Influence of marine heatwave likely to continue into autumn

In its Seasonal climate outlook February 2022 - April 2022 (niwa. co.nz) NIWA says sea surface temperatures in New Zealand’s coastal waters ranged from 0.9°C to 1.9°C above average.

In the Wairarapa, NIWA says temperatures are likely to be above average or near average over the next three months with periods of high humidity and warm overnight temperatures.

“It is therefore important that when regional spore counts start trending upwards to reach 20,000 to gather a picture of your own farm.

“Similarly, it is not uncommon for spore counts to decrease unusually early or unusually late. Therefore do not stop your management program until you are certain that the spore counts are trending down and are consistently below 10,000 spores/g for three weeks,” says DairyNZ.

Cattle need to be fully dosed with zinc as soon as there is an indication that spore counts are rising on your farm.

Daily individual cow drenching at full dose is optimal for protection against FE. However, Zinc is toxic in high doses so care should be taken in calculating dose rates.

When your pasture spore counts are consistently at 10,000 or less for three weeks and this is accompanied by cooler temperatures, you can stop your management programme.

However, if you have stopped earlier than you are used to, keep an eye on regional spore counts for any spore count movements.

The booklet “Facial Eczema - Treatment and Prevention” can be downloaded from dairynz.co.nz

La Niña conditions peaked in the equatorial Paciÿ c during January, with a 75% chance for its continuation during the next three months, with the marine heatwave conditions continuing to have an upward in˝ uence on air temperatures and humidity.

In late January, abnormally dry conditions were occurring across the Wairarapa, according to NIWA’s New Zealand Drought Index.

A reduction in westerly winds may lead to fewer hot days than normal, however.

Rainfall totals are about equally likely to be near normal or above normal.

That said, heavy rainfall events which can lead to abrupt and rapid increases in river ˝ ows and soil moisture, and extended dry spells could both be possible.

NIWA says weather-sensitive groups should keep a close eye on day-to-day forecasts.

Soil moisture levels and river ˝ ows are most likely to be near normal.