Behaviour of trifloxystrobin and tebuconazole on grapes under semi‐arid tropical climatic conditions

BACKGROUND: A mixture of trifloxystrobin and tebuconazole is excellent in controlling both powdery and downy mildew of grapes. The objective of the present work was to study the behaviour of trifloxystrobin and tebuconazole on grape berries and soil following treatment with Nativo 75 WG, a formulation containing both fungicides (trifloxystrobin 250 + tebuconazole 500 g kg^?1). This study was carried out for planned registration of this mixture for use on grapes in India. RESULTS: Initial residue deposits of trifloxystrobin and tebuconazole on grapes were below their maximum residue limit (MRL) of 0.5 and 2 mg kg^?1, respectively, when Nativo 75 WG was applied at the recommended dose of 175 g product ha^?1. The residues dissipated gradually to 0.02 and 0.05 mg kg^?1 by 30 days, and were below the quantifiable limit of 0.01 mg kg^?1 at the time of harvest (60 days after the last treatment). Trifloxystrobin and tebuconazole dissipated at a pre‐harvest interval (PHI) of 36 and 34 days, respectively, from the recommended treatment dose. The acid metabolite of trifloxystrobin, CGA 321 113, was not detected in grape berries at any point in time. Soil at harvest was free of any pesticide residues. CONCLUSION: Residue levels of both trifloxystrobin and tebuconazole were below MRLs when grapes were harvested 30 days after the last of four applications of 175 g product ha^?1 (trifloxystrobin 44 g AI ha^?1, tebuconazole 88 g AI ha^?1) under the semi‐arid tropical climatic conditions of India. Copyright © 2010 Society of Chemical Industry     

Parasitism of macroconidia, chlamydospores and hyphae of Fusarium culmorum by mycoparasitic Pythium species

Parasitism of macroconidia and endoconidial chlamydospores of Fusarium culmorum by Pythium oligandrum was studied on water agar (WA), corn-meal agar (CMA) and glass slides. Loss of cytoplasmic content in F. culmorum spores was followed by complete degradation, and P. oligandrum produced an abundance of oogonia on the parasitized macroconidia. A simple method for assessing the relative aggressiveness of isolates is presented, based on the percentage of macroconidial cells devoid of cytoplasm. Parasitism of macroconidia by P. acanthophoron , P. oligandrum and P. periplocum , but not by the plant pathogenic species, P. tracheiphilum , was demonstrated by this method. Interactions between hyphae of P. oligandrum and F. culmorum on WA resulted in an increase in the number of oogonia of P. oligandrum and a decrease in the sporulation of F. culmorum . The ability of isolates of P. oligandrum , P. periplocum , P. acanthophoron and P. mycoparasiticum to suppress disease symptoms caused by F. culmorum on barley seedlings was demonstrated in a greenhouse test.     

Computerized soil data used in agricultural water planning, Denmark

Abstract. A nationwide soil database system has been established containing soil maps, analytical data, and soil classification. The system has been widely used in agricultural planning at county and national level. This paper describes the basic data used for the soil database system, and the exploitation of this system in agricultural water planning. The principles for calculating the irrigation need at county level are given and also those for nationwide mapping of the potential need for drainage. Mapping of potentially acid sulphate soils, which has given rise to legislation on drainage of wetlands, is described, and the future use of the soil database system in agricultural water planning is discussed.     

Sickness, mortality and the buller steer syndrome in a western Canadian feedlot

Objective To determine if an association existed between sickness, mortality and bullers in a western Canadian feedlot.
Design A retrospective epidemiological study.
Animals 78,445 male cattle that entered a 24,000-head feedlot in western Canada from 1991 to 1993.
Procedure Animal health records for bullers were collected and analysed to see if they were at greater risk of sickness and mortality than other steers, and to see if pens with a high prevalence of bullers also had a high prevalence of sickness and mortality.
Results The prevalence of bullers increased with increasing age of cattle on arrival at the feedlot (R = 0.36; P < 0.001). Sickness and mortality decreased with increasing age of cattle on arrival. However, sickness and mortality in bullers relative to other steers actually increased with increasing age on arrival suggesting an interaction existed between sickness and bullers. Bullers were significantly (P < 0.05) more likely to get sick and to die than other steers. In all cases, there was a strong temporal association between sickness and bullers, with sickness and bullers mostly occurring within the first 30 days of the feeding period. On average, pens of cattle with a high prevalence of bullers did not have a correspondingly high prevalence of sickness or mortality.
Conclusion This study suggests that sickness is an effect modifier of dominance behaviour and therefore bullers in feedlot steers. Bullers should always be checked for signs of sickness and treated accordingly. Further research is needed to investigate the effects of sickness on dominance behaviour in pens of feedlot cattle.     

A review of various parasites of rabbits

The increased interest in breeding and production of rabbits has initiated the present work, in which a review on the occurrence, significance and control of some important parasite infections of the domestic rabbit is given. In wild rabbits parasite diseases often affect single animals, whereas the intensive production of domestic rabbits typically has to deal with parasites as herd problems which in some cases may invalidate the economy of commercial rabbitries. The most important parasite diseases of the domestic rabbit comprise coccidiosis caused by Eimeria-spp. and ear mange caused by Psoroptes cuniculi.     

Blocking ELISA's for the distinction between antibodies against European and American strains of porcine reproductive and respiratory syndrome virus

A double blocking ELISA was developed in order to satisfy the need for large scale serological screening for PRRS and simultaneous distinction between infection with European and American strains of PRRSV in pig herds. The Immunoperoxidase monolayer assay (IPMA) and the double blocking ELISA enabled distinction on serological basis between infection with European and American strains of PRRSV. The distinction was possible from about day 7 after infection of pigs with PRRSV. The double blocking ELISA enabled the distinction at later stages of infection compared to the IPMA, irrespective of the strain involved.     

Hounsfield Unit dynamics of adipose tissue and non-adipose soft tissues in growing pigs

Changes in the Hounsfield Unit value of adipose tissue and of non-adipose soft tissue during growth are poorly documented. This study examines the HU of these tissues in growing pigs. Computer tomography scans were made in nine growing pigs on three occasions, approximately four weeks apart. Average body weight was 51, 94, and 121 kg for each successive scan. Images from the level of the diaphragm to the hips were analyzed. The mean HU and its standard deviation, for adipose tissue and for non-adipose soft tissues was determined for each pig. The mean adipose tissue HU for all pigs was -90, -98 and -101 on the first, middle and last scans, respectively. Corresponding HU values for non-adipose soft tissues were, 52, 51 and 49. There was a significant difference (p<0.01) between HU at each scan time for each set of tissues.