The effects of sarcotesta and storage temperature on the longevity of seeds of five papaya (Carica papaya) landraces.

Abstract

The study was done to investigate the effects of sarcotesta and storage temperature on seed longevity in papaya ( Carica papaya). Seeds extracted from ripe fruits of five different landraces (FUTM-Da, FUTM-Gmk, FUTM-Gmg, FUTM-Coe and FUTM-Gkw) were shade-dried to a moisture of about 10% with or without the removal of the sarcotesta. Samples of the dry seeds of the different landraces were packaged in paper envelopes and stored at 12O C or 30O C. Seedling emergence in top soil was tested immediately after seed drying and at 4, 8, 12, 16 and 20 weeks of storage. Values obtained which did not differ significantly between seeds with or without sarcotesta, were low (13 to 60%) prior to storage in all landraces. An increase was however recorded within the first four to eight weeks after storage irrespective of treatment. At the peak, seedling emergence of up to about 70% to 90% in seeds stored without sarcotesta were recorded, whereas the maximum emergence of seedlings from seeds with sarcotesta was mostly between 52% and 75%. The superiority of 12O C over 30O C in terms of viability maintenance was more consistent in seeds stored without sarcotesta,,seeds stored without sarcotesta stored better than those with sarcotesta. In all treatments, seedling emergence decreased after a maximum value was recorded. However, viability was best maintained in FUTM-Co without sarcotesta.