对四川省南充市仪陇县二点时蝉及其所传播的玉米鼠耳病的田间消长规律以及玉米受害后的产量损失状况进行了研究。结果表明:温度低于16℃时,玉米不发病;28℃和31℃时玉米鼠耳病的潜伏期较短,分别为4.85和4.64d。在高、中、低3个海拔高度上,玉米鼠耳病的田间消长动态受二点叶蝉种群发生动态的影响,并于5月下旬至6月上旬达到最大病情指数,分别为5.75、10.97和9.09。玉米的生长和产量均受到玉米鼠耳病发生程度的影响,随着该病病级的上升,玉米株高、地面直径、穗长、穗粗、穗粒数、穗粒重及千粒重均相应下降。通过二元线性回归方程对玉米单穗籽粒重损失率作通径分析,表明在玉米的产量构成中.千粒重下降是导致产量损失的主要因子。
With laboratory trial and field investigation, this paper studied the epidemic dynamics of maize wallaby ear disease (MWED) transmitted by Cicadulina bipunctella, and assessed the maize damage caused by the disease. The results showed that the maize plants infected by MWED did not show any obvious symptoms at 16 ℃, and the shortest latent period of MWED was 4. 85 and 4. 64 days at 28℃ and 31℃, respectively. At high, medium, and low altitudes, the occurrence and development of MWED were all closely related to the developing dynamics of vector leafhoppers. The disease index increased with increasing density of vector leafhoppers, and reached its maximum (5.75, 10. 97 and 9.09, respectively) from the last ten days of May to the first ten days of June. The maize plant height, stem diameter, ear length, ear width, kernel number and weight per ear, and 1 000 kernels weight decreased with increasing disease rank. The path analysis of binary linear regression equation on the loss of kernel weight per ear showed that the decrease of 1 000 kernels weight was the main factor of yield loss in the components of maize output.