Chemical control of Botrytis cinerea and Sclerotinia sclerotiorum on dwarf snap beans

Two sprays of vinclozolin (0.5 kg a.i. ha^–1) or procymidone (0.5 kg a.i. ha^–1), the first at the beginning of flowering and the second two weeks later, gave the best control ofBotrytis cinerea on dwarf snap beans (Phaseolus vulgaris). Good results were also obtained with iprodione and with thiophanate-methyl. Vinclozolin and procymidone at the same program were the most active fungicides againstSclerotinia sclerotiorum. Treatments with the latter two fungicides resulted in increased yields of pods and had no influence on colour and quality of the pods. Residue levels were below the tolerances.Samenvatting Twee bespuitingen met vinchlozolin (0,5 kg a.i. ha^–1) of procymidon (0,5 kg a.i. ha^–1), de eerste in het stadium begin bloei en de tweede 14 dagen later tijdens de peulzetting, waren voldoende omB. cinerea in stamslabonen te bestrijden. Tevens werden goede resultaten verkregen met iprodion en thiofanaat-methyl. Vinchlozolin en procymidon gaven volgens hetzelfde schema toegepast ook de beste werking tegenS. sclerotiorum. Toepassingen van deze laatste twee fungiciden leverden een hogere peulopbrengst en hadden geen invloed op de kleur en de kwaliteit van de peulen. Het residugehalte in de peulen lag beneden de toelaatbare grens.This research was subsidized by the Instituut tot Aanmoediging van het Wetenschappelijk Onderzoek in Nijverheid en Landbouw (IWONL).     

Comparison of the persistent activity of ivermectin, abamectin, doramectin and moxidectin in cattle in Zambia

The persistent efficacy of four commercially available macrocyclic lactones (ML) in maintaining reduced faecal egg counts in cattle grazing naturally infested pastures was evaluated in 44 zebu animals aged 1–2 years in Zambia. The study started in February (rainy season) when the strongyle egg output was increasing. Four days before the start of the trial, all animals were treated with a double dose of oxfendazole. They were then divided into five groups which were again treated on day 0. Groups A, D, I and M received 0.2 mg kg⁻¹ of abamectin, doramectin, ivermectin and moxidectin, respectively. Animals of group C received albendazole (7.5 mg kg⁻¹). Faecal samples were collected twice a week for egg counts and larval differentiation. Faecal egg counts in the C group increased from day 21 onwards and plateaued from day 42 between 180 and 380 eggs per gram. The main genera found in cultures were Cooperia (90%) and Haemonchus (7%). Faecal egg excretion in groups M, A, D and I started on day 35, 42, 42 and 45, respectively. subsequently and until day 84, average counts in these four groups were always significantly lower than in group C. Compared with albendazole, all four ML gave over 95% reduction in cumulative faecal egg counts for 42 days after treatment. The percentage efficacy was still over 84% by day 84 when an average cumulative egg count of 11 320 eggs per gram faeces was calculated in group C. In addition, there was no significant difference in efficacy between the four ML groups at any of the sampling dates. During the trial no significant difference in weight gain between any of the groups was observed.     

Assessing resistance against macrocyclic lactones in gastro-intestinal nematodes in cattle using the faecal egg count reduction test and the controlled efficacy test

The main objective of the present study was to evaluate the accuracy of the faecal egg count reduction test (FECRT) to assess the resistance status of ivermectin (IVM)-resistant isolates of the cattle nematodes Ostertagia ostertagi and Cooperia oncophora, using the controlled efficacy test (worm counts) as a reference. The second objective was to investigate whether both IVM-resistant isolates showed side-resistance against moxidectin (MOX) under controlled conditions. Thirty male Holstein calves were experimentally infected with 25,000 L3 of an IVM-resistant O. ostertagi isolate and 25,000 L3 of an IVM-resistant C. oncophora isolate. Twenty-eight days later the calves were randomly divided into 2 treatment groups and 1 untreated control group. Animals in groups 1 and 2 received MOX (Cydectin(?) 1%, Pfizer) and IVM (Ivomec(?) 1%, Merial) respectively, by subcutaneous injection at a dose rate of 0.2mg/kg bodyweight. Faecal samples were collected 7 and 14days after treatment and animals were necropsied 14/15days post-treatment. Both the FECRT and the controlled efficacy test demonstrated that the O. ostertagi and C. oncophora isolates were resistant against IVM, with efficacies below 90%. The IVM-resistant O. ostertagia isolate was still susceptible to MOX treatment, as shown by over 99% reduction in egg counts and worm burden. The FECRT suggested borderline resistance against MOX in the IVM-resistant C. oncophora isolate, with egg count reductions between 97% (95% CI: 76; 100) at day 7 and 86% (95% CI: 49; 96) at day 14. However, the controlled efficacy test clearly showed MOX-resistance, with a decrease of only 31% (95% CI: -12; 57) in C. oncophora worm numbers. After MOX treatment, a significantly lower number of eggs per female C. oncophora worms was counted compared to the control group (43% reduction). Due to this reduced fecundity, the FECRT may fail to detect MOX-resistance.     

Evaluation of 3 Serological Tests for Early Detection Of Leptospira‐specific Antibodies in Experimentally Infected Dogs

Background

Leptospirosis in dogs is a disease of global importance. Early detection and appropriate therapeutic intervention are necessary to resolve infection and prevent zoonotic transmission. However, its diagnosis is hindered by nonspecific clinical signs and lack of rapid diagnostic tests of early infection. Recently, 2 rapid point‐of‐care tests (WITNESS Lepto [WITNESS Lepto, Zoetis LLC, Kalamazoo, MI, USA] and SNAP Lepto [SNAP Lepto, IDEXX Laboratories, Westbrook, ME, USA]) for detection of Leptospira‐specific antibodies in canine sera were developed.

Hypothesis

Immunoglobulin M‐based WITNESS Lepto containing multiple detection antigens can detect Leptospira‐specific antibodies to common leptospiral serovars earlier in the course of infection as compared to microscopic agglutination test (MAT) and SNAP Lepto.

Animals

Four groups of 8 6‐ to 8‐month‐old male Beagle dogs were used.

Methods

Thirty‐two healthy seronegative dogs were inoculated experimentally with serovars Canicola, Grippotyphosa, Icterohaemorrhagiae, and Pomona (8 dogs/serovar). Acute‐phase sera were collected at regular intervals and monitored for Leptospira‐specific antibodies by WITNESS Lepto, MAT, and SNAP Lepto.

Results

Seroconversion was detected in all dogs by day 10 by WITNESS Lepto and in 30 of 32 dogs by day 14 by MAT. The SNAP Lepto test detected seroconversion in 3 dogs during the 2 weeks postchallenge.

Conclusions

Immunoglobulin M‐based WITNESS Lepto detected immune responses specific to multiple leptospiral serovars early in the course of infection and identified seroconversion in all animals earlier than did the gold standard MAT. The SNAP Lepto test displayed considerably lower and inconsistent performance during the study period. At the point‐of‐care, WITNESS Lepto should be the test of choice for rapid and reliable screening of acutely ill dogs suspected to have leptospirosis.     

Equine exudative canker: an (auto-)immune disease?

Equine canker is a chronic, hyperplastic, exudative pododermatitis affecting one or more feet. Although many causes and treatments have been suggested, the cause of the disease is still unknown and most probably multifactorial. Local treatments include radical surgical debridement of the diseased hoof tissue and application of caustic substances, antibiotics, and pressure bandaging. Nevertheless, the number of recurrences is high (45%). This article presents a 3-year-old New Forest pony-cross mare in which all horny structures (frogs, coronets, spurs, chestnuts) of all feet were affected. Bacteriological and fungal cultures of the frogs were found negative for the pathogens tested. Papilloma virus was not found. Clinical findings raised the hypothesis that the non-specific hyperplastic inflammation of these horn-like structures might have been caused by an (auto-)immune reaction. On the basis of the clinical findings, the pony was treated with surgical debridement of the frogs of a diagonal pair of feet and oral administration of prednisolone (1 mg/kg sid). The frogs, coronets, spurs, and chestnuts of all four feet healed completely within 8 weeks, thus making an (auto-)immune reaction more likely. In conclusion, this case report raised the hypothesis that an aspecific, hyperplastic inflammation of all four feet ('equine canker') and other horny structures may be caused by an (auto-)immune reaction, and that corticosteroids (prednisolone 1 mg/kg sid per os) are effective as treatment.     

Small forest patches as pollinator habitat: oases in an agricultural desert?

Landscape Ecology - Small forest fragments are often the most abundant type of semi-natural habitat in intensive agricultural landscapes. Wild pollinators can use these forest patches as nesting or...     

The effect of mass-flowering orchards and semi-natural habitat on bumblebee colony performance

Landscape Ecology - Bumblebees are important pollinators for agricultural crops and wild plants. However, agricultural intensification and loss of semi-natural habitat may have adverse effects on...