Polanco L R, Rodrigues F A, Moreira E N, Duarte H S S, Cacique I S, Valente L A, Vieira R F, Paula Júnior T J, Vale F X R
Viçosa Federal University, Department of Plant Pathology, Laboratory of Host-Parasite Interaction, Viçosa, MG, 36570-000, Brazil.
Paraná Federal University, Plant Protection Department, SCA-DFF, Curitiba, Paraná State, 80035-050, Brazil.
Plant Dis. 2014 Jan;98(1):84-89. doi: 10.1094/PDIS-03-13-0251-RE.
This study aimed to determine whether foliar sprays of potassium silicate (KSi), sodium molybdate (NaMo), or a combination of both (KSi + NaMo), with or without the fungicide azoxystrobin (Azox), could reduce anthracnose symptoms and, consequently increase yield. Two two-by-four factorial experiments, consisting of untreated or fungicide treated, as well as sprays of KSi, NaMo, KSi + NaMo, and no spray (control), were arranged in a randomized block design with three replications. Treatments were as follows: treatment 1, KSi spray; treatment 2, NaMo spray; treatment 3, KSi + NaMo spray; treatment 4, Azox spray; treatment 5, Azox + KSi spray; treatment 6, Azox + NaMo spray, treatment 7, Azox + KSi + NaMo spray; and treatment 8, control (no KSi, NaMo, or Azox). The KSi, NaMo, and Azox treatments were sprayed at the rates of 35 g/liter, 90 g/ha, and 120 g a.i./ha, respectively. The KSi was applied at 20, 27, 40, and 55 days after sowing (das). The NaMo was sprayed only at 27 das whereas the fungicide was sprayed at 27, 40, and 55 das. Plants were inoculated with Colletotrichum lindemuthianum at 23 das. Azox reduced the mean area under disease progress curve (AUDPC) by 63% and mean yield was increased by 150%. Similarly, the mean AUDPC was reduced by 29, 14, and 41% with KSi, NaMo, and KSi + NaMo sprays, respectively, while mean yield increased by 13, 20, and 47%, with KSi, NaMo, or KSi + NaMo sprays, respectively. The variables leaf area index (LAI), leaf area index duration (LAD), healthy leaf area duration (HAD), and radiation intercepted (RI) were not affected by KSi spray. The values for the variables LAI, healthy leaf area index (HLAI), LAD, HAD, RI, intercepted radiation of the healthy leaf area, and healthy leaf area absorption were significantly increased as a result of NaMo spray. The results of the present study support the novel possibility of using a foliar spray of KSi in association with NaMo to decrease anthracnose symptoms in bean plants and, consequently, achieve greater yield.
本研究旨在确定叶面喷施硅酸钾（KSi）、钼酸钠（NaMo）或两者组合（KSi + NaMo），无论是否添加杀菌剂嘧菌酯（Azox），是否能够减轻炭疽病症状，从而提高产量。进行了两个2×4析因试验，设置了未处理或杀菌剂处理，以及KSi、NaMo、KSi + NaMo喷施和不喷施（对照）处理，采用随机区组设计，重复三次。处理如下：处理1，喷施KSi；处理2，喷施NaMo；处理3，喷施KSi + NaMo；处理4，喷施Azox；处理5，喷施Azox + KSi；处理6，喷施Azox + NaMo；处理7，喷施Azox + KSi + NaMo；处理8，对照（不喷施KSi、NaMo或Azox）。KSi、NaMo和Azox的喷施量分别为35克/升、90克/公顷和120克有效成分/公顷。KSi在播种后20、27、40和55天施用。NaMo仅在播种后27天喷施，而杀菌剂在播种后27、40和55天喷施。在播种后23天给植株接种菜豆炭疽菌。Azox使病情进展曲线下的平均面积（AUDPC）降低了63%，平均产量提高了150%。同样，喷施KSi、NaMo和KSi + NaMo分别使平均AUDPC降低了29%、14%和41%，而喷施KSi、NaMo或KSi + NaMo分别使平均产量提高了13%、20%和47%。叶面积指数（LAI）、叶面积指数持续期（LAD）、健康叶面积持续期（HAD）和截获辐射（RI）等变量不受KSi喷施的影响。喷施NaMo使LAI、健康叶面积指数（HLAI）、LAD、HAD、RI、健康叶面积截获辐射和健康叶面积吸收等变量的值显著增加。本研究结果支持了叶面喷施KSi与NaMo相结合以减轻菜豆植株炭疽病症状并从而实现更高产量的新可能性。
