Poplar rust in Canterbury N.Z.: Research project as required for the subject of plant pathology in part fulfilment of a Diploma of Agricultural Science

Abstract

This is a project studying the Poplar leaf Rust Fungi present in Canterbury New Zealand 1975. It includes a Review of the Literature, a description of the fungi, and various experiments carried out. The following conclusions are based on the results of those experiments. The species of Poplar leaf rust present in Canterbury is Melampsora laricipopulina this from the appearance and length of the uredospores. An agar surface was preferred to glass by the uredospores, also distilled water as against tap water, light or absence of light had no effect on the germination (germination defined as appearance of germ tube) of the uredospores. The spores germinated at higher percentages in higher concentrated spore suspensions. The temperature range of 10°C to 20°C appears to be the range preferred for germination of the uredospores. Viability of the spores is maintained at a high level of percent germination at low temperatures and low relative humidity. Both the fungicides Benomyl and Copper oxychloride at high concentrations in the media have some controlling effect but copper oxychloride was overall a better control in preventing germination and so damage to the poplar leaves by the uredospores. Poplar Rust was not found on the poplar leaves in the South Island until January 1975; by the end of March many Poplars were defoliated in the Canterbury Area.