Evaluation of additional nitrogen doses on the growth and yield performance in jute (Corchorus olitorius L.) in Bangladesh

Nitrogen (N) is a key macronutrient governing plant growth, biomass accumulation and fibre development in jute (Corchorus olitorius L.). However, both insufficient and excessive N application can adversely affect fibre productivity and resource-use efficiency. Due to improper nutrient management in Bangladesh, the jute fibre yields have steadily declined. To address this, a field experiment was conducted at the Regional Jute Research Station, Kishoreganj, Bangladesh during March–September 2023 using the jute variety BJRI Tossa Pat-8. The experiment was arranged in a randomised complete block design (RCBD) with 3 replications. Six N treatments were evaluated: T₁ = no N (control), T₂ = recommended nitrogen dose (RDN) 80 kg ha-1, T₃ = 120 % RDN (96 kg ha-1), T₄ = 140 % RDN (112 kg ha-1), T₅ = 160 % RDN (128 kg ha-1) and T₆ = 180 % RDN (144 kg ha-¹). Nitrogen application significantly affected all measured growth and yield parameters. The tallest plants (291 cm) and highest number of leaves (113.34 plant-1) were recorded under T₆, whereas the greatest basal stem diameter (19.46 mm), fresh weight (3.53 kg plant-1) and stem weight without leaves were obtained under T₄. Fibre yield increased with N application up to T₄ and then declined at higher application rates. The maximum fibre yield (3.21 t ha-1) and stick yield (6.71 t ha-1) were achieved with T₄, while the lowest values were observed in the control treatment. Harvest index was highest in T₂ (33.43 %) and lowest in T₆ (24.83 %), indicating reduced assimilate partitioning efficiency under excessive N supply. Correlation and principal component analyses (PCA) revealed strong positive associations between plant height, stem diameter and fibre yield. Application of 140 % of the RDN (T₄) which is application of 112 kg ha-1 provided the optimal balance between vegetative growth and fibre production, resulting in the highest fibre and stick yields. Excessive N promoted luxuriant vegetative growth but reduced harvest index and fibre productivity. Therefore, applying 140 % of the RDN may be an effective nutrient management strategy for maximising jute yield under similar conditions of Bangladesh.