Total of 69 open-pollinated family seeds were harvested from the clonal seed orchard of Pinus thunbergii, and planted at Jeju and Anmyon in 1992. When the progenies were 16 years old, height, DBH and volume growth were measured. The results showed that al

Height-growth analysis was used to examine forest structure and compare Pterocarya rhoifolia and Fraxinus spaethiana growth characteristics within and between each species in two P. rhoifolia-dominant and two F. spaethiana established contemporaneously in the sere, species vertical stratification 25 years after stand initiation was such that P. rhoifolia dominated the overstory but F. spaethiana the understory, including that P. rhoifolia grew about 4 times more rapidly. Similarly, F. spaethiana dominated the overstory but not the understory, in a stand where it established mainly by itself, 25 years after initiation. However, comparing the two different stands, P. rhoifolia overstory heights were about two times greater than F. spaethiana. This suggests that in a disturbance regime, forest regeneration is affected by height-growth patterns such that P. rhoifolia's ability to achieverapid height growth allows it to dominate where lights growth allows it to dominate where light resources are continuously abundant.

The objectives of this study were to examine the genetic variation of 20-year-old tree height and to estimate heritabilities and genetic gains of Korean white pine. Analysis of variance showed that families and family x block interaction had the significant (p=0.01) effects on tree height. However, family variation appears to be much greater than the variation due to family x block interaction. Individual tree heritability was higher (hI2=0.73) than family heritability, (hF2=0.83) therefore, combined selection showed the largest genetic gain (17.76%) in a given equal intensity of selection.

묘삼 재배시 원야토와 약토의 적정 혼합비율을 설정하고 해가림 시설 설치시 기존관행 방법의 문제점을 개선하고 작업효율을 높이기 위하여 시험을 수행 한 결과는 다음과 같다. (1) 상토조제시 약토의 적정 구성비율 설정시험에서 약토함량이 증가할수록 고상은 감소하고, 공극율과 기상, 토양중 OM과 P2O5 함량이 증가하는 경향이었다. (2) 약토함량별 지상부 생육은 약토함량 증가에 따라 엽면적, 엽록소는 증가하였으며, 지하부 생육중 근경과 근중이 증가하였다. (3) 약토조성별 규격묘 생산량은 백마사 약토비율이 10:1처리에서 사용가능 묘삼은 750개/칸 수준으로 양호하였다. 2. 해가림 (일복) 전주목 적정높이를 설정하기 위한 시험에서 (4) 전주높이별 광량은 전주높이가 높을수록 광량이 많았으며 평균지온은 전주높이가 150 cm에서 낮아 광량과 지온은 비례하였다. (5) 해가림 시설 전주목 높이가 낮을수록 엽록소 함량과 근중이 증가하는 경향이었고, 사용가능 묘삼수는 처리간 유의성은 없었으며, 또한 관행보다는 그 수가 적었지만 전주높이 150 cm에서 740개/칸로 높았다.

Growth and yield of licorice were investigated under the different conditions of ridge height, planting density, and irrigation in order to establish its cultural practices for the domestic production with the aim to substitute the import. Seedlings were grown under low ridge(20cm) and high ridge(40cm) in low density plot(60×30cm) and high density plot(40×30cm), respectively. The low ridge cultivation of large seedlings increased plant height and root length under low density, and stem and root diameter under high density compared to the high ridge cultivation. In the high ridge cultivation, high density plot was 1.1 to 1.3 times in plant height, root length, stem and root diameter as high as low density one. Fresh and dry weight of plant and root in high ridge were 1.3 to 1.5 times as high as those in low one. The growth of small seedlings(4~10g) were generally poor compared to that of large seedlings. High density plot in low ridge showed the good growth characteristics including plant height, root length, stem and root diameter, and number of branch. High density plot was 1.4 to 1.6 times in fresh and dry weight of plant and root as high as low density plot. In the seasonal changes of growth under various irrigation regimes, the twice irrigation a day produced the more number of leaf than the other regimes since around 46 days after transplanting. The former irrigation resulted in 1.2 to 1.4 times in plant height as long as the other irrigations around 26 days after transplanting and then the difference was increased to 1.6 to 2.0 times around 64 days after transplanting. Under the twice irrigation a day, plant height, root length, stem diameter, root diameter, number of leaf, fresh plant weight, dry plant weight, fresh root weight, dry root weight were 1.6 to 2.0, 1.1, 1.2 to 1.6, 1.3 to 1.8, 1.9 to 2.7, 1.7 to 8.0, 1.6 to 2.8,2.0 to 3.0, 1.6 to 2.7 times as high as those under the other irrigation regimes, respectively.

Excessive soil water in paddy field induces growth losses during the vegetative stages of soybean plants. Our objectives were to know growth responses of soybean as affected by the level of ridge heights. A field experiment was conducted at the Research Farm of Korea University near Seoul in 1996. Ten cultivars of soybean (Glycine max (L.) Merrill) were planted at the ridge heights of 10, 30, and 50cm in paddy soil on 27 June. Total dry matter accumulation at the 10cm ridge height was severely decreased until the growth stage of R5 as compared to the ridge heights of 30 and 50cm, and this decrement was mainly due to both reduced leaf and stem dry weights. However, seed dry weight was not significantly decreased at the lower ridge height with the increment of harvest index. Cultivar differences were found on seed dry weight, crop growth rate from R1 to R5, and leaf/stem ratio of R5. From the above results, soybean growth responses to excessive soil water in paddy field were different between seed filling stage and late vegetative to early reproductive growth stages