• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.4
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• pp.311-316
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• 2017

The relationship between mean air temperature after heading and starch characteristics of colored rice grains was investigated using three colored rice cultivars. Pasting temperature within each rice cultivar with different harvest times differed. The pasting temperatures of two rice cultivars, Hongjinju and Joseongheugchal, reached the highest at 40 days after heading and decreased during the late harvest time. Distribution of amylopectin in the Hongjinju rice cultivar at the earlier harvest time contained a greater number of very short chains with the degree of polymerization (DP) between 6 and 12 and fewer chains with a DP from 13 to 24 than that of the later harvest time. However, there was little difference in the distribution of the longer chains of $25{\leq}DP{\geq}36$ and $37{\leq}DP$ for latter harvest times compared to that of the earlier ones. It was suggested that the structure of amylopectin affected the varietal differences in patterns of chain length of amylopectin during grain filling. In addition, the control of ripening was different from that causing the pigment effects in the fine structure of amylopectin in the three colored rice cultivars. Larger starch granules were observed in the Joseongheugchal rice cultivar and smaller granules occurred in the Hongjinju rice cultivar. The present study revealed that later harvest times led to a clear increase in the mean granule size of starch in the three colored rice cultivars.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.3
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• pp.67-74
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• 1979

Peanut was cultured with varying planting density and sowing date with and without vinyl-film mulching. Vinyl-film mulching raised soil temperature 4.6$^{\circ}C$ higher than the non-mulched during April and early May, but later-on the soil temperature was similar between the two treatments. The ripening and slender grain ratio increased with closer spacing and earlier sowing. Compared with ordinary cultural practices of May 10th sowing without mulching the peanut yield increased by 9% by mulching sown May 10th, and by 49% by mulching and early sowing April 20th.

• Korean Journal of Agricultural Science
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• v.12 no.2
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• pp.199-205
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• 1985

1. Alternaria tenuis, Cladosporium cladosporioides, Curvularia lunata Fusarium semitectum, Gerlachia oryzae, Phoma sp. Trichoconiella padwickii were found associated with ear blighting of rice plants. The frequency of isolation of the fungi was found to be higher from the severely discolored rice grains than that from the brownish spotted grains, but H. oryzae was encounted highly from the latter. 2. Higher counts of Alternaria tenuis, Helminthosporium oryzae, Trichoconiella padwickii, Fusarium moniliforme, Fusarium semitectum were observed under alternating cycles of 12hrs of light and darkness than under complete darkness but G. oryzae was encountered highly under darkness in the blotter. While no difference in the occurrence of the other fungi was recorded under l2hr NUV light-12hr darkness cycles and darkness. 3. A. tenuis and C. cladosporioides were encountered highly at the lower temp. $(15^{\circ}C)$ but Phoma sp. was occurred highly at the higher temp. $(30^{\circ}C)$ when the seeds were incubated in the blotter. 4. Artificial inoculation of the fungi in the ears of rice plants caused severe discoloration of rice grains and reduced 1,000 grain weights and grain ripening percentage.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.4
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• pp.334-341
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• 1992

The effects of the various pattern of paddy-upland switching system on rice yield and the nutrient absorption characteristics were examined in the paddy field of Seokcheon silty soil for three years from 1989 to 1991. The obtained results of the two years from 1990 to 1991 are as follows : 1. Rice grain yields were high in the order of potato-cabbage>soybean>continuous paddy plot for the second and third year. Among the rice yield components the numbers of grains per panicle and the rate of ripening grain exerted the yield increase. 2. The contents and absorption amounts of nutrient in harvested straw plant increased with the incease of rice yields during the second and third year(1990~1991). The amounts of all nutrient absorption increased with the increased level of nitrogen fertilization at the third year(1991). 3. The periodical change of leaf green color was responded well with the content of ammonia concentration of soil solution.

• Korean Journal of Agricultural Science
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• v.20 no.2
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• pp.103-108
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• 1993

This experiment was conducted to study the effects of pre-cultivation of chines milk vetch (Astragulas sinicus L.) on rice (Oryza sativa L, cv. Daecheongbye) growth and development. This experiment treatments were conducted by eight ; control 1 (stardard fertilizer ; N:P:K=0.3:0.2:0.2g/pot), control 2 (none fertilizer), root of C.M.V (chines milk vetch), shoot of C.M.V, whole plant of C.M.V, and root, shoot and whole plant of C.M.V+fertilizing N. Plant hight of rice was more than that control 1 in maximum tillering stage, heading stage and ripening stage. Tillering numbers per hill were the most in whole plant of C.M.V+fertilizing as whole growth and development period. And panicle per hill, spikelet per paincle, filled grain ratio and 1,000 grain weight were more in fertilized C.M.V than those control 1.

• Korean Journal of Agricultural Science
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• v.9 no.1
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• pp.231-238
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• 1982

The study was done to determine the proper transplanting dates and seedling ages of rice when mechanical transplanting was attempted. Heading dates of the Milyang #23, developed from Tong-il rice was delayed by delayed transplanting and the percent of filling grain was also low. The proper heading dates for the variety should be the first part of August and the transplanting should be done by the end of May. The presumed last days for the transplantation was considered early part of June. 30 to 40 days old seedlings were very effective to have healthy rooting systems. However, the Milyang #15 had shown more tolerance to the late transplantation than Milyang #23 and the degree of delaying heading dates due to the delayed transplantation was rather smaller than that of the Milyang #23. Even when the Milyang #15 was transplanted on June 30, the heading dates were around the middle of August and the ripening percentage was comparatively high and yield was also high. Therefore, the proper heading dates of the Milyang #15 might be around the middle of August and transplanting dates should be the first part of June. The possible last dates of transplantation of the Milyang #15 was assumed to be the last days of June and the proper seedling ages would be 20 to 30 day after sowing.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.331-331
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• 2017

This study was conducted to know the influence of air temperature and sunshine duration on yield, chemical component, pigment color difference and starch characteristics of two colored rice cultivars in the plain area of Yeongnam province in Korea. The $L^*$, $a^*$, and $b^*$ value of brown rice in Hongjinju and Josaengheugchal rice cultivars was significantly different at continuous cultivated years, 2015 and 2016. The $L^*$, $b^*$ value of two colored rice was significantly increased in 2016 compared to 2015. The $a^*$ value of Josengheugchal rice cultivar was also significantly higher at 2016 than at 2015. It can be noticed the $a^*$, $b^*$, $L^*$ values in Josaengheugchal varied more than those in Hongjinju. Air temperature during ripening period in 2016 was higher than 2015, especially minimum temperature was too high to proper maturation for rice quality. In Josaengheugchal rice cultivar, sunshine duration after heading was longer in 2016 than in 2015. On the contrary, Hongjinju rice cultivar was ripened under condition of insufficient sunshine duration in 2016. The short growing duration by high temperature and long shiny duration made the lack of pigment for Josaengheugchal brown rice. In Hongjinju rice cultivar, shorten sunshine duration and higher night temperature were the source of the pigment deficiency. The grain size of rice which produced in 2016 was bigger than that of 2015 in both rice cultivars. The 1,000 grain weight of rice from 2016 was also bigger than that of 2015. Head rice ratio was high in the rice cultivars produced in 2015. Protein of milled rice in 2016 was more decreased than that of 2015 in Josaengheugchal rice cultivar, it showed reverse result in Hongjinju rice cultivar. Amylose contents of milled rice in 2016 were more decreased than that of 2015 in Hongjinju rice cultivar. Branch chain length distribution of amylopectin was shown a distinct difference between Josaengheugchal and Hongjinju rice flours by each produced year. Josaengheugchal rice cultivar produced in 2015 had a higher amount of short chains than that of 2016 rice starches. In Josaengheugchal rice cultivar, the pasting temperature and peak, trough, breakdown, final viscosity increased in rice flour which produced at 2016, whereas the setback viscosity and peak time showed lower value than those of rice from 2015. The most pasting properties (except of setback viscosity) of rice starch in Hongjinju rice cultivar grown in 2015 were higher than those of rice cultivar produced in 2016.

• Korean Journal of Weed Science
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• v.7 no.1
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• pp.98-106
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• 1987

The effect of carbofuran (2, 3-Dihydro-2,2-dimethyl-benzofuran-7-ylmethyl carbamate) on rice growth was evaluated as a direct growth stimulant of rice. For this, several laboratory and field trials conducted from 1981 to 1986 at the Yeongnam Crop Experiment Station. Carbofuran solution affected the germination of rice seed. The growth of seminal roots was adversely affected by the increase of carbofuran concentrations while the length of single root became longer with the concentration increment up to 50 ppm. Carbofuran application (0.18g ai/$m^2$) at the rice nurserybed significantly enhanced the rice growth and recovered from the Low temperature damage. The enhancement effect was more pronounced at the plot that applied carbofuran before rice seeding as soil incorporation than top-dressing. The effect of growth enhancement further extended to transplanted lowland rice. This effect was greater at double cropping area (late of June transplanting) compared to single cropping area (May transplanting). Among important agronomic traits, the increment of panicle number was the most important direct effect for increasing rice grain yield by carbofuran application. Carbofuran application also exhibited the reducing effect against low temperature damage at reductive division stage and at rice heading stage and against submergence damage at booting stage through enhancement of fertile grain ratio, ripening ratio or photosynthetic activity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.2
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• pp.125-136
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• 1981

This experiment was conducted to study the influence of different cultivation periods on some morphological and agronomic characteristics of rice plant at Iri, the Honam plain, in 1979. Early maturing varieties showed little delay in heading with late transplanting, but intermediate and late maturing varieties showed more than 7 day delay in heading. The number of days required to reach heading was over 55 and 67 days after transplanting in early and intermediate-late maturing varieties, respectively. There was significantly postitive correlation between the length of vegetative stage and the grain yield. The mean temperature during ripening period was significantly correlated with the grain yield and the percentage of filled grains. The length, width, and thickness of leaf increased with earlier transplanting and the elongation degree between upper and lower leaves showed the same tendency. The productivity of dry matter and the translocation rate of photosynthate to spikelet decreased with late transplanting mainly due to low temperature. LAI was also influenced by transplanting date showing close correlation with yield. Early transplanting was desirable for assimilation and dry matter accumulation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.13
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• pp.107-118
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• 1973

Experiments were carried out to study the effectiveness of METAP as a slow released fertilizer on the growth, grain yield and its components of paddy rice, and to compare its effects with those of single fertilizers in the fields of 3 Crop Experiment Stations and 7 provincial Offices of Rural Development. The effectiveness of METAP seems to be different according to the physical and chemical characteristics of soil, the time of application, climatic conditions, variety and cultural methods. Therefore, the experimental results obtained from the above experiment are summurized as follows: 1. When METAP was applied into sandy soil, grain yield was increased due to increase of the number of panicles, and split application of METAP was more effective than basal only. However, in the reclaimed soil, not heavily percolated soil and fertile soil, no differences were observed between MET AP and single fertilizer applied plot. 2. When a rice variety, 'TONGIL' which is sensitive to the low temperature and produce higher yield in the early transplanting, was not transplanted early and air temperature is relatively lower during the ripening stage, the percentage of ripened grains and 1,000 grains weight were not higher in the METAP applied plots than in the single fertilizer applied plots.