Impact of Leaf Roller (Diaphania pulverulentalis) Infestation on the Mineral Nutrition of Mulberry (Morus spp.) Varieties

Mulberry (Morus spp.) foliage is the exclusive food for the silkworm, Bombyx mori L. The healthy growth of silkworm and its economic traits such as larval, cocoon and grainage parameters are known to be influenced largely by the nutritional status of the leaves fed to them. The mineral elements comprise major part of nutritional quality of mulberry leaves, which may alter due to injury caused by pests and diseases. Therefore, an attempt was made to know the variations in the mineral nutrition of mulberry foliage under leaf roller (Diaphania pulverulentalis) infestation. Six macro (nitrogen, phosphorus, potassium, calcium, magnesium and sulphur) and seven micro nutrients (zinc, iron, manganese, copper, boron, molybdenum and chloride) were analysed in six popular indigenous mulberry varieties (M5, MR2, Mysore local, S36, S54 and V1). The nutrients decreased in the pest - infested leaves of almost all the varieties except nitrogen and potassium in Mysore local and V1, phosphorus in S36 and V1, magnesium in M5 and Mysore local and sulphur in V1, zinc in S36 and S54, boron in S36 and chloride in Mysore local varieties where they were increased. However, no changes were observed in the contents of nitrogen and potassium in MR2, phosphorus in MR2 and Mysore local, calcium in M5, S36 and V1, magnesium in S54 and V1 and sulphur in M5, S36 and S54, zinc in V1, iron in M5, Mysore local and V1, manganese in M5, copper in S54 and V1, boron in M5, MR2, Mysore local and V1, molybdenum in M5, MR2, S54 and V1 and chloride in M5, S54 and V1 varieties. These variations in the mineral nutrients results in the nutritional inferiority of mulberry leaves. Feeding such leaves will affect the growth and development of silkworms which in turn adversely brings down the quality of silk production.