Japan reports record heat impact on crops as adaptation measures expand

Japan recorded its hottest summer on record in 2025, intensifying pressure on fruit and vegetable production and accelerating the shift toward heat-tolerant varieties and cooling technologies, according to the latest climate impact report released by the Ministry of Agriculture, Forestry and Fisheries (MAFF).

The report shows the country’s average temperature deviation reached +2.36°C, the highest since records began in 1898. In response, farmers expanded the planting of heat-resistant rice varieties by 42,000 hectares, bringing the total area to 248,000 hectares, or 18.2% of all table rice production.

Crops

High temperatures affected a wide range of fruit and vegetable crops across Japan.

In apples, poor fruit set linked to heat during flowering was reported in 40-50% of production areas nationwide, rising to 60–70% in northern regions. Grapes and satsuma mandarins also showed delayed or uneven colouring, particularly in western Japan, where impacts were recorded in 40-60% of growing areas.

Vegetables faced similar stress. Tomato crops experienced reduced flowering and fruit set in 40-50% of planted areas nationwide, while strawberries saw delayed bud formation in up to 70-80% of production zones in western Japan.

Measures

Producers are increasingly adopting practical adaptation tools to stabilise yields.

For fruit crops, switching to better-colouring varieties has proven effective, while mandarin growers are using night-time cooling systems. In vegetable production, shading materials, heat protection covers and plant cooling techniques are being widely introduced to maintain crop development during hot periods.

The report also notes a gradual diversification of production into crops better suited to warmer conditions, including avocado and okra cultivation in several prefectures.

MAFF expects climate adaptation to remain a central priority for Japan’s horticulture sector, as rising temperatures continue to reshape crop performance and regional production strategies. The ministry is encouraging wider adoption of proven heat-mitigation practices to support stable supply and protect farm productivity in the coming seasons.

source: maff.go.jp

photo: MAFF via facebook.com