• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.4
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• pp.1-9
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• 1980

To determine the optimum harvest time of recent rice varieties from Indica/Japonica remote crosses, leading varieties Suweon 264 and Milyang 23 were tested for the changes in dry matter weight and moisture content of grain, shattering, shelling ratio, milling ratio, and apparant physical quality during grain development at 5 day-intervals from 20 days to 55 days after heading. The results are summarized as follows: 1. Grain weight (dry matter) reached its maximum (physiological maturity) at 30 days after flowering (DAF) in Suweon 264, and at 35 days in Milyang 23, and thereafter it did not change significantly until 55 DAF. 2. Time course of decrease in grain moisture content (Y, %) during maturation (X, DAF) consisted of two linear phases, i.e. a fast and a slow period: Y=68.245-1.33X until 34DAF, and Y=23.025-0.470X until 55DAF after 34DAF in Suweon 264; Y=73.62-1.634X until 24.5DAF, and Y=33.59-0.570X until 55DAF after 24.5DAF in Milyang 23. Two varieties showed the same grain moisture content of 28% (wet basis) at physiological maturity in spite of the distinct differences in the heading date, time of physiological maturity and thereby ripening climate. 3. Force to shatter a grain ranged about 90 to 100g in Milyang 23, and about 200 to 250g in Suweon 264 and in a Japonica variety, Jinheung. The force, however, did not change significantly with harvest time from 35DAF to 50DAF. 4. The changes in the ratios of shelling, milling, broken rice and tinted rice with harvest time were insignificant during a period from 35DAF to 55DAF. However, ratios of green rice and white belly rice decreased significantly with delay in harvest time during 10 days after physiological maturity. 5. The best time of harvest for maximum yield and good quality is thought to be 10 days after physiological maturity, and grain moisture content at this time was about 20% on wet basis.

• Horticultural Science & Technology
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• v.35 no.4
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• pp.418-430
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• 2017

The objective of this study was to understand the combined effect of shading treatment and harvest time on pungency, ascorbic acid content, market-quality pepper yield, and photosynthetic activity in a yellow 'Star Flame' and 'Fire Flame' F1 hybrid pepper cultivar (Capsicum annuum). Plants were cultivated in a greenhouse under white, red, and green shading nets and compared to those grown under unshaded control conditions. The ascorbic acid and pungency parameters were analyzed by high-performance liquid chromatographic methods. Ascorbic acid, a compound of high nutritive value in pepper, was highest in fruits gathered during the first summer harvest in both hybrids. The ascorbic acid content was found to be further increased in fruits from plants grown under white net shading in both 'Star Flame' and 'Fire Flame'. Total capsaicinoid contents in 'Star Flame' were influenced by the interaction of shading treatment and harvest time (p = 0.004), with the lowest amounts ($241.2-251.5mg{\cdot}kg^{-1}$ fresh weight) resulting from white and red shading treatments at the early autumn harvest. In 'Fire Flame', both shading treatment (p = 0.009) and harvest time (p < 0.001) affected total capsaicinoid contents. We observed significantly higher total capsaicinoid contents in control fruits compared to that resulting from red and green shading treatments at the second harvest, and that resulting from red shading treatment at the third harvest. Analysis of photosynthetic activity revealed a significant and negative correlation between Fv/Fm values and total capsaicinoid contents in both hybrids (p < 0.001). Based on the obtained results, the harvest of peppers during summer should be promoted to produce fruits with high pungency.

• Journal of Biosystems Engineering
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• v.24 no.5
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• pp.399-406
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• 1999

This study was conducted to investigate the labor requirements and transportation cost of paddy for the different harvest and transportation systems for obtaining a basic reference to the improvement of present harvest-transportation systems. One hundred and eighty five farm households with sack type combine harvester and thirty farm households with bulk type combine harvester were surveyed for thirty counties from eight provinces except jeju and also eleven Rice Processing Complex were covered for this survey. This survey was carried from 8th. October 1997 to 5th. November 1997. For the labor requirements, bulk trailer system require 6.8th/ha, 10.3/ha for sack harvest-tractor trailer, and 8.8h/ha for bulk harvest-container bag. The machinery utilization cost for the different paddy harvest-transportation systems, combine sack harvest-tractor trailer system is 282 thousand won/ha, and most economical compared with other systems. Combine bulk harvest with tractor system was 416 thousands won/ha and combine bulk harvest with container bag system was 446 thousands won/ha. In order to propagate bulk harvest-transportation system, a proper bulk transportation means with considering road condition in the paddy field and paddy size should be developed, and considering cycle time it appeared that the proper capacity of bulk container was 3.5ton at the present.

• Korean Journal of Plant Resources
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• v.8 no.3
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• pp.297-302
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• 1995

The experiment is conducted to reduce the labor and production cost with the labor save of harvest if cultivating the potatoes using the machine and the results are as follows. On labor saving effect in transparent vinyl mulching, digging working hours per 10a in the case of using tractor are 60 min., fixing + turning time is 5 min. and 30sec., the time of harvest is 65 min and 30sec., digging working hours using cultivator are 99 min. and fixing +turning time is 5 min. and 30sec., but the time of hand harvesting is 990 min. and in digging labor saving effect, tractor shows 94% in the harvesting period and harvest by cultivator 90%. On non mulching cases, the harvest by tractor takes 49 min. and 30 sec. and that by cultivator does 87 min. and 30 sec., and digging labor saving effect shows 94% in the tractor harvest and 90% in the cultivator harvest. Therefore, on the operation efficiency per hour, in the case of tractor with digger vinyl mulching and non mulching show, $0.091\sim0.121ha$ and in the case of cultivator with digger both show $0.057\sim0.069ha$, so in the mechanized harvest of potatoes, the harvest by tractor with digger is the best. On the cost and labor save for harvesting the potatoes with labor saving effect, tractor shows 19 hours and 20 min./10a in vinyl mulching and 19 hours. and 54 min./10a in non mulching, so it shows the short hours for harvesting. And labor saving effect shows $42\sim45%$ in comparison with 35 hours and 21 min. $\sim35$ hours and 23 min.($123,113\sim130,613$ won) of the hand harvest, so the cost was reduced to $71,250\sim72,225$ won. On the cultivator with diggers, vinyl mulching takes 19 hours and 55 min. and non mulching 19 hours and 38 min., so the labor saving effect and cost were reduced to $14\sim44%$ ($72,675\sim73,313$ won) in comparison with the hand harvest.

• Plant Resources
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• v.7 no.3
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• pp.206-210
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• 2004

In order to find out the optimum harvest (dipping) date combined with sowing date on yield and nutrient quality of forage rye which is suitable at the Southern part of Korea, Paldanghomil variety was grown Sep. 2001 to May 2002 at Sunchon National University, and yield and nutrient quality of plant were observed. As harvest date and sowing date were delayed, the plant length was longest, number of leaves per plant was increased in the time of May 20 clipping. Fresh yield was the heaviest in the time of May 20 clipping and Oct. l0 sowing, and the most dry matter yield was the heaviest in the time of May 20 clipping and Oct. 10 sowing. Content of crude protein was the highest and that of crude fiber such as NDF, ADF, hemicellulose, cellulose and lignin were the lowest in the late time of clipping and sowing. Further more IVDMD was high and dry matter yield and digestible dry matter yield were the highest in the time of May 20 dipping and Oct. 10 sowing. Judging from the results reported above, at optimum harvest (dipping) date combined with sowing date for yield and nutrient quality of forage rye seemed to be the time of May 20 clipping and Oct. 10 sowing.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.2
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• pp.126-133
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• 1988

To know the optimum harvest time for seed yield and seed quality a local variety of rye 'Paldang-homil'was harvested at seven different harvest times from 25 to 55 day after heading (DAH) at five-day intervals in 1984 ani 1986. Seed development, seed germination and seedling growth were observed. The l000-grain weight increased as harvest time delayed until 50 DAH in both years. Although grain yield tended to increase with delay of harvest time, the yield differences between succeding harvest time was highest between 40 DAH and 45 DAH. Germination rate of seeds harvested before 30 DAH were lower than those after 35 DAH at 20 C, but at 10 and 30 C before 35 DAH were lower after 40 DAH. Plant height and dry weight of seedlings increased with delay of harvest time up to 45 DAH in pot. Heading stages were similar among the seeds harvested 40-55 DAH. Culm length was not different among the harvest times. The optimum harvest time for seed production of rye seems to be 45 DAH (38 days after flowering).

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.2
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• pp.199-203
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• 2001

Chopi, Zanthaxylum piperitum DC., has been used as natural spice traditionally in the Far East countries including Korea. This study was performed with the object of providing basic data, firstly for the decision of the appropriate harvesting time for traditional use of chopi and secondly for developing a new spice satisfying the national dietary custom from chopi as raw material. Concerning the conte수 and its change of the proximate composition, the content of moisture and crude protein decreased in all sample, while the content of fiber and ash tended to increased with the lapse of harvest time. The content of mineral elements tended to increase in every sample with the lapse of harvest time, and contents of K and P were higher than that of Ca, Na and Mg. Every sample showed the highest content of 15~16 components of total amino acids at the first period and the content decreased gradually with the lapse of harvest time. On the basis of the first period, every sample showed the highest content of aspartic acid, the lowest content of methionine and the trace of cysteine. Free amino acids increased considerably with the lapse of harvest time for peels of chopi and minchopi broth, while the amount for leaves increased on the contrary.

• 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.