Influence of block and cell size,growing medium and insecticide dose on the behaviour and uptake of phorate by lettuce and uptake of carbofuran and chlorfenvinphos by calabrese

Phorate residues in peat blocks and lettuce were determined following incorporation of the insecticide into different block and ‘Speedling’ cell sizes. Between-block variability was influenced little by block size. Phorate oxidation was most extensive in the largest blocks containing the smallest dose. Total residue concentrations in the lettuce declined from the time of planting to harvest, although accumulation of insecticide continued and was related more to dose than to block or cell size. Residues in the lettuce at harvest exceeded the proposed maximum limit of 0.2 mg kg^?1 in some treatments. Residues at planting comprised mainly the parent sulphoxide and sulphone, but by harvest, the oxygen analogue sulphoxide and sulphone predominated. Lettuce weight was not influenced by dose but was related directly to block size. Carbofuran and chlorfenvinphos residues were determined in calabrese sown into two sizes of blocks. At planting time, carbofuran residue concentrations were 100 times greater than those of chlorfenvinphos but residues of both insecticides in the mature heads were < 0.01 mg kg^?1. Seedling weights in both sowings declined with increasing concentrations of the insecticides. It was concluded that manipulations of block size and the dose of insecticide need to be evaluated for individual insecticide/crop combinations to exploit the technique fully.     

Uptake of phorate by lettuce

Following experimental and commercial applications to soil of a granular formulalation of phorate (O,O-diethyl S-ethylthiomethyl phosphorodithioate), residues in the soil and in lettuce were determined by gas-liquid chromatography. When applied by the bow-wave method as a continuous logarithmically-changing dose ranging from approximately 0.9 to 16.0 kg a.i. ha^?1, the proportional rate of oxidation in soil of phorate sulphoxide to phorate sulphone was inversely related to dose. Ten weeks after application, total phorate residues in the soil had declined by about 35% at all dose levels. Residues in mature lettuce, from the 1-5 kg ha^?1 dose-range, comprised the parent and oxygen analogue sulphoxides and sulphones; the relative proportions of the individual metabolites were independent of dose. Over this dose-range, total residue concentrations in the crop became proportionally slightly greater with increasing dose. When single doses of 1.1, 2.0 or 2.2 kg a.i. ha^?1 were applied at drilling, the total residue concentrations in the lettuce declined from 5 mg kg^?1 in seedlings from some treatments to <0.05 mg kg^?1 at harvest. In plants raised in peat blocks containing 10 or 20 mg a.i. per block, however, residues in seedlings totalled 45-47 mg kg^?1 and declined to only 0.7 mg kg^?1 at harvest. It was concluded that bowwave applications of phorate when field-sowing lettuce were unlikely to lead to unacceptable residues in the harvested crop, but that residues in lettuce raised in phorate-treated peat blocks may be unacceptably high.     

Cervical spondylopathy in the dog—a review of thirty-five cases

The case histories of thirty-five dogs with cervical spondylopathy are described with particular emphasis on diagnosis and surgical treatment, with follow-up records of both treated and untreated cases. Some evidence is presented to show that the syndrome is an inherited defect.     

Presence of a substance in the white skin of young tulip bulbs which inhibits growth ofFusarium oxysporum

In field infections of tulip bulbs caused byF. oxysporum, soil temperature, although important, has been proved to be not the decisive factor influencing the moment of infection. The presence in the white skin tissue of young bulbs of a water soluble substance which has a growth inhibiting effect onF. oxysporum in vitro has been demonstrated. Inoculations with the fungus on the white skins were unsuccessful. In the susceptible tulip cultivar so far examined the concentration of this substance in extracts decreases during the last weeks before the bulbs mature. It is suggested that this substance is protecting the susceptible fleshy bulb scales during the greater part of the growth period and that its diminution during the final weeks enablesF. oxysporum to infect the scales during this period.     

AN INTRATHORACIC MALIGNANT PERIPHERAL NERVE SHEATH TUMOR IN A DOG

A 7-year-old, neutered male Labrador Retriever presented for a persistent, productive cough and regurgitation. Radiography, ultrasonography, and computed tomography confirmed a large, smoothly marginated intrathoracic mass causing tracheal compression. The mass was removed via a thoracotomy, and a malignant peripheral nerve sheath tumor, most likely originating from the ventral spinal nerve roots, was confirmed using immunohistochemistry.     

ULTRASONOGRAPHIC IMAGING OF THE VAGOSYMPATHETIC TRUNK IN THE DOG

The purpose of this study was to evaluate the applicability of ultrasonographic imaging of the vagosympathetic trunk in the dog. Cervical ultrasound was performed in 30 healthy dogs. In all 30 dogs the vagosympathetic trunk was detected as a hypoechoic structure in the carotid sheath, adhering the dorsomedial surface of the common carotid artery. The echotexture of the nerve was heterogeneous with anechoic areas separated by hypoechoic bands. A scanner equipped with a 5 to 8 MHz linear array probe was used for imaging and measurements. The diameter of the vagosympathetic trunk ranged from 0.59 to 2.48 mm varying in correlation to the body weight. In summary, ultrasonography is a helpful noninvasive method to image and evaluate the cervical vagosympathetic trunk in the dog.     

The use of porcine small intestinal submucosa in ten cases of feline corneal disease

Porcine small intestinal submucosa (SIS) was used as a novel graft material in the management of 10 cases of feline corneal disease. Five cases had stromal ulceration associated with trauma, ocular foreign body and/or suspected infection and required a grafting procedure. Five cases had feline sequestra that were managed by a keratectomy prior to placement of SIS as a graft material. Eight eyes healed with minimal corneal scarring with a very good cosmetic and visual result. One eye with continued aqueous leakage in the immediate postoperative period required a conjunctival pedicle graft to reinforce the SIS graft site. One eye required enucleation 48 h following grafting due to progressive keratomalacia but the SIS material remained intact.     

HYPERCALCEMIC NEPHROPATHY IN THREE DOGS: SONOGRAPHIC APPEARANCE

Persistent hypercalcemia in the dog is most commonly seen as a paraneoplastic syndrome or in association with widespread osteolytic lesions. In high concentrations calcium is a potent nephrotoxin and may cause severe and irreversible renal damage. The ultrasonographic changes in the kidneys of three dogs with hypercalcernic nephropathy are described'and compared with the changes described in the same human condition. It is suggested that ultrasound could be a useful technique for evaluation of the severity of renal damage and the potential return of renal function in such instances.     

A scale for the assessment of navel healing in newly hatched turkey poults

1. A five‐point scale has been devised for scoring the degree of navel healing of turkey poults.