scholarly journals (108) Early Flower Bud Production and Field Establishment of Two Pawpaw Cultivars on Five Seedling Rootstocks

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1039C-1039
Author(s):  
Kirk Pomper ◽  
Sheri Crabtree ◽  
Desmond R. Layne

The pawpaw [Asimina triloba (L.) Dunal] is native to the southeastern United States and has potential as a new tree fruit crop. Clonal rootstocks are not currently available for pawpaw cultivars; therefore, nurseries graft cultivars onto rootstock derived from locally available seed. Great variation in rootstock vigor with this seedstock can result in grafted trees that lack vigor and have delayed fruit production. Pawpaw rootstocks that promote precocity would be desirable to growers. The objectives of this study were to determine if rootstock source and pruning system influenced precocity and field establishment of two pawpaw cultivars. In May 2004, a rootstock trial was planted at the Kentucky State University Research Farm that consisted of `Sunflower' and `Susquehanna' budded onto five seedling rootstocks (PA-Golden, Sunflower, Susquehanna, K8-2, and commercially available seed) with either a minimal or central leader pruning system. There were eight replicate blocks with each treatment combination, for a total of 160 trees. In Fall 2005, field mortality was greatest (58%) for `Susquehanna' budded onto Susquehanna seedling rootstock, whereas mortality was about 25% with other scion/rootstock combinations. The number of flower buds present on each tree was evaluated in Feb. 2006. Rootstock and pruning method did not influence the number of trees exhibiting flower buds. However, cultivar did influence the number of trees with flower buds; more trees of `Sunflower' (48%) had flower buds than `Susquehanna' (8%), and `Sunflower' (3.46) had more flower buds per tree than Susquehanna (0.43). Pruning system did influence the number of flower buds per tree; minimal pruned trees (2.65) had more flower buds per tree than central leader (1.21) trained trees.

HortScience ◽  
2011 ◽  
Vol 46 (1) ◽  
pp. 40-42 ◽  
Author(s):  
Brian P. Pellerin ◽  
Deborah Buszard ◽  
David Iron ◽  
Charles G. Embree ◽  
Richard P. Marini ◽  
...  

Tree fruit growers use chemical and mechanical thinning techniques in an attempt to maintain regular annual flower production and maximum repeatable yields of varieties susceptible to biennial bearing. If the percentage of floral buds an apple tree could produce without causing yield depression in subsequent years was known, it would be possible to better manage crop-thinning regimes. This study proposes that thinning is a partial transfer of potential flower buds from one year to the next year and estimates the maximum repeatable sequence of flower buds without biennial bearing. The conceptual framework is tested on a 50-year simulation with 0% to 100% transfer of thinned flower buds. Results indicate that the maximum repeatable sequence of flower buds rises sharply when the final years of the orchard approach and declines when the percent transfer of thinned buds is near 0%.


Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 476
Author(s):  
Krista C. Bogiatzis ◽  
Helen M. Wallace ◽  
Stephen J. Trueman

Peony plants require temperate winter temperatures to break underground bud dormancy and allow shoot emergence and flowering in spring. This study assessed whether artificial chilling at 4 °C for 2–6 weeks could induce shoot emergence and flowering under subtropical conditions. It also assessed whether pre-treatment at cool temperatures prior to chilling, or gibberellin application after chilling, promoted shoot emergence and flowering. Artificial chilling at 4 °C for 4 or 6 weeks promoted the greatest shoot emergence. Pre-treatment at cool temperatures did not affect shoot growth or flower bud production but it improved shoot emergence from plants also treated with gibberellin. Gibberellin more than doubled the number of shoots per plant without affecting shoot length. The optimal treatment combination for shoot emergence, growth and flower bud production was pre-treatment from 20 °C to 8 °C over an 8-day period in autumn, chilling at 4 °C for 6 weeks in early winter, and treatment with 250 mL of 100 mg/L GA3, before returning plants to subtropical winter conditions. This treatment combination provided medians of 3 (0–7) and 8 (0–31) flower buds per plant in the second and third years of production, respectively. Peony flowers can be produced in subtropical climates using artificial chilling and gibberellin, allowing out-of-season market supply.


HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1039D-1040
Author(s):  
Sheri B. Crabtree ◽  
Kirk W. Pomper ◽  
Desmond R. Layne ◽  
R. Neal Peterson

The pawpaw [Asimina triloba (L.) Dunal] is a tree fruit native to the eastern United States with potential as an alternative crop for small farmers. The Pawpaw Regional Variety Trial (PRVT) was established in 1993 by Kentucky State University (KSU) and the PawPaw Foundation (PPF) and includes 28 cultivars and advanced selections planted at 12 sites. The PRVT was established at the KSU Research Farm in Frankfort, Ky., in 1998. Data has been collected on the KSU-PRVT annually since its inception. The first fruit were produced in 1999, with Middletown, Mitchell, Overleese, and Sunflower being the most precocious varieties. A frost occurred in early April 2000, decimating the crop, with only eight fruit being produced across the orchard. In 2001, 12% of the trees produced fruit, with PA-Golden having the best early production. In 2002, 68% of trees in the PRVT fruited, producing a total of 3,500 fruit. Selections with the largest fruit (over 200 g) were Susquehanna, 5-5, 4-2, and 1-7-2. In 2003, a spring frost destroyed most of the flowers and developing fruit. Only 32 out of the 224 trees in the PRVT retained fruit, a total of only 131 fruit in the entire orchard. In 2004, the PRVT produced about 25,000 fruit across the entire orchard. Selections 4-2 and 7-90 produced the largest fruit, over 200 g. Shenandoah, 10-35, and 8-20 were the highest-yielding clones, all producing over 15 kg of fruit per tree. In 2005, spring frosts and a severe summer drought diminished fruit set and retention in the PRVT, with the orchard producing 8,900 fruit. Selections 4-2, 5-5, and Susquehanna produced the largest fruit, all weighing over 200 g. The highest yielding selections were 10-35, PA-Golden, and 1-7-2, all producing over 8 kg of fruit per tree.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 437d-437
Author(s):  
Mark K. Mullinix ◽  
Paul Tvergyak

Horticulture departments have been experiencing a decline of students studying pomology and the tree fruit industry suffers from a shortage of horticulturists. Wenatchee Valley College responded to the tree fruit industry's request to develop an undergraduate pomology program. The program has an industry advisory committee, is industry oriented and emphasizes the art and the science of deciduous tree fruit production. Industry and field-based instruction is a significant component of the curriculum. The fruit industry funded the development of two laboratory orchards totaling 53 acres. Industry satisfaction and student placement is high. Wenatchee Valley College's success motivated the industry to encourage the Washington State University Dept. of Horticulture and Wenatchee Valley College to join in an educational partnership. The Washington Tree Fruit Program was implemented in 1993. It is the state's first educational program cooperatively developed by two state institutions of higher education and boasts 55 degree-seeking students. The articulated curriculum has many innovations and represents a significant departure from traditional undergraduate pomology curricula.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 447d-447
Author(s):  
Meriam Karlsson ◽  
Jeffrey Werner

Nine-week-old plants of Cyclamen persicum `Miracle Salmon' were transplanted into 10-cm pots and placed in growth chambers at 8, 12, 16, 20, or 24 °C. The irradiance was 10 mol/day per m2 during a 16-h day length. After 8 weeks, the temperature was changed to 16 °C for all plants. Expanded leaves (1 cm or larger) were counted at weekly intervals for each plant. The rate of leaf unfolding increased with temperature to 20 °C. The fastest rate at 20 °C was 0.34 ± 0.05 leaf/day. Flower buds were visible 55 ± 7 days from start of temperature treatments (118 days from seeding) for the plants grown at 12, 16, or 20 °C. Flower buds appeared 60 ± 6.9 days from initiation of treatments for plants grown at 24 °C and 93 ± 8.9 days for cyclamens grown at 8 °C. Although there was no significant difference in rate of flower bud appearance for cyclamens grown at 12, 16, or 20 °C, the number of leaves, flowers, and flower buds varied significantly among all temperature treatments. Leaf number at flowering increased from 38 ± 4.7 for plants at 12 °C to 77 ± 8.3 at 24 °C. Flowers and flower buds increased from 18 ± 2.9 to 52 ± 11.0 as temperature increased from 12 to 24 °C. Plants grown at 8 °C had on average 6 ± 2 visible flower buds, but no open flowers at termination of the study (128 days from start of treatments).


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 548a-548 ◽  
Author(s):  
D.M. Glenn ◽  
G. Puterka ◽  
T. Baugher ◽  
T. Unruh ◽  
S. Drake

Hydrophobic particle film technology (HPF) is a developing pest control system for tree fruit production systems. Studies were established in Chile, and Washington, Pennsylvania, and West Virginia in the United States, to evaluate the effect of HPF technology on tree fruit yield and quality. Studies in Chile, Washington, and West Virginia demonstrated increased photosynthetic rate at the leaf level. Yield was increased in peaches (Chile) and apples (West Virginia), and fruit size was increased in apples (Washington and Pennsylvania). Increased red color in apple was demonstrated at all sites with reduced russetting and `Stayman' cracking in Pennsylvania. HPF technology appears to be an effective tool in reducing water and heat stress in tree fruit resulting in increased fruit quality.


2021 ◽  
Vol 22 (8) ◽  
pp. 3932
Author(s):  
Jing Cao ◽  
Qijiang Jin ◽  
Jiaying Kuang ◽  
Yanjie Wang ◽  
Yingchun Xu

The lotus produces flower buds at each node, yet most of them are aborted because of unfavorable environmental changes and the mechanism remains unclear. In this work, we proposed a potential novel pathway for ABA-mediated flower timing control in the lotus, which was explored by combining molecular, genetic, transcriptomic, biochemical, and pharmacologic approaches. We found that the aborting flower buds experienced extensive programmed cell death (PCD). The hormonal changes between the normal and aborting flower buds were dominated by abscisic acid (ABA). Seedlings treated with increasing concentrations of ABA exhibited a differential alleviating effect on flower bud abortion, with a maximal response at 80 μM. Transcriptome analysis further confirmed the changes of ABA content and the occurrence of PCD, and indicated the importance of PCD-related SNF1-related protein kinase 1 (NnSnRK1). The NnSnRK1-silenced lotus seedlings showed stronger flowering ability, with their flower:leaf ratio increased by 40%. When seedlings were treated with ABA, the expression level and protein kinase activity of NnSnRK1 significantly decreased. The phenotype of NnSnRK1-silenced seedlings could also be enhanced by ABA treatment and reversed by tungstate treatment. These results suggested that the decline of ABA content in lotus flower buds released its repression of NnSnRK1, which then initiated flower bud abortion.


1966 ◽  
Vol 46 (2) ◽  
pp. 141-149 ◽  
Author(s):  
Walter J. Kender ◽  
Franklin P. Eggert

A field experiment using various soil management practices showed that the most effective means to increase blueberry plant spread was through the use of a surface mulch. Peat and sawdust were of equal suitability as a mulching material influencing vegetative growth, although sawdust did result in a reduction in the number of flower buds produced when compared with peat. Mulching was associated with a higher soil moisture content than non-mulched plots.Blueberry plants growing in nitrogen-treated plots had an increased flower bud number and rhizome growth in contrast with those growing in unfertilized plots. Nitrogen fertilization was of particular benefit when applied in association with surface organic mulches.Plants growing in an undisturbed soil were more vigorous than in a homogenized or tilled soil. Sawdust was found to be detrimental to the growth of lowbush blueberry plants when incorporated into a homogenized soil.


2013 ◽  
Vol 36 (1-2) ◽  
pp. 83-94 ◽  
Author(s):  
Franciszka Jaumień

The growth of trees sprayed in spring with chlormequat is weaker, and their elongation growth ends 2 - 3 weeks earlier than that of unsprayed trees. Trees with growth inhibited by chlormequat set flower buds on the spurs and in the subapical part of long shoots. The course of flower bud differentiation starts in the second half of July and is similar to that in the apple tree.


1988 ◽  
Vol 6 (4) ◽  
pp. 122-124
Author(s):  
Kenneth C. Sanderson ◽  
Willis C. Martin ◽  
R. Bruce Reed

Spray applications of 4.2% Off-Shoot-0 (a mixture of methyl ester of fatty acids C6, C8, C10, and C12) effectively destroyed flower bud scales and flower parts on the azalea (Rhododendron simsii Plachon.) cultivars ‘Prize’ and ‘Kingfisher’. The addition of ethephon to Off-Shoot-0 did not increase the destruction of bud scales and flower parts. Dikegulac-sodium and oxathiin alone or in combination with ethephon did not significantly destroy scales or flower parts. Destructive chemical pinching agents such as dimethyl dodecylamine and n-undecanol usually were as effective as Off-Shoot-0 in killing bud scales but not flower parts. Cultivars differed slightly in their response to chemicals designed to destroy unwanted flower buds.


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