• Journal of the Korean Society of Tobacco Science
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• v.19 no.2
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• pp.77-82
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• 1997

In order to investigate biochemical activities of harvested tobacco leaves, photosynthetic rate, soluble protein contents, and peroxidale activities were analysed during different maturing period. Physiological activities of harvested leaves during maturing period were higher in topped than those of non-topped plants. Chlorophyll content and photosynthetic rate in both topped and non-topped plants decreased at 4 days and 3 days before harvest, respectively. The chloroplast numbers in topped and non-topped plants decreased at 3 days and 5 days before harvest, respectively. Changes of soluble protein and total RNA contents showed similar patterns during maturing period. Soluble protein contents were slightly decreased from 5 days before harvest in topped plants, but decreased drastically from 3 days before harvest in non-topped plants. Not much changes were found in total RNA contents in topped plants until 2 days before harvest, and it was largely decreased after 5 days before harvest in non-topped plants. The peroxidase activities drastically decreased in topped plants and increased in non-topped plants after 3 days before harvest during maturing period. The largest change of biochemical activities in tobacco leaves during maturing periods were observed at 3 days before harvest.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.2
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• pp.97-102
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• 2000

This experiment was conducted to investigate the changes of harvest index and the relationship between harvest index and yield determination factors by different planting times in the determinate soybean cultivars, Shinpaldal and Danbaeg. Optimum planting were 23 May in 1995 and 1996. Late planting were 13 June in 1995 and 6 June in 1996. Growth period from planting to physiological maturity (R7) was shortened as planting time was delayed in two cultivars due to shortening of reproductive growth period in Shinpaldal, and of vegetative growth period in Danbaeg. Stem weight was distinctly decreased in late planting compared to optimum planting, but seed weight of both cultivars was not different between planting times. Also, seed number per pod and harvest index were significantly increased in late planting and the high correlation was found between two factors. It was suggested that increase of harvest index in late planting would be related with high assimilate use efficiency due to increase of sink capacity. The results of correlation and principal component analysis for yield determination factors showed that main factor on yield determination was pod number per plant at R5 stage associated with dry matter accumulation during early reproductive growth period, seed number per pod and harvest index were the second factor, and one hundred seed weight was the third factor. The result of this experiment indicated that yield determination in soy-bean was dependent mainly on pod number per plant related to dry matter accumulation by early reproductive growth period, and the increase of seed number per pod and harvest index could compensate for yield decrease by shortening of vegetative growth period in late planting. Such result suggests that optimum planting date can be delayed from mid May to early June in improved soybean cultivars in Korea.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.687-699
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• 2013

This study was conducted to examine the effect of grafted peppers (Capsicum annuum) on different rootstocks on fruit quality. Three pepper cultivars, 'Nokkwang', 'Saengsaeng Matkkwari', and 'Shinhong' were grafted onto five commercial rootstocks that are known to be resistant to Phytophtora blight. Non-grafted or auto-grafted peppers were used as controls. Grafted plants were grown during two consecutive harvest periods by semi-forcing culture (April to August) and retarding culture (September to March the subsequent year). Full size green fruits were harvested and weighed weekly from June to August (Semi-forcing culture) and from December to March of the subsequent year (Retarding culture). The fruit size, weight, flesh thickness, and firmness were measured every month. Total marketable yield was not significantly influenced by either auto-graft of 'Nokkwang', 'Saengsaeng Matkkwari', and 'Shinhong' of pepper or grafted with the five commercial rootsctocks. By contrast, grafting influenced the apparent fruit quality of peppers. Fruit characteristics differed depending on the rootstock cultivars. However, the fruit characteristics of rootstock did not affect the fruit characteristics of scion grafted onto that rootstock. Fruit characteristics in each treatment differed among harvest time (first, second, and third harvest). Fruit quality parameters were also different as affected by the harvest period. In conclusion, apparent quality and textural property of pepper fruits were influenced by not only grafting with different rootstocks but also by the harvest period and harvest time. Accordingly, rootstock/scion combination, the scion variety and the harvest period must be carefully chosen to get the desired optimal fruit quality.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.542-546
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• 2004

Changes in contents of catechins, caffeine, free amino acids, and minerals in green tea loaves according to harvest periods were compared. Total catechin content increased from 40.61 to 52.04 mg/g, while that of caffeine decreased from 17.56 to 14.61 mg/g according to harvest periods. Regardless of harvest periods, composition of catechins was epigallocatechin (EGC)>epigallocatechin gallate (EGCg)>epicatechin (EC)>gallocatechin (GC)>epicatechin gallate (ECg)>catechin (C)>gallocatechin gallate (GCg)>catechin gallate (Cg). Free amino acid content in green tea leaves was highest in young loaves, and gradually decreased according to harvest periods. Theanine content was markedly decreased with leaf aging, suggesting taste of green tea may be changed from mild to bitter with increasing harvest period. Analyses of mineral elements in green tea leaves showed that Fe, Mn, and Mg increased with leaf aging, while Cu showed opposite trend. Results reveal that content of some chemical compounds in Korean (Posong) green tea was highly dependent on harvest period.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.406-412
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• 2014

The influence of rainfall during the ripening stage on pre-harvest sprouting, seed viability, and seed quality was investigated in two Korean rice cultivars, Shindongjin and Hopum. When the rainfall was artificially treated in a greenhouse, HP started to pre-harvest sprouting at three days of rainfall treatment (DRT), but Shindongjin did not show pre-harvest sprouting at 40 DAH treatment and just 0.3~0.8% at 50 DAH, which was much lower than 15.3~25.8% of Hopum in the same treatment. After harvest, the seed germination of Hopum decreased about 10~25% compared to non-treated seeds, but that of Shindongjin decreased much little rate than that of Hopum. The seed longevity tested by accelerated aging decreased with prolonged rainfall period in both cultivars, but the varietal difference was clear; Shindongjin could withstand longer accelerated aging than Hopum. Shindongjin maintained its germination (>50%) ability after 15 days of accelerated aging regardless of the rainfall treatment period and time, but Hopum dropped below 50% germination ability after only 5 days of accelerated aging. In conclusion, rainfall during the ripening stage induced not only pre-harvest sprouting, but also reduced seed quality and longevity during storage, which varied between two cultivars.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.4
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• pp.239-249
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• 2020

Rice flour varieties have been developed to replace wheat, and consumption of rice flour has been encouraged. damage related to pre-harvest sprouting was occurring due to a weather disaster during the ripening period. Thus, it is necessary to develop pre-harvest sprouting rate prediction system to minimize damage for pre-harvest sprouting. Rice cultivation experiments from 20 17 to 20 19 were conducted with three rice flour varieties at six regions in Gangwon-do, Chungcheongbuk-do, and Gyeongsangbuk-do. Survey components were the heading date and pre-harvest sprouting at the harvest date. The weather data were collected daily mean temperature, relative humidity, and rainfall using Automated Synoptic Observing System (ASOS) with the same region name. Gradient Boosting Machine (GBM) which is a machine learning model, was used to predict the pre-harvest sprouting rate, and the training input variables were mean temperature, relative humidity, and total rainfall. Also, the experiment for the period from days after the heading date (DAH) to the subsequent period (DA2H) was conducted to establish the period related to pre-harvest sprouting. The data were divided into training-set and vali-set for calibration of period related to pre-harvest sprouting, and test-set for validation. The result for training-set and vali-set showed the highest score for a period of 22 DAH and 24 DA2H. The result for test-set tended to overpredict pre-harvest sprouting rate on a section smaller than 3.0 %. However, the result showed a high prediction performance (R2=0.76). Therefore, it is expected that the pre-harvest sprouting rate could be able to easily predict with weather components for a specific period using machine learning.

• The Korean Journal of Food And Nutrition
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• v.35 no.6
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• pp.445-452
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• 2022

The quality and antioxidant characteristics of apios (Apios americana Medikus) according to different harvest periods and steaming treatment were investigated. The quality and antioxidant characteristics of apios were significantly different depending on harvest periods. Total starch contents was higher in 1st harvesting period as 62.32 g/100 g than other harvesting period. The water binding capacity and water solubility index was higher in 1^st harvesting period as 228.65 and 11.29% than other harvesting period. The sucrose and total free sugar contents were 3.64~8.67 and 4.49~9.54 g/100 g, respectively. Total polyphenol and flavonoid contents of apios was the highest 2^nd and 4^th harvesting period at 4.21 mg GAE/g and 611.11 ㎍ CE/g, respectively. DPPH radical scavenging activity was higher in 1st harvesting period as 84.96 mg TE/100 g than other harvesting period, and decreased as the harvest periods were delayed. ABTS radical scavenging activity and ferric-reducing antioxidant power were 43.81~47.89 mg TE/g and 231.20~264.07 mM/100 g, and increased to 50.58~51.44 mg TE/g and 342.55~384.29 mM/100 g after heat treatment. As a result, it is thought that studies on change of quality and physicochemical characteristics according to cultivation characteristics should be preceded for cultivation stability of apios.

• Journal of Forest and Environmental Science
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• v.30 no.1
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• pp.1-14
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• 2014

Timber harvest in natural forests and its implications on carbon sequestration were investigated in the Southwestern Nigeria. Data on timber harvest from forest estates for a 3-year period were collected from the official record of States' Forestry Department. The data registered the species, volume and number of timbers exploited during the study period. The data were analyzed accordingly for rate of timber harvest and carbon value of the exploited timbers using existing biomass functions. Values were compared for significant differences among states using one way analysis of variance. The results showed that the most exploited logs, in terms of volume and number of trees, have the highest amount of carbon removal. There was a variation in type of timber species being exploited from each state. The total number of harvested trees from Oyo, Ondo, Ogun, Ekiti and Osun were estimated at 100,205; 111,789; 753; 15,884 and 18,153 respectively. Total quantity of carbon removed for the 3-year period stood at 2.3 million metric tons, and this translated to 8.4 million metric tons of $CO_2$. The annual carbon and $CO_2$ removal therefore were estimated at 760,120.73 tons and 2.8 million tons/ year respectively. There were significant differences (p<0.05) in the amount of $CO_2$ removed from the five states. Based on our result, we inferred that there is increasing pressure on economic tree species and it is plausible that they are becoming scarce from the forests in Southwestern Nigeria.. If the present rate of log removal is not controlled, forests could become carbon source rather than carbon sink and the on biological conservation, wood availability and climate change may turn out grave. For the forest to perform its environmental role as carbon sink, urgent conservation measures and logging policies are needed to be put in place.

• YAKHAK HOEJI
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• v.53 no.2
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• pp.51-59
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• 2009

Quantitative analysis of (+)-catechin (C), (-)-epigallocatechin (EGC), (-)-epicatechin (EC), (-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG) and caffeine in commercial green tea was carried out by HPLC employing gradient elution of 0.1% acetic acid and acetonitrile on ODS column. The optimized HPLC method provided satisfactory linearity, accuracy and precision. The relationship between the concentration of the components and cultivated region of the commercial green tea was not significant, while the concentration of EGCG, ECG and caffeine decreased significantly in the later harvested green tea samples (p<0.01). Multivariate analysis of the components was performed in order to characterize and evaluate the cultivated region and harvest period-related variation. Hierarchical clustering and discriminant analysis were applied to classify the geographical and seasonal origins of the green tea samples. The classification accuracy of the cultivated region and harvest period by discriminant analysis was 95% and 91%, respectively, indicating that this method could be reliable and convenient for the quality control of herbal products with different origin.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.3
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• pp.254-258
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• 2002

The characteristics of yield and quality in 3 rice varieties according to harvest time of 40, 50, 60 and 70days after heading(DAH) was investigated to obtain basic information for the production of high quality rice. The protein content of milled rice increased significantly as increase the ripening period from 40 to 70DAH. The palatability value measured by rice taster was the highest in ripening period of 40DAH and decreased with increase of ripening period. The optimum time for harvest in terms of both rice yield and quality was 4050DAH in Daejinbyeo, and 4060DAH in Seojinbyeo and Chucheongbyeo, however, it was considered to be 4050DAH only for rice quality. The palatability value measured by rice taster showed a highly negative correlation with protein content of milled rice(1=-0.94$^{**}$) and cumulative ripening temperature(r=-0.79$^{**}$).