoculum concentration (P < 0.0002) significantly affect disease severity
Occurrence of Fusarium wilt on summer squash caused by Fusarium oxysporum in Assiut, Egypt
Get PDFFusarium wilt of summer squash was first noticed in April and May 2012 in Assiut- Egypt. Symptoms included wilting of the foliage, withering of older leaves and eventually died during growth. The causal pathogen was identified as Fusarium oxysporum Schlecht. Pathogenicity tests of the obtained isolates were demonstrated via artificial inoculation, and it satisfied Koch's postulates. Because summer squash is of great economic importance in Egypt, biological control of the disease was carried out by the biocontrol agent Gliocladium catenulatum. The effect of G. catenulatum against F. oxysporum was investigated in vitro and tested on summer squash plants under greenhouse conditions. G. catenulatum isolates were able to inhibit the growth of F. oxysporum in dual culture. In greenhouse, application of G. catenulatum was tested at three different times. All treatments were effective to reduce disease severity. Application of G. catenulatum preceding the inoculation with F. oxysporum reduced significantly the incidence of Fusarium wilt compared to plants inoculated with F. oxysporum alone. The disease suppression was occurred when G. catenulatum applied five days before infested soil by F. oxysporum. Obtained results indicate that G. catenulatum is very effective biocontrol agents offer potential benefit in Fusarium wilt of squash, and should be harnessed for further biocontrol applications. To our knowledge, this is the first report of F. oxysporum causing wilt of summer squash in Assiut, Egypt
Detection of viable Xanthomonas citri pv. citri, the causal agent of citrus canker in commercial fruits by isolation and PCR-based methods
Get PDFXanthomonas citri pv. citri (Xcc), the causal agent of citrus canker, is a quarantine pest in many citrus-growing countries and is strictly regulated by the international phytosanitary programs. Citrus fruits with canker-like symptoms imported from India and Pakistan were collected from Riyadh supermarkets, Saudi Arabia. Different diagnostic detection methods, including culturing, direct PCR, BIO-PCR and bioassays were applied on the sampled citrus fruits. The direct culturing on KCB medium succeeded in detecting living cells of Xcc in 49 out of the 217 lesions observed on the sampled citrus fruits. However, only 5.55 and 24.77% from lesion washates of Pakistani and Indian fruits, respectively, caused citrus canker lesions on the inoculated grapefruit and/or Mexican lime leaves compared with 100% from pure cultures. The application of 3 diagnostic primer sets (2/3, J-pth1/2 and Xac01/Xac02) confirmed the bacterial etiology of 83 out of the 217 lesions. Based on BIO-PCR assay, 57 out of 217 lesions were Xcc positive. Significant differences were observed between direct PCR and BIO-PCR results. Overall, this study shows that chemical and physical fruit treatments prior citrus fruit exportation is not 100% efficient in killing all Xcc populations. Moreover, it is essential to integrate different diagnostic techniques to improve the accuracy of detection of quarantine bacteria and consequently prevent their introduction and dissemination