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Leiv M. Mortensen 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(4):235-239
Abstract Seven species of grass and one of red clover were grown at different ozone (O3) concentrations for about five weeks in growth chambers located in a greenhouse. At an O3 concentration of 55 compared with 10 nmol mol?1 during 7 h day?1 the shoot dry weight decreased by 45% in Phleum pratense, 28% in Dactylis glomerata and Poa pratensis, 23% in Festuca rubra and 16% in Festuca pratensis, while the effects on Agrostis tenuis were not significant. No effect was found at 25 compared with 10 nmol mol?1O3. Visible O3 injury was observed in all six species at 55 nmol mol?1 and this effect was generally well correlated with the effect on the dry weights. In another experiment no effect was found with O3 concentrations of up to 62 nmol mol?1 on Lolium perénne, while the dry weight in Trifolium pratense decreased by 30% at 59 compared with that at 6 nmol mol?1. 相似文献
93.
杨梅澄清汁及浓缩汁中花色苷热降解动力学的研究 总被引:3,自引:1,他引:3
杨梅花色苷易受温度、pH值等因素的影响而发生降解,是导致产品外观品质变劣的主要原因。本文研究了杨梅澄清汁及浓缩汁内花色苷在不同pH值和不同加热温度下的热稳定性。花色苷降解动力学数据的分析结果表明:杨梅花色苷热降解属动力学一级反应,随着pH值和温度的升高,杨梅花色苷降解的半衰期(t1/2)和热降解活化能(Ea)显著下降,即花色苷的降解速度增大;同一处理条件下,浓缩果汁的t1/2明显低于澄清汁。而反应速率常数k和Ea值大于澄清果汁,说明澄清汁花色苷的热稳定性优于浓缩汁。 相似文献
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Meng Cifu Cao Zhihong Jiang Peikuen Zhou Guomo Lin XianGui Xu Qiufang 《Journal of plant nutrition》2013,36(7):1047-1058
ABSTRACT Three field experiments at three sites in east Zhejiang Province were conducted to determine the influence of applications of boron (B) on growth, yield, and quality of the red bayberry trees (Myrica rubra Sieb. et Zuca) with a manure species of “Buqizhong” in Linhai city. Ground B application or foliar B spraying significantly improved length and incidence rates of spring and summer shoots and increased fruit set rates, which resulted in the increases in fruit yield (13.7–17.5% for ground B application or 13.2–27.3% for foliar B spraying) and in improvement of fruit quality. The optimum yields were recorded with the treatments of ground B application of 40 g tree?1 of borax or foliar B spraying of 2.0 g L?1 of borax. Spring shoot incidents for the treatment of ground application of 50 g borax tree?1 every year during the experiment (4B50) were significantly higher than that for the treatment of ground application of 50 g borax tree?1 only in the first year of the experiment (B50), but the yield difference between them was not significant at P = 0.05. The increased yield effect of ground B application could last for 3 years. Boron application of red bayberry trees can be carried out by foliar-spraying 2.0 g borax L?1 every year or ground application of 50 g borax tree?1 every 3 years. The results of this study showed that application B could significantly improve the growth and increased fruit yield and quality of the red bayberry trees not exhibiting any vegetative symptoms of B deficiency. 相似文献
96.
湘西南地区紫羊茅草坪春季杂草调查结果表明,湘西南地区紫羊茅草坪中的春季杂草主要有12个科16种,禾本科杂草为白茅、白顶早熟禾;阔叶杂草为空心莲子菜、小飞蓬、一年蓬、半边莲、野艾蒿、直立婆婆纳等。其中一年蓬、小飞蓬、白茅、白顶早熟禾、半边莲、婆婆纳、野艾蒿、车前草、空心莲子菜、香附子、剪刀草等为主要杂草,为重要的防除对象;酢浆草、佛甲草、窃衣、天胡荽、卷耳等为次要杂草。防除效果研究表明,0.5%二甲四氯钠20mL/m2+0.15%高效盖草能20mL/m2比0.5%二甲四氯钠20mL/m2单独使用对阔叶杂草有效;2%猪殃净40mL/m2对紫羊茅草坪中的阔叶杂草有很好的防治效果,可以选择;0.1%高效盖草特30mL/m2+0.15%高效盖草能45mL/m2+2%猪殃净50mL/m2+0.5%二甲四氯钠30mL/m2的杂草防除效果最为理想,但不宜在紫羊茅草坪中使用。试验药剂单用或者混用都不能防除窃衣、卷耳。 相似文献
97.
Rodrigues AM Amusant N Beauchêne J Eparvier V Leménager N Baudassé C Espindola LS Stien D 《Pest management science》2011,67(11):1420-1423
BACKGROUND: Termites are degradation agents that inflict severe damage on wood. Some long‐lasting Amazonian trees can resist these insects by producing toxic secondary metabolites. These metabolites could potentially replace synthetic termiticidal products which are becoming more restricted to use. RESULTS: Sextonia rubra is resistant to termite‐induced degradation. It has been demonstrated that this species naturally produces an ethyl‐acetate‐soluble termiticidal metabolite, rubrynolide, to protect its wood. Assays in the presence of tropical and invasive termites established that both rubrynolide and crude ethyl acetate extract from S. rubra wood can be used as a treatment for the protection of sensitive woods against termites. CONCLUSION: Rubrynolide and S. rubra extract are promising candidates for the replacement of synthetic termiticides. Copyright © 2011 Society of Chemical Industry 相似文献
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