scholarly journals POINSETTIA GROWTH AND DEVELOPMENT IN RESPONSE TO DAY-NIGHT TEMPERATURE REGIME AND UNICONAZOLE.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1074c-1074
Author(s):  
Richard J. McAvoy
Keyword(s):  
Leaf Area ◽  
Temperature Regime ◽  
Dry Weight ◽  
Plant Canopy ◽  
Night Temperature ◽  
Specific Leaf Weight ◽  
Leaf Weight ◽  
Temperature Regimes ◽  
Potting Medium ◽  
Total Plant

Poinsettias, Euphorbia pulcherrima Willd. cvs Lilo and Diva Starlight, were exposed to either warm day-cool night or cool day-warm night greenhouse temperature regimes. Day time temperatures were imposed between 900 to 1600 HR. Within each temperature regime, poinsettias were grown single stem or pinched and drenched with either 0.04 or 0.08 mg a.i. uniconazole per 1.6 1 pot or grown as untreated controls. Light levels (PAR) and potting medium and plant canopy temperatures were continuously monitored.Over the course of the study, the day-night temperature differential (DIF), in the plant canopy, averaged 4.2C in the warm day regime and -1.4C in the cool day regime. The average daily temperature was lower (16.9C) in the warm day regime than in the cool day regime (18.7C).DIF treatment significantly affected final leaf area, leaf and total plant dry weight, leaf area ratio and specific leaf weight, The DIF treatment by cultivar interaction was significant for final poinsettia leaf area, stem, leaf and total plant dry weight, break number and average break length. Uniconazole significantly affected final plant height, stem and total plant dry weight, break number, average break length and specific leaf weight. Uniconazole by DIF treatment effects were not significant,

scholarly journals Seedling Growth of Catawba Rhododendron. I. Temperature Optima, Leaf Area, and Dry Weight Distribution

HortScience ◽  
1994 ◽  
Vol 29 (11) ◽  
pp. 1298-1302 ◽  
Author(s):  
D. Bradley Rowe ◽  
Stuart L. Warren ◽  
Frank A. Blazich
Keyword(s):  
Leaf Area ◽  
Seedling Growth ◽  
Weight Ratio ◽  
Dry Weight ◽  
High Elevation ◽  
Root Weight ◽  
Root Dry Weight ◽  
Leaf Weight Ratio ◽  
Leaf Weight ◽  
Total Plant

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. Shoot and root dry weights and total leaf areas of seedlings of the Yancey County provenance (high elevation) exceeded (P ≤ 0.05) those of the Johnston County (low elevation) provenance at all temperature combinations. Leaf area was maximal at 22/22C, 18/26C, and 22/26C and minimal at 30/14C (day/night). Shoot dry weight responded similarly. Root dry weight decreased linearly with increasing day temperature, but showed a quadratic response to night temperature. Leaf weight ratio (leaf dry weight: total plant dry weight) increased, while root weight ratio (root dry weight: total plant dry weight) decreased with increasing day temperature. Leaf weight ratio was consistently higher than either stem or root weight ratios. Day/night cycles of 22 to 26/22C appear optimal for seedling growth.

Relationship between Crop Growth Parameters and Seed Yield in CMS Analogues in Sunflower

Helia ◽  
2015 ◽  
Vol 38 (62) ◽  
pp. 109-120 ◽  
Author(s):  
Vikrant Tyagi ◽  
S. K. Dhillon
Keyword(s):  
Grain Yield ◽  
Leaf Area ◽  
Harvest Index ◽  
Dry Weight ◽  
Hybrid Breeding ◽  
Oleic Acid Content ◽  
Specific Leaf Weight ◽  
Area Index ◽  
Leaf Weight ◽  
Leaf Dry Weight

AbstractNine new cms analogues on the base of diversified cms sources were developed and evaluated for morphological, agronomic, physiological and biochemical traits, including the field resistance to the prevalent diseases of sunflower under Punjab conditions. As a result of this study, the most prospective cms analogues were designated for future use in hybrid breeding programme. The results revealed that selection for tall plants with large head size and high chlorophyll content may be associated with high grain yield as well as oil content and high oleic acid content in sunflower. Leaf dry weight, biological yield, harvest index, specific leaf weight and relative leaf water content had direct positive effect on grain yield. The harvest index, specific leaf weight/plant, leaf area index and leaf area had indirect effects (through leaf dry weight) on grain yield. These traits are advocated as selection criteria for grain yield improvement in sunflower.

Effects of Day and Night Temperature on Vegetative Growth of Texas Panicum (Panicum texanum)

Weed Science ◽  
1990 ◽  
Vol 38 (4-5) ◽  
pp. 365-373 ◽  
Author(s):  
David T. Patterson
Keyword(s):  
Leaf Area ◽  
Plant Biomass ◽  
Dry Weight ◽  
Maximum Growth ◽  
Temperature Threshold ◽  
Night Temperature ◽  
Temperature Regimes ◽  
Net Assimilation ◽  
Highly Correlated ◽  
C Partitioning

Texas panicum was grown in controlled-environment chambers in 16 day/night temperature regimes ranging from 19/11 to 34/26 C. After 33 days, maximum plant height, leaf area, and dry weight occurred at 34/26 C. The greatest number of tillers and leaves occurred at 34/16 C. Partitioning of plant biomass into stems increased with increasing night temperature, while partitioning into leaves tended to decrease. Partitioning of biomass into roots decreased with increasing night temperature at day temperatures of 19 or 24 C but not at 34 C. Plant dry matter production (DMP) was highly correlated with both leaf area duration (LAD) and net assimilation rate (NAR) during the first 2 weeks of growth. During the subsequent 3 weeks, DMP was highly correlated with LAD but not with NAR. The low-temperature threshold for growth of Texas panicum was approximately 11 C. Texas panicum attained 25% of its maximum growth at an average daily temperature of 21 C, 50% at 24 C, and 75% at 26 C. Texas panicum is unlikely to become a highly competitive weed outside the southern and southwestern United States.

scholarly journals Initial Growth of Seedlings of Flame Azalea in Response to Day/Night Temperature

1992 ◽  
Vol 117 (2) ◽  
pp. 216-219 ◽  
Author(s):  
Asiah A. Malek ◽  
Frank A. Blazich ◽  
Stuart L. Warren ◽  
James E. Shelton
Keyword(s):  
Leaf Area ◽  
Weight Ratio ◽  
Dry Weight ◽  
Night Temperature ◽  
Total Leaf Area ◽  
Root Dry Weight ◽  
Total Leaf ◽  
Total Plant ◽  
Top Dry Weight ◽  
Leaf Dry Weight

Seedlings of flame azalea [Rhododendron calendulaceum (Michx.) Torr] were grown for 12 weeks under long-day conditions with days at 18, 22, 26, or 30C for 9 hours in factorial combination with nights at 14, 18, 22, or 26C for 15 hours. Total plant dry weight, top dry weight, leaf area, and dry weights of leaves, stems, and roots were influenced by day and night temperatures and their interactions. Dry matter production was lowest with nights at 14C. Root, leaf, top, and total dry weights were maximized with days at 26C in combination with nights at 18 to 26C. Stem dry weight was maximized with days at 26 to 30C and nights at 22C. Leaf area was largest with days at 18 and 26C in combination with nights at 18 or 26C. Within the optimal, day/night temperature range of 26 C/18-26C for total plant dry weight, there was no evidence that alternating temperatures enhanced growth. Shoot: root ratios (top dry weight: root dry weight) were highest with days at 18 and 30C. Leaf area ratio (total leaf area: total plant dry weight) was highest and specific leaf area (total leaf area: leaf dry weight) was largest when days and nights were at 18C and were lower at higher temperatures. Regardless of day/night temperature, leaf weight ratio (leaf dry weight: total plant dry weight) was higher than either the stem weight ratio (stem dry weight: total plant dry weight) or root weight ratio (root dry weight: total plant dry weight). Net leaf photosynthetic rate increased with day temperatures up to 30C.

Manipulation of leaf area and its effect on grain yield in droughted wheat

1983 ◽  
Vol 34 (1) ◽  
pp. 23 ◽  
Author(s):  
RA Richards
Keyword(s):  
Grain Yield ◽  
Leaf Area ◽  
Water Use ◽  
Dry Weight ◽  
Plant Weight ◽  
Leaf Weight ◽  
Crop Density ◽  
Leaf Cutting ◽  
Total Plant ◽  
Use Efficiency

Modification of crop leaf area could have considerable consequences on grain yield where soil water is limited. To test this, leaf area was artificially reduced to examine the effect on three wheat cultivars in two different drought situations-one where all the water was supplied just prior to sowing, and the other where half of the water was supplied before sowing and half after sowing on eight separate occasions. Leaf area was modified by detillering and two leaf-cutting treatments, Plants were grown individually in pots 1 m tall by 0.1 m diameter at a crop density of 100 plants/m2. Leaf area and water use were measured weekly for all plants, and at maturity the yields of grain, straw and leaves, and the yield components, were measured. The defoliation treatments reduced total cumulative leaf area by about one-half. This in turn reduced the rate of early water use and resulted in the highest grain yields and harvest indices. The ratio of leaf weight to total plant weight was inversely associated with yield both within and across treatments, suggesting an excessive investment in leaves. This was also indicated in an adjacent experiment where the same cultivars, watered daily, had a similar leaf weight to that of the droughted plants, yet yielded considerably more grain. Water use efficiency (the ratio of above-ground dry weight to total water used) also had a significant influence on grain yield. These results suggest that it may be worth while modifying leaf area development in wheat genetically to improve yields under some dryland conditions.

scholarly journals Temperature and Duration of Pretreatment Effects on Growth and Development of Geraniums

HortScience ◽  
1992 ◽  
Vol 27 (3) ◽  
pp. 216-217
Author(s):  
Serge Gagnon ◽  
Blanche Dansereau
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Growth And Development ◽  
Dry Weight ◽  
Rapid Adaptation ◽  
Night Temperature ◽  
Flower Buds ◽  
Shoot Dry Weight ◽  
Temperature Regimes ◽  
Pretreatment Effects

Geranium seedlings (Pelargonium ×hortorum Bailey `Smash Hit Red') were given various cold pretreatments (CP) to obtain more rapid adaptation to constant or split-night temperature regimes. The six following CP were used: either 13C or 17/13C for 5, 10, or 15 days. The effect of these CP given at seedling stage was compared with that of control plants held at 17C at night. The CP did not significantly increase the time to first visible flower buds or to anthesis. The number of flowering stems, plant height, shoot dry weight, and leaf area of control plants were not significantly different from plants receiving CP.

Effects of Temperature and CO2Concentration on the Growth of Cotton (Gossypium hirsutum), Spurred Anoda (Anoda cristata), and Velvetleaf (Abutilon theophrasti)

Weed Science ◽  
1988 ◽  
Vol 36 (6) ◽  
pp. 751-757 ◽  
Author(s):  
David T. Patterson ◽  
Maxine T. Highsmith ◽  
Elizabeth P. Flint
Keyword(s):  
Dry Matter ◽  
Dry Weight ◽  
Net Assimilation Rate ◽  
Assimilation Rate ◽  
Short Term ◽  
Leaf Weight ◽  
Matter Production ◽  
Total Plant ◽  
Net Assimilation ◽  
Total Dry Weight

Cotton, spurred anoda, and velvetleaf were grown in controlled-environment chambers at day/night temperatures of 32/23 or 26/17 C and CO2concentrations of 350 or 700 ppm. After 5 weeks, CO2enrichment to 700 ppm increased dry matter accumulation by 38, 26, and 29% in cotton, spurred anoda, and velvetleaf, respectively, at 26/17 C and by 61, 41, and 29% at 32/23 C. Increases in leaf weight accounted for over 80% of the increase in total plant weight in cotton and spurred anoda in both temperature regimes. Leaf area was not increased by CO2enrichment. The observed increases in dry matter production with CO2enrichment were caused by increased net assimilation rate. In a second experiment, plants were grown at 350 ppm CO2and 29/23 C day/night for 17 days before exposure to 700 ppm CO2at 26/17 C for 1 week. Short-term exposure to high CO2significantly increased net assimilation rate, dry matter production, total dry weight, leaf dry weight, and specific leaf weight in comparison with plants maintained at 350 ppm CO2at 26/17 C. Increases in leaf weight in response to short-term CO2enrichment accounted for 100, 87, and 68% of the observed increase in total plant dry weight of cotton, spurred anoda, and velvetleaf, respectively. Comparisons among the species showed that CO2enrichment decreased the weed/crop ratio for total dry weight, possibly indicating a potential competitive advantage for cotton under elevated CO2, even at suboptimum temperatures.

Compensatory Responses of Common Cocklebur (Xanthium strumarium) and Velvetleaf (Abutilon theophrasti) to Partial Shading

Weed Science ◽  
1993 ◽  
Vol 41 (4) ◽  
pp. 541-547 ◽  
Author(s):  
Emilie E. Regnier ◽  
S. Kent Harrison
Keyword(s):  
Leaf Area ◽  
Shade Tolerance ◽  
Shoot Growth ◽  
Branch Length ◽  
Dry Weight ◽  
Xanthium Strumarium ◽  
Leaf Angle ◽  
Petiole Length ◽  
Partial Shading ◽  
Total Plant

Lower leaves of greenhouse-grown common cocklebur and velvetleaf were shaded to 5% of full light over a 12-d period while upper leaves remained exposed to full light to determine weed foliar and branching responses to partial shading similar to that encountered in soybean crops. Shading increased lower leaf senescence and specific leaf area, and decreased branch length and number of second-order leaves in both species compared to unshaded controls. Common cocklebur branched more extensively along the lower portion of its stem than velvetleaf under both shaded and unshaded conditions. Upper leaves of partially shaded velvetleaf were held in a more perpendicular position to the light source beginning 3 days after treatment (DAT) compared to upper leaves of unshaded plants. Shading of lower leaves caused an increase in upper (unshaded) leaf area beginning 3 and 6 DAT in velvetleaf and common cocklebur, respectively. Petiole length of upper leaves also increased in response to shading in both species. Total plant dry weight at 12 DAT was unaffected by shading in velvetleaf but was reduced 10% by shading in common cocklebur. While common cocklebur maintained greater lower shoot growth in the presence of shade than velvetleaf, there was a greater change in upper leaf angle by velvetleaf in response to shading than by common cocklebur. These results support previous field observations of apparent greater shade tolerance of common cocklebur compared to velvetleaf and indicate that both species have the ability to compensate for shading of lower leaves by altering upper shoot growth.

Comparison of Green Foxtail (Setaria viridis) and Wild Oat (Avena fatua) Growth, Development, and Competitiveness under Three Temperature Regimes

Weed Science ◽  
1993 ◽  
Vol 41 (3) ◽  
pp. 369-378 ◽  
Author(s):  
David A. Wall
Keyword(s):  
Leaf Area ◽  
Dry Weight ◽  
Mature Seed ◽  
Wild Oat ◽  
Replacement Series ◽  
Relative Growth ◽  
Temperature Regimes ◽  
Green Foxtail ◽  
Increasing Temperature ◽  
Series Study

In a replacement series study, barley was more competitive than green foxtail and wild oat at 28/22 and 22/16 C. Wild oat was more competitive with green foxtail at 22/16 C than at 28/22 C. Maximum green foxtail dry weight and leaf area was produced at 28/22 C. As temperature increased, maximum dry weight and leaf area occurred earlier during plant growth. Similarly, maximum wild oat leaf area occurred earlier with increasing temperature, but the greatest leaf area was observed at 16/10 C. Leaf area ratio (LAR) and relative growth rate (RGR) of wild oat did not differ markedly between temperature regimes. Green foxtail LAR was higher while RGR was lower at 16/10 C than at 22/16 or 28/22 C. Under the 16/10 C regime green foxtail produced little mature seed. Greatest seed numbers were produced at 28/22 C. Wild oat produced mature seed under all temperature regimes with the greatest seed numbers produced at 22/16 C.

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