排序方式: 共有3条查询结果,搜索用时 203 毫秒
1
1.
The uptake of potassium, calcium, and magnesium ions by maizeand the interrelationships among the cations have been investigatedat 48 K: Ca: Mg ratios in culture solutions. Calcium was foundto stimulate K+ and Mg++ uptake at certain cation ratios butinhibit it at others. Potassium did the same for Ca++ uptake,and Mg++ for Ca++ and K+. The uptake of Mg++ was generally enhancedby K+. The sum of the cations in the plants expressed in meqwas fairly constant for treatments of the same K+ concentrationat the low to moderate levels of K+, but at considerably higher(> 24 meq l1) K+ levels the constancy was not dependenton K+ concentration. Potassium depressed, but Mg++ stimulatedphosphorus accumulation. Calcium stimulated phosphate absorptionat certain cation ratios but had no effect at others. The plantyield increased with increasing K+ up to 24 meq l1 ofK+ after which the yield tended to fall with further increasein K+. The yield was also increased by Ca++. Magnesium increasedthe yield at certain cation ratios and either depressed it orwas without effect at others. 相似文献
2.
The effect of bicarbonate on the absorption and translocationof P32 by tomato and runner bean has been investigated. Whilebicarbonate stimulated phosphorus uptake from potassium phosphatesolutions it inhibited it from Hoagland solution. Translocationof absorbed phosphorus was inhibited in the single salt solutionbut stimulated in Hoagland solution. Bicarbonate caused morephosphorus to be concentrated in the stems and less in the leavesin Hoagland solution and the reverse was true in the single-saltsolution. It is concluded that the effect of bicarbonate onphosphorus in causing iron chlorosis in some plants is indirect. 相似文献
3.
Iron absorption by barley, pea, and runner bean is stimulatedby bicarbonate but inhibited by increasing pH. Bicarbonate stimulatestranslocation of Fe in barley but inhibits it in pea and bean.Increasing pH stimulates translocation in barley and pea withno effect in bean. The presence of other ions in the externalsolution appears to inhibit absorption but enhances translocationof Fe in bean and pea. It is concluded that whether or not bicarbonatewill induce chlorosis in a plant depends on species and variety. 相似文献
1