Effets de divers herbicides sur la croissance mycélienne de souches de Botrytis cinerea pers et de Penicillium expansum Link, sensibles ou résistantes à certains fongicides

Effects of various herbicides on mycelial growth of strains of Botrytis cinerea. Pers. and Pénicillium expansum Link, sensitive or resistant to certain fungicides Of seventy herbicides tested, thirty-eight were slightly toxic to B. cinerea (CI50, concentration giving 50% inhibition of the speed of mycelial growth, exceeding or equal to 100g of herbicide/ml of nutrient solution) and, of those, ten had no effect even at 1000 g/ml. The most active products (CI50 less than 10 g/ml) were Chlorthiamid, dichlobénil, nitrofen, propyzamide and phenolic derivatives (DNOC, ioxynil, PCP). In most cases P. expansum was less sensitive than B. cinerea except to endothal, propachlor, prynachlor and certain substituted ureas. Strains resistant to the benzimidazole fungicides (carbendazim, thiabendazole etc.) show increased sensitivity to certain carbamade herbicides (barban, chlorbufam etc.), this indicates the existence of a negative cross resistance between these groups of antimitotic pesticides. Strains resistant to the cyclic-imide fungicides (iprodionc, procymidone, vinclozolin) and to various aromatic compounds (biphenyl. chloroneb, dicloran etc.) may also be resistant to bipyridilium, dinitroanilinc and diphenylethcr herbicides, to chlorthamid. dichlobénil and oxadiazon. This cross resistance between pesticides with different biochemical modes of action has yet to be explained.     

A study of the effect of short-term progesterone treatment of serum calcium and inorganic phosphorus concentration in the rat

Four intact and four parathyroidectomized rats, fed with a low calcium diet, were treated with progesterone, 0.7 mg s.c. daily on four consecutive days, and the effects of the treatment on the serum calcium and inorganic phosphorus were investigated. Four untreated intact rats on the same diet served as controls. The treatment was found to have no influence on the concentrations of the serum calcium or inorganic phosphorus.     

Embryonic development in the blue fox

Embryos from vixens at different stages of gestation were measured and photographed. Implantation was observed 16-18 days after breeding. Differentiation and the development of characteristic features were described and embryonic loss was studied in relation to number of corpora lutea.     

Tracking the evolution of a hydrothermal event plume with a RAFOS neutrally buoyant drifter

The migration and evolution of a deep ocean hydrothermal event plume were tracked with a neutrally buoyant RAFOS float. The float remained entrained in the plume for 60 days, and the plume vorticity was calculated directly from the anticyclonic motion of the float. Concentrations of suspended particles, particulate iron, and dissolved manganese in the plume did not decay significantly during the 60 days, which indicates that event plumes would be easily detectable a year after formation.     

Essais de lutte chimique contre Aonidiella aurantii (Mask.)

Les essais de lutte chimique contre Aonidiella aurantii (Mask.) sur citronniers en Sicile ont été réalisés à l'aide d'une série de produits organo-phosphoriques en partie mélangés avec des huiles blanches, et compareés à l'efficacité des huiles blanches appliquées seules. II est apparu que les meilleurs résultats sont obtenus contre les larves et les jeunes femelles, alors que pour les femelles matures il n'a pu être enregistré une mortalité suffisante. L'analyse statistique n'a pas révélé de différences significatives entre l'efficacité de l'huile blanche et celle des autres produits testés.