PP333、GA3土灌、涂芽及叶喷对百合株高的效应研究

用不同浓度的PP333、GA3溶液分别对百合进行营养生长前期土壤浇灌、顶芽涂抹处理及叶面喷施处理,并于处理后第75 d观测其对百合株高的效应。结果表明,3种处理方式对株高的效应依次表现为:叶面喷施>土壤浇灌>顶芽涂抹;而同种处理方式中GA3的促进效果总体上要好于PP333;在各处理中,以GA3200 mg/kg叶喷的促进效应最强,而以PP3331000 mg/kg土壤浇灌的抑制效应最强。

荧光假单孢杆菌防治小麦全蚀病的初步研究

应用从小麦根部分离到的荧光假单孢杆菌株hw-5,以不同的浓度采用种子包衣、菌悬液浸种和土壤浇灌3种方法处理种子,研究该菌株对小麦全蚀病的防治效果。结果表明:这3种方法处理过的小麦种子,在苗期均对小麦全蚀病表现出一定的抗性。

小麦内生细菌对全蚀病发生的影响

采用土壤浇灌法检测了37株小麦内生细菌对盆栽小麦全蚀病发生情况及小麦幼苗生长的影响,结果表明,内生细菌GL4、GS1和GR13对小麦根系及茎基部发生全蚀病的防治效果达50%以上,其中GL4和GR13对小麦幼苗的生长有促进作用。说明利用小麦内生细菌防治全蚀病发生将可能是一种有效的方法,但内生细菌GL4和GR13对小麦全蚀病的实际防治效果有待进一步的试验观察。

重金属不同污染途径对烤烟生长发育的影响

以烤烟K326为材料,设叶面喷施和土壤浇灌2种方式分别对烤烟施加重金属Pb(20 mg/kg)、Hg(0.5 mg/kg)、Cd(25 mg/kg)、As(20 mg/kg)。采用盆栽试验在大田环境下进行,研究了重金属Pb、Hg、Cd、As在不同污染方式下对烤烟叶长、叶宽、茎围、株高、有效叶片数以及根体积生长发育的影响。结果显示,在Pb、Hg、Cd、As 4种重金属中,Pb和Hg的区别较大,土壤浇灌方式对烤烟生长发育的抑制作用比叶面喷施强;其次是As;Cd通过叶面喷施与土壤浇灌对烤烟生长影响不存在显著性差异。叶面喷施Pb对烟株有效叶片数和株高起着一定的促进作用,对根体积的影响最小。

Construction of Micropiles Using Pressure Techniques

This paper discusses the technique of casting concrete ofmicropiles with pressures and the consequence of comparisons with normal way of casting concrete （casting with gravity）. Preliminary geotechnical studies have been made in specific area in Sudan to predict the soil parameters and then an experimental work has been done for an estimated number ofmicropiles with different diameters and different techniques of placing concrete with various amount of pressure. This study was carried out to learn the usefulness of this technique in the field of structural foundations in Sudan. Capacities of micropiles were compared in cases of non-pressure casting （normal way of casting concrete） and pressure casting. Through the results, it was found that the entry of pressure factor in the operation of casting concrete increases the capacities of micropiles. The increased value of ultimate load depends on the amount of pressure applied.