Field Applications of Silicon-Based Fertilizers Against Sugarcane Yellow Mite Oligonychus sacchari

Field trials were performed to examine the effects of foliar application of three silicon-based fertilizers (Potassium silicate, Agrisil, PQ Corporation, South Africa; Potassium silicate, NTS Australia and Silamol, Roam Chemie, Belgium) against sugarcane yellow mite Oligonychus sacchari on four sugarcane varieties: CP48-103, CP57-614, CP69-1062 and SP70-1143. Two applications of these fertilizers were applied before mite infestation, and the number of mites was recorded 10, 20, 30 and 40 days after second application of the silicon fertilizers. For evaluating the effects of silicon treatments on the predatory beetle, Stethorus sp.; the number of beetles was also recorded 10, 20, 30 and 40 days after second application of the silicon fertilizers. The results showed that there was a significant difference among silicon fertilizers and control group of mite and predatory beetle's populations. The number of mites in the control group of all the varieties was between 9.17 and 14.02 after 40 days; whereas population density of mites reduced significantly in all the silicon treated plots in comparison with the control. In addition, population density of predatory beetles was affected by mite's population and the number of beetles reduced in the treated plots. However, according to the importance of applying IPM programs in fields incorporating of acaricides with other reduce-risk strategies including biological control agents should be considered as a sugarcane IPM program.