Abstract
To establish relationship with productivity, some bearing trees were selected and amino acid analysis of their leaves and flowers (males and hermaphrodite sepa-rately) was conducted. It was observed that hermaphrodite flowers had higher total amino acids concentration followed by leaves and male flowers irrespective of the productivity of the trees. Aspartic acid and glutarnic acid were found in higher con-centration both in the leaves and flowers but in the reversed order.
INTRODUCTION
Sweet lime occupies a third important position among different commercial citrus species both in acreage and production after mandarins and sweet oranges in Pakistan. Since it arrives in the market during July-September when no other table citrus cv. is available, it fetches profound return for the farmers. Sweet lime is conventionally con-sidered useful against malaria and jaundice, therefore, popular in summer. Unfortunately, the trees are frequently er-ratic in bearing. Nitrogen status of trees is generally considered agreed for the fruit production. Present studies were carried out on amino acids known as the nitrogen metabolites in order to ascertain if some relationship could be established. Arginine was reported major storage form of nitrogen (Oland, 1959). Praline and aspargine being in the largest concentration, twelve other amino acids were common in citrus leaves (Stewart, 1961). Quite a high level of proline, while smaller percentages of aspargine, aspartic acid and arginine were also detected as nitrogen storing compounds
ion citrus tracheal sap (Moreno and Martinez, 1981). a number of mineral elements like potassium, (Labanauskas and Handy, 1970), phosphorus (Rabe and Lovatt, 1984), mag-nesium and several trace elements (Stewart, 1961) were reported associated with altered amino acid metabolism in citrus. The present study was, however, pursued to in-vestigate if amino acids content of tress (as nitrogenous reserves) could be linked with the bearing habit of sweet limes.
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MATERIALS AND METHODS
Ten year old five trees raised from stem cuttings on sandy loam soil (pH 8.2) were selected. All the trees remained under observation for two years prior to their se-lection for the studies, particularly for their yield and cultural practices. Then two of the trees were categorised as poorly bearing (130 fruit average of two years) and a stan-dard bearing tree (500 fruit/tree). These trees were supplied with nitrogen @ 1.0 kg per tree in two equal splits either in spring, summer or autumn. These were also sup-plied with P, K at standard dose i.e. 750 g
