‘Hahong’ is a new nectarine cultivar from the Rural Development Administration’s National Institute of Horticultural & Herbal Science breeding program, which has been in operation since 1962. ‘Hahong’ is a midseason nectarine that produces large, attractive, and yellow sweet fruit for the fresh market. The cultivar should be widely adapted to wherever peaches and nectarines are grown to provide growers with an alternative to ‘SunGlo’ that has superior fruit quality, particularly in terms of fruit size and sweetness. In 2009, Plant Variety Protection rights were granted in the Republic of Korea.
The ‘Hahong’ nectarine [Prunus persica (Batsch) L.] originated from a cross between ‘SunGlo’ and ‘Cheonhong’ at the National Institute of Horticultural & Herbal Science under the auspices of the Rural Development Administration (RDA), Suwon, Republic of Korea, in 1990 (Fig. 1). ‘Hahong’ was first selected and propagated in 2002 for testing as Wonkyo Da-26. This selection was grafted onto Chinese wild peach (‘Maotao’) seedling rootstocks and planted in seven different sites in the Republic of Korea: Suwon (lat. 37°16′ N, long. 127°02′ E), Chuncheon (lat. 37°53′ N, long. 127°44′ E), Yesan (lat. 36°41′ N, long. 126°51′ E), Chongwon (lat. 36°33′ N, long. 127°32′ E), Cheongdo (lat. 35°39′ N, long. 128°44′ E), Jinju (lat. 35°11′ N, long. 128°06′ E), and Naju (lat. 35°01′ N, long. 126°43′ E). At all evaluation sites except Suwon, three trees each of Wonkyo Da-26 and ‘Cheonhong’ were observed from 2003 to 2008. In Suwon, six trees of Wonkyo Da-26 plus three nectarine trees, one of each ‘Suhong’, ‘Cheonhong’, and ‘SunGlo’, were observed for comparison purposes. In all tests, the trees were planted with 4 × 5 m spacing and trained to an open center form. Pruning, fertilization, and pest management were performed according to local guidelines for peach cultivation (Shin et al., 2002). The tree and fruit characteristics were evaluated according to the National Manual for Agricultural Investigation (RDA, 2003) and International Union for the Protection of New Varieties of Plants (UPOV) guidelines for the conduct of tests for distinctness, uniformity, and stability of peaches and nectarines (UPOV, 1995). ‘Hahong’ was evaluated for 6 years.
Tree and fruit bearing.
‘Hahong’ trees are large and strongly vigorous with a semiupright growth habit similar to ‘Cheonhong’ and ‘Suhong’ (Fig. 2). Compared with the standard fertilizer for peach trees, nitrogen fertilization is recommended to be reduced to 5% to 10% the usual dose for ‘Hahong’ trees to mitigate their vigor. Fruit are mainly set on medium to long (25 to 35 cm) branches. Because ‘Hahong’ is productive without alternate bearing, flower buds or fruit are recommended to be thinned to maximize the fruit size. Leaves of the ‘Hahong’ tree have reniform nectarines, and the average leaf size is 4.4 cm wide and 16.7 cm long. ‘Hahong’ has been shown to exhibit higher average yields per tree than ‘Cheonhong’, which is the leading nectarine cultivar in the Republic of Korea (National Agricultural Products Quality Management Service, 2007) (Table 1). This yield difference becomes more apparent with tree age. In 2008, a tree of ‘Hahong’ produced ≈5 kg more fruit than one of ‘Cheonhong’.
Mean fruit yield of ‘Hahong’ and ‘Cheonhong’ in Suwon, Republic of Korea, 2006–08.
‘Hahong’ in Suwon buds in late March and blooms fully in mid-April, similar to other cultivars (Table 2). Flowering in southern sites such as Cheongdo, Jinju, and Naju occurs ≈12 d earlier than in Suwon. The fruit of ‘Hahong’ ripens in mid-August, which is the middle of the peach and nectarine harvest season in the Republic of Korea. The fruit ripening time of ‘Hahong’ is ≈13 d later than that of ‘Cheonhong’; the total fruit development period of ‘Hahong’ is ≈117 d.
Seasonal growth of ‘Hahong’ compared with the nectarine cultivars Cheonhong, Suhong, and SunGlo in Suwon, Republic of Korea, 2003–08.
Flowers of ‘Hahong’ are showy as are those of ‘Cheonhong’ and ‘Suhong’ in contrast to those of ‘SunGlo’. The flowers of ‘Hahong’ are large with an average diameter of 4.26 cm. The corolla is dark pink with five round petals. The inner part of the calyx is orange and the inner wall of the ovary has no pubescences. The stigma is positioned above the purplish red anther. The flowers are fertile with numerous bright yellow pollen grains, similar to the flowers of ‘Cheonhong’, ‘Suhong’, and ‘SunGlo’.
A sample of 30 fruit was collected each year from 2006–08 to determine their characteristics. The fruit of ‘Hahong’ were ovate in shape (Table 3). The fruit ground color was creamy yellow with most of the surface covered in a solid red blush (Fig. 3). Because the fruit became colored before ripening, an optimal harvest time should be judged to avoid premature harvest. Commercially ripe fruit changes the ground color of its skin from green–yellow to creamy or pale yellow. The ground color of fruit skin is a common indicator for determining when to commercially harvest nectarines. Fruit flesh is orange–yellow with a red pigmentation of ≈30% around the outer flesh and ≈5% to 10% around the pit. The average fruit weight of ‘Hahong’ is 266 g, which is significantly greater than that of ‘Cheonhong’ at 202 g and of ‘SunGlo’ at 189 g. The large fruit size of ‘Hahong’ was achieved by thinning, leaving 15 to 20 cm between fruit. The fruit flesh at harvest time was as firm as in other comparable cultivars. Skin cracking occurred in ‘Hahong’ less frequently than in ‘Cheonhong’ (0% to 3% occurrence). The juice from 10 fruits of ‘Hahong’ was pooled to form a composite sample, and its soluble solids content (SSC) was measured using a refractometer (Atago Co., Tokyo, Japan). The titratable acidity was measured by the titration of 5 mL of juice with 0.1 N NaOH and expressed as the percent malic acid equivalent using an automatic Titroline titrator (Schott, Mainz, Germany). The average SSC of ‘Hahong’ was 12.6 oBrix, higher than that of the other cultivars, whereas the fruit acidity of ‘Hahong’ was lower than that of ‘Cheonhong’ and ‘SunGlo’ at 0.42%. The balance of sugar and acid gives the fruit a better taste than the other three cultivars. ‘Hahong’ has clingstone melting flesh similar to ‘Cheonhong’ and ‘Suhong’, whereas ‘SunGlo’ has freestone melting flesh.
Fruit characteristics of ‘Hahong’ compared with the nectarine cultivars Cheonhong, Suhong, and SunGlo in Suwon, Republic of Korea, 2006–08.
Freezing injury of ‘Hahong’ was not observed at any of the seven evaluation sites, despite a minimum temperature of –19.7 °C at Chuncheon from 2003 to 2008. ‘Hahong’ also fruited well at all evaluations, where the mean temperatures in January, the coldest month in the Republic of Korea, ranged from –3.70 to 0.95 °C.
To estimate the chilling requirements of ‘Hahong’, flowering dates from 2006–08 were compared with five cultivars whose chilling requirements are already known (Table 4). ‘Hahong’ was estimated to have a high chilling requirement of ≈800 chill units based on the concurrence of flowering time with the cultivars Flavortop (750 chill units), Earliscarlet (800 chill units), and SunGlo (850 chill units).
Flowering dates and chill units of ‘Hahong’ compared with other nectarine cultivars in Suwon, Republic of Korea, 2006–08.
‘Hahong’ showed 1% to 5% leaf or fruit lesions caused by brown rot [Monilinia fructicola (Winter) Honey] and bacterial leaf spot [Xanthomonas arboricola pv. pruni (Smith) Dye], similar to the rates in ‘Cheonhong’. However, ‘Suhong’ and ‘SunGlo’ showed 6% to 10% brown rot damage, whereas ‘SunGlo’ exhibited 6% to 10% bacterial leaf spot damage.
Plant Variety Protection for ‘Hahong’ was achieved in 2009 and registration was achieved in June 2011 after 2 years of evaluating its distinctness, uniformity, and stability according to Korean Seed Industry Law. Requests for virus non-indexed scions for research purposes may be addressed to Ji Hae Jun (email@example.com).
International Union for the Protection of New Varieties of Plants1995Guidelines for the conduct of tests for distinctness uniformity and stability. Peach Nectarine [Prunus persica (L.) Batsch]. Geneva Switzerland
National Agricultural Products Quality Management Service2007Fruit census. 5th Ed. Ministry of Agriculture and Forestry Seoul Republic of Korea
OkieW.R.1998Handbook of peach and nectarine varieties: Performance in the southeastern United States and index of names. U.S. Dept. of Agr. Byron GA
Rural Development Administration2003Manual for agricultural investigation. 4th Ed. Rural Development Administration Suwon Republic of Korea
ShinY.U.KangS.J.JeongS.B.JunJ.H.JoM.D.ChungK.H.KimS.J.ParkJ.M.YoonI.K.ParkJ.H.KimD.S.JeongD.S.KangJ.G.2002The standard manual of peach cultivation. Rural Development Administration Suwon Republic of Korea