Studies on �Kinnow� (Citrus reticulata Blanco.) Decline in Relation to Soil-Plant Nutritional Status

Abstract

�Kinnow� decline was studied in relation to soil plant nutritional status under semi arid condition of Hisar (India). There were no differences between the soil pH, electrical conductivity and calcium carbonate of healthy and declining trees. The soil under the healthy trees had significantly higher organic carbon (0.46%) than that under declining trees (0.35%). The nutrients viz., N, P, Zn, Cu, Mn and Fe in the soil under healthy and declining trees did not differ significantly except K. Leaf N, Zn, Cu, Mn and Fe were significantly more in the healthy trees. The deficiency of N, P, Zn and Mn in the leaves of both categories of trees could be attributed to low contents of these nutrients in the soil under healthy and declining trees. Growth, yield and fruit quality were better in healthy trees as compared to declining trees. The yield on kg per tree basis in declining trees reduced (8.43 kg/tree) as compared to that in healthy trees (20.74 kg/tree). Low organic carbon, soil N, Zn and Mn content could be associated with the declining problem of �Kinnow�.