Communications in agricultural and applied biological sciences最新文献

The increasing pressure of oilseed rape pests emphasized the need to improve the insecticide portfolio, i.e. register new active ingredients with new insecticide mode of action. The tested seed treatment formulation applied at 32; 40 and 50 UAT rate of containing cyantraniliprole as active substance. 40 UAT rate gives acceptable control of the Cabbage root fly in each trial. Despite the long lasting flight and egg laying period of cabbage root fly, the standard control products and also this product give 50-65% efficacy. It is enough to reduce damage of the Cabbage root fly and prevent economical damage in oilseed rape.

Mycosphaerella graminicola is a hemibiotrophic fungus that causes Septoria tritici blotch (STB), one of the most serious foliar diseases of wheat. STB can occur with a wide range of disease levels on the host, which depend not only on the pathogenicity of fungal strains, but also on the resistance of host cultivars. Here, we investigated the association between the disease level and fungal cell-wall degrading enzyme and protease activities in three wheat cultivars differing in their resistance levels against M. graminicola. The experiments were carried out in the greenhouse using artificial inoculations with the M. graminicola strain T01193. Disease symptoms scored at 21-day post-inoculation (dpi) were significantly higher on the susceptible and moderately resistant cultivars, Alixan and Premio (48% and 42% of diseased leaf area, respectively), than in the resistant one, Altigo (28% of diseased leaf area). Regarding sporulation, the rate of pycnidial density was significantly higher on Alixan (2.9) compared to Premio and Altigo (1.1 and 1.0, respectively). Further biochemical investigations revealed, by 17 dpi, significant fungal beta-1,4-endoxylanase, beta-1,4-endoglucanase and protease activities, whose amounts increased according to the pycnidial density recorded on the infected leaves. At 21 dpi, the amounts of these activities were significantly higher on Alixan compared to Premio and Altigo (0.36 U/mg, 0.63 U/mg and 2.70 mU/mg total proteins on Alixan, 0.09 U/mg, 0.19 U/mg and 0.72 mU/mg total proteins on Premio and 0.05 U/mg, 0.15 U/mg and 0.52 mU/mg total proteins on Altigo for beta-1,4-endoxylanase, beta-1,4-endoglucanase and protease activities, respectively). These results confirm the importance of CWDE and protease activities in the process of fungal sporulation during the necrotrophic phase of M. graminicola.

The wall-less bacteria of the provisory taxon 'Candidatus Phytoplasma' are obligate parasites and associated to diseases in many important crops and trees worldwide. 'Ca. Phytoplasma ulmi', assigned to 16SrV-A subgroup, is a quarantine pest and described to be associated to elm phloem necrosis, leaf yellowing, stunting, witches broom and decline in various elm species. Elm yellows phytoplasmas (EY) have been reported in several European countries but not in Ulmus laevis in Germany so far. Leaf samples from European white elms (Ulmus leavis PALL.) with and without chlorotic symptoms were investigated for EYs infection in Berlin and Brandenburg, Germany, through performing diagnostic nested PCR targeting partial rRNA operon of phytoplasmas. Specific PCR-products were obtained from 30 out of 59 samples. Partial 16S-rDNA sequences were assigned to 'Ca. P. ulmi' through sequence analysis, while sequence variation was observed. This is the first report of U. laevis infected with 'Ca. P. ulmi' in Germany.

The seeds of Phaseolus lathyroides were extracted with hexane, dichloromethane, ethyl acetate and methanol, respectively by Soxhlet apparatus. Each crude extract was examined for toxicity against the second instars of Spodoptera litura using a topical application method under laboratory conditions. The ethyl acetate extract showed the most effective mortality (LD₅₀ = 11,964 and 9,169 ppm after treated at 24 and 48 hours, respectively). Furthermore, in vivo enzyme based experiments revealed that acetylcholinesterase activity of survived S. litura (24 hours post-treatment) was increased by 12% compared to control experiments. Our result showed the possibility to develop alternative strategies by using extract from the seeds of Phaseolus lathyroides for the control of S. litura.

The thinning of fruits is a required pomotechnical measure in intensive fruit production which ensures the production of good quality fruits and high yields. Metamitron, known as inhibitor of photosynthesis, has been successfully used in the thinning of apple fruits. This study had the aim to determine the efficacy of metamitron on the thinning of apple fruits in the agroecological conditions of Serbia and to evaluate the possibility of its practical application. Two varieties of apples that are widely grown in Serbia, dared and Golden Delicious, have been chosen for this research. The experiments were carried out during 2011 and 2012 according to the EPPO PP 1/158 (3) method. Metamitron has shown a good efficacy in the thinning of apple fruits. The effect of metamitron on the thinning of apple fruits depends on multiple factors, pri- marily the application dose, time of application, apple variety, but also on the number of fruits developed. The best efficacy on the Idared variety was in plots where metamitron was applied at a dose of 1.1 kg ha⁻¹, once (in the growth stage when the fruits were 8 mm in diameter) or twice (in the growth stages when the fruits were 8 mm and 12 mm in diameter), when the number of developed fruits per tree is smaller, or 1.65 kg ha⁻¹ applied once when the fruits are 12 mm in size when a larger number of fruits per tree is developed. On the Golden Delicious variety, the best efficacy was in treatments when metamitron was applied twice (in the growth stages when the fruits were 8 mm and 12 mm in diameter) in quantities of 1.1 kg ha⁻¹, when less fruits per tree were formed or 1.65 kg ha⁻¹, applied once or twice when a larger number of fruits per tree were formed.

The supramolecular complex of β-cyclodextrin-thiabendazole-piperony butoxide (βCD-TBZ/PBO) was prepared and its structure was characterized by 1H NMR. Additionally, the antifungal activity of βCD-TBZ/PBO was investigated in comparison with the commercially available thiabendazole (TBZ) fungicide by in vitro tests and on artificially inoculated 'Okitsu' satsuma fruit dipped in water at 20 degrees C or at 50 degrees C to control postharvest blue (Penicillium italicum) and green mould (P. digitatum). β-CD-TBZ/PBO is stable for several months when stored as powder in a dark bottle. At pH 7.0 the water solubility of the βCD-TBZ/PBO complex was consistently higher than free TBZ. Water dip at 20 degrees C did not affect decay incidence caused by blue mould but favoured the development of green mould during 4-8 days of storage at 20 degrees C with respect to untreated (control) fruit. Water at 50 degrees C effectively reduced the incidence of blue mould and totally suppressed green mould during the first 4 days but lost its efficacy afterwards. By contrast, both TBZ and βCD-TBZ/PBO had a lasting effect and were equally effective in controlling green and blue mould decay when applied at 20 degrees C and 60 mg L(-1) active ingredient (a.i.). When applied at 50 degrees C and 20 mg L(-1) a.i. the activity of the complex against blue mould was inferior than the corresponding treatment with TBZ. In vitro assays revealed a significant effectiveness of βCD-TBZ/PBO complex at low concentration compared to commercial formulation of TBZ.

Habitat management involving conservative biological control could be a good crop pest management option in poor African countries. A survey was conducted from August 2013 to July 2014 in a rainfed lowland region near Pélébina, northern Benin, in order to characterize spatiotemporal landscape changes and investigate their influence on the main crop pests and their associated natural enemies. The area was mapped mainly regarding crop fields and fallows. Visual observations were recorded and a database was compiled. Major landscape composition changes were noted between rainy and dry seasons, which affected the presence of both pests and natural enemies. Cereals (rice, maize and sorghum) and cotton were grown in the humid season, and then okra (Abelmoschus esculentus) was the dominant vegetable crop in dry season. These modifications impacted fallow abundance throughout the lowland. Different cotton (e.g. Helicoverpa armigera, Dysdercus sp., Zonocerus variegatus) or rice (e.g. Diopsis longicornis, D. apicalis) pests were observed during dry season in okra crops. Dry season surveys of Poaceae in two types of fallows ('humid', 'dry') revealed the presence of very few stem borers: only 0.04% of stems sampled were infested by stem borers, with a mean of 1.13 larvae per stem. Known cereal stem borer species such as Busseola fusco, Coniesta ignefusalis, Sesamia calamistis were not clearly identified among these larvae because of their diapausing stage and white color. Unexpected pollinators (Hymenoptera Apidae, genus Braunsapis, Ceratina and Xylocopa) and predators (Crabronidae, genus Dasyproctus) were found in the stems. Sweep-net collection of insects in humid fallows allowed us to describe for the first time in Benin seven Diopsidae species (23% of adults bearing Laboulbeniomycetes ectoparasitic fungi). Some of these species were captured in rice fields during rainy season. Parasitoids (adult Chalcidoidae and Ichneumonoidae) were observed during both seasons but their impact on stem borers was hard to determine, even during the rainy season, due to their low abundance and the difficulty of identification. Predators (Reduviidae, Odonata) were found mainly in humid fallows and rice fields. Regarding our observations, we suggest the presence of alternate host crops such as okra during the dry season for rainy season crop pests. Moreover, fallows also had a real ecological role as a habitat resource for many guilds of insects (pollinators, pests, predators). The management of these landscape components should be the focus of a long-term study with the aim of enhancing pest management of rainy season crop pests.

The insecticidal activity of thymol was evaluated in the laboratory against third instar Plutella xylostella by topical application. Our previous results described mortality in P. xylostella by thymol and the present study continues investigation for its possible efficacy on egg production and development in surviving treated P. xylostella. Our results showed that thymol at a sublethal dose (0.43 µg/larvae, LD₃₀) caused pupation inhibition, adult-emergence inhibition and abnormal adults at rates of 30, 33.33 and 23.33%, respectively. Moreover, the number of eggs was also reduced by 54.33%. These results showed that thymol was active against P. xylostella larvae and can effectively control this pest.