scholarly journals The Effect of Leaf Removal–Based Physical Injury on High Seed and Crude Oil Yields in Sunflower (Helianthus annuus L.)

Author(s):  
Mustafa Yildiz ◽  
Mehdi Taher ◽  
Marieh Javani ◽  
Ramazan Beyaz ◽  
Mehtap Gursoy
1994 ◽  
Vol 74 (4) ◽  
pp. 763-766 ◽  
Author(s):  
A. A. Schneiter ◽  
B. L. Johnson

Injury to sunflower (Helianthus annuus L.) caused by hail and pests can result in financial losses to producers. This field study was conducted to determine the response of sunflower to different types and levels of physical injury. The information will assist producers in deciding whether to replant or maintain a crop. Studies were conducted at four North Dakota locations. Treatments consisted of stand reduction, terminal bud removal, and top one third of the plant cut off, imposed on either 25 or 50% of an established plant population at five stages of plant development. Plant response to injury varied among treatment stages. When plants were injured at vegetative stages V4 and V8, 98.2 and 93.2% of the treated plants produced multiple branches and heads. When plants were injured during the transition from vegetative to reproductive development (V12, R1), a greater proportion (26.1 and 20.6%, respectively) of the plants died. The majority of the plants injured at stages R1 and R3 neither died nor branched (55.5 and 96.1%, respectively); they continued to live but did not produce seed. Living injured plants reduced total crop yield more than the injured plants that died, since living injured plants continued to compete with uninjured plants for space, light, nutrients and moisture but did not contribute toward yield. Key words: Sunflower, Helianthus annuus L., hail, crop injury


2018 ◽  
Vol 53 (3) ◽  
pp. 485-498
Author(s):  
G.P. Kononenko ◽  
◽  
M.I. Ustyuzhanina ◽  
A.A. Burkin ◽  
◽  
...  

2014 ◽  
Vol 2014 (2) ◽  
pp. 83-91
Author(s):  
Alfredo Garcia-Perez ◽  
◽  
Mark Harrison ◽  
Bill Grant ◽  
◽  
...  

Helia ◽  
2000 ◽  
Vol 23 (33) ◽  
pp. 97-104
Author(s):  
F.M. Khalifa ◽  
A.A. Schneiter ◽  
E.I. El Tayeb

SUMMARY Seed germination of six sunflower (Helianthus annuus L.) hybrids was investigated across a range of eleven constant temperatures between 5°C and 45°C. Large temperature differences in germination rate 1/t (d-1), cardinal temperature (°C) and thermal time θ (°cd) were observed among hybrids. Base temperatures (Tb) varied between 3.3°C and 6.7°C whereas maximum germination temperatures (Tm) varied between 41.7°C and 48.9°C. Final germination fraction was attained at 15°C - 25°C whereas the maximum rate of germination was attained at 30.4°C - 35.6°C. The maximum germination rate of hybrid USDA 894, the cultivar with the slowest germination rate, was only 50% of that of hybrid EX 47. The low Tb and high Tm of sunflower appear to be one of the factors which explain the successful adaptation of sunflower to a wide range of temperature. These findings are discussed in relation to the origin of the crop and its wide adaptations in diverse habitats and climatic zones.


Helia ◽  
2001 ◽  
Vol 24 (35) ◽  
pp. 101-110 ◽  
Author(s):  
S. Sridhara ◽  
T.G. Prasad

SUMMARYA field experiment was conducted at Gandhi Krishi Vignana Kendra, University of Agricultural Sciences, Bangalore to study the effect of irrigation regimens on the biomass accumulation, canopy development, light interception and radiation use efficiency of sunflower. The treatments includes irrigating the plants at 0.4, 0.6, 0.8 and 1.0 cumulative pan evaporation. The results indicated that the aboveground biomass, canopy development, radiation interception and radiation use efficiency were influenced favorably by the irrigation regimens. Irrespective of the irrigation regimen, the radiation use efficiency of sunflower increased from 15 DAS to 75 DAS and then tended to decline. The decrease in RUE after anthesis is coupled with decrease in leaf nitrogen content. In general the RUE of sunflower ranged from 0.49 g MJ-1 to 1.84 g MJ-1 at different growth stages. The light transmission within the canopy increased exponentially with plant height and the canopy extension coefficient is found to be 0.8.


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