Viral disease of tomato crops (Solanum lycopesicum L.): an overview

Journal of Plant Diseases and Protection - Global production of tomato has been hampered by the increased incidences of tomato viral disease. The high genetic heterogeneity of tomato plant viruses,...     

Winter wheat pests and their natural enemies under organic farming system in Slovakia: Effect of ploughing and previous crop

Organic farming system of winter wheat was investigated in Solvakia over three years, 1995–1997. The system was carried out on a small scale (four plots of 50 m²). Neither pesticides nor inorganic fertilisers were applied. Effect of two treatments, ploughing and previous crop, on the community of pests and natural enemies was surveyed. There were two types of ploughing (shallow and deep) made in autumn before sowing. As previous crops, silage-maize and alfalfa were used each season. The effect of all factors was analysed by multivariate method, redundancy analysis (RDA) and Monte Carlo permutation to assess statistical significance. During three years, 37 taxons of pests and 27 taxons of natural enemies were recorded. The results of RDA showed that the community of insects (pests and natural enemies) was mainly influenced by temporal variation. The highest abundance of all insects was observed in 1996. The effect of the two treatments on the community of pests and natural enemies was less obvious. Pests were found to be significantly more influenced by ploughingthan by previous crop. Most of pests occurred more abundantly on plots with shallow ploughing and on plots after maize. Abundance of natural enemies were, however, significantly affected by previous crop. Majority of them were more abundant on plots after maize than after alfalfa. Ploughing had only marginally significant effect on natural enemies that were more abundant on shallow ploughed plots. Both ploughing and previous crop had only negligible effect on species diversity of natural enemies.     

A survey on the environmental impact of pond aquaculture in Hungary

The aim of the study was to survey the nutrient loads of receiving waters and evaluate the nitrogen, phosphorus and organic matter budget of the conventional fishponds in Hungary. The average nitrogen (N), phosphorus (P) and organic matter (OM) concentrations in the filling-up water of the fishponds were 2.51 ± 1.25, 0.57 ± 0.57 and 23.8 ± 13.4 mg l^?1, respectively. Contrarily, the N, P and OM concentrations in the effluents of fishponds were 1.64 ± 2.19, 0.37 ± 0.51 and 30.2 ± 20.5 mg l^?1, respectively. The sediment nutrient content in the fishponds during the operation was 5.77 ± 4.42 mg g dry sediment^?1 for N, 1.25 ± 0.75 for P and 30.5 ± 43.3 for total organic carbon. The retained nutrients represented on average 53 % (84 kg ha^?1 year^?1) of N, 74 % (21 kg ha^?1 year^?1) of P and 74 % (2400 kg ha^?1 year^?1) of OM, introduced into the fishponds. In the fishponds, the ratio of input N, P and OM accumulated in fish biomass was 18.4 ± 6.7, 10.4 ± 4.4 and 6.8 ± 2.1 %, respectively. The investigated fishponds discharged 48 % less N and 62 % less P into the recipient waters than received with the intake water. However, 78 % more OM was discharged with the effluent from the fishponds than received with the inlet and supplement water.     

Tree species and pruning regime affect crop yield on bench terraces in SW Uganda

Integration of trees on farms may exert complementary or competitive effects on crop yield. This 4 year study examined novel systems in which Alnus acuminata (alnus), Calliandra calothyrsus (calliandra), Sesbania sesban (sesbania) or a mixture of all three were grown on the degraded upper part of bench terraces in Uganda; beans or maize were grown on the more fertile lower terrace during the short and long rains. Three pruning treatments (shoot, root or shoot + root pruning) were applied to the tree rows adjacent to the crops; shoot prunings were applied as green manure to the woodlot from which they came. Pruning increased survival in calliandra and reduced survival in sesbania; alnus was unaffected. Pruning reduced tree height and stem diameter in alnus, but did not affect calliandra or sesbania. Maize yield adjacent to unpruned calliandra, alnus and sesbania or a mixture of all three was reduced by 48, 17, 6 and 24% relative to sole maize. Shoot pruning initially sustained crop performance but shoot + root pruning became necessary when tree age exceeded 2 years; shoot + root pruning increased maize yield by 88, 40, 11 and 31% in the calliandra, alnus, sesbania and tree mixture systems relative to unpruned trees. Bean yield adjacent to unpruned calliandra, alnus, sesbania and the tree mixture was 44, 31, 33 and 22% lower than in sole crops and pruning had no significant effect on crop yield. The results suggest that sesbania fallows may be used on the upper terrace without reducing crop yield on the lower terrace, whereas pruning of alnus is needed to sustain yield. Calliandra woodlots appear to be unsuitable as crop yield was reduced even after pruning.     

Candida albicans peritonitis in a dog

Objective – To describe the clinical management of a case of Candida albicans peritonitis in a dog and discuss the pathogenicity of Candida peritonitis along with treatment using the fungistatic agent, fluconazole.
Case Summary – A 15-week-old Papillon developed peritonitis secondary to enterectomy site dehiscence. A pure growth of Candida albicans was obtained from the abdominal fluid. Surgical repair of the dehiscence was performed and antifungal therapy instituted with fluconazole postoperatively. A marked exudative process was noted postoperatively with production of large volumes of fluid from the abdominal drain. Fresh frozen plasma and pentastarch were provided for oncotic support. Recovery was complicated by megaesophagus, however, the patient gradually improved and was discharged 11 days after surgery.
New or Unique Information Provided – To our knowledge, this is the first case report of successful treatment of Candida albicans peritonitis in a dog. A marked exudative process was noted during therapy requiring significant oncotic support. Resolution of the disease process was achieved with surgical intervention and antifungal therapy.     

Near-infrared spectroscopic determination of degradation in vegetable oils used to fry various foods

Near-infrared (NIR) spectroscopic methods for measuring degradation products, including total polar materials (TPMs) and free fatty acids (FFAs), in soy-based frying oil used for frying various foods have been successfully developed. Calibration models were developed using forward stepwise multiple linear regression (FSMLR) and partial least-squares (PLS) regression techniques and then tested with an independent set of validation samples. The results show that the quality of oil used for frying different foods can be measured with a single model. First-derivative treatments improved results for TPM measurement. In addition, PLS models gave better prediction results than FSMLR models. For PLS models, the best correlations (r) between the NIR-predicted data and the chemical method data for TPMs and FFAs in oils were 0.995 and 0.981, respectively. For FSMLR models, the best r values for TPMs and FFAs in oils were 0.993 and 0.963, respectively.     

Characterization and observation of animals responsible for rabies post-exposure treatment in Phnom Penh, Cambodia.

In order to provide relevant therapeutic answers to human patients exposed to risk of rabies infection who visit the Institut Pasteur du Cambodge for post-exposure treatment and to improve control of rabies in Cambodia, a pilot study was carried out in Phnom Penh Province in November and December 1997 with three objectives: characterization of the population of animals responsible for the exposure to rabies, observation of the animals concerned, and confirmation of the presence of rabies virus in the province. Between 18 November 1997 and 19 December 1997, 409 of the 741 patients treated at the Institut Pasteur du Cambodge because of an exposure to a known rabies vector were included in the study. The animals concerned were: 401 dogs (98%), six monkeys (1.5%) and two cats (0.5%). Three-hundred-and-seventy of the animals (90.5%) were owned, 4 (1%) were unowned but were available for characterization and observation, and 35 (8.6%) had an unknown ownership status and were not available for further study. The exposures occurred on private property in 84% of the cases, and 80 of the 370 owned animals (22%) lived in the same home as had the patient. The 374 animals with known ownership status were examined. Five were already dead and two of these five dogs had presented clinical signs typical of those of rabies. The male:female sex ratio of the dogs was 2.1:1. The 369 live animals were placed under observation for 10 d immediately after exposure of the humans had taken place. At the end of the period none of the animals had developed clinical signs of rabies, three had died of diseases other than rabies, and one was lost. Tests for the rabies nucleocapsid antigen were positive in two cases (the two suspected rabid dogs), confirming the presence of rabies in Phnom Penh Province. Consequently, we recommend measures to improve the control of rabies in Cambodia.     

Production of Bioflocculant by Staphylococcus cohnii ssp. from Palm Oil Mill Effluent (POME)

Staphylococcus cohnii ssp. was found to produce a bioflocculant with high flocculating activity for kaolin suspension. Using optimized culture conditions, a flocculating activity of 70.3?% at a bioflocculation concentration of 0.3?mg/L at pH 7 with Ca²⁺ as the cation and 88.9?% in 1.2?mg/L of bioflocculant concentration for Al³⁺ as the cation was obtained for bacteria that were incubated at temperature of 40?°C for 2-day incubation period. It was found to be effective for flocculation of a kaolin suspension over weakly acidic pH (6?C8); divalent and trivalent (Ca²⁺ and Al³⁺) enhanced the flocculating activity. This bioflocculant possesses a good flocculating activity, which can be promoted by the addition of trivalent and bivalent cations in kaolin suspension.     

Photocatalytic Degradation of Reactive Black 5 by Fish Scale-Loaded TiO2 Composites

Titania and TiO₂/fish scale composites at different mass ratios (90:10, 70:30, and 50:50) were prepared by sol?Cgel method for application as photocatalysts in this study. Fish scale, synthesized TiO₂, and TiO₂/fish scale composites were characterized by using X-ray diffraction (XRD), scanning electron microscope (SEM), and nitrogen sorption. Their photocatalytic activities were evaluated through the degradation of Reactive Black 5 (RB 5) under solar light irradiation. The effects of irradiation time, catalyst loading, and mass ratios of TiO₂/fish scale composites on the photocatalytic degradation of RB 5 were investigated. The results revealed that the photocatalytic activity of TiO₂/fish scale composites showed compatible and enhanced degradation compared to the synthesized titania.