不同缓释肥用量对莴笋品质的效应

通过盆栽试验研究了不同缓释肥（SR）用量对莴笋产量和品质的效应。结果表明：不同施肥处理间莴笋产量有极显著差异。不同缓释肥用量处理提高莴笋产量32．3％～59．9％，以SR（M）〉SR（L）〉SR（H），莴笋产量与缓释肥用量间存在二次回归关系（Y＝-10．7　x^2＋60．62x＋11．2R^2—0．9872），缓释肥的增产效率以SR（L）〉SR（M）〉SR（H）．不同缓释肥用量处理提高莴笋叶绿素a、叶绿素a＋b含量和叶绿素a／b达38．9％～88．9％和20．5％～58．9％和6．3％～40．7％，增加莴笋叶绿素b含量28．7％～33．3％（SR（M）处理除外）。除SR（L）处理使莴笋可溶性糖含量降低32．7％外，不同缓释肥用量处理提高莴笋硝酸盐、Vc、可溶性糖和氨基酸含量达10．3％～27．0％，40．9％～151．7％，11．5％～19．2％和0．4％～61．1％。结合产量和品质来看，缓释肥用量处理中SR（M）是莴笋获得高产优质的最佳处理。

Effect of Slow Released Fertilizer Rates on Quality of Lettuce

In a pot experiment, the effect of slow release fertilizer (SR) rates on quality and yield of lettuce was studied. The results indicated that there was remarkably difference between the yield of lettuce. SR obviously increased lettuce yield by 32.3% to 59.9%, and the yield was in the order of SR(M)>SR(L)>SR(H). A significant quadratic regression existed between slow release fertilizer rates and yield of lettuce (Y=-10.7x2+60.62x+11.2, R2=0.987 2). The yield increase efficiency of three slow release fertilizer treatments appeared in the order of SR(L)>SR(M)>SR(H). The content of chlorophyll a, chlorophyll a+b and chlorophyll a/b in lettuce were enhanced by 38.9%~88.9%, 20.5%~58.9% and 6.3%~40.7%, respectively. The content of chlorophyll b was increased by 28.7%~33.3% in SR(L) and SR(H) treatment. The nitrate, Vc, solubility sugar and amino acid content of lettuce were increased by 10.3%~27.0%, 40.9%~151.7%, 11.5%~19.2% and 0.4%~61.1%, respectively, with the exception of SR(L) treatment, which decreased soluble sugar content of lettuce by 32.7%. Taking yield and quality into consideration, the optimum treatment was the SR(M) for higher yield and better quality of lettuce.