Effect of RED and FAR-RED LEDs on the Fruit Quality of &amp;#x2018;Hongro&amp;#x2019;/M.26 Apple

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.

Section: 재료 및 방법unclassified

Influence of Tree Thinning on Vegetative Growth, Yield and Fruit Quality of ‘Fuji’/M.9 Apple Trees in the High Density Orchard

Kweon¹,

Sagong²

2023

“…meter CR-400, Konica minolta, Japan)를 이용하여 각각 의 과실을 3부분(양광면, 음광면, 중간부분)으로 구분하여 측 정한 후, 평균하여 Hunter's a 값으로 표시하였다. 가용성 고 형물 함량은 시험주별 5개의 과실을 1개씩 분쇄하여 착즙한 후 110 mm 거름종이(Filter paper, Advantec, Japan)로 걸러 디지털당도계(PR-100, Atago, Japan)로 측정하였고, 산 함량은 각 과실의 과즙 5 mL를 증류수 20 mL로 희석한 후 0.1 N NaOH로 적정하여 pH 8.1이 되는 점의 적정치를 환산하여 나타내었다[17]…”

unclassified

Influence of Delaying Winter Pruning on Shoot Growth and Fruit Quality of ‘Fuji’/M.9 Apple Tree

Kweon¹,

Sagong²

2022

Self Cite

BACKGROUND:The freezing injury by pruning can be reduced by suspending pruning work when severe cold weather (-23 to -49°C) is forecast. Minimum air temperature of the study area, Gunwi region at February 3, 2012 was -21.9°C, and the subzero temperature continued until April 8, 2012. 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 March 26 for dormant, April 3 for bud break, and May 2 for full bloom. The winter pruning at full bloom significantly reduced fruit weight for two years compared with the control (winter pruning at dormant), and shoot growth 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, since the fruit quality was not affected. The delayed pruning at full bloom resulted in decreased fruit weight, though shoot growth, fruit quality, and return bloom were not affected by the delayed pruning. So, the delayed pruning should be considered carefully only for the fruit tree orchards in diseases.

“…가용성 고형물 함량은 시험주별 10개의 과실을 1개씩 분쇄하여 착즙한 후 모아 110 mm 거름종이(Filter paper, Advantec, Japan)로 걸러 디지 털당도계(PR-100, Atago, Japan)로 측정하였다. 산 함량은 각 과실의 과즙 5 mL를 증류수 20 mL로 희석한 후 0.1 N NaOH로 적정하여 pH 8.1이 되는 점의 적정치를 환산하여 나타내었다[18].…”

unclassified

Influence of Summer Pruning Time on Shoot Growth and Fruit Quality of ‘Fuji’/M.9 Apple Tree Damaged by the Low Air Temperature at Flowering Period

Kweon¹,

Sagong²

2022

BACKGROUND:The low temperature at flowering period 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 significantly 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 summer pruning at 30 July had the highest fruit weight, but return 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.