GROWTH-CHARACTERISTICS AND EFFECT OF NITR OGEN AND POTASSIUM TOPDRESSING ON THICKENING GROWTH OF BULBS IN SPRING-PLANTED EDIBLE LILY (LILIUM-LEICHTLINII VAR MAXIMOWICZII BAKER)

The growth characteristics of spring-planted edible lilies, sown in po ts and fields, were investigated. The effect of nitrogen and potassium topdressing on the thickening growth of the bulbs was also examined. The growth period of the edible lily could be divided into the followi ng four stages. In the first stage, from planting to sprouting, the fo liage grew using the materials stored in the bulb. In the second stage , from leaves expanding to flower bud appearing, the foliage vigorousl y developed and started to transfer photosynthetic products from the a bove ground parts to the subterranean parts. The third stage was from flower bud expanding to middle August, which would be flowering time u nless being disbudded. In this stage, the leaf area and dry weight of the tops continued to increase, and the old bulb increased dry weight most vigorously among the subterranean organs. In the fourth stage, fr om middle August to harvesting, the growth of the foliage almost stopp ed, and the new bulb mainly showed the increase of dry weight. By a ni trogen and potassium topdressing after the flower bud appeared, the ro ot growth became more active, and the nutrient absorption and the dry matter production continued until the latter growth stage. Therefore, the topdressing resulted in the continuous growth of bulbs during the fourth stage, and consequently increased the yield.