嫁接冬瓜干物质以及氮、磷、钾养分累积与分配特性研究

嫁接冬瓜和自根苗冬瓜需肥规律存在一定差异,明确嫁接苗养分吸收利用规律可以提高嫁接苗冬瓜的产量。采用大田栽培试验,研究嫁接冬瓜干物质和N、P、K养分吸收利用动态变化。结果表明：（1）嫁接苗和自根苗冬瓜干物质、氮、磷、钾养分吸收积累特征基本一致,各生育期干物质、氮、磷、钾养分净吸收积累和累积速率随着生育期推进不断递增,但嫁接苗干物质、氮、磷、钾养分累积量和累积速率总体上高于自根苗。（2）冬瓜干物质在果实发育期前累积速率慢,在果实发育期累积速率快;嫁接苗在果实发育期前冬瓜干物质累积量仅占整个生育期总累积量的23.5%,其中59.65%~67.74%干物质量分配在叶片上;果实发育期干物质净累积量占全生育期的76.5%,其中52.85%~ 72.57%干物质分配在果实上。（3）纵观整个生育期,嫁接苗冬瓜N、P、K吸收利用比例为1.0∶0.20∶1.31,但各个生育期的养分吸收利用比例差异很大,各生育期N、K的吸收比例依次为1.0∶0.1∶0.16,1.0∶0.1∶0.37,1.0∶0.13∶1.01,1.0∶0.22∶1.39以及1.0∶0.24∶1.65。（4）嫁接苗平均每生产1 t冬瓜果实所需要的N为1.70 kg,P为0.34 kg,K为2.24 kg,其中N需求量显著少于自根苗,P需求量显著高于自根苗。

Dry Matter and Nutrient Accumulation and Distribution Characteristics of N,P and K in Grafted Wax Gourd

There are a certain difference in fertilizer requirement rule,nutrient uptake and utilization patterns between grafted wax gourd and self-rooted wax gourd.A field experiment was conducted to understand the accumulation and distribution characteristics of the dry matter and nutrient in grafted wax gourd and self-rooted wax gourd.The characteristics of the dry matter accumulation and nutrient uptake for both wax gourd were similar.The net accumulation amount and accumulation rate of dry matter,N,P and K increased with the growth period,with the grafted wax gourd higher than with the self-rooted seedlings.23.5% of the total dry matter was accumulated before fruit development stage,of which 52.85%~72.57% was allocated in the leaves.76.5% of the total dry matte was accumulated in fruits from fruit development stage to the end,of which 59.65%~67.74% was allocated in fruits.The NPK absorbing ratio of grafted wax gourd was 1.0;0.20:1.31 throughout growth season,while with a greatly different nutrient accumulation characteristic between different growth stages.The NPK absorbing ratio of the five different development stage for seedling stage,stretch tendril stage,florescence stage,previous fruit development stage and middle and late fruit development stage in turn was 1.0∶0.1∶0.16,1.0∶0.1∶0.37,1.0∶0.13∶1.01,1.0∶0.22∶1.39 and 1.0∶0.24∶1.65.To obtain a ton of fruit,the N,P,K requirement for grafted wax gourd was 1.70 kg,0.34 kg and 2.24 kg respectively,with significantly less N and more P than that for self-rooted wax gourd.