• Korean Journal of Medicinal Crop Science
• /
• v.1 no.2
• /
• pp.162-165
• /
• 1993

To determine optimal sowing date of Job's Tears in southern-Region of Korea,Job's Tears cv. Local cultivars Ewon and Heuksuk were grown under the three different sowing dates. As sowing date was delayed, the heading and maturing date were delayed also and yield components such as plant height, stem diameter, number of stems, weight of 100grains and that of 1 l, etc. were the highest at the sowing date of Apr. 15. Yield of stem and seed were the heaviest in Apr. 15 seeding and they were light in the early or late sowing, Judging from the results reported above, optimum seeding date of Job's Tears seemed to be Apr. 15.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.27 no.1
• /
• pp.49-54
• /
• 1982

Experiments were carried out to establish physiological maturity determination criteria with reference to visibly easy measurement in barley in 1980 at Suweon. Thirty-three cultivars and lines from 500 crossing blocks were classified into 4 heading groups, and 5 variables; moisture content, discoloration of awn, exsertion, lemma and flag leaf were measured. There were highly negative correlations between heading date and ripening periods (r=-0.656$^{**}$ ), so early heading types had longer ripening periods. Comparing with the variables used for maturity determination, moisture content and discoloration of lemma were most sensitive to development of grain-filling. Those two variables, alone or in combination could be used to screen many genotypes of barley for physiological maturity. In determination of maturity with reference to visibly easy measurement, color of lemma changed stably and was the most useful way and discolor of flag leaf increased the accuracy of determination. The color of lemma at this time was Grayish yellow, and the mean moisture content was about 33 percent in 33 barley cultivars and lines.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.19 no.4
• /
• pp.339-346
• /
• 1999

This experiment was carried out to determine harvest date and cultivar effects on the agronomic characteristics, forage yield, and quality of fall sown oat (Avena sativa L.) at the forage experimental field, College of Agriculture and Life Sciences, Seoul National University, Suweon from August to November 1993. The experiment was arranged in a split plot design with three replications. The main plots were consisted of the harvesting dates, suchas early (11 October), mid(21 October), and late(1 November), the subplots were consisted of different maturities of oat cultivars, such as 'West', 'Cayuse' and 'Magnum'. The first heading date of an early maturing culivar, West, was observed on 10 October, and the heading increased up to 30% at the late harvesting date. The average dry matter (DM) content of oat cultivars increased significantly from 12.8 to 15.9% as the growing stage progressed(p<0.01). The average dry matter percentage of West, Cayuse, and Magnum was 15.4, 13.4, and 13.5%, respectively. The crude protein (CP) content of oat cultivars decreased significantly from 20.1 to 13.3% as the harvesting date was delayed(p<0.01), and the CP contents of midseason and late maturing cultivars, Cayuse and Magnum, respectively, were significantly higher than that of an early maturing cultivar West (p<0.01). The mid harvesting date showed the highest acid detergent fiber(ADF) and neutral detergent fiber (NDF) contents than the other harvesting dates, and an early maturing cultivar West had higher ADF and NDF contents than the midseason and late maturing cultivars, Cayuse and Magnum, respectively. The in vitro dry matter digestibility(IVDMD) of oat cultivar West decreased as the harvesting date was delayed, but that of Cayuse and Magnum decreased only by the mid harvesting date. Cayuse and Magnum showed 3~4% higher digestibility than West. The correlation coefficient between IVDMD and ADF content was -0.86. The average dry matter yield of oat cultivars increased from 2,901 to 5,901kg/ha as the harvesting date was delayed(p<0.01), but no significant difference was found among oat cultivars. The corrdelation coefficient between DM yield and gorwing degree days(GDD) was +0.86. The results of this study indicate that a delay in harvesting date would be recommendable for the increase of dry matter yield when fall-sown oat is grown. Especially, the DM yield of the midseason and late maturing cultivars, Cayuse and Magnum, respectively, can be increased without much change of forage quality although the harvesting date are delayed.

• Korean Journal of Weed Science
• /
• v.12 no.1
• /
• pp.31-38
• /
• 1992

This study was conducted to investigate the effect of plant growth retardants on the growth and characters related with lodging in rice. The results are summarized as follows. Plant height which is closely related to lodging was significantly inhibited by the application of inabenfide, paclobutrazol, and uniconazole. Among the tested application times, inabenfide, paclobutrazol, and uniconazole were the most effective in inhibiting plant height at 30, 20, 20 days before heading respectively. Inabenfide was markedly effective in reducing the lower (4th) internode length, whereas paclobutrazol and uniconazole were more effective in reducing the upper (3rd and 2nd) internode length. Internode wall of rice plant treated with chemicals was tended to be thickened as compared with control. Heading date was not influenced by inabenfide, but paclobutrazol and uniconazole were inhibited 1 or 2 days in heading date as compared with control. Lodging index was the most reduced when inabenfide was applied 30 days before heading with 160g ai whereas paclobutrazol and uniconazole were applied 15 days before heading with 12, 1.2g ai per 10a, respectively. All the treatments inhibited the lodging of rice but control was completely lodged. Yield treated with these chemicals was prevented by 10-12% of yield decrease occurred by lodging. As a conclusion, inabenfide with 120 or 160g ai at 40 or 30 days before heading, paclobutrazol with 12g ai at 15 days before heading, arid uniconazole with 1.2g ai at 15 days before heading appear to be the most practical application time and rate for preventing lodging in paddy rice.

• Korean Journal of Agricultural Science
• /
• v.45 no.3
• /
• pp.355-363
• /
• 2018

This study was conducted to investigate suitable rice cultivars for various rice based cropping systems in a paddy field in the Yeongnam plain area. Thirteen rice cultivars (5 early, 3 medium and 5 mid-late maturing cultivars) and three transplanting dates (June 5, June 25 and July 5) were evaluated in this study. The mid-late and early maturing cultivars for the July 5 and June 25 transplanting headed before August 30 which is the safe heading date in the Yeongnam plain area, ranging from Aug. 26 - 28 and Aug. 18 - 23, respectively. The safe harvest time of rice for double and triple cropping systems should be before the middle of October for the cultivation of the succeeding winter crops. The rice yield was the highest for the June 5 transplanting regardless of the rice cultivars, and it gradually decreased as the transplanting date was delayed from June 5 to July 5 due to a decrease in the spikelet numbers per panicle number and in the ripened grain rate. In contrast, the other yield parameters that include the panicle number per $m^2$, the 1,000-brown rice weight, and the ripened grain ratio were not significantly affected. The result indicates that based on the milled rice, heading time and harvest time, a medium maturing cultivar (Haiami and Samdeog) would be applicable to a winter barley/wheat, garlic/onion-summer rice double cropping, while a mid-late cultivar (Saeilmi, Saenuri and Hyunpoom) would be suitable for a spring potato/waxy corn-summer rice double cropping in the Yeongnam plain area. On the other hand, an early maturing cultivar (Unkwang, Jokwang and Haedamssal) would be preferable for a triple cropping because of the short growth period of rice.

• Molecules and Cells
• /
• v.38 no.1
• /
• pp.81-88
• /
• 2015

Flowering time (or heading date) is controlled by intrinsic genetic programs in response to environmental cues, such as photoperiod and temperature. Rice, a facultative short-day (SD) plant, flowers early in SD and late in long-day (LD) conditions. Casein kinases (CKs) generally act as positive regulators in many signaling pathways in plants. In rice, Heading date 6 (Hd6) and Hd16 encode $CK2{\alpha}$ and CKI, respectively, and mainly function to delay flowering time. Additionally, the major LD-dependent floral repressors Hd2/Oryza sativa Pseudo-Response Regulator 37 (OsPRR37;hereafter PRR37) and Ghd7 also confer strong photoperiod sensitivity. In floral induction, Hd16 acts upstream of Ghd7 and CKI interacts with and phosphorylates Ghd7. In addition, Hd6 and Hd16 also act upstream of Hd2. However, whether CKI and $CK2{\alpha}$ directly regulate the function of PRR37 remains unclear. Here, we use in vitro pull-down and in vivo bimolecular fluorescence complementation assays to show that CKI and $CK2{\alpha}$ interact with PRR37. We further use in vitro kinase assays to show that CKI and $CK2{\alpha}$ phosphorylate different regions of PRR37. Our results indicate that direct posttranslational modification of PRR37 mediates the genetic interactions between these two protein kinases and PRR37. The significance of CK-mediated phosphorylation for PRR37 and Ghd7 function is discussed.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.27 no.3
• /
• pp.206-217
• /
• 1982

This experiment was conducted to study about nutrient absorption of flag leaf and chaff of rice plant different transplanting date with elevations. Heading stage was delayed by destructive cold temperature or late transplanting. Plant analyses revealed that above poor plants also had higher total nitrogen content, but ower silicate in the flag leaf and sterile chaff. Total nitrogen and silica contents to accumulated in flag leaf between yield was significant high correlation. The chaff of late transplanting and sterility was high total nitrogen. Relationship between silicate absorption and total nitrogen of chaff was significant high correlation. Ripening temperature after heading stage was influenced total nitrogen of chaff. Phosphate, potassium, calssium and silicate contents of chaff increased hight ripening temperature but total nitrogen decreased. Therefore, inorganic element contents of chaff was closely connected with grain sterility.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.26 no.2
• /
• pp.174-178
• /
• 1981

The experiment was dealt with an investigations on the agronomic potential of primary octraploid triticale in comparion with Chokwang, a major common wheat, local rye cultivar and new triticale selection Suweon #1 and Suweon #2. This octaploid triticale was originated from the cross of Jukoku #81 x Local rye cultivar. The results obtained were summarized as follows; Cold tolerance of the P-Tcl was better than those of the wheat cultivar Chokwang, triticale varieties Suweon #1 and Suweon #2, and comparable to local rye. Culm length of P-Tel was 113cm that was intermediate between the wheat and rye, and its culm thickness was thiner than the checks except the rye. Lateness of heading and maturing date of the P-Tel seemed to be over-dominant. However, flowering date after heading was 3 to 7 days earlier than the Suweon #1 and Suweon #2. Yield potential of the P-Tel was poor in comparision with the triticale cultivar Suweon #1 and Suweon #2 which was attributed to the low fertility and less number of the heads per squ are meter. If it was . improved the low fertility and less number of the valid tillers through the cross with the good secondary triticale it seemed to be an useful material for triticale breeding, expecially for improving cold tolerant winter triticale varieties in Korea.

• Korean Journal of Weed Science
• /
• v.15 no.2
• /
• pp.105-114
• /
• 1995

Differences in critical period of weed competition were investigated among five types of rice(Oryza sativa L.) cultivation. Increase in weed-free period resulted in 1-2 days delay of heading date in machine transplanting and direct-seeding as compared with complete weed-free plot. When weedy period increased, there was no difference in heading date in transplanting cultivations. In direct-seeding, however, weedy period of 7-10 weeks after seeding(WAS) resulted in 4-7 days delay of heading date, whereas further increase in the weedy period caused rather 5-6 days advance in heading date. Weed-free period did not significantly affect yield components in conventional hand transplanting. In machine transplanting with 30-day-old seedling decreases in percent ripening and 1,000-grain weight were caused by weeds emerged within 4 weeks after transplanting(WAT). All yield components were decreased due to weedy period in machine transplanting with 10-day-old seedling. In direct-seeding weedy periods caused to decrease in number of panicles, number of spikelets, percent ripening, and 1,000-grain weight were 8-9, 4-5, 3-4, and 8-10 WAS, respectively. The critical periods of weed competition were determined as the following. In conventional hand transplanting weed-free must be maintained for either 4 weeks after transplanting or the rest period after 8 WAT. In machine transplanting with 30-day-old seedling weed-free must keep for either 5 weeks after transplanting or the rest period after 8 WAT. In machine transplanting with 10-day-old seedling weeds must be removed for either 5 weeks after transplanting or the rest period after 7 WAT. Weed-free must be kept between 5 and 7 WAS in flood direct-seeded rice and between 6 and 9 WAS in dry direct-seeded rice.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.11
• /
• pp.1653-1659
• /
• 2015

This study compared physicochemical properties and antioxidant activities according to different harvest times in five varieties of black rice (BR). Five cultivars of BR, Nunkeunheukchal (NKHC), Sinnongheugchal (SNHC), Sintoheugmi (STHM), Josaengheugchal (JSHC), and Heugjinju (HJJ), were selected for the study. Cultivars were transplanted on June 20th and cultivated by the Department of Southern Area Crop Science, NICS in Miryang, Korea. Heading dates of NKHC, SNHC, STHM, JSHC, and HJJ were Aug. 17th, Aug. 30th, Sep. 1st, Aug. 20th, and Aug. 12th, respectively. The five different harvest times were as follows; 35, 40, 45, 50, and 55 days after heading date. The highest level of anthocyanin was 35 days after heading date in all varieties. Levels of anthocyanin in NKHC, SNHC, STHM, JSHC, and HJJ were 164, 203, 251, 67, and 210 mg/100 g, respectively. Content of anthocyanin significantly decreased 35 days after heading in four varieties, excluding JSHC. Highest DPPH $IC_{50}$ values were 57, 29, 10, and $27{\mu}g/mL$ in NKHC, SN HC, STHM, and JSHC extracts, respectively. Highest ABTS $IC_{50}$ values were 24, 13, 9, and $11{\mu}g/mL$ in NKHC, SNHC, STHM, and JSHC extracts, respectively. The antioxidant activities were highest 35 days after the heading date and significantly decreased in four varieties, excluding HJJ. The antioxidant activity of HJJ showed no significant difference, according to harvest time. This study suggests that the content of anthocyanin and antioxidant activity could be considered as factors affecting optimal harvest period to produce highly qualified black rice.