Effect of interactive nutrition of sulphur (S) and boron (B) on agronomic, physiological, and yield attributes of Cút glutinous rice (Oryza sativa var. glutinosa) in Quang Ngai

Abstract

Low and unstable productivity of Cút glutinous rice in Quang Ngai is largely attributed to nutrient-deficient acidic soils and increasing heat stress during the reproductive stage. Identifying an optimum sulfur and boron nutrition strategy is therefore essential to improve grain yield, quality, and production sustainability. Based on this, the study was conducted over two consecutive Autumn–Winter paddy (2024-2025) in Nghia Giang commune, Quang Ngai province, Vietnam to evaluate the efficiency of combined sulphur (S) and boron (B) application on special Cút glutinous rice variety. A two-factor experiment was laid out in a Randomized Complete Block Design (RCBD) with four S levels (0, 15, 30, and 45 kg S/ha) and four B levels (0, 1.5, 3.0 and 4.5 kg B/ha) atop a basal fertilizer dose (5 tons manure + 90 N + 50 P2O5 + 60 K2O/ha), replicated three times. Analysis of 12 agro-biological indicators revealed that the S × B interaction decisively influenced rice yield. While vegetative growth and grain dimensions remained relatively stable, yield components (panicle number, grain filling rate) and physiological parameters (CO2 absorption) responded strongly to fertilizer treatments. The treatment with combined with proved most superior, maximizing the filled grain rate (88.8-92.7%) and actual yield (4.33-4.52 t/ha), which was 20–30% higher than the control. These results confirm the synergistic role of S and B in improving photosynthetic efficiency and pollination, providing a scientific basis for sustainable intensive cultivation of Cút glutinous rice variety.