Role Of Phalaris In Australia

Press, Volume CII, Issue 30026, 10 January 1963, Page 12

Role Of Phalaris In Australia

Phalaris Tuberosa is one of the most important perennial grass species in Australia. Scientists and fanners alike are not, however, completely satisfied with it and are interested in either improving it or replacing it by something that will grow better in the colder months of the year. The legume of equal importance is subterranean clover. Mr R. M. Moore, an assistant chief of the plant industry division of the Commonwealth Scientific and Industrial Research Organisation, recalled last month that some 24 years ago a New Zealander, Dr. McTaggart, who had been In charge of plant introduction, had come to the conclusion from trials carried out on the old Duntroon station near Canberra that phalaris was a worthless grass because stock would not eat it. He had found that out of a series of plots of different pasture species phalaris was the last that stock would touch. It nad nevertheless proved to be the most persistent and productive species under the conditions of low fertility then prevailing and for these reasons in spite of its relative unpalatability interest had been taken in It It had been found that where animals had nothing else to eat they ate it and did well on it. This conviction had been strengthened over the years and Mr Moore said that phalaris had Shown itself to be a truly remarkable grass in that it could withstand very neavy grazing in the most severe drought and then when the rains came it would regenerate again without lowing any apparent ill effects from drought or heavy grazing. The mistake that most farmers made with phalaris in Australia was that when they established it they treated it like a stand of lucerne —they coddled it. This was the worst thing that they could do. It had to be heavily stocked as it was a strong growing species and if allowed to get away it would become coarse and less attractive than it was inherently.

In the Canberra area Mr Moore said that they had been able to carry five sheep to the acre on phalaris without any trouble in spite of droughts or other climatic conditions. In 1956 he said that the annual rainfall had been 42 inches and in the following year 11 inches with only eight in the growing season. Experimentally nine sheep have been carried to the acre and in the last two years 14 sheep had been carried to the acre. The weaknesses of phalaris were that it made poor quality hay and if the seasonal conditions were such that subterranean clover failed to germinate or germinated and was then killed by dry conditions stock might develop phalaris staggers on pasture containing only young phalaris. This seemed to be associated with a deficiency of cobalt and it could be effectively prevented by topdressing the pasture with cobalt or putting a cobalt bullet into the rumen. Another condition called phalaris sudden death had last occurred in 1960. This occurred on old established pastures which were phalaris dominant Animals collapsed after, for example, being disturbed by a dog. There was no warning that the animal was going to die. It normally collapsed and died very quickly and post mortem examinations revealed no abnormal conditions. It had not been possible to get to the bottom of this trouble nor to reproduce it experimentally. Mr Moore said that all he had been able to determine was that such phalaris pastures were high in nitrate nitrogen, but the condition in the animals was not the classical nitrate poisoning. It seemed that the condition was associated with high fertility pastures with soils and plants high in nitrate nitrogen. The condition, he said, might have some relationship with ill-thrift in the sense that young pasture coming away in autumn might be high' in nitrate nitrogen and thus unpalatable. Animals eating phalaris had, however, got used to eating an unpalatable species and when sudden death occurred they had nothing else to eat. Mr Moore said that his division had done a lot of study of management of pastures on which wool producing sheep were run. They had not in fact found any grazing management system that gave better production than continuous grazing. These studies had, however, indicated that on the tablelands a possible factor limiting production was the low temperatures recorded In the winter. Consequently they were looking at the possibility of increasing production in the winter by using species other than phalaris. Two species that were very interesting were Brignoles cocksfoot from France and a tail fescue called Demeter from North Africa.

A study was also being made of the different capacities of strains of rhizobium to fix nitrogen under low temperature conditions in the hope of defining strains which would continue to fix nitrogen in the colder months and thus keep the essential legumes growing and overcome limitation of nitrogen if this was the limiting factor.

An attempt was also being made to try to breed into phalaris greater winter productivity. Two expeditions had been to the Mediterranean to collect strains of phalaris and subterranean clover and some of this material was being used in hybrids to try to produce greater winter production. A hydrid had been produced between phalaris tuberosa and phalaris arundinacea which was quite promising and was now under test It looked as it might outyield phalaris tuberosa both in winter and summer.