‘Migamjosaeng’ (Diospyros kaki Thunb.) is a new pollination-variant non-astringent type (PVNA) persimmon cultivar developed by Sweet Persimmon Research Institute of Gyeongnam Agricultural Research & Extension Services. This cultivar was selected among the seedlings obtained from the cross between ‘Mazumotowase-Fuyu’ and ‘Nishimurawase’ in 1995. The seedlings were cultivated from 1996 to 2001 and ‘Migamjosaeng’ was selected in 2002. The tree growth habit and fruit characteristics of ‘Migamjosaeng’ were investigated from 2004 to 2007. The tree growth habit was moderate vigor and showed spreading shape. Flowers bloomed only in female flowers. The flowering time was similar to that of ‘Nishimurawase’ (control) in late May, but the harvest time was about 3 days earlier than ‘Nishimurawase’ in late September. ‘Migamjosaeng’ is characterized by its beautiful orange skin color with round flat shape of fruits. Average fruit size was about 160g. Soluble solids were 16.6°Brix and higher than that of control (14.5°Brix), which contributed to its excellent tastiness. It was noteworthy that occurrence of calyx-end cracked fruits and striped fruit was very rare compared with the control. Therefore, ‘Migamjosaeng’ trees produced marketable fruits much higher than the control tree. Flesh firmness was slightly high and similar to ‘Nishimurawase’.

In order to develop a sprayable ethylene antagonist, unlike 1-methylcyclopropene (MCP), we synthesized 2-decylcyclopropene-1-carboxylic acid ethyl ester (DCPE) as a derivative of cyclopropene and tested its effect on the flesh softening of ‘Fuyu’ persimmon fruits. The fruits on trees were sprayed with 4·10-4 M DCPE solution before harvest. After harvest, the persimmon fruits were stored at a low temperature for 1.5 months. The ripening progress of the fruits was then evaluated during storage at ambient temperature (20℃). Flesh softening, a measure of ethylene response, was considerably delayed up to 7 days after DCPE treatment. However control fruits was rapidly softened after 3-day storage. The treatment effect of DCPE at 4·10-4 M was also compared to that of 1-MCP at 1 ppm. DCPE was storable at refrigerated conditions for at least one month without any loss. The results show that DCPE could be a potential sprayable agent for the prevention of flesh softening of persimmon fruit.

본 연구는 친환경단감과원의 부유(Diospyros kaki ‘Fuyu’) 과실을 대상으로 창원과 창녕지역에서 발생한 저온내습(2012년 11월 2일)으로 인한 가을 동상해발생과 식재위치(표고) 및 나무 내에서의 착과 방향의 관계를 알아보고자 수행되었다. 창녕지역 과원의 과중과 과실횡경은 착과방향에 의해 강하게 영향을 받았으며(p<0.01), 과실종경과 동상해발생은 식재위치(p<0.01)와 깊은 관계가 있는 것으로 나타났다. 과실경도와 과실종경은 각각 착과방향과 식재위치의 영향을 받는 것으로 밝혀졌다(p<0.05). 특히 동상해는 과원 하단에 식재된 나무의 과실(15.2%)과 잎(약 90%)에서 심하게 나타나 동상해의 주요 요인이 과원의 지형적 특징인 것으로 나타났다. 과실 동상해를 입은 과실은 과피에 수침상 반점이나 흔적이 발생했다. 한편 창원지역의 과원에서는 과실횡경이 식재위치의 영향을 받은 것(p<0.05)을 제외하고 식재위치와 착과방향이 과실의 생육 및 동상해발생에 영향을 주지 않았다.