Correlation of AM fungi and Azotobacter with growth, fruit yield, soil and nutritional status of citrus orchards in north-western Himalayan region of India

摘要

The present investigation was carried out with the objective to find out the relationship of soil microflora especially, AM fungi and Azotobacter with growth, yield and nutritional status of citrus orchards growing in Shiwalik hill ranges of north-western Himalayan region of India. A simple linear correlation analysis was carried out between all possible combinations. It has been observed that AM spore population and per cent root colonization was positively and significantly correlated with shoot extension growth, leaf area, yield, soil organic carbon, available N, Cu, Zn, Fe and Mn , total leaf N, P and micronutrients . A weak and non- significant relationship were observed between AM spore population and soil pH, EC, available P and K contents, whereas, per cent root colonization was negatively and significantly related with soil pH only. However, AM spore population exhibited negative and significant relationship with K content of leaf. The relationship of Azotobacter count with leaf area, soilorganic carbon, available N, Cu, Zn and Fe content, and leaf N, P and Mn was observed to be positive and significant but it was found to be positive and non-significant with shoot extension growth and fruit yield. However, this relationship was negativeand significant with available P content, but it was weak and non-significant with soil pH, EC, available K and micronutrients (Cu, Zn and Fe) content of leaf.