scholarly journals Benzyladenine as A Chemical Thinner for `McIntosh' Apples. I. Fruit Thinning Effect1s and Associated Relationships with Photosynthesis, Assimilate Translocation, and Nonstructural Carbohydrates

2000 ◽  
Vol 125 (2) ◽  
pp. 169-176 ◽  
Author(s):  
Rongcai Yuan ◽  
Duane W. Greene
Keyword(s):  
Dark Respiration ◽  
Soluble Sugars ◽  
Fruit Size ◽  
Net Photosynthesis ◽  
Nonstructural Carbohydrates ◽  
Total Soluble Sugars ◽  
Fruit Abscission ◽  
Fruit Thinning ◽  
Total Nonstructural Carbohydrates ◽  
Carbohydrate Levels

BA was applied at 50 or 100 mg·L-1 to `More-Spur McIntosh'/Malling 7 (M.7) apple trees [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.] at the 10 mm stage of fruit development. BA thinned fruit and increased fruit size. There were two distinguishable peaks of fruit abscission during `June drop'. BA accentuated the naturally occurring waves of fruit abscission, and enhanced translocation of 14C-sorbitol from leaves to fruit when applied directly to the fruit, but not when applied directly to the leaves. Net photosynthesis was decreased and dark respiration was increased when temperature following BA application was high (30 °C), whereas there was no effect when temperature was lower (20 °C). Total nonstructural carbohydrates, total soluble sugars, and starch in the leaves decreased dramatically over the 12- or 13-day observation period, regardless of BA treatment. These carbohydrate concentrations in the leaves were lowered further by BA application. Abscising fruit, based on specific reddening of the pedicel, had higher carbohydrate levels than persisting fruit, regardless of BA application. We conclude that BA thins fruit, at least in part, by increasing dark respiration and decreasing net photosynthesis. Chemical name used: N-(phenylmethyl)-1H-purine-6-amine [benzyladenine (BA)].

scholarly journals Seasonal Patterns of Carbohydrates and Proline in Jojoba Clones that Differ in Frost Susceptibility

HortScience ◽  
1990 ◽  
Vol 25 (1) ◽  
pp. 103-105 ◽  
Author(s):  
Mubarak S. Khalafalla ◽  
David A. Palzkill
Keyword(s):  
Seasonal Changes ◽  
Soluble Sugars ◽  
Leaf Tissue ◽  
Early Summer ◽  
Seasonal Patterns ◽  
Nonstructural Carbohydrates ◽  
Resistant Clone ◽  
Total Soluble Sugars ◽  
Total Nonstructural Carbohydrates ◽  
Sugar Levels

Total nonstructural carbohydrates (TNC), starch, total soluble sugars, sucrose, and proline concentrations were monitored for 18 months in leaf tissue of two jojoba [Simmondsia chinensis (Link) Schneider] clones that differ in frost susceptibility. Seasonal changes in TNC and starch concentrations, with maxima in the winter and minima in summer, were significant. Sugar levels decreased from fall to spring and increased during early summer. The more frost-resistant clone (C-1) had significantly higher sugar concentrations during most of the study than the less frost-resistant clone (C-2). Proline concentrations largely followed the trends found for TNC. The C-1 clone had the higher levels of proline, except when C-2 was frost-injured. Growth trends were similiar between C-1 and C-2, with a major growth flush from March to May. Relatively high levels of starch preceded growth flushes.

scholarly journals Effect of Benzyladenine (BA) on Fruit Thinning and Carbohydrate Status in Apples

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 525D-525
Author(s):  
Rongcai Yuan ◽  
Duane W. Greene
Keyword(s):  
Fruit Set ◽  
Dark Respiration ◽  
Fruit Size ◽  
Net Photosynthesis ◽  
Seed Abortion ◽  
Seed Number ◽  
Fruit Thinning ◽  
Control Fruit ◽  
Viable Seeds ◽  
Carbohydrate Status

BA applied at the 10-mm stage at 50 and 100 ppm thinned, increased fruit size, and seed abortion. Net photosynthesis was decreased and dark respiration was increased when temperature following BA application was high (30°C), whereas there was no effect when temperature was lower (20°C). The seed number in abscising fruit was greater in BA-treated fruit than in control fruit. The number of viable seeds in BA-treated fruit was reduced. Tipping the bourse shoot increased fruit set, regardless of BA treatment. BA did not thin fruit with 25 leaves or greater. The translocation of 14C-sorbital from leaves to fruit was promoted by BA application to the fruit, but not when BA was applied to the leaves. The thinning induced by BA will be discussed in relation to available carbohydrate.

Correlation Between the Rates of Foliar Dark Respiration and Net Photosynthesis in Some Tropical Dicot Weeds

Weed Science ◽  
1987 ◽  
Vol 35 (2) ◽  
pp. 141-144 ◽  
Author(s):  
G. Rajendrudu ◽  
J. S. Rama Prasad ◽  
V. S. Rama Das
Keyword(s):  
Respiration Rate ◽  
Dark Respiration ◽  
Leaf Age ◽  
Net Photosynthesis ◽  
Dark Respiration Rate ◽  
Weed Species ◽  
Unit Leaf ◽  
Positive Linear Correlation ◽  
Carbohydrate Levels ◽  
Photosynthetic Type

The rates of foliar dark respiration and net photosynthesis in attached leaves of 25 C3, C4, and C3-C4 intermediate dicotyledonous weed species were determined using the infrared gas analyzer. The ratio of dark respiration to photosynthesis per unit leaf area in attached leaves of each species was inversely proportional to leaf age. Highly significant, positive linear correlation was observed between the rates of foliar dark respiration and net photosynthetic CO2 uptake in dicot weeds irrespective of the photosynthetic type. The higher foliar dark respiration rate found in some of the weed species can be attributed in part to the higher carbohydrate levels as generated by a rapid photosynthetic CO2 assimilation. The significance of higher dark respiration rate in relation to carbon and energy economy of weeds is discussed.

scholarly journals EFFECT OF ROOTSTOCK AND ORCHARD FLOOR MANAGEMENT ON CARBOHYDRATE LEVELS OF `REDHAVEN' PEACH

HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1167f-1167
Author(s):  
Danielle R. Ellis ◽  
Gregory L. Reighard.
Keyword(s):  
Management System ◽  
Prunus Persica ◽  
Soluble Sugars ◽  
The Other ◽  
Total Soluble Sugars ◽  
Orchard Floor Management ◽  
Carbohydrate Fraction ◽  
Dormant Season ◽  
Carbohydrate Levels

Trees of `Redhaven' peach [Prunus persica (L.) Batsch] budded to `Lovell', `Bailey', and `Nemaguard' rootstocks were grown with bahiagrass or cultivated orchard middles. Terminal shoots were collected once a month through the dormant season. `Redhaven' on `Lovell' had significantly higher levels of sucrose, sorbitol, total soluble sugars, starch and total non-structural carbohydrates than `Redhaven' on `Nemaguard'. However, there were no significant differences in any carbohydrate fraction between `Redhaven' on `Bailey' and the other rootstocks. Orchard floor management system had no significant effect on carbohydrate levels.

Fruit thinning affects photosynthetic activity, carbohydrate levels, and shoot and fruit development of olive trees grown under semiarid conditions

2013 ◽  
Vol 40 (11) ◽  
pp. 1179 ◽  
Author(s):  
Afef Haouari ◽  
Marie-Christine Van Labeke ◽  
Kathy Steppe ◽  
Fethi Ben Mariem ◽  
Mohamed Braham ◽  
...  
Keyword(s):  
Fruit Ripening ◽  
Soluble Sugars ◽  
Intercellular Co2 Concentration ◽  
Fruit Size ◽  
Olive Tree ◽  
Carbohydrate Content ◽  
Crop Load ◽  
Chlorophyll Fluorescence Parameters ◽  
Fruit Thinning ◽  
Fruit Load

Olive (Olea europaea L.) production is marked by annual oscillations as trees alternate from high to low crop loads in successive years. Gas exchanges and carbohydrate content of leaves and fruits in olive tree (O. europaea cv. Besbassi) were monitored at pit hardening and fruit ripening. After fruit set, three crop loads were applied (100%, 50% and 25% of the initial fruit load) by manual thinning. Severe fruit thinning reduced photosynthesis, stomatal conductance and intercellular CO2 concentration. Crop load had no significant effect on chlorophyll fluorescence parameters. The reduction of 75% of the initial crop load favoured the accumulation of starch in leaves and soluble sugars in leaves and fruits. The reduction in initial fruit load had a significant positive effect on the current year’s shoot elongation and on inflorescence number the following spring. To increase the fruit size, a strong thinning (75%) was necessary, which coincided with the highest shoot vigour. Moderate thinning (50%) hardly affected leaf carbohydrate content and fruit size, but photosynthetic capacity was only limited at fruit ripening.

scholarly journals Effects of Metamitron under Different Relative Humidity Conditions on the Fruit Abscission of Malus domestica Borkh. Cultivars

Horticulturae ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. 89
Author(s):  
Nídia Rosa ◽  
Wim Verjans ◽  
Glória Àvila ◽  
Joaquim Carbó ◽  
Joan Bonany ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Malus Domestica ◽  
Morphological Characteristics ◽  
Net Photosynthesis ◽  
Fruit Weight ◽  
Malus Domestica Borkh ◽  
Fruit Abscission ◽  
Fruit Thinning ◽  
Before And After ◽  
The Impact

Metamitron is an apple (Malus domestica Borkh.) fruit thinner that acts by reducing the photosynthetic capacity of trees. Relative humidity may influence thinning efficacy; however, the broadness of this effect is not yet fully understood. Trials were set in Sint-Truiden (Belgium) in 2018 and Lleida and Girona (Spain) in 2019, using 4-year-old cvs. Braeburn and Elstar trees in Belgium, and 16-year-old cv. Golden Reinders trees in Spain. Four treatments were implemented at the stage of 12–14 mm fruit diameter: (a) CTR—control, trees under natural environmental conditions; (b) HH—high humidity, trees submitted to artificially increased air relative humidity applied for 3 h prior to the beginning of the experiment; (c) MET—trees sprayed with 247.5 mg/L metamitron; (d) MET + HH—trees submitted to the combination of increased humidity (HH) and metamitron (MET) application. In Belgium, metamitron absorption by leaves was greater than in Spain. This might be related to morphological characteristics of the leaves which developed under greater natural relative humidity levels in Belgium than in Spain. Compared to MET alone, ‘Braeburn’ and ‘Elstar’ demonstrated significantly greater metamitron absorption, 59% and 84%, respectively, under MET + HH, accompanied by declines in leaf net photosynthesis (10% and 32%, respectively) and sucrose (31% and 26%, respectively). At harvest, MET + HH treatment reduced yield by 24% and 32% in ‘Braeburn’ and ‘Elstar’, respectively, when compared with MET alone. A large reduction (considered over thinning) in the yield of ‘Elstar’ occurred. In contrast, metamitron absorption by ‘Golden Reinders’ using MET alone was similar to MET + HH; however, there was a slight foliar sugar reduction in the latter treatment. In addition, both treatments enhanced shoot growth and increased fruit abscission with similar improvements in fruit weight and size. In this study, high relative humidity enhanced fruit thinning efficacy under certain circumstances, such as age or genetic predisposal, which left the tree more susceptible to a negative carbohydrate balance. For instance, ‘Braeburn’ and ‘Elstar’ were easier to thin when compared to ‘Golden Reinders’. In addition, this study raises a question that requires further research regarding the impact of HH before and after spraying as well as its effect in combination with higher temperatures.

scholarly journals Production Temperatures Influence Growth and Physiology of Leatherleaf Fern

HortScience ◽  
1994 ◽  
Vol 29 (2) ◽  
pp. 67-70 ◽  
Author(s):  
Robert H. Stamps ◽  
Terril A. Nell ◽  
James E. Barrett
Keyword(s):  
Temperature Regime ◽  
Dark Respiration ◽  
Soluble Sugars ◽  
Light Saturation ◽  
Temperature Regimes ◽  
Use Efficiency ◽  
Carbohydrate Levels ◽  
Rumohra Adiantiformis ◽  
Mass Basis ◽  
Two Temperature

Leatherleaf fern [Rumohra adiantiformis (Forst.) Ching] fronds produced under a high-temperature regime (HTR, 30 day/25C night) grew faster and produced sori earlier than those in a low-temperature regime (LTR, 20 day/15C night). Abaxial diffusive conductance was lower for HTR-grown fronds. Light-saturated net CO2 assimilation rates (Pn) and dark respiration were lower for HTR fronds, but light-saturated Pn efficiencies (chlorophyll basis); light compensation points; and soluble sugars, starch, and nonstructural carbohydrate levels were similar for the two regimes. Transpiration and water-use efficiency (mass basis) at light saturation were similar for fronds from both temperature treatments. Comparison of physiological characteristics of fronds from the two temperature regimes revealed no differences that might account for reduced postharvest longevity of fronds produced at the higher temperatures.

Seasonal changes in carbohydrate levels in tissues of Carex lacustris

1979 ◽  
Vol 57 (20) ◽  
pp. 2140-2144 ◽  
Author(s):  
Scott J. Roseff ◽  
John M. Bernard
Keyword(s):  
Seasonal Changes ◽  
Dry Weight ◽  
Nonstructural Carbohydrates ◽  
Total Nonstructural Carbohydrates ◽  
Carbohydrate Levels ◽  
Carex Lacustris

Seasonal changes in total nonstructural carbohydrates (TNC) levels in aboveground and belowground tissues of Carex lacustris were determined. TNC concentrations of aboveground tissues averaged 15–20% of the dry weight throughout the year, ranging from 31.3% in newly emerged shoots in September to 3.1% in mostly dead shoots in December. Belowground, TNC concentrations ranged from a low of 16.4% in young rhizomes in midsummer to a high of 44.9% in late October.TNC content of shoots was 68.5 g/m2 on May 5, increasing to a peak of 224.5 g/m2on August 5. Levels declined to a low of 31.6 g/m2 by December 5, of which 74% was found in young shoots about to overwinter. Belowground TNC was 107.5 g/m2 on May 8, declined somewhat into June, then increased to a maximum of 240 g/m2 on October 24. The data indicate these belowground reserves are important for the species to overwinter successfully.The difference between the minimum TNC content of the sedge biomass in late May and the peak in October represented a gain over the summer of approximately 205 g/m2.

scholarly journals Seedling Growth of Catawba Rhododendron. II. Photosynthesis and Carbohydrate Accumulation and Export

HortScience ◽  
1994 ◽  
Vol 29 (11) ◽  
pp. 1303-1308 ◽  
Author(s):  
D. Bradley Rowe ◽  
Stuart L. Warren ◽  
Frank A. Blazich ◽  
D. Mason Pharr
Keyword(s):  
Seedling Growth ◽  
Net Photosynthesis ◽  
High Elevation ◽  
Controlled Environment ◽  
Nonstructural Carbohydrates ◽  
Night Temperature ◽  
Carbohydrate Accumulation ◽  
Lower Elevation ◽  
Quadratic Response ◽  
Carbohydrate Levels

Catawba rhododendron (Rhododendron catawbiense Michx.) seedlings of two provenances, Johnston County, N.C. (35°45′N, 78°12′W, elevation = 67 m), and Yancey County, N.C. (35°45′N, 82°16′W, elevation = 1954 m), were grown in controlled-environment chambers for 18 weeks with days at 18, 22, 26, or 30C in factorial combination with nights at 14, 18, 22, or 26C. Seedlings of the higher-elevation provenance generally exhibited higher net leaf photosynthetic rates (PN)s than those from the lower elevation at all temperature combinations. Thus, it appears seedlings of the high-elevation provenance possess greater relative thermotolerance, expressed as net photosynthesis, than the low-elevation provenance. Eighty-seven days after initiation (DAI) of the experiment, PN showed a quadratic response to increasing day temperature, with the maximum occurring at 22C, whereas PN decreased linearly with increasing night temperature. At 122 DAI, PN increased linearly with increasing day temperature with nights at 22 and 26C. Highest PNs were at 30/22C and 26/22C. Carbohydrate export increased with increasing day temperature, whereas the response to night temperature was minimal. High levels of nonstructural carbohydrates occurred at thermoperiods (22/22C and 26/22C) that optimize seedling growth. However, definitive trends relating seedling growth to PNs, leaf carbohydrate levels, or to the amount of carbohydrate exported from the leaves were difficult to generalize due to numerous day × night interactions.

scholarly journals Carbohydrate Metabolism in Creeping Bentgrass as Influenced by Two Summer Irrigation Practices

2008 ◽  
Vol 133 (5) ◽  
pp. 678-683 ◽  
Author(s):  
Jinmin Fu ◽  
Peter H. Dernoeden
Keyword(s):  
Root Zone ◽  
Leaf Tissue ◽  
Net Photosynthesis ◽  
Creeping Bentgrass ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Total Nonstructural Carbohydrates ◽  
Putting Green ◽  
Sucrose Storage ◽  
Carbohydrate Levels

This field study was conducted to investigate carbon metabolic responses to deep and infrequent (DI) versus light and frequent (LF) irrigation in ‘Providence’ creeping bentgrass (Agrostis stolonifera L.). LF irrigation was performed daily to wet soil to a depth of 4 to 6 cm, whereas DI irrigation was performed at leaf wilt to wet soil to a depth of ≥24 cm. The creeping bentgrass was seeded into a sand-based root zone in 2005 and was maintained as a putting green during the 2006 and 2007 study years. Canopy net photosynthesis (Pn) and whole plant respiration (Rw) were monitored, and water-soluble carbohydrates [WSC (i.e., glucose, fructose, and sucrose)], storage carbohydrates [SC (i.e., fructan and starch)], and total nonstructural carbohydrates [TNC (i.e., the sum of water soluble and storage sugars)] in leaf and root tissue were quantified. Creeping bentgrass subjected to DI irrigation had a lower Pn and a generally similar Rw compared with LF-irrigated bentgrass. DI irrigated bentgrass generally had greater levels of WSC and TNC in leaf tissue in 2006 and similar levels in 2007 when compared with LF-irrigated bentgrass. Leaf SC levels were higher in DI- than LF-irrigated bentgrass in both years. Creeping bentgrass roots subjected to DI irrigation generally had greater SC and TNC levels in both years than were found in LF-irrigated plants. Root WSC levels were higher (2006) or similar (2007) in DI- versus LF-irrigated bentgrass. Irrigating creeping bentgrass at wilt rather than daily to maintain moist soil generally resulted in higher carbohydrate levels in leaves and roots, which may enable creeping bentgrass to better tolerate and recover from drought and other stresses.

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