保水剂对番茄生长及水分利用效率的影响

在砂与木屑复合基质中加入不同用量的保水剂,测定基质物理性状,并进行不同水分处理条件下番茄盆栽试验,以研究保水剂对番茄生长及水分利用效率的影响。结果表明:在每1 L基质分别加入1、2、4、8 g保水剂时,与对照(未加保水剂)相比,基质持水量分别增加16.35%、34.00%、61.29%和135.16%,容重分别降低3.61%、5.37%、9.42%和14.64%;在水分耗竭试验中,番茄萎蔫天数分别延长13.92%、22.79%、31.65%和45.5%,干物质量分别增加7.90%、21.60%、57.08%、179.50%,株高、叶片数、茎粗、鲜质量也都随保水剂用量的增加而明显增加;在基质相对水分质量分数分别为55%、70%、85%及100%4种处理下的番茄水分胁迫试验中,每1 L基质施用2 g保水剂时,与对照(未加保水剂)相比,水分利用效率分别提高29.93%、28.06%、14.36%、7.42%,株高、生物量也随水分胁迫程度加重而明显提高。

Effects of water retaining agent on tomato growth and water use efficiency

Using tomato as test crop grown in the substrates made from sand and wood scraps,with different rates of water retaining agent(WRA),pot experiments were conducted with different water treatments to study the effects of WRA on the growth and water use efficiency(WUE).The physical characteristics of substrate before tomato plantation were also measured.The results showed that the water holding capacity of the substrate was significantly increased along with the increase of WRA rates of application.As com-pared with control treatment(no addition of WRA),at the rates of 1,2,4 and 8 g WRA per liter of substrate,water holding capacity was increased by 16.35%,34.00%,61.29% and 135.16%,respectively.And the bulk density was decreased by 3.61%,5.37%,9.42% and 14.64%,respectively.In the experiment under water exhausted condition,as compared with control,the wilting time of plant was postponed by 13.92%,22.79%,31.65% and 45.5%,while the dry mass was increased by 7.90%,21.60%,57.08% and 179.50%,re-spectively.The plant height,leaf number,stem diameter and fresh weight were increased markedly with WRA rates of application.When relative moisture content in the substrate was 55%,70%,85% and 100% and the dosage of WRA was 2 g.L-1,water use effi-ciency was increased by 29.93%,28.06%,14.36% and 7.42% over control,respectively.Plant height and biomass weight was also increased as water stress became serious.