FACTORS INFLUENCING THE DEVELOPMENT OF PRIMARY DORMANCY IN WILD OAT SEEDS

1979 ◽  
Vol 59 (3) ◽  
pp. 777-784 ◽  
Author(s):  
STEVEN G. RICHARDSON
Keyword(s):  
Gibberellic Acid ◽  
Wild Oat ◽  
Night Temperature ◽  
Primary Dormancy ◽  
Factors Influencing ◽  
Seed Maturity ◽  
Oat Seeds ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
Mature Seeds

Germination in response to gibberellic acid was used as an assay for wild oat seed dormancy. In growth chamber studies removal of glumes, a 5 °C reduction in night temperature (20 °C day/15 °C night vs. constant 20 °C), and a shorter photoperiod (12 vs. 18 h) during the period following panicle emergence reduced subsequent germination (increased dormancy) of mature seeds. Dormancy of field-grown wild oat seeds increased with increasing seed maturity and was affected by planting location and associated crop.

scholarly journals Polyamine Application Effects on Gibberellic Acid Content in Creeping Bentgrass during Drought Stress

2017 ◽  
Vol 142 (2) ◽  
pp. 135-142 ◽  
Author(s):  
Sanalkumar Krishnan ◽  
Emily B. Merewitz
Keyword(s):  
Drought Stress ◽  
Gibberellic Acid ◽  
Abiotic Stress Tolerance ◽  
Photochemical Efficiency ◽  
Canopy Temperature ◽  
Creeping Bentgrass ◽  
Relative Water ◽  
Consistent Basis ◽  
Chamber Studies ◽  
Growth Chamber Studies

Polyamines (PAs), spermine (Spm), and spermidine (Spd) may enhance the abiotic stress tolerance and growth of creeping bentgrass (Agrostis stolonifera). Growth chamber studies were conducted to investigate the effect of PA application on the physiological response and hormone content in creeping bentgrass ‘Penn-G2’ under drought. Spm (1 mm) and Spd (5 mm) were applied exogenously under drought or well-watered conditions. PA-treated plants maintained significantly higher turf quality (TQ), relative water content (RWC), photochemical efficiency, and membrane health while maintaining lower canopy temperature. Spm at the 1-mm rate had a 2.46-fold higher osmotic adjustment (OA) at 10 d compared with control plants. A greater content of gibberellic acid (GA) isoforms (GA1, GA4, and GA20) were observed compared with controls during both studies for PA-treated plants under drought. After 7 days of drought stress in Expt.1, GA1 levels were 3.26 higher for Spm 1-mm-treated plants compared with drought controls. GA4 contents were 69% and 65% higher compared with drought-stressed-untreated plants for Spd 5-mm application after 9 and 11 days. Higher levels of GA20 were observed at 10 days (Spd 5 mm, 108.9% higher) due to PA treatment compared with drought controls. In addition to differential regulation of GA isoforms, we observed enhanced abscisic acid (ABA) due to PA application; however, not on a consistent basis. This study showed that PA application may play a role in GA1, GA4, and ABA accumulation in creeping bentgrass ‘Penn G-2’ under drought stress.

scholarly journals 232 Inverse Day/Night Temperature Influences Yield and Canopy Height of Hydroponically Grown Sweetpotato

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 431B-431 ◽  
Author(s):  
D.G. Mortley ◽  
J.H. Hill ◽  
C.K. Bonsi ◽  
W.A. Hill ◽  
C.E. Morris
Keyword(s):  
Canopy Height ◽  
Growth Chamber ◽  
Photon Flux ◽  
Root Production ◽  
Storage Root ◽  
Night Temperature ◽  
Nutrient Film Technique ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
Hydroponically Grown

Growth chamber studies were conducted to determine if inverse day/night temperature could control canopy height of sweetpotato without adversely affecting storage root yield. Four 15-cm-long vine cuttings of TU-82-155 sweetpotato were grown in rectangular nutrient film technique hydroponic troughs for 120 days. Two troughs were placed into each of six reach-in growth chambers and subjected to 24/18, 26/20, 28/22, 18/24, 20/26, and 22/28 °C, respectively. Growth chamber conditions included a 12/12-h photoperiod, 70% RH, and photosynthetic photon flux of 1000 μmol·m-2·s-1 at canopy level. Total and edible storage root yields were reduced by 50% among plants grown under cool days/warm nights regimes. Harvest index was similar among treatments except for the low value obtained at 22/28 °C. Canopy height was positively correlated with the change in temperature, and for every 2 °C decrease there was a 3.1 centimeter decrease in canopy height. Inverse day/night temperature effectively controlled canopy height but at the expense of storage root production.

STUDIES ON THE BIOLOGY OF WILD OATS. I. DORMANCY, GERMINATION AND EMERGENCE

1976 ◽  
Vol 56 (3) ◽  
pp. 611-618 ◽  
Author(s):  
M. P. SHARMA ◽  
W. H. VANDEN BORN ◽  
D. K. McBEATH
Keyword(s):  
Seedling Emergence ◽  
Control Program ◽  
Field Capacity ◽  
Kernel Weight ◽  
Wild Oat ◽  
Water Extracts ◽  
Percent Germination ◽  
Oat Seeds ◽  
Mature Seeds ◽  
Practical Implications

Mature seeds of wild oat (Avena fatua L.) from Alberta were completely dormant when freshly harvested. About 46% of the seeds lost their dormancy during storage for 33 wk at room temperature. Gibberellic acid was very effective in overcoming dormancy in freshly harvested or stored seeds. Water extracts from dormant wild oat seeds were more inhibitory than water extracts from non-dormant seeds to germination of wild oat seeds. A number of chemicals, viz., nitrates of potassium, ammonium and sodium, cytokinins (benzyladenine, kinetin), and thiourea, were effective to varying degrees in stimulating the germination and emergence of seeds. Percent germination and emergence of seedlings was maximum at temperatures ranging from 10 to 21 C, although germination and emergence were slower at 10 C than at the higher temperatures. A temperature of 32 C was detrimental to normal germination and emergence. Maximum seedling emergence occurred when soil moisture was maintained at 50 or 75% of the field capacity. At field capacity moisture levels, no seedlings emerged and nearly all the seeds had rotted within 11 days of planting. Planting depths of 2–8 cm were best for seedling emergence. From greater planting depths the rate and percent emergence were greater for larger seeds than for smaller or medium-sized seeds (separated on the basis of kernel weight). Time to maximum emergence was 8, 11–13 and 13–17 days from depths of 0.5–3 cm, 4–12 cm and 16–20 cm, respectively. Practical implications of some of these findings in a wild oat control program are discussed.

Growth Characteristics of Wild Oat (Avena fatua) in the Pacific Northwest

Weed Science ◽  
1983 ◽  
Vol 31 (2) ◽  
pp. 226-229 ◽  
Author(s):  
Larry A. Morrow ◽  
David R. Gealy
Keyword(s):  
Pacific Northwest ◽  
Avena Fatua ◽  
Field Conditions ◽  
Maximum Height ◽  
Wild Oat ◽  
The Pacific ◽  
Anther Extrusion ◽  
Oat Seeds ◽  
Mature Seeds ◽  
Number Of Seeds

Wild oat (Avena fatua L.) seedlings from mature seeds emerged in silt loam from depths up to 17.5 cm in the greenhouse or 15 cm under field conditions. No emergence occurred from greater depths. Under field conditions, the greatest percentage of shoots emerged from seeds planted 5 cm deep. Wild oat in a space-planted nursery produced an average of 19 tillers, reached a maximum height of 79 cm, and produced an average of 1072 seeds. The number of tillers per plant, the number of seeds per panicle, and the total number of seeds per plant increased with an increase in annual precipitation. Wild oat seeds harvested as early as 3 days after anther extrusion germinated, but seeds harvested 6 or 7 days after anther extrusion germinated more rapidly.

Adenosine triphosphate and adenylate energy charge in relation to dormancy of wild oat seeds

1983 ◽  
Vol 61 (12) ◽  
pp. 3349-3354 ◽  
Author(s):  
Stephen W. Adkins ◽  
James D. Ross
Keyword(s):  
Gibberellic Acid ◽  
Adenosine Triphosphate ◽  
Energy Charge ◽  
Avena Fatua ◽  
The State ◽  
Limiting Factors ◽  
Adenylate Energy Charge ◽  
Wild Oat ◽  
Oat Seeds ◽  
Adenosine Phosphates

Adenosine phosphates, expressed as ATP and energy charge levels, were compared in genetically identical dormant and nondormant caryopses of wild oat (Avena fatua L.). Air-dry nondormant caryopses had a larger pool of ATP and a higher energy charge than dormant caryopses. During the early hours of imbibition of water by dormant caryopses, ATP levels and energy charge increased indicating they are not limiting factors for germination. Moreover, during the induction of germination in dormant caryopses by gibberellic acid (GA3), changes in energy charge were similar to those observed on water, indicating that GA3 does not overcome dormancy simply by elevating energy charge levels. In a second study, ATP and energy charge were measured in initially dormant caryopses incubated under conditions of temperature that either removed or retained dormancy. Both embryo and endosperm extracts demonstrated correlations between levels of ATP or energy charge with temperature of incubation but not with the state of dormancy. The conclusions drawn from both lines of investigation do not support the hypothesis that release of dormancy is related to the metabolism of adenosine phosphates in caryopses of wild oat.

COMPETITION BETWEEN BARLEY AND WILD OATS AS AFFECTED BY NITROGEN, BARBAN AND TIME OF SEEDING

1970 ◽  
Vol 50 (5) ◽  
pp. 541-550 ◽  
Author(s):  
D. K. McBEATH ◽  
D. A. DEW ◽  
H. A. FRIESEN
Keyword(s):  
Field Experiments ◽  
Avena Fatua ◽  
Growth Chamber ◽  
Wild Oat ◽  
Short Term ◽  
Reciprocal Relationships ◽  
Wild Oats ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
Main Effects

Main effects and interactions of nitrogen, barban (4-chloro-2-butynyl m-chlorocarbanilate) and time of seeding of wild oats (Avena fatua L.) in relation to barley were investigated in factorial growth chamber and field experiments. Culms and yield of barley were increased by nitrogen and barban in both experiments, and increased by each delay in wild oat seeding in the growth chamber only. Culms and yield of wild oats were increased by nitrogen in the growth chamber but not in the field, and were decreased by barban and delayed seeding in both experiments. Competition between the two species growing together is demonstrated by reciprocal relationships between culm numbers and yield of the two species. Similar results were obtained for most main effects and interactions in the two experiments, indicating that competitive and nutrient stresses developed in short term growth chamber studies can be used for the prediction of results under field conditions.

Effects of prolonged light on germination of six lines of wild oat (Avena fatua)

1991 ◽  
Vol 69 (7) ◽  
pp. 1414-1417 ◽  
Author(s):  
J. Q. Hou ◽  
G. M. Simpson
Keyword(s):  
Seed Germination ◽  
Genetic Variability ◽  
Gibberellic Acid ◽  
Red Light ◽  
Avena Fatua ◽  
Wild Oat ◽  
Inhibitory Effects ◽  
Light Responses ◽  
Light Reaction ◽  
Oat Seeds

Effects of prolonged light irradiation on seed germination of wild oat (Avena fatua L.) were studied in three nondormant and three dormant genetic lines. Light responses were observed in each of the lines tested. The expression of the light reaction is related to the genetic variability and dormancy states of the seeds. The light reaction can be observed in the dormant lines by removing the dormancy blocks in the seeds either through afterripening or by treatment with gibberellic acid or azide. Prolonged far-red, blue, and white light are inhibitory to germination. Prolonged red light had neutral, or inhibitory, effects compared with the corresponding dark germination. Germination responses to light depend on both the condition of phyto-chrome established by the light environment and the state of dormancy in wild oat seeds. Key words: phytochrome, dormancy, afterripening, genotype, gibberellin, azide.

EFFECTS OF PLANTING DATE ON THE GROWTH AND DEVELOPMENT OF NARROW-LEAVED HAWK’S-BEARD

1978 ◽  
Vol 58 (4) ◽  
pp. 1087-1094 ◽  
Author(s):  
A. L. DARWENT ◽  
J. S. McKENZIE
Keyword(s):  
Dark Period ◽  
Growing Season ◽  
Planting Date ◽  
Light Period ◽  
Crepis Tectorum ◽  
Winter Annuals ◽  
Winter Annual ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
Mature Seeds

Narrow-leaved hawk’s-beard (Crepis tectorum L.) planted prior to 6 June bolted and produced mature seeds as a summer annual. Plantings on 16 June bolted but not all reached maturity during the same growing season. Narrow-leaved hawk’s-beard planted in early July developed in one of three ways: (1) bolted and produced mature seeds as a summer annual, (2) bolted but produced no mature seeds in the year of planting, or (3) developed as a winter annual. Plantings made after 15 July developed as winter annuals. Survival of winter annuals the following spring ranged from 12 to 46% for July plantings to 80 to 90% for August–September plantings. No plants survived from the mid-October plantings. In growth chamber studies at 20 °C, bolting occurred in all plants at an 18-h photoperiod but not in plants at a 14-h photoperiod. The percentage of plants bolting under photoperiods between 14 and 18 h was intermediate. When grown under the same photoperiod, reducing the temperature to 18 °C during the light period and 5 °C during the dark period did not affect the percentage of plants bolting. These results suggest that photoperiod plays a major role in determining the pattern of development of narrow-leaved hawk’s-beard.

Plant Response to Herbicide Placement in Soil

Weed Science ◽  
1969 ◽  
Vol 17 (4) ◽  
pp. 475-478 ◽  
Author(s):  
Roy K. Nishimoto ◽  
Arnold P. Appleby ◽  
William R. Furtick
Keyword(s):  
Temperature Regime ◽  
Buffer Zone ◽  
Moisture Loss ◽  
Setaria Viridis ◽  
Night Temperature ◽  
Green Foxtail ◽  
Plastic Bag ◽  
Root Exposure ◽  
Chamber Studies ◽  
Growth Chamber Studies

Greenhouse and growth chamber studies were conducted to investigate effects of herbicide placement in soil on toxicity to emerging seedlings. The use of a technique involving a plastic bag over the plants for 3 to 4 weeks to reduce soil moisture loss did not change the apparent site of 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine) uptake by green foxtail (Setaria viridis(L.) Beauv.) or oats (Avena sativaL.). Atrazine was more effective on oats through root exposure and more effective on green foxtail through shoot exposure when an untreated buffer zone around the seed was used. But in subsequent studies without the buffer zone, atrazine was most active when placed immediately below the seed of both oats and green foxtail. Proximity to the seed increased effectiveness of atrazine,S-ethyl dipropylthiocarbamate (EPTC), and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron). Also, a narrow concentrated layer of these three herbicides adjacent to the seed was more effective than a wider dilute layer above or below the seed. A diurnal fluctuating temperature regime with a low night temperature increased toxicity of EPTC to oats through root exposure, when compared to a constant temperature regime.

scholarly journals Stable Isotope Biogeochemistry of Seabird Guano Fertilization: Results from Growth Chamber Studies with Maize (Zea Mays)

PLoS ONE ◽  
2012 ◽  
Vol 7 (3) ◽  
pp. e33741 ◽  
Author(s):  
Paul Szpak ◽  
Fred J. Longstaffe ◽  
Jean-François Millaire ◽  
Christine D. White
Keyword(s):  
Zea Mays ◽  
Stable Isotope ◽  
Growth Chamber ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
Seabird Guano
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