Optimization of seed rate and nutrient management levels can reduce lodging damage and improve yield, quality and energetics of subtropical flax

Subtropical flax crop often faces an acute problem of lodging owing to having medium to severe winds coupled with occasional rains during its maturity time. To address this problem an experiment was conducted with three different seed rates and six different nutrient managements for two consecutive years during 2019-20 and 2020-21 at Pantnagar. From this two-year study, it was observed that the higher seed rate of 100 kg ha(-1) resulted in the maximum plant population, plant height, fibre yield as well as quality among the different seed rate levels. However, lower stem diameter, higher fresh weight of the stem, centre of gravity and poor tensile performance with higher seed rate exhibited lower values of lodging safety indicators. Considering the different nutrient managements, application of 90 kg ha(-1) nitrogen (N), 30 kg ha(-1 )phosphate (P2O5) and 45 kg ha(-1) potassium (K) was found to be the best in terms of reduction of lodging vulnerability with better yield, quality and net energy output of fibre production with saving about 25% of the N input. The seed rate of 100 kg ha-1 when combined with 90 kg ha(-1) N, 30 kg ha(-1) P2O5 and 45 kg ha(-1)K(2)O resulted in optimum crop performance and the lowest lodging under subtropical humid region. The calculated lodging indicators were found exponentially related with actual lodging. The experiment further reveled that lodging damage directly impacts fibre quality and proportion of long fibre in the total fibre yield.