崇左蔗区螟虫为害造成产量和糖分损失及生防效果

Cane Borers, Their Loss to Cane Yield and Sugar Content and Their Bio-control

目的:为探明广西主要蔗区由于长期连作造成原料蔗生产受螟害损失程度、构成和规律,为有效防控甘蔗螟害,达到高产优质和可持续发展的目的,形成环境友好型生产模式提供科学的决策依据。研究方法:在广西南宁东亚糖业集团所属的5个糖厂蔗区,田间取样调查新植和宿根蔗1008个样本,78600个甘蔗植株二点螟、条螟的株害率、节害率、断尾率,取样检测蔗蔗糖分,通过数理统计方法估测螟虫对原料蔗产量和甘蔗蔗糖分降低和经济的损失。结果:①本蔗区二点螟和条螟对甘蔗植株平均株害率为40.14%,其中二点螟的株害率为16.71%,条螟为23.43%。平均蔗节为害率为7.02%。②螟虫造成原料蔗减产幅度为4.941～14.7375 t/hm2,平均减产10.203 t/hm2,减产率为14.42%。广西南宁东亚糖业集团所属的5个糖厂蔗区2010～2011榨季测算螟虫造成原料蔗的减产量高达131.18万t。③产量损失的构成,其中中前期螟害死苗造成减产4.2645 t/hm2,中后期因条螟造成断头死尾减产5.9385 t/hm2,条螟已成为该蔗区的主要螟虫种类。④螟虫蛀害造成甘蔗蔗糖分损失平均为0.6733个百分点,测算该蔗区由蔗糖分损失造成的蔗糖减产达5.004万t。⑤该蔗区因螟虫造成原料蔗减产和蔗糖分降低2部分的蔗糖损失高达22.799万t。⑥根据当年价格测算,造成的经济损失11.837亿元,其中农民损失6.559亿元,糖厂损失5.2447亿元。东亚糖业集团公司利用赤眼蜂防治甘蔗螟虫面积达18000hm2次?调查结果,寄生蜂的防治效果达到30.2%。

Aim： the loss of sugarcane yield, sugar content and their effective components damaged by cane bores in Guangxi cane area with continuous cane growing was studied to provide a scientific control of cane borers and to achieve high yield and quality, eco-friend and sustainable development of sugar industry. Methods： 1008 samples of 78600 cane stalks from both planting and ratoon crop were taken from 5 cane production area attached to the Guangxi Nanning East Asia Sugar Co., Ltd., to investigate the rate of bored stalks, bored nodes, and broken stalks damaged by Chilo infuscantellus and Proceras venosatum. Mathematical and statistical analysis were employed to estimate the loss of cane yield and sugar content. Results： （1）The rate of bored stalks damaged by borers was 40.14%, including 16.71% from Chilo infuscantellus, 23.43% from Proceras venosatum. The average rate of bored nodes was 7.02%. （2）Cane yield loss was 4.941-14.7375 t/hm2, with 10.203 t/hm2 being the average, a decrease of 14.42%, which resulted a loss of 1.3118 million tons of sugar productivity to the Sugar Co., Ltd. for the 2010/11 milling season. （3）Yield loss included 4.2645 t/hm2 from the loss of millable stalks caused at early stage, 5.939 t/hm2 from broken stalks damaged by Proceras venosatum at middle and later cane growing stage. The bore ofProceras venosatum was a dominant pest in Guangxi cane area at present. （4）A decrease of 0.6733% （absolute value） in sugar content were estimated to be from borer damage, it means a loss of 50040 tons in sugar productivity. （5）A total sugar production loss of 0.22799 million tons was resulted by borers. （6）According to the yearly price, economic loss of 1183.7 million yuan （RMB） was created, including 655.9 million yuan for the farmers and 524.47 million yuan for the enterprises. Trichogramma was produced by the Guangxi Nanning East Asia Sugar Co., Ltd. and released to cane fields for borer control covering an area of 18000 hm2 with efficacy of 30.2%.