of AVG and NAA treatments on fruit drop or fruit firmness at normal and delayed harvests within the same apple orchard over a prolonged period. This article describes natural patterns of fruit drop within a commercial orchard of ‘Scarletspur Delicious
C.R. Unrath, J.D. Obermiller, A. Green, and S.J. McArtney
S.R. Drake, T.A. Eisele, D.C. Elfving, M.A. Drake, S.L. Drake, and D.B. Visser
In a study conducted over three crop seasons, Ethrel (ETH) increased the Brix, sucrose, and sorbitol content of 'Scarletspur Delicious' apple juice while reducing the fructose content. Both longer preharvest exposure to, and higher concentrations of, ETH had a stronger influence than application closer to harvest and/or at lesser amounts. Time of ETH application tended to influence individual carbohydrates more so than amount of ETH applied. ETH reduced total acidity and also reduced apple juice individual acid (quinic and malic) contents with longer preharvest exposure or higher concentrations. Aminoethoxyvinylglycine [AVG (ReTain)] reduced both Brix and sucrose content of 'Scarletspur Delicious' apple juice, but had no influence on either total acidity or individual acid contents. Combinations of AVG with ETH tended to counteract the influence of either used alone on total Brix, carbohydrates, total acidity and individual acids. Mineral content of 'Scarletspur Delicious' apple juice was not strongly influenced by application of either ETH or AVG.
S.R. Drake, D.C. Elfving, M.A. Drake, T.A. Eisele, S.L. Drake, and D.B. Visser
This study was conducted over two crop seasons using `Scarletspur Delicious' and `Gale Gala' apple trees (Malus ×domestica). The bioregulators aminoethoxyvinylglycine (AVG), ethephon (ETH), and 1-methylcyclopropene (MCP) were applied at various times before or after harvest. Fruit response was evaluated at harvest and after regular atmosphere (RA) and controlled atmosphere (CA) storage [2.0% oxygen (O2) and <2.0% carbon dioxide (CO2) at 0 °C] and quality of whole and juice apple products evaluated. AVG reduced starch loss and ethylene production, enhanced firmness, and reduced cracking in `Gale Gala,' but reduced sensory acceptance of apples and apple juice. ETH intensified starch loss, ethylene production, and reduced firmness, but did not affect `Gale Gala' fruit cracking. AVG followed by ETH reduced starch loss, ethylene production, and cracking and maintained firmness. This combination also aided in sensory acceptance of apples but reduced sensory preference of apple juice. Exposure to postharvest MCP improved flesh firmness retention and reduced ethylene production after both RA and CA storage. MCP either favored or reduced sensory acceptance of whole apples, depending on the particular season, but reduced sensory preference of apple juice. Sensory scores for `Scarletspur Delicious' apples were more strongly modified by bioregulators than were `Gale Gala' apples.
Don C. Elfving, Stephen R. Drake, A. Nathan Reed, and Dwayne B. Visser
sprayable 1-MCP to ‘Scarletspur Delicious’ and ‘Cameo’ apple trees in the orchard and compare the effects of sprayable 1-MCP versus postharvest 1-MCP applications, as well as with preharvest treatment with AVG, on fruit quality after short- and long
Don C. Elfving and Dwayne B. Visser
A new bioregulator, cyclanilide (CYC, Bayer Environmental Science, Montvale, N.J.), was tested for growth-related effects on apple trees over three years. Although treatment with CYC produced small reductions in shoot length, its principal effect was to stimulate the formation of lateral shoots on current-season's shoot growth and from spurs on older wood. CYC treatment of `Scarletspur Delicious' apple trees in the nursery more than doubled the formation of well-developed feathers with wide crotch angles (≈60°) and with no effect on final tree height. CYC appeared to flatten the apples and reduce fruit size in one trial. CYC appears promising for lateral branch induction in apple, especially in the nursery. Chemical names used: 1-(2,4-dichlorophenylaminocarbonyl)-cyclopropane carboxylic acid (Cyclanilide); calcium 3-oxido-4-propionyl-5-oxo-4-propionylcyclohex-3-enecarboxylate (prohexadione-Ca, Apogee); N-(phenylmethyl)-1H-purine-6-amine + gibberellins A4A7 (Promalin); polyoxyethylenepolypropoxypropanol, dihydroxypropane, 2-butoxyethanol (Regulaid).
`Scarletspur Delicious' and `Gale Gala' (Drake et al., p. 16 ) . AVG enhanced firmness retention and storability, and eliminated fruit cracking in `Gale Gala'. Ethephon enhanced fruit color, soluble solids, and sensory acceptance, but reduced firmness. Fruit
Jennifer R. DeEll and Behrouz Ehsani-Moghaddam
fruit maturity of ‘Law Rome’ and ‘Golden Delicious’ apples in Pennsylvania ( McArtney et al., 2008 ) as well as ‘Scarletspur Delicious’ and ‘Cameo’ apples in Washington ( Elfving et al., 2007 ). In contrast, McArtney et al. (2009) recently showed
production of some modern apple varieties, particularly if harvest is delayed. Unrath et al. (p. 620) followed natural fruit drop in the same ‘Scarletspur Delicious’ orchard over an 11-year period, and report that delaying harvest by only 1 week resulted in
Jaume Lordan, Terence L. Robinson, Mario Miranda Sazo, Win Cowgill, Brent L. Black, Leslie Huffman, Kristy Grigg-McGuffin, Poliana Francescatto, and Steve McArtney
observed on ‘Macoun’, ‘Fuji’, ‘Aceymac’, and ‘Empire’ in a previous experiment in NY ( Miranda Sazo and Robinson, 2011 ). Conversely, Elfving and Visser (2005) did not observe leader growth differences either on ‘Fuji’, ‘Cameo’, or ‘Scarletspur Delicious
Valeria Sigal Escalada and Douglas D. Archbold
, D.C. Drake, M.A. Drake, S.L. Visser, D.B. 2005 Effects of the bioregulators aminoethoxyvinylglycine and ethephon on Brix, carbohydrates, acid, and mineral concentrations in ‘Scarletspur Delicious’ apple juice