Document Type : Research Paper
Authors
1
Research Associate Professor. Rice Research Institute of Iran (RRII), Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran
2
Researcher. Rice Research Institute of Iran (RRII), Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran
3
Research Assistant Professor. Rice Research Institute of Iran (RRII), Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran
4
B.Sc. Rice Research Institute of Iran (RRII), Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran
5
Research Associate Professor, Rice Research Institute of Iran (RRII), Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran
10.22124/cr.2024.27295.1820
Abstract
Introduction
Sheath blight disease of rice caused by Rhizoctonia solani AG-1 IA, has been recognized as an economically significant disease, which significantly reduces rice yield and seed quality. Currently, the most important method to manage the disease of rice sheath blight is agricultural methods and the use of fungicides in the field. Among the effective agricultural methods in managing this disease is the optimal and suitable application of chemical fertilizers. Potassium silicate fertilizer is one of the effective and useful chemical fertilizers in controlling and reducing the sheath blight disease. Application of this element especially in poor or insufficient soils can be effective in controlling sheath blight disease. The objective of this study was to investigate the effect of foliar application of potassium silicate fertilizer on grain yield and sheath blight disease control under field conditions.
Materials and methods
A virulent isolate of R. solani was prepared on a mixture of rice hull and grain and used as an inoculum. This experiment was conducted as factorial with two factors based on randomized complete block design in three replications in Rice Research Institute of Iran (RRII), during 2021 and 2022. The first factor was different concentrations of foliar spraying at five levels including 0 (control), one, two and three kg/ha of potassium silicate fertilizer and one lit/ha of propiconazole fungicide and the second factor was frequency of foliar spraying at two levels including one time (at the beginning of tillering stage) and two times (at the beginning of tillering and booting stages). The measured traits were disease severity, disease incidence and grain yield. Analysis of variance was done using SAS software and comparison of means was done using Tukey’s test at 5% probability level.
Research findings
These results of the present study showed that the use of potassium silicate fertilizer at the rate of two kg/ha in the field conditions reduced rice leaf sheath blight disease. These results indicated that under the conditions of potassium silicate fertilizer application, the severity of sheath blight disease was 13.00% and 12.47%, and the disease incidence was 14.12% and 13.9% in the first and second years of the experiment, respectively, while with the use of propiconazole fungicide, the disease severity was 11.21% and 10.77% and the disease incidence 10.97% and 10.60% in the first and second years, respectively. Furthermore, the disease severity in the first and second years in control treatment was measured as 15.85% and 16.02% and the disease incidence 20.63% and 20.8%, respectively. Although the effect of potassium silicate fertilizer in reducing the disease development (disease severity and incidence) was lower than the effect of propiconazole fungicide, it had a suitable inhibitory effect in disease development compared to the control treatment. Therefore, in the fields where sensitive cultivars to rice sheath blight disease have already been cultivated or the disease with high severity has been observed and the field is prone to infection with sheat blight disease, the use of potassium silicate fertilizer combined with propiconazole fungicide can be recommended to control the disease.
Conclusion
The results of this study showed that the use of potassium silicate fertilizer at the rate of two kg/ha once at the tillering stage of rice reduced the development of sheath blight disease. Also, there was no significant difference in reducing the disease severity and incidence between the higher concentration of potassium silicate fertilizer investigated in this experiment (three kg/ha) and the concentration recommended by the manufacturer (two kg/ha), as well as the use of fertilizer between one stage (at the beginning of tillering) and two stages of plant growth (at the beginning of tillering and booting). Therefore, it is suggested to use a lower concentration of potassium silicate fertilizer (two kg/ha) only once at the beginning of tillering stage to reduce rice leaf sheath blight disease.
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