Bacterial leaf blight resistance and productivity performance of rice on single and mixture planting

Abstract

The core of Indonesian agricultural development policy is to meet the demand of rice as staple food. The improved varieties which have been used still faced constraints such as abiotic and biotic stress. One of the important biotic stress is Bacterial Leaf Blight disease caused by Xanthomonas oryzae pv. oryzae. According to the previous research, mixture varieties planting could reduce disease intensity and increase the yield. The aim of this research was to find out the genotype that resistance to BLB, yield stability, genetic variability and other characters stability on single and mixture planting. The experiment used 17 genotypes as treatments which consisted of 7 cultivars and 10 cultivar mixtures with different resistance to BLB background. The trial was designed in Randomized Complete Block Design and replicated three times. The trial was conducted during two seasons in Majalengka and Pacitan. The characters observed were Bacterial Leaf Blight spreading, plant height, number of panicle per hill, number of well-filled grain per panicle, number of unfilled grain per panicle, number of total grain per panicle, 1000 grains weight, well-filled grain percentage, yield per ha and sink size. The disease spreading data was used to analyze the first appearance of disease, disease incidence, disease severity and Area Under Disease Progress Curve (AUDPC). The yield data was used to analyze yield stability and genetic parameters, while agronomic characters data was used to analyze the difference between two seasons and between single and mixture genotype using t test. According to the result of analysis, there was no difference between single and mixture genotype on the first appearance of disease, disease incidence, disease severity and AUDPC. The result of combine and stability analysis showed that genotype, season and their interactions influenced the yield; and the stable, unstable and specific single and mixture genotype could be determined. According to t test to other characters, there was no difference between single and mixture genotype. Based on the result of the analysis, the effect of mixture to reduce the Bacterial Leaf Blight disease and to increase the yield has not been known yet.