인력 적과 시기가 '감홍'/M.9 사과나무의 고두증상 발생과 과실품질에 미치는 영향

권헌중,사공동훈,Kweon, Hun-Joong,Sagong, Dong-Hoon 한국생물환경조절학회 2021 생물환경조절학회지 Vol.30 No.4

This study was conducted to investigate the effect of time of hand-thinning on vegetative growth, bitter pit incidence, fruit quality, and return bloom in 'Gamhong'/M.9 apple trees. The time of hand-thinning were 3, 5, 7 and 9 weeks after full bloom, and the primary thinning (leaving only the king fruit on cluster) and secondary thinning (adjusting crop load) were conducted at the same time. The time of hand-thinning was correlated to the vegetative growth, average fruit wight, yield, soluble solids content, bitter pit incidence, and return bloom, negatively, and to the yield of middle grade fruits (fruit weight was 250-299g and none pit on fruit surface) per tree, calcium contents of leaves, and fruit red color, positively. There was no significant effect of time of hand-thinning on fruit firmness, titratable acidity, and total incomes per tree. In conclusion, if the time of hand-thinning of 'Gamhong'/M.9 apple tree was completed at 9 weeks after full bloom, it could produce about 300g of high-quality fruit without bitter pit. 본 시험은 '감홍'/M.9 사과나무의 인력 적과 시기가 영양생장, 고두증상, 과실품질 및 이듬해 개화율에 미치는 영향을 조사하고자 실시하였다. 인력 적과 시기는 만개 후 3, 5, 7, 9주였으며, 1차 적과(중심과만 남기는 적과)와 2차 적과(착과수 조절을 위한 적과)는 동시에 이루어졌다. 인력 적과 시기는 영양 생장, 평균 과중, 생산량, 가용성 고형물 함량, 고두증상 발생률 및 이듬해 개화율과 역의 상관관계를 가졌으나 나무별 중급 과실(과중이 214-299g이면서 고두증상이 발생하지 않은 과실)의 생산량, 잎 내 칼슘 함량 및 과실의 착색 정도와는 정의 상관관계를 가졌다. 과실의 경도, 산 함량 및 나무 당 총 조수입은 인력 적과 시기에 영향을 받지 않았다. 결론적으로, '감홍'/M.9 사과나무의 인력 적과가 만개 후 9주에 마무리되면 고두증상이 없는 300g 정도의 고품질 과실을 생산할 수 있었다.

성목기 ‘감홍’/M.9 사과나무의 착과수준이 고두증상 및 과실품질에 미치는 영향

권헌중,박무용,송양익,이동용,사공동훈 한국환경농학회 2019 한국환경농학회지 Vol.38 No.3

BACKGROUND: The 'Gamhong' cultivar, middle season apple with big fruit size and high soluble solid content, has been bred in Korea. However, it was hard to cultivate the cultivar in Korea by serious bitter pit. The relationships between shoot growth, fruit size, and bitter pit may be affected by crop load. This study was conducted for 2 years (7~8 years after planting) to investigate vegetative growth, fruit quality, bitter pit incidence, return bloom, and gross income for optimum crop load of 'Gamhong'/M.9 adult apple tree. METHODS AND RESULTS: The crop load was assigned to 4 different object ranges as follow: 45~64, 65~84, 85~104, and 105~124 fruits per tree. The vegetative growth, average fruit weight, percentage of fruits heavier than 375 g, soluble solid content, and return bloom increased significantly at the crop load range of 45~64 fruits. However, the lowest total gross income per tree may have been caused by the highest bitter pit incidence and the lowest yield per tree in any other crop load range. The total gross income and yield per tree increased significantly at the crop load range of 105~124 fruits and return bloom dropped to 40%, and hence it was possible to occur biennial bearing. It was 85~104 fruits that biennial bearing did not occur and total gross income was as high as the crop load range of 105~124 fruits. Also, the yield of high grade fruits per tree, with fruit weight of 400~499 g and none bitter pit on fruit surface, was highest at the crop load range of 85~104 fruits, compared to other crop load range. CONCLUSION: In considering fruit size, bitter pit incidence, return bloom, and gross income, the optimum crop load range of 'Gamhong'/M.9 adult apple tree in high density orchard was 85~104 fruits per tree.

개화기에 저온 피해를 받은 ‘후지’/M.9 사과나무의 하계전정 시기가 신초생장 및 과실품질에 미치는 영향

권헌중,사공동훈 한국환경농학회 2022 한국환경농학회지 Vol.41 No.4

BACKGROUND: The low temperature at flowering periꠓod break the balance between vegetative and reproductive growth of apple tree. Summer pruning has been used to control vegetative growth. So, this study was conducted to investigate the effect of summer pruning time on shoot growth and fruit quality of ‘Fuji’/M.9 apple trees damaged by the low temperature at flowering period. METHODS AND RESULTS: The following treatments were applied to tree : a) control (no summer pruning), b) pruned 26 June, c) pruned 30 July, d) pruned 28 August, and e) pruned 26 September. The summer pruning sigꠓnificantly increased light penetration and fruit red color by reducing the total shoot growth compared with control. And the summer pruning control the outbreak of apple valsa canker. But the summer pruning at the end of June increased regrowth of shoot and pruning weight compared with the summer pruning at the end of August. The summꠓer pruning at 30 July had the highest fruit weight, but reꠓturn bloom was the highest in the summer pruning at 28 August. CONCLUSION(S): These results indicated the optimum summer pruning time of ‘Fuji’/M.9 apple trees damaged by the low temperature at flowering period were the end of August. .

동계전정 지연이 ‘후지’/M.9 사과나무의 신초생장 및 과실품질에 미치는 영향

권헌중,사공동훈 한국환경농학회 2022 한국환경농학회지 Vol.41 No.3

BACKGROUND : The freezing injury by pruning can be reduced by suspending pruning work when severe cold weather (-23 to –49oC) is forecast. Minimum air temperature of Gunwi region at 3 February was –21.9oC, and the subzero temperature was occurred until 8 April. So, this study was conducted in two years to investigate the effect of delaying winter pruning until full bloom on shoot growth and fruit quality of ‘Fuji’/M.9 apple trees. METHODS AND RESULTS : The time of pruning were dormant (26 March), bud break (3 April), full bloom (2 May). The winter pruning at full bloom significantly reduced fruit weight for two years compared with the control (winter pruning at dormant), and shoot growth of that was reduced only in the following year. There was no significant effect of delaying winter pruning at bud break on soluble solid content, fruit red color, return bloom, and pruning weight for two years compared with the control. CONCLUSION(S) : These results indicated the delaying winter pruning at bud break of ‘Fuji’/M.9 apple tree did not offer any disadvantage over comparable dormant pruning as shoot growth, fruit quality and return bloom, and delayed pruning at full bloom should not be used on trees with less than optimum vigor. .

지연 Controlled Atmosphere(CA)저장이 저장 중 ‘후지’ 과실의 품질에 미치는 영향

권헌중,정명근,최동근,이진욱,강인규,정희영 (사) 한국생물환경조절학회 2013 생물환경조절학회지 Vol.22 No.3

This study was conducted to investigate the effect of delayed controlled atmosphere (CA) storage on fruit quality and the incidence of storage disorders during CA storage of ‘Fuji’ apples (Malus x domestica Borkh.). In the first year of experiment, ‘Fuji’ apples showed 40% of watercore disorder at the commercial harvest time (Oct. 22). Twenty days delayed CA storage caused to develop the incidence of flesh browning while 30 days delayed CA storage did not. In the second year of experiment, watercore was increased with delaying harvest time. As the estabilishment of delayed CA storage was delayed, the incidence of flesh browning increased at 10 to 30 days delayed CA storage but 40 days delayed CA storage did not have any flesh browning incidence. Respiration rate increased with extending the storage duration. Delayed CA storage reduced respiration rate but was not different compared to the rapid CA. Ethylene production rate was lower in delayed CA storage than in cold storage but higher in delayed CA storage, compared to rapid CA storage. Titratable acidity was lower in delayed CA storage as CA storage progressed. Firmness was not different between rapid CA storage and delayed CA storage after 8 months of CA storage. Therefore, the results indicate that delayed CA storage should be a promising approach to reduce the risk development of flesh browning and watercore during CA storage of ‘Fuji’ apples. 본 연구애서는 ‘후지’ 사과의 CA 저장을 실용화하기위하여 수확시기와 일정기간 저온저장한 후 CA 환경을설정하는 지연 CA 처리가 저장 중 내부갈변장해와 과실품질에 미치는 영향을 조사하였다. 1차 년도에 ‘후지’사과를 10월 22일에 수확하였을 때 밀병 발생율이 40%였고, CA 환경 조성(O2 2.5 ± 0.5% + CO2 2.5 ± 0.5%)을20일 지연 CA 저장하였을 때는 내부갈변이 발생하였으나, 30일 지연 CA 저장에서는 내부갈변이 발생하지 않았다. 2차 년도에는 수확시기가 늦어질수록 밀병 발생율이 높았고, 이러한 과실은 10~30일 지연 CA 처리구에서 내부갈변장해가 발생하였으나, 40일 지연 CA 처리구에서는 내부갈변장해가 발생하지 않았다. 호흡량은 저온저장 과실에서는 저장기간이 길어질수록 급격히 증가하였으나 지연 CA 저장에서는 호흡량이 낮게 유지되었고,급속 CA 저장에 비해서 차이를 보이지 않았다. 에틸렌발생량은 지연 CA 저장한 과실들이 저온저장에 비해서낮았으나, 급속 CA 저장에 비해서는 다소 높은 발생량을 보였다. 산 함량은 지연 CA 저장이 급속 CA 저장에비해 저장기간이 길어질수록 감소하는 경향이었고, 경도는 저장 8개월 후에도 급속 CA 처리구와 지연 CA 처리구간에는 차이를 보이지 않았다.

Relationship between Preharvest Factors and the Incidence of Storage Disorders in ‘Fuji’ Apples during CA Storage

권헌중,김목종,문용선,이진욱,최철,최동근,이동훈,강인규 한국원예학회 2012 원예과학기술지 Vol.30 No.1

This study was carried out to evaluate the effect of pre-harvest factors on fruit quality and the incidence of storage disorders in ‘Fuji’ apple during CA storage. Incidence of storage disorders varied, depending on the growing regions, field conditions, and altitude of the orchards. Results indicated that fruit maturity may play a crucial role in the incidence and severity of flesh browning and watercore. The incidence of these storage disorders increased with fruit maturity until 180 days after full bloom (DAFB). In addition,occurrence of watercore was correlated with the incidence of flesh browning during CA storage. The incidence of flesh browning was positively correlated with the sum of the diurnal temperature range from September through October and amount of precipitation from August to October in 1996-1999 growing years. These results suggested that ‘Fuji’ apple should be harvested no later than 180 DAFB because the late harvested fruits were prone to development of watercore which was correlated with the incidence of flesh browing during CA storage in Korea.

고밀식 사과원에서의 간벌이 ‘후지’/M.9 사과나무의 영양생장, 생산량 및 과실품질에 미치는 영향

권헌중,사공동훈 한국환경농학회 2023 한국환경농학회지 Vol.42 No.2

As apple trees mature, it is important to maintain good light distribution within the canopy to produce marketable fruits. Tree thinning is the selective removal of a proportion of trees growing in the orchard to provide more growing space and a good light environment for the remaining trees. This study was conducted over 3 years (14–16 years after planting) to investigate the influence of tree thinning on vegetative growth, yield, fruit quality, and blooming in the 14 years old slender spindle ‘Fuji’/M.9 apple trees planted with the tree space of 3.2 x 1.2 m. The trees were placed in a control group (no thinning; 260 trees per 10 a) or a tree thinning group (thinned 50% of the control; 130 trees per 10 a). The tree thinning successfully improved light penetration, yield per tree, fruit red color, and yield efficiency for 3 years, and the tree thinning controlled the occurrence of biennial bearing. However, tree thinning significantly decreased accumulated yield per 10 a compared with the control. The vegetative growth, yield per tree, soluble solid contents, and blooming were not clear by the occurrence of biennial bearing in the control. These results indicated that tree thinning was a good method for improving light penetration and preventing biennial bearing in the old ‘Fuji’/M.9 high-density apple orchards. .

[발표자료_사례발표] 국가연구기관의 사과연구 사례

권헌중 한국농촌경제연구원 2012 한국농촌경제연구원 연구자료 Vol.- No.-

휴면기 저온 누적 시간 및 발아 후 변온이 국내 주요 사과품종의 개화에 미치는 영향

권헌중,박무용,송양익,사공동훈 한국농림기상학회 2017 한국농림기상학회지 Vol.19 No.4

This study was carried out to examine the base temperature to flowering and the average days to flowering by accumulated hours of low temperature (5.0oC) or changing temperature after bud breaking. Over-all, the prediction of flowering time in the commercial apple cultivars (‘Fuji’ and ‘Tsugaru’) and apple cultivars (‘Chukwang’, ‘Gamhong’, ‘Hongan’, ‘Honggeum’, ‘Hongro’, ‘Hongso’, ‘Hwahong’, ‘Summer dream’, ‘Sunhong’) bred in Korea at the Gunwi region for 4 years(from 2009 to 2012) was investigated. Also, this study estimated the flowering time when the air temperature of Gunwi region rises at 5.0oC was investigated using the same data. The range of accumulated hours of low temperature (chilling requirement) was from 0 hour to 1,671 hours, and the range of high temperature (heat requirements) to flowering after low temperature treatment was from 5.0oC to 29.0oC. The treatments of changing temperature after bud breaking were classified as constant temperature treatment (control) and 5.0∼10.0oC elevation or descent treatments. The results show that the average days to flowering was longer with shorter accumulated hours of low temperature, and the average days from bud breaking to flowering of 0 hour treatment was longer about 2∼4 weeks than that of 1,335∼1,503 hours treatments. In comparing to apple cultivars, the all cultivars were not flowered under 10.0oC after bud breaking, and the cultivars with low chilling requirements needed low heat requirements for flowering. The average days to flowering of treatments that the air temperature after bud breaking was controlled about 15.0oC was shorter about 1∼3 weeks than that of treatments was controlled about 10.0oC. In the treatment of changing temperature after bud breaking, the average days from bud breaking to flowering of temperature elevation treatment was shorter than that of constant temperature treatment. By use of these results, the base temperature to flowering of main apple cultivars in Korea was seemed to 10.0oC, and if the air temperature of Gunwi region rises about 5.0oC than that of current, the flowering time was estimated to be delayed by 1 week. 본 시험은 품종별 개화가 가능한 기준온도와 저온(5.0oC) 누적시간 및 발아 후 변온에 따른 평균 개화소요일수를 구명하여 국내 주요 사과품종(‘후지’, ‘쓰가루’)들과 국내에서 육성한 품종(‘추광’, ‘감홍’, ‘홍안’, ‘홍금’, ‘홍로’, ‘홍소’, ‘화홍’, ‘섬머드림’, ‘선홍’)들의 개화기를 예측하고자 군위지역에서 4년(2009-2012년)동안 조사하였다. 또한, 이들 자료를 이용하여 군위지역 기온이 현재보다 5.0oC 상승되었을 때의 개화시기를 추정하였다. 저온(5.0oC) 누적시간(저온요구도)의 처리 범위는 0∼1,671hr 정도였고, 저온 처리 후 개화를 위한 고온(고온요구도) 처리 범위는 5.0∼29.0oC 정도였다. 발아 후 변온 처리구들은 항온구(대조구), 5.0∼10.0oC 상승구 및 하강구로 분류하였다. 결과를 살펴보면, 저온에서의 누적시간이 짧을수록 개화소요일수가 길어지는 경향이 있었으며, 0hr 처리구의 발아 후 개화까지의 소요된 일수는 1,335∼1,503hr 처리구보다 2∼4주 정도 길었다. 품종 별로는 모든 품종이 발아 후 기온이 10.0oC 미만일 때 개화를 하지 못하였고, 저온요구도가 낮은 품종일수록 개화에 필요한 고온요구도가 낮았다. 발아 후 기온을 15.0oC로 조절된 처리구들의 개화소요일수는 10.0oC 처리구들보다 1∼3주 정도 빨랐다. 발아 후 변온 처리에서는 발아 후 기온 상승 처리구들의 발아 후 개화까지 소요된 일수가 항온 처리구보다 짧았다. 이상의 결과를 종합해보면, 국내 주요 사과품종들의 개화 기준온도는 10.0oC로 생각되었으며, 군위지역의 기온이 지금보다 5.0oC 정도 상승된다고 가정하면, 개화기는 1주 정도 지연될 것으로 예측되었다.

CO₂ 및 기온 상승이 '후지'/M.9 사과나무의 광합성, 신초생장 및 과실품질에 미치는 영향

권헌중,사공동훈,박무용,송양익,정경호,남종철,한점화,도경란,Kweon, Hun-Joong,Sagong, Dong-Hoon,Park, Moo-Yong,Song, Yang-Yik,Chung, Kyeong-Ho,Nam, Jong-Chul,Han, Jeom-Hwa,Do, Gyung-Ran 한국농림기상학회 2013 한국농림기상학회지 Vol.15 No.4

본 시험은 기후변화의 영향과 관련하여 기온 및 $CO_2$ 농도 상승이 '후지'/M.9 사과나무의 광합성 및 과실품질에 미치는 영향을 알아보고자 지난 4년(2009-2012)동안 시험이 이루어졌다. 처리구들은 'Ambient' (대기온도+대기 $CO_2$ 농도), 'High $CO_2$'(대기온도+상승 $CO_2$ 농도), 'High Temp'. (상승온도+대기 $CO_2$ 농도), 'High $CO_2$+High Temp'. (상승온도+상승 $CO_2$ 농도)이었다. 상승온도 처리구들은 대기온도보다 $4^{\circ}C$ 상승시켰고, 상승 $CO_2$ 농도 처리구들은 $700{\mu}mol{\cdot}mol^{-1}$로 유지하였다. 4년 동안 매년 처리기간은 4월말부터 11월초까지였다. $CO_2$ 상승은 기공전도도와 잎의 엽록체함량(SPAD 계량기 값)을 감소시켰으나, 광합성속도, 세포 내 $CO_2$ 농도(Ci) 및 잎의 전분함량은 증가시켰다. 수체생장에 있어, 기온 상승은 나무당 총 신초수와 총 신초생장량을 증가시켰으나, $CO_2$ 상승은 평균 신초장을 감소시켰다. 과실품질에 있어, $CO_2$ 상승은 착색, 가용성 고형물 함량, 및 에틸렌 발생량을 증진시켰다. 결론적으로, $CO_2$ 농도가 상승되면 생육초기에 사과나무의 광합성속도가 증가되었으나 생육후기에는 $CO_2$ 상승에 따른 광합성속도 증진 효과가 감소되었다. 반면에 기온 상승은 생육초기 광합성속도를 감소시켰으나 생육후기에 광합성속도를 증진시키는 경향이 있었다. $CO_2$와 기온의 동시 상승은 각 요인에 의한 광합성 감소 정도가 줄어드는 경향이 있었다. This study was conducted to find out the influence of elevated atmospheric $CO_2$ concentrations and air temperature on photosynthesis and fruit quality of 'Fuji'/M.9 apple trees and to investigate these to the effects of climate change during the last four years (2009-2012). The treatments employed were: 'Ambient' (ambient temperature + ambient $CO_2$ concentration); 'High $CO_2$' (ambient temperature + elevated $CO_2$ concentration); 'High Temp'. (elevated temperature + ambient $CO_2$ concentration); and 'High $CO_2$ + High Temp'. (elevated temperature + elevated $CO_2$ concentration). The elevated temperature plots were maintained at $4^{\circ}C$ higher than ambient air temperature, while the elevated $CO_2$ plots were maintained at 700 ${\mu}mol{\cdot}mol^{-1}$. Annual treatment period was applied from end of April to beginning of November for four years. Results showed that elevated $CO_2$ decreased stomatal conductance and leaf SPAD value, but increased photosynthetic rate, intercellular $CO_2$ concentration (Ci), and starch content of mesophyll tissue. In the vegetative growth, elevated temperature increased total number of shoot and total shoot growth per tree, but elevated $CO_2$ decreased average shoot length. In the fruit quality, elevated $CO_2$ increased soluble solid content, fruit red color, and ethylene production. In conclusion, elevated $CO_2$ increased photosynthetic rate of apples during the early growth, but effect of increased photosynthetic rate due to elevated $CO_2$ was decreased during latter growth stage. Elevated temperature, on the other hand, tended to decrease photosynthetic rate of apples during the early growth, but that tended to increase during latter growth stage. Both elevated $CO_2$ and temperature tended to decrease the degree of decreased photosynthetic rate due to each factor.