Some Effects of Sodium Chloride on Germination and Seedling Growth of Sugar Beet

Soaking sugar-beet seed in 1.0 M sodium chloride solution killed 6 per cent of the seeds but the remainder germinated when transferred to more dilute (< 0.28 M) solutions. Small differences in the concentration of dilute sodium chloride did not change the number of seeds which germinated but greatly affected water uptake and seedling growth. For example, after 10 days at 15 °C, radical length decreased almost linearly from 50 to 5 mm when the concentration increased from 0 to 0.2 M. Presoaking seed in water increased the concentration tolerated without reduction in growth. Advancing seed (presoaking followed by airdrying) increased seedling yield by 70 per cent by decreasing the time taken to emerge, increasing the number of seeds which germinated and eliminating the detrimental effects of small amounts of sodium chloride. Advancing seed also marginally reduced the variation in seedling yield in laboratory and controlled environment experiments. To minimize the risk of killing seeds or decreasing seedling growth it seems that no more than the recommended quantity (377 kg ha−1) of sodium chloride should be applied to sugar-beet crops.