为筛选出防治旱砂西瓜连作障碍的适宜药剂，有效解决旱砂西瓜连作障碍问题。以靖远县主栽西瓜品种林丰金牌10号为指示品种，选用5种不同药剂在多年连茬旱砂西瓜田西瓜苗期进行灌根处理，分析比较了不同药剂处理对旱砂西瓜产量和品质的影响。结果表明，96%硫酸铜颗粒剂500倍液、2%中生·四霉素水剂1 000倍液、根腾菌剂600倍液灌根处理的旱砂西瓜植株存活率最高，均为99%，较对照喷清水高1个百分点。1.8%辛菌胺醋酸盐水剂800倍液灌根处理旱砂西瓜叶片的叶绿素含量最高，为54.9 g/mg，较对照喷清水增加2.7 g/mg；根腾菌剂600倍液灌根处理旱砂西瓜叶片的氮素含量最高，为4.5 g/kg，与对照喷清水持平。1.8%辛菌胺醋酸盐水剂800倍液灌根处理防病效果最佳，对枯萎病的防效达到62.99%，对蔓枯病的防效达到68.32%。根腾菌剂600倍液灌根处理的旱砂西瓜折合产量最高，为62 244.00 kg/hm2，较对照喷清水增产28.7%；1.8%辛菌胺醋酸盐水剂800倍液灌根、2%中生·四霉素水剂1 000倍液次之，均为58 187.25 kg/hm2，均较对照喷清水增产20.3%。96%硫酸铜颗粒剂500倍液灌根处理的旱砂西瓜果实中心糖、阳面边糖、阴面边糖含量均最高，分别为13.5%、11.0%、9.2%。综合比较，利用96%硫酸铜颗粒剂500倍液、根腾菌剂600倍液在旱砂西瓜苗期进行灌根处理，既能够显著防治砂田西瓜病害，又能够提高旱砂西瓜产量和品质，并且防治成本较低，效果较好，建议推广应用。

In order to select suitable medicaments for the obstacle of watermelon continuous cropping, by using the dominant watermelon variety Linfengjinpai 10 as the indicator variety, 5 different medicaments were selected for root drenching treatment at seedling stage to analyze the effects of different medicaments on the yield and quality of watermelon in gravel- mulched fields in Jingyuan County. Survival rates of gravel- mulched watermelon peaked in root drenching treatments using 96% copper sulfate granules 500 times diluted liquid, 2% tetramycin water agent 1 000 times diluted liquid, and root bacteria agent 600 times diluted liquid, respectively, which all reached 99% and were all 1 percent higher that that of the control (water spray), respectively.Chlorophyll content in leaves peaked in root drenching treatments using 1.8% cinnamamide acetate aqueous solution 800 times diluted liquid which was 54.9 g/mg and was 2.7 g/mg higher than that of the control. Nitrogen content in leaves peaked in root drenching treatments using root bacteria agent 600 times diluted liquid which was 4.5 g/kg and was the same level as the number in the control. root drenching treatments using 1.8% cinnamamide acetate aqueous solution 800 times diluted liquid showed the best control effect agintst watermelon soil-borne diseases, with the control effect of 62.99% on fusarium wilt and 68.32% on gummy stem blight of watermelon. Average yield of watermelon peaked in root drenching treatments using root bacteria agent 600 times diluted liquid, which was 62 244.00 kg/ha and was 28.7% higher than that of the control, followed by treatment using 1.8% cinnamamide acetate aqueous solution 800 times diluted liquid and treatment using 2% tetramycin water agent 1 000 times diluted liquid, respectively, which were all 58 187.25 kg/ha and were 20.3% higher than that of the control. Fruit sugar contents in the center, sunny side and shady side were all the highest in the treatment using 96% copper sulfate granules 500 times diluted liquid, which were 13.5%, 11.0% and 9.2%, respectively. Comparision showed that seedling drenching treatments using 96% copper sulfate granules 500 times diluted liquid or root bacteria agent 600 times diluted liquid could significantly prevent and control watermelon diseases in gravel-mulched fields, as well as improve the yield and quality of gravel-mulched watermelon. The cost of prevention and control is relatively low, and the effect is ideal for further promotion.

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