Assessment of Mycorrhizal Colonization and Soil Biological Attributes in Healthy and Declining Khasi Mandarin (Citrus reticulata Blanco) Orchards in Acidic Inceptisols

Abstract

Background: Khasi mandarin (Citrus reticulata Blanco) a loose-skinned commercial cultivar is one of the premier citrus species native to sub-tropical hill zones of Northeast India. But this fruit crop suffers a serious threat due to the dieback condition in the present years. Methods: Khasi mandarin orchards of different categories viz. young non-bearing orchards, bearing healthy orchards, bearing old orchards and declining orchards were selected for the study from the sub-tropical hill zones of acidic Inceptisols at varying altitudes of less than 150 m to greater than 1400 m amsl. In those selected orchards, a series of soil physico-chemical, biological and microbiological attributes were characterized in the healthy as well as in the declining orchards. Result: The results revealed that both the physico-chemical and biological parameters in the healthy orchards were found to be significantly (P≤0.05) higher than the declining orchards. Further, the mycorrhizal colonization effectively influenced the composition of microbial structure in the rhizospheric zone, affecting the health and vigour of the plant.