New Zealand Agricultural Intelligence

Pearson r = 0.42 — Moderate positive correlation. Warmer years tend to see higher kiwifruit output, as subtropical Gold varieties benefit from heat accumulation during flowering and fruit development. However, 2023's lower crop despite warm temps reflects the weather extremes (Cyclone Gabrielle) overriding the temperature effect.

Pearson r = 0.68 — Strong positive correlation between rainfall and wine grape volume — wetter years produced larger harvests (2022 was both the wettest and largest crush). This is partly because moderate rain supports vine growth. Extreme events (Cyclone Gabrielle 2023) caused localised losses but nationwide volumes remain driven by total water availability, especially in Marlborough.

Pearson r = -0.55 — Moderate inverse correlation. Canterbury wheat performs better in cooler years (2024/25 cooler season → best feed wheat yields). Excessive warmth can shorten grain fill periods and increase moisture stress, reducing milling quality.

Pearson r = -0.72 — Strong inverse correlation. Higher rainfall accelerates base cation leaching, lowering soil pH over time. NZ's wettest regions (West Coast, Waikato) require more frequent lime applications to maintain target pH ranges for pasture and cropping.

Pearson r = -0.38 — Weak to moderate negative correlation between windiness and crop quality indices. NE-dominant La Niña years (2021–22) brought warmer, more settled conditions beneficial for fruit quality. The shift to W-SW winds in 2024–25 correlated with more variable growing conditions and lower grape yields.