Vietnam has rapidly emerged as a major global durian producer, marked by dramatic expansion and record yields in recent years. In 2024, Vietnam's durian output reached approximately 1.43 million tons, a year-on-year increase of nearly 25%. The industry is projected to continue growing at about 7.2% annually through 202. Durian in Vietnam flowers naturally in December–January and is harvested from May to June in the Mekong Delta, coinciding with the effect of the dry season. Off-season flowering (out-of-phase with the natural cycle) is widely practiced extending the harvest window, capture higher prices, and reduce competitive overlap. The current practices for inducing off-season durian flowering in Vietnam are the water stress, plastic mulching, and growth regulators, managed with precise irrigation and timing, to achieve reliable, high-value, year-round harvests. Biostimulants contribute to enhancing plant physiological responses, improving nutrient uptake, and increasing stress tolerance, which aids in reliable flower induction outside the usual season. Thus, the biostimulant application for off-season durian flowering in Vietnam could play supportive ways for high quality durian production and economic benefits for durian farmers. In this study, we evaluated the effectiveness of the foliar fertilizers (Seamel FLOR and Amix SILK) on the Off-season flowers inducing process of in Ri 6 durian trees variety to improve flower quality, reduce fruit drop, and increase fruit setting. The results showed that the treatment with Seamel FLOR (3 ml/L) produced the best outcomes during flowering stage. Our collective results demonstrated the importance of integrating a foliar application program in durian production, particularly for influencing off-season flowering

Biostimulants, Seamel FLOR and Amix SILK, off-season

Among the treatments tested, treatment 1 (Seamel FLOR + PBZ application) demonstrated the best performance in promoting flowering and improving flower quality in Durian. Treatment 1 accelerated flowering timing by 10 days compared to the control, and produced the highest number of flower clusters per branch (8.5–16.5 clusters). It also increased the number of flowers per cluster and resulted in longer flowers. Additionally, treatment 1 effectively reduced the rate of flower drop during the late stages, indicating better flower retention. These results highlight the significant potential of Seamel FLOR in enhancing floral development and reproductive development

Truong Thanh Xuan Lien, Nguyen Chi Long and Nguyen Viet Thanh (2025). Foliar Application of Biostimulant Seamel Positively Adjusted the Off-season Flowers Ri 6 durian Trees. Biological Forum, 17(9): 01-06