Puzzling weather at Mystery Creek

By Philippa Stevenson
Agricultural editor

Two seeming essentials of farming life - discussing the weather and attending the National Agricultural Fieldays - are set to coincide this week.

The fieldays at Mystery Creek, near Hamilton, begin on Wednesday and are again expected to attract more than 100,000 visitors to the agricultural show which in 31 years has become the largest in the Southern Hemisphere.

The major theme of the four day event is weather - a subject whose topicality is growing as New Zealand experiences changes brought by swings between the La Nina and El Nino climate patterns, say climatologists.

The National Institute of Water and Atmospheric Research (Niwa) said autumn had been the third warmest since records began in 1853.

Spokesman Dr Jim Salinger said the national average temperature of 14.4degC was 1.2degC above the 1961-1990 average.

Autumn climate extremes were due to a combination of more frequent anticyclones, often centred near the Chatham Islands, which brought more warm northerlies over the North Island, and nor-westers over the far south.

"This is a reasonably typical La Nina pattern," he said.

The season was exceptionally dry in central Marlborough, and in the east of the South Island from just south of Christchurch to Dunedin.

As a result soil moisture levels in those districts were just about exhausted. Rainfall was also much lower than normal in the Waikato.

Dr Salinger will present a paper at Fieldays seminars on Friday and Saturday on the changing climate.

Niwa would also respond to the growing need for seasonal information next month when it launched its national climate centre and produced its first three-month, seasonal outlook on July 16.

The centre would involve forecasters in Auckland, Wellington and Christchurch predicting upcoming weather patterns which would include soil moisture levels and river flows.

Meanwhile, researchers from HortResearch's national climate laboratory will be at the fieldays to explain the benefits for crop development of being able to dial up the season required.

Among them will be stonefruit breeder, Mike Malone, who has developed ornamental crabapples given the name Snow Charm and Snow Bright which are covered in white flowers in spring, and masses of bright red fruit in autumn.

Around 900 companies exhibit at the fieldays and last year they achieved a leap in export orders to more than $1.9 million of confirmed sales. The figure was double the 1997 figure and almost $800,000 more than the previous best of $1.11 million in 1992. Confirmed New Zealand sales for 1998 were around $47.1 million, down on 1997's $49.65 million.

Prime Minister Jenny Shipley is expected to open the fieldays at midday on Wednesday.