A recent study published by the Institute of Vegetable and Floriculture Sciences identifies air temperature during anthesis as a key factor influencing fruit size in sweet pepper, providing growers with new insights into environmental management for improved yields.
Fruit size in horticultural crops is influenced by belowground factors (water and nutrient supply), aboveground factors (temperature, humidity, photosynthate availability, and fruit load), and cultivar differences. In hydroponic systems, water and nutrients can be optimized, making cultivar choice and aboveground conditions the primary determinants of fruit size. These aboveground factors are particularly important for sweet pepper fruit size, especially in widely grown bell-type cultivars.
Researchers were motivated to clarify the causes of fluctuations in sweet pepper fruit size due to the variations observed at production sites in Japan, which span from subtropical to subarctic zones.
Researchers monitored sweet pepper development under varying temperature conditions to determine how the timing of heat or cooler periods affected fruit growth. The results showed that air temperature during the anthesis stage—the period when flowers are fully open and pollination occurs—played a decisive role in determining final fruit size.
Favorable temperatures during this critical stage supported better pollination, fruit set, and subsequent growth, leading to larger marketable peppers. In contrast, suboptimal temperatures during anthesis reduced fruit size, regardless of later growing conditions.
These findings emphasize the importance of closely managing greenhouse or field environments during anthesis to maximize pepper productivity. The research also provides a framework for breeders and growers to refine cultivation practices in the face of increasingly variable climate conditions.
The full articles can be found on the Journal of the American Society for Horticultural Science electronic journal website at the link here.
