Shoot.Root Growth and Nodule Formation of White Clover as Affected by Removal of Cotyledon and Unifoliolate

자엽 및 단엽 제법에 따른 White Clover 지상부 및 지하부 생장과 근류유형

Slow seedling growth rate and nodulation failure of white clover (Trifolium repens L.) has been limited its good establishment to pastures. The experiment was done to determine the effect of removal of cotyledon and unifoliolate on the shoot, root growth, and nodule formation of 4 white clover cultivars for 8 weeks after the treatment. Four white clover cv. Regal (large leaf), Louisiana S-I (medium-large leaf), Grasslands Huia (mediumsmall leaf), and Aberystwyth S184 (small leaf), were grown in IOcm plastic pot containing 2:l:l soi1:sand:peat moss mixture until grown to cotyledon or unifoliolate stage and then removed one (Cl) or two cotyledons (C2) at cotyledon stage, and unifoliolate only (U), unifoliolate and one cotyledon (UCl) or unifoliolate and two cotyledons (UC2) at the unifoliolate stage, and the plants were sampled at 4, 6 and 8 weeks after the treatments. The intact plants had greater shoot and root dry weights, and no. of nodules than removal-treated ones. Removal treatments at cotyledon stage, the dry weight and no. of nodules more decreased in C1 and C2 than that of unifoliolate stage. While the severer cotyledon removal, the more reduction. Although the dry weights and no. of nodules steadily inclined with regrowing period, the former were higher in Regal and La. S-1 than in the others since 6 weeks after removal treatment but the latter was more in S 184 than in the others 8 weeks after removal treatment. Relationship between no. of nodules and shoot or root dry weight was analysed as linear mode while the earlier and severe removal, the steeper slope. It was concluded that severer damage of cotyledon and unifoliolate had detrimental effects on the shoot and root growth, nodule formation, and aftermath establishment of white clover.