Volume 27, 406

Tropical Grasslands (1993) Volume 27, 406–413

Tropical pasture establishment.
17. Prospects for using weather prediction to reduce pasture establishment risk

R.C. STONE¹ and G.M. McKEON²

¹Agricultural Production Systems Research Unit, QDPI/CSIRO, Toowoomba, Queensland, Australia;
²Queensland Department of Primary Industries, Brisbane, Queensland, Australia

Abstract

Relationships between Southern Oscillation Index (SOI) phases, that include a change of SOI value from month to month, and summer pasture sowing opportunities at a number of locations in northern Australia have been investigated. The number of planting opportunities, date of first planting opportunity, number of days to second opportunity and the probability of obtaining a planting opportunity were all significantly related to the SOI phase for the previous December. The degree of relationship varied with the location being analysed.
Planting opportunities at locations in the more northern and western areas were affected to a greater degree by the El Niño/Southern Oscillation than those at other locations. Low SOI values during December appeared to be related to fewer planting opportunities, higher probability of not receiving a planting opportunity at all, higher probability of not receiving a second planting opportunity, and a longer interval between planting opportunities.
The relationship between the 30–50 Day Oscillation and planting opportunity was investigated. On 50–60% of occasions, passage of the 30–50 Day Oscillation was associated with a planting opportunity within the following 10 days and 30–50 days later.