Korean Journal of Environmental Agriculture (한국환경농학회지)

The Korean Society of Environmental Agriculture (한국환경농학회)
권호 표지
DOI QR코드

DOI QR Code

Fruit Quality of Rabbiteye Blueberry as Affected by Manual Floral Buds Thinning

블루베리 인력적화 시기와 방법이 과실특성에 미치는 영향

  • Kim, Hong Lim (Namhae Branch, National Institute of Horticultural and Herbal Science, Rural Development Administration) ;
  • Chae, Won-Byoung (Department of Environmental Horticulture, College of Life and Resource Science, Dankook University) ;
  • Kim, Jin-Gook (Department of Horticulture, College of Agriculture and Life Science, Gyeongsang National University) ;
  • Lee, Mock-hee (Namhae Branch, National Institute of Horticultural and Herbal Science, Rural Development Administration) ;
  • Rhee, Han-Cheol (Namhae Branch, National Institute of Horticultural and Herbal Science, Rural Development Administration) ;
  • Kim, Seung-Hui (Department of Fruit Science, Korea National College of Agriculture and Fisheries) ;
  • Kwack, Yong-Bum (Department of Fruit Science, Korea National College of Agriculture and Fisheries)
  • 김홍림 (농촌진흥청 국립원예특작과학원 남해출장소) ;
  • 채원병 (단국대학교 생명자원과학대학 환경원예학과) ;
  • 김진국 (국립 경상대학교 농업생명과학대학 원예학과) ;
  • 이목희 (농촌진흥청 국립원예특작과학원 남해출장소) ;
  • 이한철 (농촌진흥청 국립원예특작과학원 남해출장소) ;
  • 김승희 (국립 한국농수산대학 과수학과) ;
  • 곽용범 (국립 한국농수산대학 과수학과)
  • Received : 2019.08.14
  • Accepted : 2019.09.24
  • Published : 2019.09.30
Download PDF
⟨ Previous Next ⟩

Abstract

BACKGROUND: Increase in the ratio of small berries in blueberry production decreases the farmers' profits due to weakening market competitiveness and lowering harvest efficiency. One of the reasons for increased small berries is over fruit-load. For improving productivity and competitiveness of blueberry in Korea, hand-thinning can be applied to increase fruit quality before the developing adequate chemical thinning methods. This study was conducted to investigate the proper timing and methods for floral buds thinning in rabbiteye blueberry. METHODS AND RESULTS: Eight years old bushes of rabbiteye bluberries 'Brightwell' as a primary cultivar and 'Powderblue' as a pollinizer were used for this study. Fruit size distribution by leaf-to-fruit ratio was investigated by counting the number of leaves and fruits in canes of 127 'Brightwell' plants whose fruit set varied. Fifty percent of flowers/floral buds were removed in four different floral buds stages such as bud swell, late pink bud, full bloom, and petal fall, and the consumed time for thinning and fruit characteristics were recorded to investigate the effect and proper timing of floral buds thinning. Fruit weight and soluble solids content tended to increase in proportion to leaf-to-fruit ratio and the production of the number of fruits less than 13 mm in diameter decreased when leaf-to-fruit ratio was more than 2.5. Manual floral buds thinning by hands was fastest in full bloom stage and slowest in bud swelling stage. In all cultivars, fruit size was significantly smaller in non-thinning treatment than thinning, and there was, however, no significant difference in total fruit yield. The number of fruits less than 13 mm in diameter increased in both cultivars as floral buds thinning was delayed. Consumed time for picking 90% berries out of total berries per bush was shortest in full bloom stage thinning in 'Brightwell' and bud swelling, full bloom thinning in 'Powderblue'. These were 25 and 20 days faster than no thinning, respectively. CONCLUSION: Although the effect of floral buds thinning varied depending on the cultivars, our results confirmed that floral buds thinning was effective for the early intensive harvesting and the increase of the large fruit ratio and the harvesting productivity. Also, in order to increase thinning efficiency, it is recommended to remove the flower buds before the full bloom stage.

블루베리의 소과비율 증가는 시장 경쟁력 하락과 수확생산성 악화로 농가의 채산성을 악화시킨다. 본 연구는 래빗아이 블루베리를 대상으로 적화 시기, 방법에 따른 과실특성, 생산성을 구명하여 농가현장에 적용하고자 수행하였다. 시험수는 8년생 'Brightwell'를 주 대상으로 하였으며, 수분수로 'Powderblue'를 사용하였다. 엽과비에 따른 과실크기 분포는 착과량이 다양한 127주의 'Brightwell'을 대상으로, 주당 1개의 결과모지를 선정하여 잎과 과실수를 계수하였다. 적화시기에 따른 효과 구명을 위해 꽃눈 발달 단계별로 구분하여 착화량의 50%를 제거하였고, 이때 소요되는 시간과 과실특성을 조사, 비교하였다. 블루베리 과중과 당도는 엽과비와 같은 경향으로 증가했으며, 직경 13 mm미만, 이상으로 구분한 과실크기 분포비율은 엽과비 2.5수준에서 반전되었다. 꽃눈 발달단계별 손 적화 속도는 만개기(Full bloom) 적화가 가장 빨랐으며, 발아초기(Bud swell) 적화가 가장 늦었다. 적화시기에 따른 과중과 직경 13 mm 미만 소과비율은 조사품종 모두 무 적화와 비교해 뚜렷한 차이를 나타냈으나 주당 수량은 유의차가 없었다. 소과비율은 두 품종 모두 적화시기가 늦을수록 증가하는 경향이었으며, 낙화기(Petal fall) 적화는 무적화와 유사한 결과를 나타냈다. 누적 수확량 90%에 도달한 시점은 'Brightwell'은 만개기(Full bloom) 적화, 'Powderblue'는 발아초기(Bud swell), 만개기(Full bloom) 적화처리에서 가장 빨리 도달했다. 이는 무 적화와 비교하여 수확이 각각 25일, 20일 빨랐다. 따라서 본 연구는 적화 정도에 따른 효과는 품종에 따라 차이가 있지만, 적화는 조기 집약수확과 대과비율 및 수확생산성 증가에 효과적이었음을 확인하였고, 적화효율성을 높이기 위해서는 만개기(Full bloom) 전에 결과지 선단 화총의 하단부 꽃눈을 제거하는 것이 효과적일 것으로 사료된다.

Keywords

References

  1. Ayala, M., & Andrade, M. P. (2009). Effects of fruiting spur thinning on fruit quality and vegetative growth of sweet cherry (Prunus avium). Ciencia e Investigacion Agraria, 36(3), 443-450.
  2. Cartagena, J. R., Matta, F. B., & Spiers, J. M. (1994). Chemical fruit thinning of Vaccinium ashei Reade. Journal of the American Society for Horticultural Science, 119(6), 1133-1136. https://doi.org/10.21273/JASHS.119.6.1133
  3. Ehlenfeldt, M. K. (1998). Enhance bud production in highbush blueberry (Vaccinium corymbosum L.) in response to paclobutrazol. HortScience, 33(1), 75-77. https://doi.org/10.21273/HORTSCI.33.1.75
  4. El-Boray, M. S., Shalan, A. M., & Khouri, Z. M. (2013). Effect of different thinning techniques on fruit set, leaf area, yield and fruit quality parameters of Prunus persica L. Batsch cv. Floridaprince. Trends in Horticultural Research, 3(1), 1-13. https://doi.org/10.3923/thr.2013.1.13
  5. Gough, R. E. (1994). The highbush blueberry and its management, pp. 137-149. The Haworth Press, Inc. Binghamton, NY.
  6. Gough, R. E., & Shutak, V. G. (1978). Anatomy and Morphology of cultivated highbush blueberry. Rhode Island Agricultural Experiment Station Bulletin, 423.
  7. Gough, R. E., Shutak, V. G., & Hauke. R. L. (1978). Growth and development of highbush blueberry. I. Vegetative growth. Journal of the American Society for Horticultural Science, 103, 94-97.
  8. Greene, D. W., Hauschild, K. I., & Krupa, J. (2001). Effect of blossom thinners on fruit set and fruit size of peaches. HortTechnology, 11(2), 179-183. https://doi.org/10.21273/HORTTECH.11.2.179
  9. Huang, Y. H., Johnson, C. E., & Sundberg, M. D. (1997). Floral morphology and development of 'Sharpblue' southern highbush blueberry in Louisiana. Journal of the American Society for Horticultural Science, 122(5), 630-633. https://doi.org/10.21273/JASHS.122.5.630
  10. Johnson, L. K., Malladi, A., & NeSmith, D. S. (2011). Differences in cell number facilitate fruit size variation in rabbiteye blueberry genotypes. Journal of the American Society for Horticultural Science, 136(1), 10-15. https://doi.org/10.21273/JASHS.136.1.10
  11. Lechaudel, M., Joas, J., Caro, Y., Genard, M., & Jannoyer, M. (2005). Leaf: fruit ratio and irrigation supply affect seasonal changes in minerals, organic acids and sugars of mango fruit. Journal of the Science of Food and Agriculture, 85(2), 251-260. https://doi.org/10.1002/jsfa.1968
  12. Lyrene, P. M. (1984). Late pruning, twig orientation, and flower bud formation in rabbiteye blueberry. HortScience, 19, 98-99.
  13. Maust, B. E., Williamson, J. G., & Darnell, R. L. (1999). Flower bud density affects vegetative and fruit development in field-grown southern highbush blueberry. HortScience, 34(4), 607-610. https://doi.org/10.21273/HORTSCI.34.4.607
  14. Milic, B., Tarlanovic, J., Keserovic, Z., Magazin, N., Miodragovic, M., & Popara, G. (2018). Bioregulators can improve fruit size, yield and plant growth of northern highbush blueberry (Vaccinium corymbosum L.). Scientia Horticulturae, 235, 214-220. https://doi.org/10.1016/j.scienta.2018.03.004
  15. Retamales, J. B., & Hancock, J. F. (2012). Blueberries, pp. 213-217, CABI.
  16. Seehuber, C., Damerow, L., & Blanke, M. (2011). Regulation of source: sink relationship, fruit set, fruit growth and fruit quality in European plum (Prunus domestica L.) -using thinning for crop load management. Plant Growth Regulation, 65(2), 335-341. https://doi.org/10.1007/s10725-011-9606-x
  17. Shutak, V. G. (1980). The cultivated highbush blueberry: twenty years of research. Rhode Island Agricultural Experiment Station Bulletin, 428.
  18. Strik, B. C., & Buller. G. (2004). Effect of in-row spacing and early cropping on yield and dry weight partitioning of three highbush blueberry cultivars the first two years after planting. Small Fruits Review, 3(1), 141-147. https://doi.org/10.1300/J301v03n01_14
  19. Strik, B. C., Buller, G., & Hellman, E. (2003). Pruning severity affects yield, berry weight, and hand harvest efficiency of highbush blueberry. HortScience, 38(2), 196-199. https://doi.org/10.21273/HORTSCI.38.2.196
  20. Suzuki, A., Shimizu, T., & Aoba, K. (1998). Effects of leaf/ fruit ratio and pollen density on highbush blueberry fruit quality and maturation. Journal of the Japanese Society for Horticultural Science, 67(5), 739-743. https://doi.org/10.2503/jjshs.67.739
  21. Williamson, J. G., & NeSmith, D. S. (2007). Effect of CPPU application on southern highbush blueberries. HortScience, 42(7), 1612-1615. https://doi.org/10.21273/HORTSCI.42.7.1612