INCIDENCE OF ENDOPHYTES IN SEED LINES AND THEIR CONTROL WITH FUNGICIDES

Two seed transmitted endophytic fungi occur in many New Zealand ryegrasses. The percentage of viable endophytes in commercial seed is influenced by the incidence of endophytes in cultivar parent plants and the seed storage conditions. Endophytes may be killed in infected plants by drenching benomyl into the soil around plants or by spraying prochloraz on the foliage. Infected seed can be treated with lg of prochloraz/kg of seed to kill the endophytes. Keywords: Endophytic fungi, ryegrass staggers, seed transmission, fungicides.</jats:p

Importance of diseases in herbage seed production

Yield and quality of herbage seed can be affected by many diseases. In New Zealand the most important diseases of grasses are rusts, especially stem rust on ryegrasses, cocksfoot and timothy; head smut of bromes; and ergot of paspalum. Blind-seed disease is of minor importance on ryegrass at present. Clover yield can be affected by rot, scorch and stem nematode. These diseases and others are discussed in relation to changing farming practices, and disease control measures are suggested. Keywords: Herbage seed production, diseases, Puccinia graminis, Ustilago bullata, Claviceps paspali, Gloeotinia temulenta</jats:p

CROWN RUST AND PASTURE PRODUCTION

THERE is much information available on New Zealand's grasslands which indicates the vast difference between various theoretical plant (Mitchell, 1963) and animal (Hutton, 1963) production potentials and what is actually achieved in practice. Although these potentials are often regarded with scepticism, the fact remains that many research and demonstration farms and top farmers now produce quantities of animal products per acre which would have appeared ridiculously high a few years ago. Further, much grassland research is concerned with the identification of factors limiting the attainment of these potentials, as shown by work on treading (Edmond, 1966), nutrient cycling under grazing systems (Sears, 1953), and the optimum stage and intensity of defoliation of pasture plants (Brougham, 1961).</jats:p