Maintaining 'Sellable Quality' Even Under Extreme Heat: Biostimulant Trials Confirm Effects in 92% of Fruit Vegetables

AGRI SMILE Co., Ltd. (Headquarters: Chiyoda-ku, Tokyo; President and CEO: Takaya Nakanishi) announces that in biostimulant trials conducted across 106 JAs, 69 crops, and 1,500 hectares nationwide, yield or quality improvements were confirmed in 92% of fields growing fruit vegetables such as tomatoes, cucumbers, eggplants, and bell peppers. Effects including stabilization of yield and premium-grade rates, reduction of off-grade produce, and stable fruit setting under high-temperature conditions have been confirmed, indicating potential contributions not only to increased farmer income but also to the stable supply of fruit vegetables.

※1: AGRI SMILE, "Launching pilot introduction and effectiveness verification of biostimulant materials in compliance with MAFF guidelines across 32 prefectures and 100 JAs" (July 2025) https://prtimes.jp/main/html/rd/p/000000046.000039438.html

Background

According to the Japan Meteorological Agency, Japan’s annual average temperature in 2024 exceeded the normal baseline (1991–2020 average) by 1.48°C, with summer average temperatures 2.36°C higher—marking the highest on record※2. In recent years, in addition to rising temperatures, the prolonged duration of heatwaves has expanded impacts on agricultural production nationwide.

Among crops, fruit vegetables such as tomatoes, cucumbers, eggplants, and bell peppers are particularly susceptible to adverse effects from high temperatures, including poor fruit set, flower drop, inadequate fruit enlargement, uneven coloring, and smaller fruit size. For fruit vegetables, market value is directly tied not only to yield but also to quality factors such as shape, size, color luster, and shelf life. Therefore, rising temperatures do not merely reduce yields but also lower the proportion of marketable produce, affecting farmer incomes, distribution prices, and supply stability.

In this context, AGRI SMILE has collaborated with JA groups and regional agricultural experiment stations to scientifically evaluate and promote biostimulant materials as a technology to achieve stable production under climate change. In 2025, large-scale trials were conducted across 106 JAs, 69 crops, and 1,500 hectares, with cost-effectiveness confirmed in 80% of the 200 fields where harvest and economic evaluations were completed※3.

However, challenges and desired outcomes vary by crop. For fruit vegetables in particular, maintaining quality that meets shipping standards under high temperatures—alongside securing yield—significantly impacts farm profitability. Therefore, as a follow-up to the nationwide trials, AGRI SMILE is now releasing verification results and case studies of biostimulant use in fruit vegetable production regions.

※2: Japan Meteorological Agency (July 2025), "Climate Change Monitoring Report" https://www.data.jma.go.jp/cpdinfo/monitor/index.html

※3: AGRI SMILE, "Utilizing verification data from 1,500 hectares across 106 JAs and 69 crops, cost-effectiveness of biostimulant materials confirmed in 80% of 200 evaluated fields" (December 2025) https://prtimes.jp/main/html/rd/p/000000052.000039438.html