万寿菊秸秆的杀线作用及其对黄瓜植株生长的影响

利用万寿菊(Tagetes erecta)秸秆水提取物研究了其对南方根结线虫(Meloidogyne incognita)的抑杀作用,并通过盆栽试验研究了万寿菊秸秆对接种南方根结线虫后黄瓜(Cucumis sativus)植株生长的影响.结果表明:在水提取物试验中,线虫死亡率随万寿菊水提物浓度的升高和处理时间的延长逐渐升高,水提物处理12h后,质量分数分别为1.5%、1.0%和0.5%的3个处理与对照的线虫死亡率分别为89.4%、69.5%、44.2%;0、24h后3个处理的死亡率均为100%,对照仍为0.盆栽接种试验中,万寿菊秸秆在黄瓜播种前10d混入热处理过的土壤中,黄瓜植株收获时,0.5%、1.0%和2.0%的万寿菊秸秆添加率都不同程度地降低了黄瓜植株根结数,其中秸杆0.5%和2.0%的添加率对根结数的降低程度显著(P0.05),0.5%和1.0%的添加率对黄瓜植株株高、茎粗、地上部鲜质量、总鲜质量和总干质量均未产生负面影响,对根系生长还起到了一定促进作用,使得地下部鲜质量和根冠比增加,但2.0%添加率对黄瓜植株的生长产生了严重的负面影响,使得植株株高、茎粗、地上部和地下部分鲜质量、总鲜质量和总干质量均显著降低(P0.05);0.5%、1.0%和2.0%的万寿菊秸杆添加率均降低了黄瓜植株叶片叶绿素质量分数和净光合速率.以上结果说明,在控制好万寿菊秸秆添加率的基础上利用万寿菊秸秆防治黄瓜南方根结线虫具有一定的可行性,但应注意万寿菊秸秆对黄瓜植株光合色素和净光合速率的影响.

NEMATICIDAL EFFECT OF TAGETES ERECTA STEM AND ITS EFFECT ON GROWTH OF CUCUMIS SATIVUS PLANT

Aqueous extract of Tagetes erecta was used to test its potential to suppress root-knot nematode Meloidogyne incognita,T.erecta stem was evaluated for its effect on the growth of cucumber(Cucumis sativus) inoculated with M.incognita.Longer incubation time as well as higher concentration of T.erecta aqueous extract resulted in higher M.incognita mortality.Twelve hours after incubation,M.incognita mortality rates were 89.4%,69.5% and 44.2%,for extract concentrations of 1.5%,1.0% and 0.5% respectively,and mortality rate was 0 in control.Mortality rates were 100% under all concentrations 24 hours after incubation,mortality rate remained at 0 in control.T.erecta stem at addition rate of 0.5%,1.0%,2.0% were mixed with thermally treated soil 10 days before cucumber sowing.Cucumbers showed varied degrees of reduction in root knot number under different stem addition rates.Significant reduction in root knot numbers was observed at addition rate of 0.5% and 2.0%;whereas both root growth and root-shoot ratio increased at 0.5% and 1.0% addition rates,but no negative changes in plant height,shoot diameter,shoot fresh weight,total fresh or dry weight were found.At addition rate of 2.0%,growth of cucumber plant was suppressed,resulting in marked decreases in plant height,shoot diameter,shoot fresh weight,total fresh and dry weight.Both chlorophyll content and net photosynthesis rate in cucumber leaves decreased at 0.5%,1.0% and 2.0% addition rates.These data indicated that T.erecta stem could be used to control M.incognita growth on cucumber plant at suitable addition rates,but negative effect of T.erecta stem on photosynthetic pigments and net photosynthesis rate of cucumber plant should be taken into consideration.