Basal application of composts prepared from agricultural by-products affected the growth, nutrient contents and yield of <i>Chrysanthemum indicum</i> L. grown organically

This study was conducted to evaluate the influences of composts applying at different times on the growth, nutrient accumulation and yield of chrysanthemum plant.The research was conducted at Vietnam National University of Agriculture in Vietnam in 2023.Two types of compost were C3 (compost was prepared from rice straw, cow manure and elephant grass) and C4 (compost was prepared from rice straw, cow manure and cabbage leaves).The application times were T1 (20 days before transplanting), T2 (10 days before transplanting) and T3 (1 day before transplanting).The parameters of the growth, nutrient contents, yield of chrysanthemum were evaluated.The results showed that the C3 and C4 composts had similar effects on the growth and yield of chrysanthemum.Earlier application of compost caused the significantly higher values of the growth and yield parameters in comparison with later application.T1 treatment gave the highest values of experimental indicators.The combination effects of compost types and application times on the growth and yield of chrysanthemum were significantly different when comparing among the treatments.Application of C3 or C4 composts at 20 days before transplanting was both good for chrysanthemum growth with the highest values of LAI (0.911 and 0.958 of C3 and C4 treatment at bud stage), dry weight (175.85 and 163.87 g plant -1 of C3 and C4 treatment in harvesting stage) and yield (18.64 and 18.16 quintal ha -1 of C3 and C4 treatment).