• Current Research on Agriculture and Life Sciences
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• v.31 no.3
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• pp.209-216
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• 2013

This study compared the antioxidant activity and functional constituents of the peel, flesh,and placenta of oriental melons according to the harvest time. The sample oriental melons were harvested during the major harvest time (from June to August) and divided into peel, flesh, and placenta. To examine the antioxidant activity and functional constituents, the sample melons were extracted using EtOH. As a result, the functional constituents and antioxidant activity of the oriental melons were found to change according to the harvest time. The total phenol and total flavonoid contents were highest in the samples harvested in June, and lowest in the samples harvested in July. Meanwhile, the antioxidant activities were estimated using an ABTS and FRAP assay, where the samples harvested in June also showed the strongest the antioxidant potential, while the samples harvested in July showed significantly lower antioxidant activities. This means that the climate influences the synthesis of secondary metabolites. The above data also suggests that oriental melons harvested in June contain more functional phytochemicals, making them more beneficial for human health.

• Korean Journal of Remote Sensing
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• v.37 no.2
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• pp.337-357
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• 2021

Because the growth of paddy rice is affected by meteorological factors, the selection of appropriate meteorological variables is essential to build a rice yield prediction model. This paper examines the suitability of multiple meteorological datasets for the rice yield modeling in South Korea, 1996-2019, and a hindcast experiment for rice yield using a machine learning method by considering the nonlinear relationships between meteorological variables and the rice yield. In addition to the ASOS in-situ observations, we used CRU-JRA ver. 2.1 and ERA5 reanalysis. From the multiple meteorological datasets, we extracted the four common variables (air temperature, relative humidity, solar radiation, and precipitation) and analyzed the characteristics of each data and the associations with rice yields. CRU-JRA ver. 2.1 showed an overall agreement with the other datasets. While relative humidity had a rare relationship with rice yields, solar radiation showed a somewhat high correlation with rice yields. Using the air temperature, solar radiation, and precipitation of July, August, and September, we built a random forest model for the hindcast experiments of rice yields. The model with CRU-JRA ver. 2.1 showed the best performance with a correlation coefficient of 0.772. The solar radiation in the prediction model had the most significant importance among the variables, which is in accordance with the generic agricultural knowledge. This paper has an implication for selecting from multiple meteorological datasets for rice yield modeling.

• Smart Media Journal
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• v.8 no.1
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• pp.74-81
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• 2019

Recently, machine learning technology has had a significant impact on society, particularly in the medical, manufacturing, marketing, finance, broadcasting, and agricultural aspects of human lives. In this paper, we study how to apply machine learning techniques to foods, which have the greatest influence on the human survival. In the field of Smart Farm, which integrates the Internet of Things (IoT) technology into agriculture, we focus on optimizing the crop growth environment by monitoring the growth environment in real time. KT Smart Farm Solution 2.0 has adopted machine learning to optimize temperature and humidity in the greenhouse. Most existing smart farm businesses mainly focus on controlling the growth environment and improving productivity. On the other hand, in this study, we are studying how to apply machine learning with respect to harvest time so that we will be able to harvest fruits of the highest quality and ship them at an excellent cost. In order to apply machine learning techniques to the field of smart farms, it is important to acquire abundant voluminous data. Therefore, to apply accurate machine learning technology, it is necessary to continuously collect large data. Therefore, the color, value, internal temperature, and moisture of greenhouse-grown fruits are collected and secured in real time using color, weight, and temperature/humidity sensors. The proposed FPSML provides an architecture that can be used repeatedly for a similar fruit crop. It allows for a more accurate harvest time as massive data is accumulated continuously.

• Korean Journal of Agricultural and Forest Meteorology
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• v.26 no.2
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• pp.103-113
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• 2024

The effect of harvesting time on the growth, marketable tuber yield, and tuber quality of spring potato (Solanum tuberosum L. cv. Dami) were analyzed in the southern paddy fields in order to determine the optimal harvesting time. At 30-50 days after flowering, the total and marketable tuber yields of spring potato reached their maxima and commercial tuber rate was also high. External defects such as tuber malformation or crack did not occur until 40 days after flowering, but after that, secondary growth such as shooting appeared. Among the nutrient compositions of tubers, carbohydrate content accounted for more than 60% of tuber dry weight without significant difference among harvesting times until 50 days after flowering. The crude protein content decreased slightly as the harvesting time was delayed. However, the mineral nutrient content of tubers decreased with delaying harvesting time and was lowest at 30-40 days after flowering. Therefore, the optimal harvesting time of spring potato was judged to be 30-40 days after flowering, when marketable tuber size and quality were great as less affected by high temperature or waterlogging under natural environmental conditions.

• Korean Journal of Agricultural Science
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• v.3 no.1
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• pp.95-104
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• 1976

This study was conducted to test the harvesting operation of two kinds of rice varieties such as Milyang #15 and Tong-il with a imported two furrow Japanese combine and was performed to find out the operational accuracy of it, the adaptability of this machine, and the feasibility of supplying this machine to rural area in Korea. The results obtained in this study are summarized as follows; 1. The harvesting test of the Milyang #15 was carried out 5 times from the optimum harvesting operation was good regardless of its maturity. The field grain loss ratio and the rate of unthreshed paddy were all about 1 percent. 2. The field grain loss of Tong-il harvested was increased from 5.13% to 10.34% along its maturity as shown in Fig 1. In considering this, it was needed that the combine mechanism should be improved mechanically for harvesting of Tong-il rice variety. 3. The rate of unthreshed paddy of Tong-il rice variety of which stem was short was average 1.6 percent, because the sample combine used in this study was developed on basisof the long stem variety in Japan, therefore some ears owing to the uneven stem of Tong-il rice could nat reach the teeth of the threshing drum. 4. The cracking rates of brown rice depending mostly upon the revolution speed of the threshing drum(240-350 rpm) in harvesting of Tong-il and Milyang #15 were all below 1 percent, and there was no significance between two varieties. 5. Since the ears of Tong-il rice variety covered with its leaves, a lots of trashes was produced, especially when threshed in raw materials, and the cleaning and the trashout mechanisms were clogged with those trashes very often, and so these two mechanisms were needed for being improved. 6. The sample combine of which track pressure was $0.19kg/cm^2$ could drive on the soft ground of which sinking was even 25cm as shown in Fig 3. But in considering the reaping height adjustment, 5cm sinking may be afford to drive the combine on the irregular sinking level ground without any readjustment of the resaping height. 7. The harvesting expenses per ha. by the sample combine of which annual coverage area is 4.7 ha. under conditions that the yearly workable days is 40, percentage of days being good for harvesting operation is 60%, field efficiency is 56%, working speed is 0.273m/sec, and daily workable hours is 8 hrs is reasonable to spread this combine to rural area in Korea, comparing to the expenses by the conventional harvesting expenses, if mechanical improvement is supplemented so as to harvest Tong-il rice. 8. In order to harvest Tong-il rice, the two furrow combine should be needed some mechanical improvements that divider can control not to touch ears of paddy, the space between the feeding chain and the thrshing drum is reduced, trash treatment apparatus must be improved, fore and rear adjust-interval is enlarged, and width of track must be enlarged so as to drive on the soft ground.

• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.59-65
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• 1984

Effect of ripening methods and harvesting time on vitamin content of 5 tomato varieties was investigated in 1978 and 1979. Ascorbic acid content in the breaker ripened tomatoes was significantly higher than that in the vine ripened tomatoes, and the result was consistent for two consecutive years. Ascorbic acid content in the vine ripened tomatoes markedly increased as the season progressed, early harvested tomatoes containing significantly less ascorbic acid. Carotene content was not significantly affected by the ripening method. Higher carotene content, however, was observed for tomatoes harvested in the late season. This result could indicate the effect of temperature for carotenogenesis around the harvest time. Thiamin and riboflavin contents in the vine ripened tomatoes were significantly higher than those in the breaker ripened tomatoes in the 1978 season, but these differences were not observed in the 1979 season. Thiamin and riboflavin contents in the vine ripened tomatoes decreased considerably as the season progressed. Thiamin and riboflavin contents in tomatoes harvested in the early season were significantly higher than those in the mid and late seasons.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.4
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• pp.294-303
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• 2018

To set an optimal harvest time for five main whole-crop silage (WCS) rice cultivars, Nokyang (Ny), Mogwoo (Mw), Mogyang (My), Nokwoo (Nw) and Yeongwoo(Yw), based on feed value and dry matter yield, we analyzed water content (WC), feed values such as percent crude protein (CP), crude fat (CF), crude ash (CA), neutral detergent fiber (NDF), acid detergent fiber (ADF), estimated total digestible nutrients (TDN), and calculated their dry matter yield (DMY). These parameters were estimated at the booting stage and every 10 days from start of heading to 45 days after heading (DAH) to identify the optimal harvest time for these rice varieties. In all varieties, except Ny, the WC was about 65% on the $30^{th}$ DAH. In terms of WC, it is judged that there would be no major problem in preparing high quality silage when harvested between 20~30 DAH for Ny and about 30 days for the other cultivars. The CP and CA decreased significantly as the harvest time was delayed in all varieties (p<0.05). However, the CF in the tested varieties generally declined as DAH increased, and then increased again(p<0.05). The decrease in ADF and NDF was significantly different from the booting stage to 45 DAH in all varieties (p<0.05) and the estimated TDN increased gradually in all varieties as the harvest time was delayed. The TDN of all varieties, except Nw, was over 70% around 30 DAH. As harvest time was delayed, the DMY for all WCS rice increased significantly (p<0.05). The maximum DMY for each cultivar was observed at 45 DAH, however, no significant difference (p<0.05) was seen after 40 DAH for Ny and Yw, 30 DAH for Mw and Nw, and 20 DAH for My. Considering these results and others factors such as lodging, shattering, digestibility of grains, conversion of eating rice, etc., the optimal harvest time for silage use of all WCS rice tested was generally the yellow ripening stage, at about 30 DAH (30~40 DAH for Ny and Mw, and 30 DAH for My, Nw and Yw).

• Proceedings of the Korean Society of Crop Science Conference
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• 2021.04a
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• pp.141-141
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• 2021

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.1
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• pp.50-56
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• 2020

The field experiment was carried out to evaluate changes of dry matter productivity and feed value of Italian ryegrass and triticale at different growth stages in Wonju from 2018 to 2019. Italian ryegrass and triticale forages were harvested at an interval of seven days from May to June. The dry matter yield of Italian ryegrass with 7,870 kg/ha harvested on May 16 was significantly higher than that harvested on May 3 and May 9. The dry matter yield of triticale with 12,050 kg/ha harvested on June 7 was significantly higher than that harvested from May 3 to May 16. The crude protein yields harvested on May 16 were 890 kg/ha for Italian ryegrass and 1,103 kg/ha for triticale and were significantly higher than those harvested on May 3 and May 9. The total digestible nutrient yield(TDN) of Italian ryegrass with 5,223 kg/ha harvested on May 16 was significantly higher than that harvested on May 3 and May 9. The total digestible nutrient yield of triticale with 8,277 kg/ha harvested on June 7 was significantly higher than that harvested during May, but not different from that harvested after June 7. Considering the dry matter yield, crude protein yield and total digestible nutrient yield, it is suggested that the optimal harvesting times for Italian ryegrass and triticale seem to be May 16 and June 7, respectively.

• Current Research on Agriculture and Life Sciences
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• v.27
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• pp.1-6
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• 2009

Persimmon occupied the second largest cultivation area next to apple among the fruits in Korea. Since 70 % of its cultivating field is located at slope, the efficiency of its harvesting operation is very low. Also, the traditional persimmon harvest apparatus does not seem to be efficient to use due to a structural problem. In this paper, the author has analyzed the physical properties of persimmon friut-stem system and compared detachment force with developed persimmon harvest apparatus and traditional persimmon harvest apparatus in order to solve the problems mentioned above. The results of the research are summarized as follows : 1. The weight of the persimmon is shown as 157 g on average, the lengths of stem's major axis and minor axis is shown as 4.6 mm and 3.7 mm on average, respectively, sectional area of stem is shown as $13.9mm^2$ on average and the stem length is shown as 13.6 mm on average. 2 In case of the traditional persimmon harvest apparatus, the detachment force needed when a persimmon was detached from its stem was shown as 86.3 N on average. 3. In case of the developed persimmon harvest apparatus, detachment force needed when a persimmon was detached from its stem was shown as 72.6 N on average.