GROWTH, CARBON ACQUISITION, AND SOURCE-SINK RELATIONSHIPS IN `TITAN' RED RASPBERRY

Seasonal changes in growth, photosynthetic rates, temperature, and light response curves of `Titan' red raspberry (Rubus idaeus L.) were obtained from potted plants grown under field conditions. Primocane dry weight accumulation underwent two phases of linear growth at the beginning and the end of the season, but growth slowed during fruiting. This slower rate of dry weight accumulation also coincided with an increase in root dry weight. Primocane NAR and SLA were highest early in the season. Light response curves differed depending on cane type and time of year. Floricane photosynthetic rates (A) were high during the fruiting period, while primocane A rates remained steady throughout the season. Both primocane and floricane leaflets displayed a midday drop in A rate, with a partial recovery in late afternoon. Photosynthetic rates of both primocane and floricane leaves were very sensitive to high temperatures. Temporal convergence of sink demand from fruit, primocanes, and roots occurs when plants experience high temperatures. This may account for low realized yields in raspberry and the high level of yield component compensation typical of source-limited plants.

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Growth, Carbon Acquisition, and Source-Sink Relationships in `Titan' Red Raspberry

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.119.6.1163 ◽

1994 ◽

Vol 119 (6) ◽

pp. 1163-1168 ◽

Cited By ~ 14

Author(s):

Gina E. Fernandez ◽

Marvin P. Pritts

Keyword(s):

Accumulation Rate ◽

Light Response ◽

Dry Weight ◽

Rubus Idaeus ◽

Field Conditions ◽

Partial Recovery ◽

Red Raspberry ◽

Response Curves ◽

Photosynthetic Rates ◽

Light Response Curves

Seasonal changes in growth, mean maximal photosynthetic rates, and the temperature and light response curves of `Titan' red raspberry (Rubus idaeus L.) were obtained from potted plants grown under field conditions. Primocane dry weight accumulation increased steadily at the beginning and the end of the season, but growth slowed midseason during fruiting. The slower midseason dry-weight accumulation rate coincided with an increase in root dry weight. Primocane net assimilation rate (NAR) was highest early in the season. Floricane photosynthetic rates (A) were highest during the fruiting period, while primocane A remained steady throughout the season. Primocane and floricane leaflets displayed a midday depression in A under field conditions, with a partial recovery in the late afternoon. Photosynthetic rates of primocane and floricane leaves were very sensitive to temperature, exhibiting a decline from 15 to 40C. Light-response curves differed depending on cane type and time of year. A temporal convergence of sink demand from fruit, primocanes, and roots occurs when plants experience high temperatures. These factors may account for low red raspberry yield.

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Photosynthetic Rate, Flowering, and Yield Component Alteration in Hazelnut in Response to Different Light Environments

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.121.6.1103 ◽

1996 ◽

Vol 121 (6) ◽

pp. 1103-1111 ◽

Cited By ~ 22

Author(s):

Cheryl R. Hampson ◽

Anita N. Azarenko ◽

John R. Potter

Keyword(s):

Photosynthetic Rate ◽

Dark Respiration ◽

Stomatal Density ◽

Chlorophyll Concentration ◽

Light Response ◽

Dry Weight ◽

Yield Component ◽

Response Curves ◽

Photosynthetic Rates ◽

Light Response Curves

In hazelnut (Corylus avellana L.), vigorous vegetative growth and traditional orchard practices that include little or no pruning combine to produce a dense, shady canopy. A study designed to quantify the effect of shade on reproduction and photosynthetic rate in this shade-tolerant species was undertaken to assess whether some degree of pruning might improve productivity. Shade cloth was used to exclude 30%, 47%, 63%, 73%, or 92% of ambient sunlight from whole `Ennis' and `Barcelona' trees from mid-May until harvest. Photosynthetic light response curves were obtained for leaves that had developed in full sunlight, deep inside the canopy of unshaded trees, or in 92% shade. Light-saturated net photosynthetic rates were 12.0, 6.1, and 9.3 μmol·m-2·s-1 of CO2 and dark respiration rates were 2.0, 1.1, and 0.7 μmol·m-2·s-1 of CO2, respectively, for the three light regimes. Light-saturated photosynthetic rates of leaves from 30% or 63% shade differed little from the control (0% shade). Area per leaf increased by 49% and chlorophyll concentration (dry weight basis) by 157% as shading increased from 0% to 92%. Shading to 92% reduced specific leaf weight (68%), stomatal density (30%), light compensation point (69%), and dark respiration rate (63%) compared to controls. Female inflorescence density declined by about one-third and male inflorescence density by 64% to 74% in the most heavily shaded trees of both cultivars compared to controls. Shade was more detrimental to yield than flowering: yield per tree dropped by >80%, from 2.9 to 3.4 kg in full sun to 0.6 to 0.9 kg in 92% shade. Shade reduced yield primarily by decreasing nut number and secondarily by decreasing nut size. The incidence of several kernel defects increased as shade increased. Therefore, hazelnut leaves showed considerable capacity to adapt structurally and functionally to shade, but improving light penetration into the canopy would probably increase orchard productivity.

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Comparative Net Photosynthesis of Four Hevea brasiliensis Clonal Seedlings

Experimental Agriculture ◽

10.1017/s0014479700008978 ◽

1978 ◽

Vol 14 (4) ◽

pp. 337-340 ◽

Cited By ~ 9

Author(s):

Zahar Samsuddin ◽

Ivan Impens

Keyword(s):

Hevea Brasiliensis ◽

Light Response ◽

Net Photosynthesis ◽

Response Curves ◽

Photosynthetic Rates ◽

Light Response Curves ◽

Single Leaf

SUMMARYSingle-leaf net photosynthesis versus light response curves of four Hevea brasiliensis clonal seedlings showed that it was possible to divide photosynthetic rates into high and low classes.

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Shading Affects Morphology, Dry-matter Partitioning, and Photosynthetic Response of Greenhouse-grown `Chardonnay' Grapevines

HortScience ◽

10.21273/hortsci.39.1.65 ◽

2004 ◽

Vol 39 (1) ◽

pp. 65-70 ◽

Cited By ~ 5

Author(s):

Justine E. Vanden Heuvel ◽

John T.A. Proctor ◽

K. Helen Fisher ◽

J. Alan Sullivan

Keyword(s):

Dry Matter ◽

Dark Respiration ◽

Light Response ◽

Leaf Size ◽

Dry Weight ◽

Volume Density ◽

Response Curves ◽

Dry Matter Partitioning ◽

Light Response Curves ◽

Whole Plant

In order to gain an understanding of the capacity of severely shaded leaves to be productive in dense canopies, the effects of increased shading on morphology, dry-matter partitioning, and whole-plant net carbon exchange rate (NCER) were investigated on greenhouse-grown Vitis vinifera L. `Chardonnay' grapevines. Vines were subjected to whole-plant shading levels of 0%, 54%, 90%, and 99% of direct sun 3 weeks after potting. Data were collected 8 to 10 weeks after potting. Nonlinear regression was used to investigate the relationship of leaf morphological traits and organ dry weights to increased shading. Leaf size was maintained with increased shading to approximately the 90% shading level, while leaf fresh weight, volume, density, and thickness were immediately reduced with increased shading. Root dry weight was most affected by increased shading, and root to shoot ratio was reduced. When nonlinear regressions were produced for light response curves, light compensation point was reduced by approximately 49% by moderate shading, and 61% by severe shading. Shaded leaves approached the asymptote of the light response curve more quickly, and had reduced dark respiration rates, indicating that the morphological compensation responses by the vine allow shaded leaves to use available light more efficiently. However, the long-term ramifications of reduced root growth in the current year on vines with shaded leaves may be significant.

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The influence of the hemiparasitic angiosperm Cassytha pubescens on photosynthesis of its host Cytisus scoparius

Functional Plant Biology ◽

10.1071/fp09135 ◽

2010 ◽

Vol 37 (1) ◽

pp. 14 ◽

Cited By ~ 10

Author(s):

Hao Shen ◽

Jane N. Prider ◽

José M. Facelli ◽

Jennifer R. Watling

Keyword(s):

Carbon Fixation ◽

Stomatal Closure ◽

Light Response ◽

Poor Performance ◽

Quantum Yields ◽

Cytisus Scoparius ◽

Response Curves ◽

Photosynthetic Rates ◽

Invasive Shrub ◽

Light Response Curves

Infection with Cassytha pubescens R.Br, an Australian native hemiparasitic plant, can lead to death of the invasive shrub, Cytisus scoparius L. Link (Scotch broom). We examined the influence of C. pubescens on photosynthetic physiology of C. scoparius to determine whether this might contribute to death of infected plants. Infected C. scoparius had significantly lower photosynthetic rates, stomatal conductance and transpiration, and higher Ci (internal [CO2]), than uninfected plants. Rapid light response curves, determined using chlorophyll fluorescence, indicated significantly lower light-saturated electron transport rates and lower quantum yields for infected plants relative to uninfected plants. However, Rubisco content did not differ between infected and uninfected plants, suggesting the lower photosynthetic rates were most likely due to stomatal closure, rather than lower photosynthetic capacity. As a consequence of lower assimilation rates, PSII efficiency was lower in infected plants than uninfected plants across the diurnal cycle. Infected plants also had significantly lower pre-dawn Fv/Fm values and slower recovery from exposure to high light than uninfected plants. Our results suggest that infected C. scoparius are more susceptible to photodamage than uninfected plants. Combined with lower carbon fixation rates, this could contribute to the poor performance and even death of infected plants.

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Impact of an Open Trellis on Canopy Growth, Light Interception, Yield, and Leaf Physiology of Red Raspberry (Rubus idaeus)

HortScience ◽

10.21273/hortsci.33.3.468b ◽

1998 ◽

Vol 33 (3) ◽

pp. 468b-468

Author(s):

Stephen F. Klauer ◽

J. Scott Cameron ◽

Chuhe Chen

Keyword(s):

Leaf Area ◽

Total Nitrogen ◽

Dry Weight ◽

Light Interception ◽

Rubus Idaeus ◽

Above Ground Biomass ◽

Red Raspberry ◽

Leaf Physiology ◽

Total Dry Weight ◽

Upper Third

After promising results were obtained with an open-style split trellis (two top wires) in its initial year, two new trials were established in 1997 in northwest (Lynden) and southwest (Woodland) Washington. For the split trellis, actual yields were 33% (machine-picked 1/2 season) and 17% (hand-picked) greater, respectively, for the two locations compared to the conventional trellis (one top wire). In Woodland, canes from the split trellis had 33% more berries, 55% more laterals, 69% more leaves, and 25% greater leaf area compared with the conventional trellis. Greatest enhancement of these components was in the upper third of the canopy. Laterals were also shorter in this area of the split canopy, but there was no difference in average total length of lateral/cane between trellis types. Total dry weight/cane was 22% greater in the split trellis, but component partitioning/cane was consistent between the two systems with fruit + laterals (43%) having the greatest above-ground biomass, followed by the stem (30% to 33%) and the leaves (21% to 22%). Measurement of canopy width, circumference, and light interception showed that the split-trellis canopy filled in more quickly, and was larger from preanthesis through postharvest. Light interception near the top of the split canopy was 30% greater 1 month before harvest with 98% interception near the top and middle of that canopy. There was no difference between the trellis types in leaf CO2 assimilation, spectra, or fluorescence through the fruiting season, or in total nitrogen of postharvest primocane leaves.

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