초록
'신고'배에서 나타나는 과피얼룩과 발생을 경감하기 위하여 생육기 동안 몇 가지를 처리한 결과는 다음과 같다. 배과피얼룩 증상은 유과기(5월 25일)부터 발생하기 시작하여 수확 시까지 나타났으며 과육에는 전혀 발생하지 않았다. 과피얼룩과 발생은 수세가 정상적인 나무, 지베렐린 과경 도포 처리에서 현저하게 낮았으나, 아미노산 수체살포는 큰 차이가 없었다. 봉지에서는 칼슘이 코팅된 봉지 및 석회유황합제가 코팅된 봉지에서 과피얼룩과 발생이 낮았다. 봉지 내지에 석회유황합제 및 콩기름 도포는 과피얼룩이 아닌 약해를 유발시켰다. 과피얼룩 발생과의 수피 및 과피는 K 농도가 높았으나 엽에서는 T-N 및 K 농도는 오히려 낮았다.
BACKGROUND: Caused by cultural environment, the fruit skin stain results in serious damages to pear fruit. Particularly susceptible to this damage, 'Niitaka' pear accounts for 82% of pear cultivation in Korea and many farmers growing the pear trees have suffered economic losses due to fruit skin stain. This study investigated the effect of different treatments of 'Niitaka' pear during growing period on the occurrence of fruit skin stain. METHODS AND RESULTS: The treatments in the field included gibberellin (GA) paste, spraying with amino acid tree fertilizer, functional bagging, and coating of the inner paper bag with agents. The relationships between tree vigor, mineral nutrition concentration and fruit skin stain occurrence were also investigated. The fruit skin stain symptoms occurred from young fruit (May 25) until harvest. There was no exposed fruit flesh. The occurrence of fruit skin stain was significantly reduced in normal tree (shoot length 110 cm), as well as using GA paste treatment, and bagging in calcium and lime sulfur coated bags. However, spraying with amino acid tree fertilizer made no difference in comparison to control. In addition, bags in which the inner paper was coated with lime sulfur and soybean oil resulted in chemical injury to the fruit skin caused by bagging. The K concentration of shoot wood and fruit skin were higher than those of the control. Also, there were lower T-N, K concentration of leaf. CONCLUSION: These results suggest that occurrence of fruit skin stain in 'Niitaka' pear fruits during the growing period can be reduced by GA paste and bagging in calcium and lime sulfur coated bags. The symptoms of chemical injury to the fruit skin caused by bagging in lime sulfur and soybean oil coated inner paper were different compared to skin stain occurring in fruit during the growing period.