Influence of Cutting Diameter on Survival and Height Growth in Populus nigra×P. maximowiczii F₁ Clones

Populus nigra×P. maximowiczii F₁의 삽수직경(揷穗直徑)이 활착(活着)과 수고생장(樹高生長)에 미치는 영향(影響)

Survival and height growth affected by cutting diameter were studied to find out the optimum size of cuttings in Populus nigra${\times}$p. maximowiczii $F_1$ clones. The size of the cuttings should be at least 8mm, when 80 percent of survival rate is considered as a standard. The height growth was increased with increase of cutting diameter for two months after planting and, after two months, effect of cutting diameter on height growth was decreased since July. However, the survival rate and height growth of large cuttings (above 13mm) showed better than small cuttings (below 13mm), when the cutting sizes are divided into two groups. Height growth per day was reached at peak during August, and then it was gradually decreased. It was considered that the height growth terminated in early 10 days of October.

Populus nigra${\times}$P. maximowiczii의 적정삽수(適正揷穗) 굵기를 구명(究明)하기 위하여 삽수직경별(揷穗直徑別) Clone별(別) 활착률(活着率)과 수고생장(樹高生長)을 연구(硏究)한 결과(結果)는 다음과 같다. 활착률(活着率) 80% 이상(以上)을 기준(基準)할 때 삽수(揷穗)굵기는 최소(最小) 8mm 이상(以上)이어야 하며 수고생장(樹高生長)과의 관계(關係)는 삽목(揷木) 후(後) 2개월(個月)까지는 삽수직경(揷穗直徑)이 클수록 수고(樹高)도 커지나 이러한 효과(効果)는 2개월(個月) 이후(以後) 즉(即) 7월(月)부터 점차 감소(減少)되는 경향(傾向)을 보였다. 삽수(揷樹)의 굵기가 13mm 이상(以上)되면 그 이하(以下)의 삽수(揷穗)보다도 현격(懸隔)히 활착률(活着率)(92.7%)이 높아지며 수고생장(樹高生長)도 좋아지는 경향(傾向)을 보였다. 일일수고생장(日日樹高生長)은 8월중(月中)에 최고점(最高點)에 달(達)했으며 이후(以後) 점차 감소(減少)하면서 10월(月) 상순(上旬)에는 거의 정지(停止)되는 것으로 추정(推定)된다.