不同施药量对氮高效利用水稻品种桂育11号病虫防治效果和产量的影响

Effect of Pesticide Dosage on Control Effect of Pests and Diseases and Yield of High-efficiency Nitrogen Utilization Rice Cultivar Guiyu No.11

【目的】分析不同施药量对不同施氮量条件下氮高效利用水稻品种桂育11号病虫防治效果及产量的影响,为推广优质高产氮高效利用水稻品种及实现农药化肥减施增效提供科学依据。【方法】以氮高效利用水稻品种桂育11号为研究对象,在施用高、中和低氮(分别为施纯氮225、150和75 kg/hm2)水稻的分蘖期和孕穗期喷施农药常量(每公顷喷施20%氯虫苯甲酰胺SC 150m L+50%吡蚜酮WP 300 g+30%爱苗SC 300 m L+75%三环唑WP 450 g)+30%(B1处理)、常量(B2处理)和常量-30%(B3处理),以不喷施农药为对照(CK);采用平行跳跃取样法调查施药前后不同施氮量桂育11号的病虫发生情况,计算防治效果。【结果】在不同施氮量条件下各施药量处理对桂育11号稻飞虱的防治效果均在92.00%以上,其中,在中、低氮条件下,B3处理第2次施药后10 d的稻飞虱防治效果均在97.00%以上。在各施氮量条件下,第1次施药后10 d B1、B2和B3处理的稻纵卷叶螟防治效果均低于63.43%,第2次施药后10 d B1、B2和B3处理的稻纵卷叶螟防治效果均高于91.00%,其中,在低氮条件下B2处理的稻纵卷叶螟防治效果与B1处理差异不显著(P> 0.05,下同),在中氮条件下B2处理的稻纵卷叶螟防治效果显著低于B3处理(P <0.05,下同);在高氮条件下,第1次施药后10 d各施药量处理的稻纵卷叶螟防治效果间差异均不显著,第2次施药后10 d的稻纵卷叶螟防治效果随着施药量的减少显著增加。在各施氮量条件下,B1、B2和B3处理的水稻纹枯病病株防效及病指防效均无显著差异;B1、B2和B3处理的水稻产量均显著高于对照,其中在中、低氮条件下均以B1处理处理最高;在同一施药量条件下,以中施氮量水平的水稻产量最高,为8252.85~8847.75 kg/hm2。方差分析结果表明,施药量和施氮量单独作用及二者间的交互作用对稻飞虱和稻纵卷叶螟发生及桂育11号产量具有显著或极显著(P <0.01)影响,仅施药量单独作用显著影响水稻纹枯病的发生。【结论】种植桂育11号需同时考虑施氮量和施药量对其产量的影响;在中氮条件下桂育11号的产量高于低氮和高氮条件,且减量30%施药的产量在各施氮量条件下均与常量施药和加量30%施药的产量差异不显著。因此,以减氮20%+减药30%+施药2次的方式进行氮高效利用水稻品种的田间管理,可达到农药化肥减施增效目的。

【Objective】The effect of different pesticide dosages on control effect of diseases and pests and yield of high-efficiency nitrogen utilization rice variety Guiyu No.11 in differ-ent nitrogen application conditions was studied in order to pro-vide scientific basis of achieving reduction and efficiency of pes-ticides and fertilizers at promoting high-quality,high-yield and high-efficiency nitrogen utilization rice varieties.【Method】High-efficiency nitrogen utilization rice variety Guiyu No.11 was used as tested material,spraying with 20%chlorantranilip-role SC 150 mL+50%pymetrozine WP 300 g+30%armure compound pesticide(compound by difenoconazole and propiconazole)SC 300 mL+75%tricyclazole WP 450 g at three dosage,increasing conventional dosage by 30%(B1),conventional dosage(B2,current pesticide dosage used in farmers’fields)and reducing conventional dosage by 30%(B3)at rice tillering stage and booting stage in high,medium and low nitrogen levels(pure nitrogen 225,150 and 75 kg/hm2 respectively),and control with non-pesticide application.Parallel jumping sampling method was used to investigate incidence of rice diseases and pests on Guiyu No.11,and then calculated control effect.【Result】The results showed that the control effect of all pesticide application treatments to rice planthoppers on Guiyu No.11 in all nitrogen applica-tion conditions was over 92%,and the rice planthoppers control effect in B3 was over 97.00%at medium and low nitrogen conditions.The control effect of rice leaf roller in B1,B2 and B3 after the first application was lower than 63.43%,but more than 91.00%after the second application,and the control effect in B2 was not significantly difference than that of in B1 at low nitrogen condition(P>0.05,the same be-low),but significantly higher than B3 at medium nitrogen condition(P<0.05,the same as below).The control effect of rice leaf roller in all pesticide dosages was no significantly difference after 10 days of the first application,and increased significantly with the increase of dosage after 10 days of the second application.The control effect of disease plant and disease index of rice sheath blight in all pesticide dosage treat-ments at high,medium and low nitrogen application conditions was not significantly different.The yield of Guiyu No.11 in B1,B2 and B3 treatments at high,medium and low nitrogen application conditions was significantly higher than CK,but it was the highest in B1 under me-dium and low nitrogen application conditions.Under the same pesticide dosage treatment,the highest yield showed at medium nitrogen appli-cation condition which was 8252-8847 kg/hm2.The variance analysis results indicated that the pesticide and nitrogen application amount single action and their interactions had significant or extremely significant effects(P<0.01)on rice planthopper,leaf roller and yield of Guiyu No.11,while the spread of rice sheath blight affected only by pesticide dosage alone.【Conclusion】When planting Guiyu No.11,the effect of nitrogen and pesticides application amount on the yield should be considered simultaneously.Under medium nitrogen condition,the yield of Guiyu No.11 is higher than high and low nitrogen conditions.The yield under reducing nitrogen and pesticides application amount by 30%in all nitrogen conditions has no significantly difference with that under increasing nitrogen and pesticides application amount by 30%.Therefore,field management of rice varieties with high nitrogen utilization by reducing nitrogen 20%+reducing pesticide 20%+two applications could achieve the purpose of reducing nitrogen and pesticide and increasing yield in field.