scholarly journals 660 Reducing Floral Initiation and Return Bloom in Stone Fruit Trees: Applications and Implications in Fruit Production

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 561F-562
Author(s):  
Stephen M. Southwick
Keyword(s):  
Prunus Persica ◽  
Fruit Set ◽  
Fruit Size ◽  
Fruit Production ◽  
Prunus Armeniaca ◽  
Climatic Conditions ◽  
Stone Fruit ◽  
Labor Costs ◽  
Flower Number ◽  
Prunus Salicina

Commercially grown apricots (Prunus armeniaca), peaches (Prunus persica), nectarines (Prunus persica), plums (Prunus salicina and Prunus domestica), and pluots (Prunus salicina × Prunus armeniaca) have a tendency to produce high numbers of flowers. These flowers often set and produce more fruit than trees can adequately size to meet market standards. When excessive fruit set occurs, removal of fruit by hand-thinning is common to ensure that fruit size meets market standards. Over the years there have been numerous attempts to find chemical or physical techniques that would help to reduce costs associated with and improve efficiencies of hand-thinning; however, using alternate strategies to hand-thinning have not been widely adopted in stone fruit production. In the past 10 years, through the continuing efforts of scientists throughout the world in public and private institutions and business, it appears that there are chemical sprays capable of reducing the need for hand-thinning in stone fruit. Management of flowering by reducing the number of flowers on apricot, peach, nectarine, plum, and prune has shown promise under climatic conditions such as those found in the San Joaquin Valley of California. By applying gibberellins during May through July, flowers in many stone fruit cultivars can be reduced in the following season. The reduction in flower number does not generally lead to an increase in fruit set. As a result, fruit numbers are reduced, the need for hand thinning can be reduced, and in some cases eliminated. There are risks associated with reducing flower number before climatic conditions during bloom or final fruit set are known. However, given the changes in labor costs and market demands, especially in the developed world, the benefits may outweigh the risks. The application and implications of these summer gibberellin applications toward reducing flower numbers will be discussed as it relates to commercial stone fruit growing.

scholarly journals Reducing Flowering with Gibberellins to Increase Fruit Size in Stone Fruit Trees: Applications And Implications in Fruit Production

2000 ◽  
Vol 10 (4) ◽  
pp. 744-751 ◽  
Author(s):  
Stephen M. Southwick ◽  
Kitren Glozer
Keyword(s):  
Fruit Set ◽  
Relevant Literature ◽  
Fruit Size ◽  
Fruit Trees ◽  
Fruit Production ◽  
Prunus Armeniaca ◽  
Climatic Conditions ◽  
Stone Fruit ◽  
Labor Costs ◽  
Floral Buds

Many commercially grown stone fruit including apricots (Prunus armeniaca L.), peaches and nectarines [P. persica (L.) Batsch], plums (P. salicina Lindl., P. domestica L.), prunes (P. domestica L.), and pluots (P. salicina × P. armeniaca) have a tendency to produce high numbers of flowers. These flowers often set and produce more fruit than trees can adequately size to meet market standards. When excessive fruit set occurs, removal of fruit by hand thinning is necessary in most Prunus L. species to ensure that remaining fruit attain marketable size and reduce biennial bearing. Over the years there have been numerous attempts to find chemical or physical techniques that would help to reduce the costs associated with and improve efficiencies of hand thinning, however, alternate strategies to hand thinning have not been widely adopted for stone fruit production. In the past 10 years, several chemical treatments have shown promise for reducing hand thinning needs in stone fruit. Management of flowering by chemically reducing the number of flowers has been particularly promising on stone fruit in the Sacramento and San Joaquin Valleys of California. Gibberellins (GAs) applied during May through July, have reduced flowering in the following season in many stone fruit cultivars without affecting percentage of flowers producing fruit. As a result, fruit numbers are reduced, the need for hand thinning is reduced and in some cases eliminated, and better quality fruit are produced. There are risks associated with reducing flower number before climatic conditions during bloom or final fruit set are known. However, given the changes in labor costs and market demands, the benefits may outweigh the risks. This paper reviews relevant literature on thinning of stone fruit by gibberellins, and summarizes research reports of fruit thinning with GAs conducted between 1987 and the present in California. The term thin or chemically thin with regard to the action of GA on floral buds is used in this paper, consistent with the literature, although the authors recognize that the action of GA is primarily to inhibit the initiation of floral apices, rather than reduce the number of preformed flowers. At relatively high concentrations, GA may also kill floral buds. Chemical names used: gibberellic acid, potassium gibberellate.

scholarly journals Improving Fruit Firmness and Reducing the Need for Hand-thinning in Peach by using Sprays of Release® LC

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 764E-765
Author(s):  
Stephen M. Southwick ◽  
James T. Yeager ◽  
Kitren G. Weis
Keyword(s):  
Untreated Control ◽  
Prunus Persica ◽  
Fruit Size ◽  
Shoot Length ◽  
Stone Fruit ◽  
Fruit Firmness ◽  
Flesh Color ◽  
Flower Number ◽  
Individual Weight ◽  
Fruit Maturity

`Loadel' cling peach [Prunus persica (L.) Batsch] trees were sprayed with Release® LC (Abbott Laboratories, North Chicago, Ill.) in 1993. Preharvest (harvested 16 July) sprays of 50, 75, 100, and 120 ppm applied on 15 June improved fruit firmness without altering fruit maturity (flesh color by commercial standards) in 1993. In the following 1994 season, flower number per centimeter of shoot length was reduced by sprays ranging from 50 to 120 ppm applied on 15 June and 9 July. No hand-thinning was required on trees treated on 15 June. Trees treated 9 July had 50% fewer fruit removed than on untreated trees, where more than 3000 fruit were removed by hand-thinning. Salable yield was higher than untreated control trees where Release® LC had been applied at 50 ppm on 15 June and 9 July. Fruit size equaled those of hand-thinned controls. As concentration increased on 15 June, salable yield decreased linearly. Fruit size (diameter and individual weight) increased with reductions in salable yield. Interestingly, fruit were evenly distributed along shoots after Release® LC treatment, similar to those found after hand-thinning. Release® LC will be available for commercial chemical thinning of stone fruit in California during 1995. Additional results from peach and other stone fruit will be presented.

scholarly journals 952 PB 449 HYDROGEN CYANAMIDE ENHANCEMENT OF FRUIT SET

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 570c-570 ◽  
Author(s):  
Jason C. Powell ◽  
Calvin G. Lyons
Keyword(s):  
Detrimental Effect ◽  
Prunus Persica ◽  
Fruit Set ◽  
Fruit Size ◽  
Field Trials ◽  
The State ◽  
Fruit Crops ◽  
Labor Costs ◽  
Hydrogen Cyanamide ◽  
Insight Into

The state of Texas suffers from a lack of chilling one out of every five years. Reduced yield in temperature fruit crops such as peach (Prunus persica) is one detrimental effect associated withinadequate chilling. Field trials with hydrogen cyanamide (Dormex) have demonstrated that a one to two percent solution applied six weeks prior to bloom will substitute for inadequate chilling of up to 150 hours. Field trials with this chemical have provided further insight into some other possible benefits associated with its use such as: increased marketable yields of fruit crops, enhanced fruit size, and an earlier more concentrated harvest. Advantages noted by the use of this product include a possible earlier crop and reduced labor costs.

Protected Culture Systems for Strawberry Production

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 459d-459
Author(s):  
Fumiomi Takeda ◽  
Paul R. Adler ◽  
D. Michael Glenn
Keyword(s):  
Light Intensity ◽  
Fruit Size ◽  
Fruit Production ◽  
Hydroponic Culture ◽  
Production Cycle ◽  
Soilless Culture ◽  
Labor Costs ◽  
Culture Systems ◽  
Nutrient Film Technique ◽  
Plant Densities

Strawberry plants (cvs. Camarosa, Chandler, Sweet Charlie, Primetime, Jewel, and Tribute) were grown in soilless culture systems in a greenhouse from October to May. Fresh-dug and runner-tip Aplug® plants were transplanted into two systems: vertically stacked pots (24 plants/m2) containing perlite and horizontal nutrient film technique troughs (13 plants/m2). Plants were fertigated continuously with recirculating nutrient solution. In a 7-month production cycle, the plug plants bloomed earlier and produced more fruit during the first month of harvest (December) than the fresh-dug plants. Higher yields from plug plants were a result of more fruit numbers and not larger fruit size. Fruit production averaged 6.0 and 3.5 kg/m2 in the trough and pot systems, respectively. The vertical growing system allows greater plant densities, but light intensity reaching the plants in the lower sections of the tower can be less than 20% of levels measured at the top. Establishment costs of protected culture systems are higher, but production is earlier and labor costs are typically reduced. Greenhouse hydroponic culture systems could extend the winter strawberry production to more northern locations.

scholarly journals Heading of shoots and hand thinning of flowers and fruits on 'BRS Kampai' peach trees

2017 ◽  
Vol 52 (11) ◽  
pp. 1006-1016 ◽  
Author(s):  
Paula Duarte de Oliveira ◽  
Gilmar Arduino Bettio Marodin ◽  
Gustavo Klamer de Almeida ◽  
Mateus Pereira Gonzatto ◽  
Daniel Chamorro Darde
Keyword(s):  
High Frequency ◽  
Prunus Persica ◽  
Fruit Size ◽  
Fruit Production ◽  
No Production ◽  
Full Bloom ◽  
Fruit Thinning ◽  
Heading Control ◽  
Peach Trees

Abstract: The objective of this work was to evaluate the effect of shoot heading and of hand thinning in different development stages of flowers and fruits on the fruit production and quality of 'BRS Kampai' peach (Prunus persica) trees. The experiment was performed during three crop years, under the conditions of the “Depressão Central” region in the state of Rio Grande do Sul, Brazil, and the treatments were: T1, heading of half of the mixed shoot; T2, heading of one third of the mixed shoot; T3, flower thinning in the pink bud stage; T4, thinning at full bloom; T5, thinning of fruit with 5 mm; T6, thinning of fruit with 20 mm; and T7, no thinning or heading (control). Fruit production and quality were evaluated. Plants with no thinning were more productive, but showed high frequency of fruits with a diameter smaller than 60 mm. Shoot heading reduced production per tree and resulted in small-sized fruit. Thinning time did not affect production, and fruit size was greater when thinning was performed at the bloom stage. 'BRS Kampai' peach trees can be thinned starting at bloom, which provides greater fruit size, with no production loss.

scholarly journals EFFECTS OF HYDROGEN CYANAMIDE ON APPLE AND PLUM FRUIT THINNING

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 690a-690
Author(s):  
Esmaeil Fallahi ◽  
Brenda R. Simons ◽  
John K. Fellman ◽  
W. Michael Colt
Keyword(s):  
Malus Domestica ◽  
Fruit Set ◽  
Fruit Size ◽  
Apple Fruit ◽  
Fruit Weight ◽  
Full Bloom ◽  
Hydrogen Cyanamide ◽  
Fruit Thinning ◽  
Prunus Salicina

Influence of various concentrations of hydrogen cyanamide (HC) on fruit thinning of `Rome Beauty' apple (Malus domestica Borkh.), `Friar,' and `Simka' plums (Prunus salicina Lindley) were studied. A full bloom application of HC at all tested concentrations decreased `Rome Beauty' apple fruit set and yield, and increased fruit weight. Hydrogen cyanamide at 0.25% (V/V) resulted in adequate apple thinning, indicated by the production of an ideal fruit weight. Prebloom and full bloom applications of HC at greater than 0.75% reduced plum fruit set and yield in `Friar.' Full bloom application of HC at 0.25% to 0.50% showed a satisfactory fruit set, yield, and fruit size in `Friar' plum. Full bloom application decreased fruit set and yield in `Simka' plum. Hand thinning, as well as chemical thinning, is recommended for plums.

scholarly journals EFFECTS OF HYDROGEN CYANAMIDE ON STONE FRUIT THINNING

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1122a-1122
Author(s):  
Esmaeil Fallahi ◽  
Michael Colt ◽  
S. Krishna Mohan ◽  
John Fellman
Keyword(s):  
Fruit Set ◽  
Fruit Size ◽  
Stone Fruit ◽  
Severe Toxicity ◽  
Full Bloom ◽  
Hydrogen Cyanamide ◽  
Fruit Number ◽  
Fruit Thinning

Influence of prebloom and full bloom applications of hydrogen cyanamide on `Simka' and `Friar' plums in Southwest Idaho and `Florda Prince' peach in Southwest Arizona was studied. Prebloom application of 0.5% hydrogen cyanamide caused severe toxicity to the fruit buds in `Friar' lure, while 2% hydrogen cyanamide did not cause toxicity in `Simka' plum. `Simka' fruit was effectively thinned with 1-2% prebloom application. At full bloom, 1.5% hydrogen cyanamide caused severe flower and leaf burning in both `Friar' and `Simka' plums, while concentrations between 0.1% and 1% thinned flowers (fruits) in both of the plum cultivars. Influence of hydrogen cyanamide on final fruit set, fruit size and maturity are also studied. Prebloom or full bloom applications of 2% or 3% hydrogen cyanamide eliminated 95 to 100% of the blooms, while application of this chemical at 1% sufficiently thinned the fruit. Number of commercially packed large peaches in trees receiving 1% hydrogen cyanamide was the same as that in trees thinned by hand, suggesting hydrogen cyanamide as a potential chemical for stone fruit thinning.

The effect of summer shading on flower bud morphogenesis in apricot (Prunus armeniaca L.)

2013 ◽  
Vol 8 (1) ◽  
pp. 54-63 ◽  
Author(s):  
Susanna Bartolini ◽  
Raffaella Viti ◽  
Lucia Andreini
Keyword(s):  
Fruit Set ◽  
Prunus Armeniaca ◽  
Climatic Conditions ◽  
Regular Growth ◽  
Xylem Differentiation ◽  
Flower Bud ◽  
Primary Xylem ◽  
Floral Differentiation ◽  
Prunus Armeniaca L ◽  
Bud Growth

AbstractThe aim of this investigation was to assess whether imposed summer shading treatments in apricot (Prunus armeniaca L.) can affect the main phenological phases related to the floral morphogenesis (floral differentiation, xylogenesis), flower bud growth and quality in terms of bud capacity to set fruit. Experimental trials were carried out on fully-grown trees of ‘San Castrese’ and ‘Stark Early Orange’ cultivars characterized by different biological and agronomical traits to which shadings were imposed in July and August. Histological analysis was carried out from summer onwards in order to determine the evolution of floral bud differentiation, and the acropetal progression of primary xylem differentiation along the flower bud axis. Periodical recordings to evaluate the bud drop, blooming time, flowering and fruit set rates were performed also. These shade treatments determined a temporary shutdown of floral differentiation, slowed xylem progression up to the resumption of flower bud growth and a reduced entity of flowering and fruit set. These events were particularly marked in ‘San Castrese’ cultivar, which is well known for its adaptability to different climatic conditions. These findings suggest that adequate light penetration within the canopy during the summer season could be the determining factor when defining the qualitative traits of flower buds and their regular growth, and ultimately to obtain good and constant crops.

scholarly journals Varietal Wealth of Prunus Species

2021 ◽  
Author(s):  
Amit Kumar ◽  
Mahendra Kumar Sharma ◽  
Tajamul Farooq Wani ◽  
Anil Sharma ◽  
Gepu Nyorak
Keyword(s):  
Prunus Persica ◽  
Prunus Avium ◽  
Sour Cherry ◽  
Prunus Dulcis ◽  
Prunus Armeniaca ◽  
Stone Fruits ◽  
Prunus Salicina ◽  
Major Species ◽  
Prunus Cerasoides ◽  
Black Beauty

Genus Prunus includes all the stone fruits (peach, nectarine, plum, apricot, almond and cherry) comprise around 98 species and classified under three subgenera namely: Amygdalus (peaches, nectraine and almonds), Prunophora (plums and apricots) and Cerasus (cherries). Genus Prunus have attained a prime position among all the temperate fruit crops as delicious edible drupe, and many species have ornamental values as well. Major species of importance are Prunus persica (peach), Prunus armeniaca (apricot), Prunus salicina (Japanese plum), Prunus domestica (European plum), Prunus americana (American plum), Prunus avium (Sweet cherry), Prunus cerasus (Sour cherry), Prunus dulcis (almond), Prunus ceracifera (Cherry plum), Prunus mira (Behmi), Prunus cerasoides (Wild Himalayan cherry), Prunus mahaleb (Mahaleb cherry) etc. Interspecific hybrids namely: plumcots, pluots and apriums also produce very delicious edible fruits. Commercial cultivars of different stone fruits are J H Hale, Cresthaven, Flordasun, Florda Prince, Elberta, Glohaven, July Elberta, Redhaven, Kanto 5, Sun Haven etc. of peaches, Fantasia, Mayfire, Red Gold, Snow Queen etc. belongs to nectarine, Turkey, Charmagz, Perfection, St. Ambroise, Royal, New Castle etc. are apricots, Santa Rosa, Black Beauty, Kelsey, Green Gage, Methley, Satsuma, Frontier, Burbank etc. are plums, Regina, Burlat, Lapins, Kordia, Stella, Bing, Van, Black Heart, Compact Lambert, Compact Stella etc. are cherries, and California Paper Shell, IXL, Mission, Nonpareil, Drake, Ne Plus Ultra, Pranyaj, Merced etc. are almonds.

scholarly journals The fertilization problems of cultivated red- and black currant varieties in Hungary

2002 ◽  
Vol 8 (2) ◽  
Author(s):  
A. Porpáczy
Keyword(s):  
Fruit Set ◽  
Fruit Production ◽  
Important Change ◽  
Climatic Conditions ◽  
Commercial Production ◽  
Black Currant ◽  
Small Fruit ◽  
Soft Fruit ◽  
Labour Power ◽  
Red Currant

Small fruits have a modest share in the fruit production of Hungarys. Red currant was grown traditionally in home gardens 60-70 years ago. Commercial production was established only in the surroundings of some town. The black currant was unknown until after Wold War II. An important change occured in small fruit production in the 1950s. Socialist countries, which had cheaper labour power, made efforts to meet these demands. In this time we produced 25.000 t. Presently the country produces 13-15.000 tons currant fruit yearly 60% from this is black currant, which has a better market. It is our own interest to make our currant production more profitable. The currant is the second most widely cultivated soft fruit. Our product is disposed mostly on EU markets. There was no breeding activity in this field in Hungary earlier. Cultivars used were mostly of foreign origin (W. European; Boskoop Giant, Silvergieter, Wellington XXX, Russian; Altaiskaya Desertnaya, Neosupaiuschaiasya, N. European; Brikltorp, Ojebyn). Besides well-known advantageous this cultivars have also some defects mainly unfavourable—adaptation to climatic conditions, which caused fertilisation problems, reduced the fruit set and uneven growth with decreased yields (Dénes & Porpáczy, 1999). About 140 black currant cultivars were investigated during the last four decades in our variety trials and only four of them were introduced with satisfying yielding capacity (3.5-5.5 t/ha).

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