scholarly journals Rice–weed competition in response to nitrogen form under high and low transpirational demand

2021 ◽  
Author(s):  
Duy Hoang Vu ◽  
Sabine Stuerz ◽  
Folkard Asch
Keyword(s):  
Weed Competition ◽  
Nitrogen Form

Crop-weed competition between maize (Zea maysL.) andConvolvulus arvensisL. in substitutive experiments

2006 ◽  
Vol 34 (1) ◽  
pp. 541-544
Author(s):  
G. Kazinczi ◽  
J. Horváth ◽  
A. Takács ◽  
M. Nádasy
Keyword(s):  
Weed Competition ◽  
Crop Weed Competition

Physiological and molecular features of allelopathic and non-allelopathic rice in response to weed competition

2019 ◽  
Vol 47 (2) ◽  
pp. 167-180
Author(s):  
H B. Wang ◽  
Q. Zhang ◽  
Z H. Lin ◽  
J. Y. Li ◽  
S X. Lin ◽  
...  
Keyword(s):  
Weed Competition ◽  
Molecular Features

scholarly journals Fitness of F1 hybrids between 10 maternal wild soybean populations and transgenic soybean

2021 ◽  
Author(s):  
Jin Yue Liu ◽  
Ze Wen Sheng ◽  
Yu Qi Hu ◽  
Qi Liu ◽  
Sheng Qiang ◽  
...  
Keyword(s):  
Seed Weight ◽  
Wild Soybean ◽  
F1 Hybrids ◽  
Weed Competition ◽  
Transgenic Soybean ◽  
Wild Progenitor ◽  
F1 Hybrid ◽  
Dry Biomass ◽  
100 Seed Weight ◽  
Pod Number

AbstractThe releasing of transgenic soybeans (Glycine max (L.) Merr.) into farming systems raises concerns that transgenes might escape from the soybeans via pollen into their endemic wild relatives, the wild soybean (Glycine soja Sieb. et Zucc.). The fitness of F1 hybrids obtained from 10 wild soybean populations collected from China and transgenic glyphosate-resistant soybean was measured without weed competition, as well as one JLBC-1 F1 hybrid under weed competition. All crossed seeds emerged at a lower rate from 13.33–63.33%. Compared with those of their wild progenitors, most F1 hybrids were shorter, smaller, and with decreased aboveground dry biomass, pod number, and 100-seed weight. All F1 hybrids had lower pollen viability and filled seeds per plant. Finally, the composite fitness of nine F1 hybrids was significantly lower. One exceptional F1 hybrid was IMBT F1, in which the composite fitness was 1.28, which was similar to that of its wild progenitor due to the similarities in pod number, increased aboveground dry biomass, and 100-seed weight. Under weed competition, plant height, aboveground dry biomass, pod number per plant, filled seed number per plant, and 100-seed weight of JLBC-1 F1 were lower than those of the wild progenitor JLBC-1. JLBC-1 F1 hybrids produced 60 filled seeds per plant. Therefore, F1 hybrids could emerge and produce offspring. Thus, effective measures should be taken to prevent gene flow from transgenic soybean to wild soybean to avoid the production F1 hybrids when releasing transgenic soybean in fields in the future.

scholarly journals The Effect of Weed Competition on Apple Fruit Quality

2017 ◽  
Vol 45 (1) ◽  
pp. 120-125 ◽  
Author(s):  
Ersin ATAY ◽  
Seckin GARGIN ◽  
Ahmet ESITKEN ◽  
N. Pinar GUZEL ◽  
A. Nilgun ATAY ◽  
...  
Keyword(s):  
Fruit Quality ◽  
Fruit Weight ◽  
Apple Orchard ◽  
High Density ◽  
Soluble Solids ◽  
Limiting Factor ◽  
Weed Competition ◽  
Soluble Solids Content ◽  
Solids Content ◽  
Potassium Magnesium

Orchard performance is influenced by weed competition. In this study, the effects of weed competition on nutrient contents, chemical and physical fruit quality properties were sought. The study was carried out in a high-density apple orchard (‘Golden Delicious’/M.9) over two consecutive growing seasons. The effect of weed competition was studied at three different levels: weak, moderate and strong. Fruit firmness, soluble solids content, macronutrients (such as nitrogen, potassium and calcium) and potassium+magnesium/calcium ratio in fruit were significantly affected by weed competition. Strong weed competition negatively affected soluble solids content and potassium+magnesium/calcium ratio. In both trial years, soluble solids content was significantly higher in weak weed competition. In the first year of the study, soluble solids content ranged between 13.77±0.06% (strong weed competition) and 15.20±0.10% (weak weed competition). In the following year, soluble solids content values were determined as 13.13±0.23% in strong weed competition and 13.83±0.21% in weak weed competition. Weak weed competition showed superiority for fruit weight and potassium+magnesium/calcium ratio. As a whole, this study indicates that insufficient weed control in tree rows might be a limiting factor for fruit quality in high-density apple orchards.

Modelling the influence of weed competition on the growth of young Pinus radiata at a dryland site

2003 ◽  
Vol 178 (3) ◽  
pp. 271-286 ◽  
Author(s):  
Michael S. Watt ◽  
David Whitehead ◽  
Brian Richardson ◽  
Euan G. Mason ◽  
Alan C. Leckie
Keyword(s):  
Pinus Radiata ◽  
Weed Competition

Nitrogen form, time and rate of application, and nitrification inhibitor effects on crop production

2014 ◽  
Vol 94 (2) ◽  
pp. 425-432 ◽  
Author(s):  
R. E. Karamanos ◽  
K. Hanson ◽  
F. C. Stevenson
Keyword(s):  
Crop Production ◽  
Protein Concentration ◽  
Wheat Yield ◽  
Nitrification Inhibitor ◽  
N Fertilizer ◽  
Nitrogen Form ◽  
Anhydrous Ammonia ◽  
N Concentration ◽  
Fertilizer Rates ◽  
Better Than

Karamanos, R., Hanson, K. and Stevenson, F. C. 2014. Nitrogen form, time and rate of application, and nitrification inhibitor effects on crop production. Can. J. Plant Sci. 94: 425–432. Nitrogen management options for anhydrous ammonia (NH3) and urea were compared in a barley–wheat–canola–wheat cropping sequence (2007–2010) at Watrous and Lake Lenore, SK. The treatment design included a factorial arrangement of N fertilizer form (NH3versus urea), nitrification inhibitor application, time of N application (mid-September, mid- to late October, and spring) and four N fertilizer rates (0, 40, 80 and 120 kg ha−1). Anhydrous ammonia applications at 40 kg N ha−1in 2008 (fall) and in 2010 (all times of application) resulted in wheat yield reductions relative to the same applications for urea. For wheat years, yield was reduced for both fall versus spring N fertilizer applications, when no nitrification inhibitor was applied and the inclusion of nitrification inhibitor maintained wheat yield at similar levels across all times of N fertilizer applications, regardless of form. Protein concentration was approximately 2 g kg−1greater with urea compared with NH3at both sites in 2008 and only at Watrous in 2010. Also, early versus late fall N fertilizer applications consistently increased N concentration of grain only for the 40 and/or 80 kg N ha−1rates. Effects of nitrification inhibitor on N concentration were not frequent and appeared to be minimal. Urea had greater agronomic efficiency (AE) than NH3at the lower N fertilizer rates. The nitrification inhibitor had a positive effect on wheat AE only for early fall N fertilizer applications. It can be concluded that for maximum yields NH3or urea will be suitable if applied at rates of 80 kg N ha−1and greater. If N fertilizer is applied at 40 kg N ha−1, especially in fall without inhibitor, urea is better. In terms of protein concentration for wheat, urea seemed to better than NH3and fall was better than spring application.

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