A major limitation to organic apple [ Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] production is the available fungicide options for apple scab, a significant disease of apples in humid production regions. Apple scab can have
Morgan L. Cromwell, Lorraine P. Berkett, Heather M. Darby, and Takamaru Ashikaga
Yong Zhang, Chunxia Fu, Yujing Yan, Xiaodan Fan, Yan’an Wang, and Ming Li
synthesis, carbohydrate metabolism, and cell division ( Hacisalihoglu et al., 2003 ). Apple production has been increasing worldwide but fruit quality is a limiting factor in achieving the economic potential of apple crops. Sugar is an important index for
Sara Serra, Rachel Leisso, Luca Giordani, Lee Kalcsits, and Stefano Musacchi
The apple variety, ‘Honeycrisp’, is a premium fresh fruit marketplace variety ( Embree et al., 2007 ; Rosenberger et al., 2004 ) selected in Minnesota. As such, it is well adapted to northern climatic conditions ( Luby and Bedford, 1990
Chikako Honda, Hideo Bessho, Mari Murai, Hiroshi Iwanami, Shigeki Moriya, Kazuyuki Abe, Masato Wada, Yuki Moriya-Tanaka, Hiroko Hayama, and Miho Tatsuki
Red coloration in apple fruit skin is the result of the accumulation of anthocyanin, which is classified as a flavonoid compound. The regulation of anthocyanin synthesis in apple fruit skin is of interest because the red coloration of apples is an
C.G. Embree, B.H. Lesser, and A.D. Crowe
The effects of 30 Kentville Stock Clone (KSC) selections on fruit size and color of `McIntosh' and `Delicious' apples (Malus domestica Borkh.) were monitored over 5 years. Fruit size was influenced by the rootstock and, when averaged over the duration of the study, ranged from 108 to 132 g and 131 to 161 g for `McIntosh' and `Delicious', respectively. Variation in fruit size due to crop load (CL) was greater for `McIntosh' than for `Delicious'. Fruit color was influenced by the rootstock in all years for `McIntosh' and in 3 of 5 years for `Delicious'; it was strongly associated with tree size for `Delicious' only. An overall performance index, which also included price based on quality, was developed, and the best performers in each size group were: semidwarf KSC 18 and 28; semivigorous KSC 7, 11, and 24; and vigorous KSC 3 and 6.
Ismail A. Hussein and Donald C. Slack
The effect of three vigor-control apple (Malus domestics Borkh.) rootstock (seedling, MM.106, and M.7a) on fruit diameter of three cultivars ('Red Delicious', `Granny Smith', and `Gala') was studied over two growing seasons (1990-91) in the arid climate of Willcox, Ariz. Daily fruit growth rate (DFGR) and effective fruit growth period (EFGP) data indicate cultivar differences in DFGR as well as EFGP. Cultivars with a high DFGR had a relatively shorter EFGP. Rootstock had no significant effect on EFGP. Cultivar x rootstock interaction on fruit diameter was significant for DFGR, but not for EFGP. `Red Delicious' and `Granny Smith' trees produced larger fruits on MM.106 and M.7a than on seedling rootstock. For `Gala', there was no significant effect of all rootstock on fruit diameter.
Gayle M. Volk, Christopher M. Richards, Adam D. Henk, Ann Reilley, Diane D. Miller, and Philip L. Forsline
The wild apple species Malus sieversii (Ledeb.) M. Roem. is native to xeric regions and high mountain ranges of Kazakhstan, the Kyrgyz Republic, China, Tajikistan, Uzbekistan, and Turkmenistan ( Yan et al., 2008 ). With a wide range of edible
Gayle M. Volk, Christopher M. Richards, Ann A. Reilley, Adam D. Henk, Patrick A. Reeves, Philip L. Forsline, and Herb S. Aldwinckle
., 1996 ; Volk et al., 2005 ). For example, M. sieversii populations in Kazakhstan were shown to have regional structure with most of the diversity represented within half-sib families. Malus sieversii wild apples are generally larger and sweeter than
John C. Beaulieu
The author thanks Dean Liere and Alex May, Syngenta Seeds, Inc., Rogers Brand Vegetable Seeds, for supplying cantaloupe; Gene Lester for supplying honeydew; Ken Gross for supplying apples; and Jeanne M. Lea and Debbie Harrell for volatile
Takashi Sato, Tsuyoshi Kudo, Tomoko Akada, Yuhya Wakasa, Minoru Niizeki, and Takeo Harada
The onset of apple [Malus sylvestris (L.) Mill. Var. domestica (Borkh.)Mansf.] fruit maturity is preceded by the production of ethylene, the ripening hormone, which induces fruit ripening. The amount of ethylene produced by the fruit correlates with the level of transcription of the ripening-specific 1-aminocyclopropane-1-carboxylate (ACC) synthase genes. We have found that an allele (MdACS1-2), which contains an inserted retroposon-like sequence at the 5'-flanking region, is transcribed at a lower level than the wild-type (MdACS1-1). MdACS1-2/2 homozygous fruit produce a lower level of ethylene at the climacteric stage than do the wild type fruit. We have also found that the preharvest drop rates of apple cultivars and strains of MdACS1-2/2 trees have less fruit drop than the MdACS1-1/1 or MdACS1-1/2 trees. Treatment of the MdACS1-1/2 trees with 1-MCP, an ethylene receptor blocker, further decreased fruit drop. Analysis of commercial apple cultivars for the presence of the MdACS1-2/2 allele may help in the early detection of apple cultivars with a low fruit drop rate.