观赏兼油料树种水冬瓜,通过高接换头后,使雄株变为雌株,保持有原雄株生长势强的特点,结果性能比接穗母株良好,是一种行之有效的方法。水冬瓜雌雄异株,雄株往往占30—50％,影响种子产量的提高。近年来,一些单位通过芽接,育大苗,开花后定植,在改造雄株上取得了一定结果。但对已成林的水冬瓜如何改造,改造后将取得什么结果,尚无详尽报导。1970年6月,我们在本所南五台试验站,对已开花的水冬瓜雄株进行了高接换头试验。试验用芽接法,接穗为已开花优良雌株的1年生枝条。芽片盾形,芽上约0.5厘米,芽下 Ornamental and oil species water melon, high through the head, the male plant into a female plant, maintaining the strong growth of the original male plant characteristics, the results than the scion mother plant is good, is an effective method. Water melon dioecious, male plants often account for 30-50%, affecting the improvement of seed yield. In recent years, some units through budding, breeding large seedlings, planting after flowering, in the transformation of male plants have achieved some results. However, what has been achieved after the transformation of the water melon that has just become a forest has not yet been fully reported. In June 1970, we conducted a high head-to-head test on the flowering watermelon male plants at the South Wutai Experimental Station. Test bud method, the scion for the female flowers have been excellent 1-year-old branches. Shoot film shield, shoot about 0.5 cm, bud under