Occurrence of Downy Mildew on Sunflower in South Africa

Downy mildew, caused by Plasmopara halstedii (Farl.) Berl. & De Toni in Sacc., is an economically important disease of sunflower (Helianthus annuus L.) in Europe and the United States (1). The disease was first noticed in South Africa in a commercial field near Standerton and in a seed production field near Kroonstad during the 1993 to 1994 planting season. During the 1995 to 1996 season, downy mildew was found in experimental hybrids near Heilbron, and in commercial fields near Heil-bron, Marikana, and Potchefstroom. At Heilbron, five hybrids were infected with P. halstedii, whereas three others showed symptoms of downy mildew at Potchefstroom and Marikana. All commercially cultivated hybrids have been developed in South Africa. Disease incidence in all the fields was low, with less than 1% of plants affected by the disease. Diseased plants were dwarfed and displayed veinal chlorosis of leaves typically associated with downy mildew of sunflower. White fungal growth commonly occurred on lower leaf surfaces. Sunflower seedlings inoculated with P. halstedii produced symptoms characteristic of downy mildew. The occurrence of the disease in many geographic areas and on various hybrids in South Africa suggests that the fungus is well established. Recent outbreaks can be attributed to the cool, wet, climatic conditions of the 1993 to 1994 and 1995 to 1996 seasons. The susceptibility of local hybrids suggests that downy mildew is a potentially dangerous disease of sunflower in South Africa. Reference: (1) J. F. Miller and T. J. Gulya. Crop Sci. 27:210, 1987.

Verpleegadministrasie in gesondheidsdienste

Nursing administration, as a sub-system of health administration, is excercised within an environment characterised by a number of conflicts. The nurse leader can cope with these conflicts through prevention, solution or conflict regulation. Administrative leadership brings a new dimension to nursing administration which must be taken into account. It makes specific demands regarding the selection, training, development and utilisation of the nurse administrator. The author comes to the conclusion that the quality of nurse leaders is high and that they make an indispensable contribution to health services. For an even more meaningful contribution the author advises the institution of structured policy advisory teams in hospitals, joint post-graduate training of doctors and nurses for health administration and, from time to time, freeing nurses to other selected occupations to develop better understanding.