Abstract
The incidence and severity of paspalum leaf blight (PLB) and yield of infected plants in soil cores subjected to water stress under different irrigation and fertiliser regimes, and the effects of water potential on germination and growth of Ascochyta paspali, were investigated. Symptoms of PLB were produced more rapidly when paspalum plants infected with A. paspali were subjected to water stress, and disease severity (per cent diseased dry matter) was significantly higher in water-stressed plants compared to those subjected to basal or flood irrigation. The addition of NPK fertiliser had no effect on PLB incidence or severity but dry matter yields of uninoculated plants were significantly increased compared to inoculated plants. Yields of inoculated fertilised plants also differed significantly between irrigation treatments. Germination and growth in vitro of A. paspali declined at water potentials below −1.2 MPa and ceased at -4 MPa. Sporulation was inhibited at −1.9 MPa. The results indicate that pastures affected by PLB need to be well irrigated and fertilised to alleviate the loss of dry matter production caused by this disease.
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Morley, T.B., William, B.L. & Price, T.V. The effects of water stress on the incidence and severity of paspalum leaf blight and on Ascochyta paspali . Australasian Plant Pathology 22, 105–110 (1993). https://doi.org/10.1071/APP9930105
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DOI: https://doi.org/10.1071/APP9930105