1975 Clover scorch

(Feb 1976) This report covers the three major clover scorch activities for the year: A) The tolerance screening at Denmark. B) The dry matter production in the second year of a mowing trial, in which clovers with and without scorch were compared the previous year. C) A summary of the first four years of a disease incidence survey - and an examination of some meteorological factors in relation to disease development. The first two were done jointly with Dr C.M. Francis. The following tentative hypotheses are advanced to explain the regional differences in the distribution of clover scorch: a) The disease becomes established easily and develops seriously in those areas with mild winter temperatures and many rainy days, especially in spring; i.e, the south and southern coastal areas (note that most of the serious scorch in the Manjimup district is in the Northcliffe area - which is very close to the coast. b) The disease has not become serious in much of the Great Southern and other inland areas in which sub clover. grows well because of the colder winter temperatures - and the higher likelihood of extended dryer periods in spring. c) The disease is not a problem in the northern areas because of a combination of warmer temperatures and less rainy days - in winter and spring. d) Occasional outbreaks in areas such as Badgingarra, Bannister and Kojonup, which are far removed from the bad scorch areas, indicates that the organism is spread over most of the sub clover areas, It also suggests that occasionally temperature and moisture conditions are conducive to disease development - but their relatively short duration means that the disease does not get the opportunity to spread seriously. Climatic data needs to be fully examined in conjunction with aspects of disease infection, spread and spore survival before much more can be said about the distribution of the disease (in relation to location and time). 74D

1977 Summary of results of field experiments (January 1978)

1. Inoculation. 1.1. High rainfall. 1.2. Low rainfall. 2. Clover Scorch. 3. Rye grass toxicity. LIST OF EXPERIMENTS 1. The responses of varieties of Trifolium yanninicum to inoculation with different strains of rhizobia - Denmark. 2. The response of T. yanninicum to inoculation over two growing seasons - Denmark. 3. The response of white and strawberry clovers to inoculation - Denmark. 4. The response of sub clover to inoculation - spaced row trial - Merredin. 5. The response of sub clover to inoculation - plot trial (Not sampled) - Merredin. 6. The response of sub clover to inoculation - spaced row trial (Not sampled) - Wilgoyne. 7. The response of sub clover to inoculation - plot trial (Not sampled) - Wilgoyne. 8. The response of sub clover to inoculation - spaced row trial - Bunjil. 9. The response of sub clover to inoculation - plot trial - Bunjil. 10. The response of sub clover to inoculation - spaced row trial - Perenjori. 11. The response of sub clover to inoculation - plot trial - Perenjori. 12. Clover varietal screening for tolerance to clover scorch - Denmark. 13. Attempts at inducing slime and gall development on ryegrass in the glasshouse

Summary of experimental results 1979 - Annual Rye Grass Toxicity

79KA15 The susceptibility of grasses to yellow slime disease 79KA16 The effect of gall burial on gall and slime production by annual rye grass sown into land with a history of ryegrass toxicity The effect of bacterial galls on development of slime and galls on ryegrass inoculated with nematode gall

Lupin and Serradella Inoculation Experiments

BACKGROUND: During 1967 there were a number of reports of poor establishment of Weiko and Uniwhite lupins. Because of the possibility of either delayed nodulation or insufficient nitrogen fixation being involved, an experiment was conducted during 1968 to examine a range of lupin rhizobia isolates in the field (a summary of this experiment was circulated during 1969). In this experiment two strains, WU425 and WU43, showed sufficient promise to warrant additional testing in 1969

Legume seed inoculation

List of experiments 1. 8ONA9A - The response of inoculated and non-inoculated field peas to fertilizer nitrogen on land not previously sown to peas. NARROGIN. 2. 8ONA9B - The response of inoculated and non-inoculated field peas to fertilizer nitrogen on land previously sown to peas. 3. 79GES8 - The performance of different strains of Rhizobium meliloti on different medics. TENINDEWA (Second year)

Screening of clovers for resistance to clover scorch

Clover Scorch (Jointly with Dr C.M. Francis). One thousand four hundred and seventy six legumes were screened in the field at the Denmark Research Station for susceptibility to clover scorch. They comprised 1440 subterranean clovers, eight other Trifoliums, two medics and 26 serradellas. The clovers from Australia gave interesting results. Thirty four of them were selections of Seaton Park, chosen by R.C. Rossiter and W. J. Collins on the basis of their variation. They did not differ in their reaction to clover scorch; all gave rating of 9. Twenty-six lines of Woogenellup from W.A. and 12 of Woogenellup and Morrar from N.S.W. were also tested. The Western Australian lines comprised 9 certified lines and 17 farmer samples from throughout the State (Esperance, Gairdner River, Kojanerrup, Albany and Ravensthorpe). They were tested because some farmers claimed that there appeared to be variation between lines and sources of Woogenellup in susceptibility to clover scorch; - all gave similar, high ratings at Denmark. The 12 lines of Woogenellup and Morrar also gave similar and high ratings. Sixty one per cent of the 309 cross breds gave low ratings (Table 2). Some crosses were quite unsuccessful, e.g. Midland B x Gingin, where 26 of the 27 crosses gave exceptionally high disease ratings. Others were the reverse, e.g. Dalkeith x 47308C and Dinninup x Daliak x Toodyay C where the majority proved very resistant

Clover scorch: Summary of 1974 experiments

Experiments reported in this summary were conducted jointly with CM Francis. 1. Variety Screening - During 1974, two hundred and fifty-four varieties were screened for resistance to Kabatiella caulivora in small plots at Denmark. The test varieties included 49 that showed up as promising in previous years. The remainder included all the untested accessions for which sufficient seed was available. There were 239 sub. sp. Subterranean, 14 sub, sp. Yanninicum and 1 Brachycalycinum... - The plots were periodically inoculated with infected debris and rated for disease severity on a number of occasions. Lists of the most and least resistant clovers are shown in Tables 1 and 2 respectively. Most of the more promising ones were clovers that had proved most tolerant in earlier tests. - 2. Clover production and kabatiella - In 1973 an experiment at Denmark Research Station showed that the herbage production and particularly seed production of susceptible varieties was greatly reduced by clover scorch. The seed production of the more resistant varieties was not greatly affected. The trial was repeated in 1974 on a better drained soil using a wider range of clovers (Table 3)... The disease greatly affected the seed production of Yarloop and Woogenellup and had very little effect on Y26 and Mt. Barker (Table 3)... 3. DISEASE INCIDENCE SURVEY Overall the disease was more severe in 1973 than 1972. The Margaret River is the most severely affected area. (Table 4)

1975 Field experiments on legume seed inoculation

(January 1976) LIST OF EXPERIMENTS 1. The effect of cobalt and seed inoculation on Unicrop lupins. GREEN RANGE 2. The effect of cobalt and seed inoculation on Unicrop lupins. BRAMLEY RESEARCH STATION 3. The effect of cobalt and seed inoculation on Unicrop lupins. McALINDEN 4. The effect; of cobalt and seed inoculation on Unicrop lupins. CHOWERUP 5. The effect of cobalt and seed inoculation on Unicrop lupins. ALANO OKA 6. The effect of cobalt and seed inoculation on Unicrop lupins. LANCELIN 7. The effect of inoculation on Uni crop lupins. KATANNING 8. The effect of inoculation on Uni crop lupins. BORDEN 9. The effect of inoculation on Uni crop lupins. WOODANILLING 10. The effect of superphosphate drilled with the seed on the nodulation of lupins. LANCELIN 11. The effect of manganese sulphate drilled with the seed on the nodulation of lupins. LANCELIN 12. The effect of superphosphate drilled with the seed on the nodulation of lupins. WANDERING 13. The effect of manganese sulphate drilled with the seed on the nodulation of lupins. WANDERING 14. The effect of method of inoculation and fungicides on the nodulation and growth of field peas. BREMER BAY ROAD 15. The response of some new early subterranean clovers to inoculation. MERREDIN INTRODUCTION Most of the field work was aimed at extending our knowledge of where responses to seed inoculation might be obtained in Western Australia. In some experiments this aim was combined with that of ascertaining the extent of the soils on which lupins responded to soil applications of cobalt (jointly with Mr J.W. Gartrell). Unfortunately, many trials were compromised by inadequate nodulation of the plants by the inoculant rhizobia. This was why the two trials examining the effect of drilled fertilizer on nodulation (75M028, 29 were repeated with late sowings at Wandering (75NA32,33). Only one of the six cobalt experiments (the one at Lancelin) showed a response to cobalt. This may mean that Lancelin is indeed the only area low enough in cobalt to give a response. Also, there may have been differences in seed quality (cobalt cotitent of seed). Note that the seed used in the very responsive 1973 and 1974 trials came from the West Midlands and had very low cobalt levels (in the order o