Earliness in Flowering and Dwarfism in Relation to Internode Length and Tree Height in Papaya (Carica papaya L.)

The Malaysian Agricultural Research and Development Institute (MARDI)has an extensive papaya germplasm collection at Serdang with 52 accessions, 19 of which are local and 33 introduced. Economic traits such as fruit weight, flesh colour and total soluble solids have been documented previously, while studies on the earliness in flowering and dwarfism in relation to internode length and tree height have not been attempted. In this study, time to flowering, tree height and internode length were recorded six months after sowing. Five plants were randomly sampled from each accession for data recording. Internode length was found to be positively associated with tree height (r=0.75). Similarly, number of nodes to first flower was positively correlated to earliness in flowering (r=0.54)- with lower number of nodes indicating earlier flowering. Results from this study showed that two accessions, Baixinho Sta Amalina and Puerto Rico 217, were particularly outstanding in dwarf stature and earliness in flowering. These accessions will be useful parents for improving precocity and reducing tree height in future papaya breeding programmes.