@article{oai:u-ryukyu.repo.nii.ac.jp:02002933, author = {野瀬, 昭博 and 仲間, 操 and 宮里, 清松 and 村山, 盛一 and Nose, Akihiro and Nakama, Misao and Miyazato, Kiyomatsu and Murayama, Seiichi}, issue = {34}, journal = {琉球大学農学部学術報告, The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus}, month = {Dec}, note = {栽植密度が,夏植え一次株出しサトウキビの生産に及ぼす影響を2種類の土壌条件下で乾物生産の面から調査した。供試したサトウキビ品種はNCo310,栽植密度は株間40cm×畦間135cm(標準区),同20cm×135cm(密植区)の2種類,土壌は泥灰岩土壌とサンゴ石灰岩土壌である。得られた結果の概要は以下の通りである。1)2月の収量調査では,泥灰岩土壌畑標準区で8.1ton/10a,Brix17.0度,同密植区で7.6ton/10a,16.7度,サンゴ石灰岩土壌密植区で6.2ton/10a,16.8度と,原料茎収量に密植の効果は認められなかった。2)単位土地面積当り総重あるいは茎重は,泥灰岩土壌畑においては2種類の栽植区で2月の最終調査日まで増大し続けた。しかし,サンゴ石灰岩土壌畑において総重は12月から2月にかけて減少,茎重は定常値に達した(図1)。3)単位土地面積当りの茎数は12月に密植区で12.5∿13.6本/m^2と多くなるものの収穫期及び生育の前期では殆ど差がなかった(表1)。4)個体群生長速度(CGR)は,6∿10月という夏季に泥灰岩土壌標準区で18∿17g/m^2/dayを示し,サンゴ石灰岩土壌密植区で8∿10月のCGRが同様になるものの,密植区のCGRは小さかった(図3)。5)葉面積指数(LAI)は,何れの区においても2.5を越すことがなく,LAIに密植の効果が現れなかった(図3)。6)CGRは純同化率(NAR)と有為な正の相関(r=0.914)をしめし,LAIとは無相関であった。7)8月下旬での群落吸光係数はLAIが-1.3∿-3.1の範囲でLAIの増大にともない負の大きい値となった(図7)。8)乾物の器官への分配率は,6月から2月の調査期間を通し,茎への分配が60∿80%と常に高い値を示した(図4)。, The effect of planting density on the growth of the first ratoon crop of summer planted sugar cane was investigated with the field of two soil types on aspects of dry matter production. Sugar cane variety used in the experiments was NCo 310 (Succharum officinarum L.). Planting density was 40cm×135cm for standard block, and 20cm×135cm for dense planting block both in intrarow spacing and row width; and the soil type was marl soil and coral limestone soil. Results obtained are as follows : In this study dense planting did not affect the cane yield. For example, the final cane yield and brix for standard block and dense planting block both in marl soil field were 8.1 tons per 10 a and 17 degreee, 7.6 tons per 10 a and 16.7 degree, respectively. On the other hand, those for dense planting block in coral limestone soil were 6.2 tons per 10 a and 16.7 degree. In the experiments in marl soil, total dry weight including dead part and dry stalk weight both per unit land area kept increasing in the two planting density blocks until the last experiment day in February. In the coral limestone soil, however, the total dry weight was decreasing in the dense planting block during December and February, while dry stalk weight kept a constnt value in the same block and during the same period. The number of stalks per unit land area in December was larger in dense planting block by 2.5 to 3.6 per one m^2 than in standard block, but there was not much difference at harvest time and in the first part of growth stage (Table 1). Crop growth rate (CGR) of standard block in marl soil showed the value of 17-18g/m^2/day during the summer period of June to October, and that of dense planting block in coral limestone soil was almost the same value of 17-18g/m^2/day during August and October. In other periods except to the above mentioned periods, CGR was small (Fig.3). Leaf area index (LAI) in each block did not exceed 2.5,and the effect of planting density on LAI was not found (Fig.3). CGR showed a statistically significant positive correlation to net assimilation rate (NAR) with r=0.914,but it did not to LAI. Community light extinction coefficient (K) in the last ten days of August gave large negative values as LAI increased to the range of 1.3-3.1 (Fig.7). Distribution rate of dry matter into the stalk kept high value of 60 to 80 percent throughout the experiment period of June to February (Fig.4)., 紀要論文}, pages = {1--10}, title = {栽植密度及び土壌型が夏植え一次株出しサトウキビの生産特性に及ぼす影響(農学科)}, year = {1987} }