• Journal of Forest and Environmental Science
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• v.38 no.4
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• pp.256-262
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• 2022

The timing of seed harvesting is an important decision in the management of seed orchards because it affects seed quality and yield. To investigate the effect of cone harvest time on seed quality and determine the optimal harvesting time, cones were regularly collected in seven times and germination tests were performed at each harvest time in two clonal seed orchards of Chamaecyparis obtusa. As cones developed, the percentage of seed germination increased before cone moisture content began to decrease significantly. The moisture contents of cones were highest at the first collection as 68.3% and 67.3% in Jeju and Gochang seed orchards respectively. At this time, germination speed was slowest, indicating poor seed vigour. The highest germination was found at the second stage in Jeju (36.5%) and at the seventh stage in Gochang (28.6%) seed orchard. The germination speed increased as cone moisture content decreased. Additionally, changes of seed vigour differed among the developmental stages in both seed orchards. Consequently, the optimal cone harvest time of C. obtusa seed orchards in Jeju was early September when high germination percentage was obtained. In Gochang seed orchards, late October was optimal cone harvest time when the germination speed was fast and the cone moisture content decreased.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.2
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• pp.121-128
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• 2009

A field study was conducted from 2007 to 2008 at Department Rice and Winter Cereal Crop, NICS, RDA, to evaluate the effects of harvest time and cultivar on forage yield and quality. Four whole crop barley cultivars ('Youngyang', 'Wooho', 'Yuyeon' and 'Dami') were selected and harvested on five separate growth stages (heading, and intervals of 1, 2, 3 and 4 weeks after heading) in split plot design with three replications. Results from this experiment indicated significant differences due to harvest time and cultivar in dry matter yield and total digestible nutrients (TDN) yield for forage. The interaction between harvest time and cultivar was not significant. The TDN yield trends were increasing with later harvest time due to higher dry matter yield and TDN content. This experiment provides some interesting results with respects to optimum harvest time, feed value and ultimately yield for the different whole crop barley cultivars.

• 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.

• Journal of Biosystems Engineering
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• v.12 no.2
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• pp.44-59
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• 1987

The objectives of this study were to analyze and develop the model systems of rice post-harvest systems from drying to processing, and to develop a bulk system among them which requires minimum system cost and less operating time. The significance of this study was the development of a computer program (PPSARR). The PPSARR makes it possible to evaluate quantitatively the performance and economics of the rice post-harvest systems. The results show that the rice post-harvest bulk system requires less time and cost such as 37-60% and 46-59% of those of the sack system, respectively. Also, the former requires less manpower than the latter. For not more than 1,800 ton of rough rice production, the bulk system which is "drying & storage by IBDS-transport-milling" is recommended, and for more than 1,800 ton, the one which is "drying & storage by IBDS - transport - storing at flat storage improved - transport - processing by RPC" is recommended.

• Korean Journal of Medicinal Crop Science
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• v.23 no.4
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• pp.311-318
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• 2015

This study had been conducted to investigate the effect of some plant growth regulators inducing fruit enlargement and optimal harvest time in Sageretia thea. Two hundred fifty $mg/{\ell}$ mepiquat chloride treatment, $1mg/{\ell}$ thidiazuron treatment on full bloom, and $200mg/{\ell}$ gibberellic acid treatment on 7 days before full bloom resulted in the increase of 21.7% in weight, and $200mg/{\ell}$ gibberellic acid treatment 7 days before full bloom, 10$mg/{\ell}$ forchlorfenuron treatment 14 days after full bloom, and $1mg/{\ell}$ thidiazuron treatment on full bloom also brought about positive effects on the enlargement of the fruit, increasing 6.3%, 6.3% and 8.1% in its transverse diameter, respectively. Furthermore, the effects of the plant growth regulator treatments on the harvest time of Sageretia thea were determined as follows: the increase in the optimal harvest time of 57.2 - 75.4%, shorter maturation period, by the treatments with $500mg/{\ell}$ mepiquat chloride 7 days after full bloom, $100mg/{\ell}$ gibberellic acid treatment on full bloom, $2.5mg/{\ell}$ forchlorofenuron 7 days after full bloom and $2mg/{\ell}$ thidiazuron treatment 7 days before full bloom; and the greater effects of plant growth regulator treatments on the fruit maturation in the following order, gibberellic acid > thidiazuron > forchlorofenuron > mepiquat chloride. The results of this study are expected to be used as a reference data to develop Sageretia thea as a new local specific crop for Jeju island.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.2
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• pp.112-117
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• 1995

A field experiment was canied out to determine the effects of harvest time (grazing, soiling and hay stage) on the grass growth, dry matter (DM) yield, nutritive value, and weed development in reed canarygrass (Phalaris arundinacea L.) pasture. The cultivars of reed canarygrass used in this study were Palaton, Venture, Castor, and Frontier (control). The grass was harvested 3 times at hay stage, 4 times at soiling stage, and 6 times at grazing stage in 1992. The average plant height was 31-41cm at grazing, 47-59cm at soiling, and 76-86cm at hay stage. Similar DM yield was observed in Palaton(12,567 kglha), Venture(l2,435kg), and Frontier(12,762kg), and the yields of 3 cultivars were significantly higher than that of Castor(ll,025kg) (P<0.05). Total yields affected by harvest time were lO,O6 1, 1 1,832, and 14,699 kg/ha at grazing, soiling, and hay stage, respectively(P<0.05). The content of crude protein (CP) was not significantly different among cultivars. CP contents by harvest time were 21.6% at grazing, 19.3% at soiling, and 18.8% at hay stage, regardless of cultivm(P<0.05). The contents of neutral detergent fiber (NDF) and acid detergent fiber (ADF) were similar among cultivars and harvest time. However, slightly higher NDF and ADF contents were found in Frontier. The contents of Ca, P, K, and Mg were not affected by cultivars and harvest time. The appearance of weeds was high in Castor, and low in Frontier. The weeds at grazing stage(33.3-60.0%) were remarkably higher than those at soiling and hay astage (ca 10%). In conclusion, it is suggested that 3-4 times (soiling and hay stage) of harvest was recommended for grass production, nutritive value, and weed control in reed canarygrass pasture, regradless of cultivars of Palation, Venture and Frontier, except Castor.

• Korean Journal of Agricultural Science
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• v.39 no.4
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• pp.503-509
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• 2012

This research aimed to investigate the effect of preharvest spray of aminoethoxyvinylglycine (AVG) on fruit quality of 'Nagasawa Hakuho' peach (Prunus persica Batsch). The efficacy of various concentrations of AVG (75 and 150 mg/L), which inhibits the ethylene biosynthesis, was evaluated under field conditions. Treatments were performed 21, 14 and 7 days before harvest, respectively. Fruit weight, flesh firmness, soluble solids content, acidity, ethylene production, respiration rate and skin color difference were determined at harvest time and during shelf-life at $25^{\circ}C$. Results indicated that the most appropriate timing of AVG spraying was 21 days before harvest at the concentration of 75 mg/L as shown higher firmness at harvest time and lower ethylene production and respiration rate during shelf-life. Spraying of AVG during near harvest period (14 to 7 days before harvest) inhibited fruit growth slightly, independent of concentration and did not affect fruit quality in 'Nagasawa Hakuho' peach.

• Journal of The Korean Society of Grassland and Forage Science
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• v.3 no.2
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• pp.86-91
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• 1983

The harvest schedule for maximum total yield and quality of orchardgrass sward was studied on the basis of theoretical analysis due to Chang's total yield equation. Harvesting at the 10% bloom stage of morphological development of orchardgrass swards was selected as a criterion which provided highest dry matter (DM) yield in conjunction with high and consistent levels of in vitro dry matter digestibility (IVD) and crude protein contents (CP) from harvest to harvest. However, since orchardrass after the 1st cutting do not bloom, the harvest time for the maximum yield and quality of orchardgrass swards is replaced by the three should time of the ceiling leaf area index (LAI).

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.26 no.2
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• pp.61-69
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• 2020

As post-harvest processes of onions are carried by a 20 kg-net package which results in high-cost and low-efficiency, especially, the insufficient drying and physical damage of onions after harvesting leads to a huge second loss in storage, we had developed a low-cost, high-efficiency post-harvest bulk handling machinery system by collecting onions on a farm using ton-bags, drying with forced air circulation, and sorting/packaging. The post-harvest bulk handling machinery system consisted of 6 devices, and this study designed an automatic feed hopper with a feeding rate control device, an inclined belt conveyor with a two-step chute, and an automatic pallet unloading device for feeding onions into the sorting/packing line. This study also analyzed the performance and control of the total system. The device had 1-ton handling capacity, but the operational condition was set to increase the capacity. The three-step filling method of pallet by the velocity control of the inclined belt conveyor was applied in the post-harvest bulk handling machinery system for the prevention of physical damage. If one worker was set to operate the total system, the time required to complete one palletized load was approximately 5 minutes and 5 seconds. The calculated daily handling capacity was approximately 94 tons, when the daily actual working time was 8 hours. When the developed system was applied to the managerial size of 2,000 ton, the processing cost per ton of the system was decreased by 19.5%, compared with the existing 20 kg-net package-based handling. The developed post-harvest bulk handling machinery system would be a good substitute for the rapid decline and aging of rural labor.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.21 no.2
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• pp.73-78
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• 2015

Persimmons on the trees are often exposed to weather condition of cold temperature before harvest, which affects the fruit quality at harvest time and later storage. This study investigated the effect of the harvest season temperature on the storage quality of 'Fuyu' sweet persimmons. Monitoring the temperature changes in the orchard showed five times of cold temperature below the freezing temperature of persimmon, $-2.1^{\circ}C$, in the harvesting period between mid October and mid November with the lowest being as low as $-5.4^{\circ}C$. Among three different harvestings, the tertiary one at mid November showed decreased 'L' value and consistently high 'a' value of color index and high reduction in hardness during 150 days storage of fruits at $0^{\circ}C$ showing freeze-injured symptoms, compared to the first one at mid October and the second one at early November. The fruits of first harvest maintained consistently hard texture with increased 'a' color value probably due to postharvest ripening. The tertiary harvest exhibited increase in fructose and glucose contents and decrease in sucrose of the fruits, being very different from the first and secondary harvests which maintained constant level of all three free sugars. Mid November with possible sudden temperature drop is unsuitable period for harvesting sweet persimmons in the quality at harvest and later storage, and thus the harvest should be designed to be done before that time.