scholarly journals Fruit Count, Fruit Weight, and Yield Relationships in `Delicious' Apple Trees on Nine Rootstock

HortScience ◽  
1993 ◽  
Vol 28 (8) ◽  
pp. 793-795 ◽  
Author(s):  
D.C. Elfving ◽  
I. Schechter

Annual yields per tree for `Starkspur Supreme Delicious' apple (Malus domestica Borkh.) trees on nine size-controlling rootstock were related linearly to number of fruit per tree at harvest each year, independent of rootstock. Mean fruit weight was inversely and less closely related to number of fruit per tree when adjusted for tree size (fruit load). Annual yield-fruit count data for 9 years analyzed together showed that the number of fruit per tree was the principal factor determining yield, regardless of rootstock or tree age. A curvilinear relationship between yield and fruit count per tree during 9 years suggests that the sink strength of an apple crop is nearly, but not precisely, proportional to the number of fruit per tree.

HortScience ◽  
1990 ◽  
Vol 25 (4) ◽  
pp. 429-430 ◽  
Author(s):  
Laura J. Lehman ◽  
C.R. Unrath ◽  
Eric Young

Mature spur-type `Delicious'/seedling apple trees (Malus domestica Borkh.) were examined for 2 years after paclobutrazol (PB) foliar sprays with or without a soil cover to direct spray runoff away from the root zone, soil sprays, or a trunk drench. Foliar sprays with runoff reduced shoot number and fruit pedicel length in the year of treatment, but had no effect on shoot length. Trees that received foliar sprays with no runoff had fewer and shorter shoots and shorter pedicels the year after treatment. Soil sprays or a trunk drench reduced shoot number and pedicel length for 2 years after application, while only soil sprays reduced fruit weight, diameter, and length. Chemical name used: β- [(4-chlorophenyl)methyl]- α -(1,1-dimethylethyl)-1 H -1,2,4,-triazol-1-ethanol (paclobutrazol).


Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 367
Author(s):  
Mateja Kišek ◽  
Kristjan Jarni ◽  
Robert Brus

This study focuses on the morphological and genetic characteristics of European crab apple (Malus sylvestris (L.) Mill.) and the occurrence of hybrids in its populations. We analyzed a total of 107 putative European crab apple trees in Slovenia: 92 from nine natural populations, five from a seed stand and 10 from a stand of unnatural origin. We also included 18 domesticated apple trees (Malus × domestica Borkh.) and two Japanese flowering crab apple trees (Malusfloribunda van Houtte) as outliers. The trees were classified into groups of European crab apples, hybrids and domesticated apples according to their morphological and genetic characteristics. Classification based on morphological traits produced different results (58.75% European crab apple, 37.11% hybrids and 4.14% domesticated apple) compared to those based on genetic analysis (70.10% European crab apple, 21.64% hybrids and 8.26% domesticated apple). When genetic and morphological characteristics were combined, only 40.20% of the trees were classified as European crab apple, and an additional group of feral cultivars of domesticated apples (6.18%) was identified. The analysis revealed that hybridization with domesticated apple is taking place in all studied natural European crab apple populations; however, hybrids and feral cultivars only occur to a limited extent. When introducing European crab apple into forests in the future, only genetically verified forest reproductive material obtained exclusively from suitable seed stands should be used.


1997 ◽  
Vol 122 (6) ◽  
pp. 837-840 ◽  
Author(s):  
Matej Stopar ◽  
Brent L. Black ◽  
Martin J. Bukovac

The effects of NAA, BA, or Accel on CO2 assimilation of shoot leaves of mature bearing Redchief `Delicious' and `Empire' apple (Malus ×domestica Borkh.) trees were evaluated over two seasons. BA at 50 mg·L-1 did not significantly affect any of the gas-exchange parameters measured. NAA (15 mg·L-1) consistently suppressed CO2 assimilation rate (from ≈10% to 24% below that of the control). This suppression was NAA-concentration dependent, continued for >15 days after treatment, and was completely overcome in `Empire', but only partially or not at all in `Delicious' when BA was combined with NAA. These results are discussed in relation to fruit thinning and NAA-induced inhibition of fruit growth in spur-type `Delicious'. Chemical names used: 2-(1-napthyl) acetic acid (NAA); N-(phenyl)-1H-purine-6-amine (BA); BA + gibberellin A (GA)4+7 (Accel).


2004 ◽  
Vol 129 (2) ◽  
pp. 175-181 ◽  
Author(s):  
Richard P. Marini

For 4 years, `Redchief Delicious' apple [Malus ×sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] trees were treated with ethephon and/or Accel (6-BA + Gibberellins 4+7) when average fruit diameter was 5.0 to 11.4 mm. Effective thinning was obtained with ethephon at concentrations >500 mg·L-1 and with Accel at concentrations of 100 to 125 mg·L-1. In only 1 year out of 4 did combinations of Accel plus ethephon reduce fruit set more than either material applied alone. Repeat applications of either material alone or in combination reduced fruit set no more than single applications. Fruit weight was negatively related to the number of fruit per tree. After adjusting fruit weight for number of fruit per tree at harvest with analysis of covariance, ethephon did not improve fruit weight at harvest, but Accel improved fruit weight in two of three experiments. The effect of combinations of Accel and ethephon on fruit weight was inconsistent. Chemical names used: 2-chloroethyl phosphonic acid (ethephon); polyothyethylleneploypropanol dihydroxy-propane 2, butoxyethanol (Regulaid); N-(phenylmethyl)-1H-purine-6-amine plus giberrellins A4 + A7 (Accel).


1955 ◽  
Vol 3 (1) ◽  
pp. 15-34
Author(s):  
W.G. Beeftink

Characteristic symptoms of salt water flood damage are described for apples, pears, plums, cherries, currants, gooseberry, walnuts, grapes and mulberries. In general the crops showed symptoms of drying out, indicating their inability to absorb enough water. A table of the approximate sensitivity of the fruit crops, and also of apple and pear varieties was compiled; there was a wider range of sensitivity in apples than in pears. The sensitivity of the chief Malling rootstocks did not appear to run parallel to their vigour. The salt content of the soil moisture was the limiting factor for apple and pear recovery; 7-8 g. per litre for apples, and 11-12 g. for pears were the limits beyond which trees could not be saved. Flooding had no influence on the growth condition of apples and pears until after it had lasted 8 or 9 weeks. Tree age had no clear effect on sensitivity, though apple trees of 25 years and over had less resistance. Deep cultivation before flooding, soil exhaustion, and general neglect had detrimental effects on tree resistance. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1969 ◽  
Vol 72 (4) ◽  
pp. 501-508
Author(s):  
Agripino Pérez ◽  
Arturo Cedeño-Maldonado ◽  
Ismael Reyes-Soto ◽  
Justo López

Studies were conducted at the Fortuna Substation for 10 years to determine the effect of 5 interstems on growth and yield components of 2 commercial mango varieties. The interstems did not significantly affect the rootstock diameter when Edward variety was the scion; however, they did with Palmer variety as scion at the 3- and 6-year stages only, Irwin interstem diameter at the 3-year stage for Edward and Palmer, and at the 6- and 9-year stages for Edward, was significantly thicker than that of the other interstems. Edward on Manzano Tetenené had the thinnest interstems. In the two varieties studied, the scion diameter was scarcely affected by the interstems at 3, 6 and 9 years after transplanting. Edward and Palmer grafted on Irwin as interstems had significantly lower scion/interstem ratios. The opposite was true when these varieties were grafted on Julie. Three years after planting, the smallest trees were those of Edward and Palmer grafted on Malda; 6 and 9 years after planting, those of Edward grafted on Malda and Manzano Tetenené. Yield efficiency decreased significantly with tree age and size. Thus, there was a negative correlation between these parameters. Edward produced significantly more fruits than Palmer at the 3-year-old stage. Edward as interstem grafted on Eldon produced significantly more fruits at the 3-, 6- and 9-year stages than when grafted on the other interstems. Palmer grafted on Eldon was significantly more precocious than when grafted on the other interstems. Malda and Manzano Tetenené as interstems significantly reduced tree size of Edward; Julie as interstem reduced the size of Palmer.


2003 ◽  
Vol 19 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Gerhard Zotz ◽  
Birgit Vollrath

We conducted a survey of the epiphyte flora growing on the stilt palm Socratea exorrhiza in a primary lowland rain forest in Panama by means of a canopy crane. For each palm in a 0.9-ha plot, we determined diameter at breast height, tree height, per cent bryophyte cover and the number, identity and attachment site of all vascular epiphytes. The 118 palm trees hosted a total of 701 epiphytes and hemi-epiphytes, belonging to 66 species. Trees were estimated to be c. 20 y old before colonization with vascular epiphytes began. Epiphyte species were highly clumped and segregated along the vertical axis of the trunk. Sequential colonization led to an increased number of species and individuals as the tree grows. Epiphytes were associated with bryophyte patches much more than expected by chance, but no species seemed to depend upon them for establishment. The influence of tree size, age and bryophyte cover on the composition of the epiphyte community are discussed.


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