scholarly journals Impact of allelopathy of sunflower (Helianthus annuus L.) roots extract on physiology of wheat (Triticum aestivum L.)

2011 ◽  
Vol 10 (65) ◽  
pp. 14465-14477 ◽  
Author(s):  
Kamal Javed
Keyword(s):  
Triticum Aestivum ◽  
Helianthus Annuus ◽  
Triticum Aestivum L ◽  
Helianthus Annuus L

Interference and Control of Wild Sunflower (Helianthus annuus L.) in Spring Wheat (Triticum aestivum L.) in Northeastern Mexico

2002 ◽  
Vol 30 (3-4) ◽  
pp. 439-446 ◽  
Author(s):  
Enrique Rosales-Robles ◽  
Jaime R. Salinas-García ◽  
Ricardo Sánchez-de-la-Cruz ◽  
Luis A. Rodríguez-del-Bosque ◽  
Valentín Esqueda-Esquivel
Keyword(s):  
Triticum Aestivum ◽  
Helianthus Annuus ◽  
Spring Wheat ◽  
Triticum Aestivum L ◽  
Wild Sunflower ◽  
Helianthus Annuus L ◽  
Northeastern Mexico ◽  
And Control

Estimation of evaporation components in agricultural crops

Biologia ◽  
2006 ◽  
Vol 61 (19) ◽  
Author(s):  
Mariusz Merta ◽  
Christina Seidler ◽  
Tatjana Fjodorowa
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Helianthus Annuus ◽  
Triticum Aestivum L ◽  
Soil Evaporation ◽  
Research Station ◽  
Agricultural Crops ◽  
Hydrological Models ◽  
Helianthus Annuus L ◽  
Interception Loss

AbstractThere are three components of the total evapotranspiration (soil evaporation, interception loss and transpiration) influenced strongly by the vegetation. Hydrological models need information about the temporally varying portions of the components. On a well equipped research station in the east of Germany all these components have been measured under corn, winter wheat and sunflower (Zea mais L., Triticum aestivum L., Helianthus annuus, L.) and calculated with different methods, respectively. The portion of soil evaporation decreased dramatically from 50% at a LAI = 0.5 to 1–5% for dense crops (LAI > 3). It was stated that transpiration and interception loss took place simultaneously.

scholarly journals SUNFLOWER COMPETITION IN WHEAT

1984 ◽  
Vol 64 (1) ◽  
pp. 105-111 ◽  
Author(s):  
GREG R. GILLESPIE ◽  
STEPHEN D. MILLER
Keyword(s):  
Triticum Aestivum ◽  
Helianthus Annuus ◽  
Flag Leaf ◽  
Wheat Yield ◽  
Triticum Aestivum L ◽  
Wheat Crop ◽  
Upper Midwest ◽  
Leaf Stage ◽  
Seeding Date ◽  
Field Season

Sunflower (Helianthus annuus L.) is grown in rotation with wheat (Triticum aestivum L.) in the upper midwest of the U.S.A. However, volunteer sunflower is often a problem in wheat planted the year following sunflower. Wheat yields as influenced by wheat seeding date and sunflower density, duration of sunflower competition and rate of sunflower control were determined in the field. Season-long sunflower competition at densities of 3, 9, and 23 plants per square metre reduced yield of the following wheat crop by an average of 11, 19, and 33%, respectively, averaged over seeding date and location. Sunflower was more competitive with wheat seeded in late than in early May, particularly at the lower sunflower densities. Wheat yield was reduced 22% when 24 sunflower plants/m2 were allowed to compete until the wheat flag-leaf stage. Wheat yields obtained were similar when volunteer sunflower was controlled by postemergence MCPA [[(4-chloro-o-tolyl)oxy] acetic acid], bromoxynil (3,5-dibromo-4-hydroxybenzonitrile), or bromoxynil plus MCPA despite the slower rate of control with MCPA compared to bromoxynil or bromoxynil plus MCPA. This research indicates that wheat following sunflower should be planted early and sunflower densities of nine plants per square metre or higher should be removed before the flag-leaf stage to prevent yield reductions.Key words: Density, duration, bromoxynil, MCPA, Helianthus annuus, Triticum aestivum

Metabolism and Export of 14C-Labelled Photosynthate From Water-Stressed Leaves

1981 ◽  
Vol 8 (2) ◽  
pp. 143 ◽  
Author(s):  
BT Watson ◽  
IF Wardlaw
Keyword(s):  
Triticum Aestivum ◽  
Water Stress ◽  
Helianthus Annuus ◽  
Plant Species ◽  
Stomatal Closure ◽  
Triticum Aestivum L ◽  
14Co2 Fixation ◽  
Co2 Levels ◽  
Wheat Leaves ◽  
Reduced Rate

The effect of water stress on the translocation of 14C-labelled photosynthate from leaves was examined in four contrasting plant species, Sorghum sudanense (Piper) Stapf. (C4, monocot), Triticum aestivum L. (C3, monocot), Amaranthus caudatus L. (C4, dicot) and Helianthus annuus L. (C3, dicot). Water stress reduced the rate of loss of 14C from the leaves of all species following a pulse application of 14CO2, but the effects of stress were most apparent in sorghum and sunflower, the species with the highest control rates of export. Slower labelling of sucrose, following the application of 14CO2, could explain the reduced rate of export of 14C from stressed wheat leaves, but this would not explain the response in sorghum. An examination of the products of 14CO2 fixation in wheat leaves suggests that the changes in metabolism of 14C under stress may be due to reduced CO2 levels, resulting from stomatal closure. In contrast the change in metabolism of 14C-labelled photosynthate due to water stress in sorghum was very different from that expected in response to reduced CO2 levels. Prevention of translocation of photosynthate out of a leaf of either wheat or sorghum, by steam killing the tissue at the base of the blade, altered the pattern of labelling of metabolites with 14C following a pulse of 14CO2. However changes in translocation due to reduced export associated with a reduction in growth under water stress did not appear to play a part in the responses observed in these experiments.

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