• Plant Resources
• /
• v.5 no.3
• /
• pp.196-201
• /
• 2002

This study was conducted to investigate the relationships between yearly variations of climatic elements and yearly variations of productivity in sesame. In addition, correlation coefficients among yield and yield components were estimated. The data of yield and yield components were investigated for 10 years from 1992 to 2001. The meteorological data gathered at the Yeosu Weather Station for the same period were used to find out the relationships between climatic elements and productivity. Yearly variation of the amount of precipitation in July and September were large with coefficients of variation(c.v.) of 64.59, 92.47%, respectively, but the variation of the average temperature in June and August were relative small. Yield and plant height greatly with c. v. of 26.24, 23.41 %, respectively, 1, 000 grain weights show more or less c.v. of 3.83% and length capsule setting show still less variation. Correlation coefficients between maximun temperature in period of cultivation(from June to September) and yield are positively significant at the level of 5.1 %, respectively. Correlation coefficients amount the plant height, length capsule setting, number of capsules per plant, weight of 1, 000 grains and seed yield were positively significant at the level of 1 %, respectively. Simple linear regression equations by the least square method are estimated for number of capsules per plant(Y$_1$) and the maximun temperature in August(X) as $Y_1$=10.1255+0.1725X, and for yield(Y$_2$) and the maximun temperature in August(X) as $Y_2$=21.6151 + 1.3724X.

• Plant Resources
• /
• v.6 no.2
• /
• pp.134-139
• /
• 2003

This study was conducted to investigate the relationships between yearly variations of meteorological elements and yearly variations of productivity in rice. In addition, correlation coefficients among yield and yield components were used to find out the relationships between meteorological elements and productivity. Yearly variation of the mean air temperature in May was large with coefficients of variation(C.V.) of 25.0%, but the variation of the duration of sunshine in May were relative small. No. of panicles per hill and 1,000 grains wt. of brown rice were great with C.V. of 21.1, 19.7%, respectively, brown rice yield show more or less C.V. of 5.5% and milled rice show still less variation. Correlation coefficients between temperatures in period of cultivation from May and yield were positive correlations. Correlation Coefficients between precipitation in period of cultivation from Sep. to Oct. and yield are positive correlations. Correlation coefficients amount the panicle length, no. of panicles, no. of spikelets, ratio of ripened grains, 1,000 grains wt. of brown rice, milled rice yield, brown rice yield and milled rice yield were positively significant at the level of 1 %, respectively.

• The Korean Journal of Ecology
• /
• v.13 no.3
• /
• pp.191-202
• /
• 1990

For the maximun yield of the forest trees in the forest management, the growth of annual ring area of the major forest trees was analysed in the four areas in South Korea. The time to the maximum productivity and the optimum cutting time for the maximum yield were estimated. The growth curve of annual ring area showed sigmoid like that of other organisms. Only the growth coefficient among the areas between Fraxinus rhynchophylla and Pinus koraiensis represented significance (5% level). The growth coefficient among forest trees between Pinus densiflora and Abies holophylla, Larix kaempferi and Carpinus laxiflora, Larix kaempferi and Quercus mongolica, Larix kaempferi and Quercus serrata, Larix kaempferi and Pinus koraiensis, and Larix kaempferi and Abies holophylla represented significance (5% level). Among eight forest trees, the time to maximum productivity (tm) of Larix kaempferi was the earliest (21.4 year), and Abies holophylla was the latest (91.9 year). The optimum cutting time for the maximum yield (tc) of L. kaempferi was the earliest (29.4 year) and that of A, holophylla was the latest (122.2 year) of all communities. The optimum cutting time for the maximum yield was 1.33 times as late as the time to the maximum productivity. If the growth of annual ring area as the forest tree for wood is regarded, L. kaempferi and P. densiflora are thought to be more economical than A. holophylla and P. koraiensis.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.7 no.2
• /
• pp.89-94
• /
• 2002

The continuous production of citric acid from dairy wastewater was investigated using calcium-alginate immobilized Asrergillus niger ATCC 9142. The citric acid productivity and yield were strongly affected by the culture conditions. The optimal pH, temperature, and dilution rate were 3.0, 30$^{\circ}C$, and 0.025 h$\^$-1/, respectively. Under optimal culture conditions, the maximum productivity, concentration, and yield of citric acid produced by the calcium-alginate immobilized Aspergillus niger were 160 mg L$\^$-1/ h$\^$-1/, 4.5 g/L, and 70.3%, respectively, The culture was continuously perfored for 20 days without any apparent loss in citric acid productivity. Conversely, under the same conditions with a batch shake-flask culture, the maximum productivity, citric acid concentration, and yield were only 63.3 mg L$\^$-1/h$\^$-1/, 4.7 g/L and 51.4%, respectively, Therefore, the results suggest that the bioreactor used in this study could be potentially used for continuous citric acid production from dairy wastewater by applying calcium-alginate immobilized Aspergillus niger.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.64 no.3
• /
• pp.53-61
• /
• 2022

This study evaluated the impacts of subsurface drainage design, i.e., spacing and depth, on agricultural productivity and environmental sustainability in two tile-drained fields (Sites A and E) under a corn-soybean rotation in the Midwestern United States. A calibrated and validated Root Zone Water Quality Model (RZWQM) was used to simulate Nitrate-N (nitrogen) losses to tile drainage and crop yields of 30 tile spacing and depth scenarios over 24 years (1992-2015). Our results presented that the narrower and deeper the tile drains are placed, the greater corn yield and Nitrate-N losses, indicating that the subsurface drainage design may cause a trade-off between agricultural productivity and environmental sustainability. The simulation results also presented that up to about 255.7% and 628.0% increase in Nitrate-N losses in Sites A and E, respectively, far outweigh the rate of increase in corn yield up to about 1.1% and 1.6% from the adjustment of tile spacing and depth. Meanwhile, the crop yield and Nitrate-N losses according to the tile configuration differed depending on the field, and the soybean yield presented inconsistent simulation results, unlike the corn yield, which together demonstrate the heterogeneous characteristic of agro-environmental systems to a subsurface drainage practice. This study demonstrates the applicability of agricultural systems models in exploring agro-environmental responses to subsurface drainage practices, which can help guide the introduction and installation of tile systems into farmlands, e.g., orchards and paddy fields, in our country.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.17 no.2
• /
• pp.150-156
• /
• 1997

This study was carried out to investigate the effects of herbicide treatment on the forage yield, nutrient productivity, weed control and persistency in the Rumex crispus dominated pasture in Suwon and in Youngam kom June, 1993 to October, 1995, respectively. It was arranged as a randomized block design with five treatments : 1. reseeding at middle August, 2. dicamba 2liter /ha+reseeding at early July, 3. dicamba 24liter ha+reseeding at middle August, 4.dicamba 2lliter /ha+reseeding at early July +dicamba 14 /ha and 5.dicamba 24liter /ha +reseeding at middle August +dicamba 1liter/ha. In the Rumex crispus dominated pasture, the treatments of dicamba 2liter ha+reseeding(early July or middle August)+dicarnba 1liter/ha were controlled 77-92% of the weed, and increased 105- 141% of forage yield and were higher 88-141% of energy (TDN and NEL) productivity compared with reseeding at middle August (control), respectively. The results indicated that herbicide treatment was effective for the control of Rumex crisps and renovation of grassland, and higher forage yield could be obtained by twice applications of dicamba.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.39 no.3
• /
• pp.141-147
• /
• 2019

The purpose of this study was to determine the effect of waterlogging duration on the growth characteristics and productivity of forage corn at different growth stages under paddy field conditions. Treatments consisted of waterlogging at two growth stages (V7 or V14) for four waterlogging durations (no waterlogging, 48 hours, 72 hours, and 96 hours, respectively). The V14 growth stage was more vulnerable to waterlogging than the V7 stage. Among the waterlogging durations, the lodging score increased at 48 hours. The stem height of forage corn decreased with the increase in waterlogging duration at the different growth stages (V7 and V14). Increase in waterlogging duration reduced the stem dry matter yield, ear dry matter yield, and total dry matter yield at both growing stages (V7 and V14). The waterlogging treatments at the V14 stage affected ear dry matter yield more than those at the V7 growing stage. Thus, the management of forage corn under paddy field conditions must be strengthened during early (V7) and grain fill stages (V14). When waterlogging occurs, surface and subsurface drainage should be implemented within 48 hours to control (no waterlogging) the groundwater level and, thus, minimize economic losses due to forage corn damage.

• Plant Resources
• /
• v.6 no.1
• /
• pp.76-80
• /
• 2003

This study was conducted to investigate the relationships between yearly variations of meteorological elements and yearly variations of productivity in hot pepper. In addition, correlation coefficients among the yields and yield components were used to find out the relationships between meteorological elements and productivity. Yearly variation of the mean air temperature in May and July showed large with coefficients of variation(C.V.) of 25.0,8.9%, respectively, but the variation of the duration of sunshine in May were relative small. Yield and plant height was greatly with C.V. of 7.14,11.6%, respectively, diameter of fruit showed more or less C.V. of 2.28% and length of fruit showed less variation. Correlation coefficients between maximum temperature in period of cultivation from May and yield are positively significant at the level of 1 %. Correlation Coefficients between precipitation in period of cultivation from May to August and yield are negative significant at the level of 5 and 1 %, respectively. Correlation coefficients amount the plant height, length of fruit, diameter of fruit per plant, and seed yield were positively significant at the level of 1 %, respectively.

• The Korean Journal of Food And Nutrition
• /
• v.8 no.1
• /
• pp.17-22
• /
• 1995

The effect of particle size of raw material on the field of extract and changes in composition of Ssang Wha Tang was investigated during manufacturing. As the size of particle was decreased the yield was increased. The yield of extract increased as much as double times as the diameter of the particle decreased from 10 m to 1 m. But the composition of extract was not varied much as the diameter of the particle differed. From these results, it is concluded that cutting method affects the productivity of Ssang Wha Tang.

• Korean Journal of Breeding Science
• /
• v.40 no.4
• /
• pp.371-376
• /
• 2008

For the purpose of breeding a high-yield superior variety of Korean raisin tree (Hovenia dulcis var. koreana Nakai), whose value as an edible and medicinal resource is increasing, tree candidates for superior individuals were selected from its 11 habitats in Korea from 1996 to 1998. A clone bank preserve was created in 1998 with 70 clones proliferated by grafting; the fruition traits (e.g., the number of fructified laterals, the average number of bunches per fructified lateral, the average number of bunches per fruiting lateral, the fruitpetiole weight per individual, and the yield per individual) of 47 clones that had bloomed and borne fruit were investigated and analyzed in 2002; five upper-ranking clones whose yield per individual exhibited a 261% improvement against the total average were picked in 2005; and three clones, including 'Poong-Sung 1', that showed a difference in their fruit petiole ripening stage, were finally selected in 2007 as high-yield new cultivars of Korean raisin tree.