Effect of potassium priming on papaya (Carica papaya 'Kamiya') seed germination and seedling growth

• Published in: Acta horticulturae no. 911; pp. 319 - 322
• Main Authors: Owino, D.O, Ouma, G
• Format: Journal Article
• Language: English
• Published: International Society for Horticultural Science 01.01.2011
• Subjects: absorption; analysis of variance; Carica papaya; dormancy; greenhouses; leaf area; leaves; papayas; planting; potassium; potassium chloride; potassium hydroxide; potassium nitrate; potassium sulfate; seed germination; seed priming; seedling growth; seedlings; seeds; temperature; tissue culture; viability; washing; winemaking; wood ash; Kenya
• ISSN: 0567-7572
• DOI: 10.17660/ActaHortic.2011.911.36

Papaya (Carica papaya L.) is an important fruit in Kenya for fresh consumption and wine production. It can be propagated by seeds, budding, cuttings or tissue culture. Seed propagation is the simplest and cheapest method of propagation but is affected by factors such as temperature, moisture loss and seed priming. Papaya seeds are classified as recalcitrant since a loss of moisture through drying has an effect on their viability. Removal of the gelatinous material around freshly harvested seeds through washing also removes the sarcotesta which causes secondary dormancy. In addition, the seeds have a hard coat and an internal germination inhibitor which hinders water absorption thus preventing germination. It is with this background that study was conducted that could improve seed germination of papaya in greenhouse controlled conditions. The experiment was carried out in 2008 at Maseno University, Kenya. The protocol consisted of seed extraction using standard methods and a subsequent floatation test to determine seed viability. The entire seeds were washed to remove the gelatinous coverage material and divided into six lots for six treatments with; 1. water, 2. potassium chloride, 3. potassium hydroxide, 4. potassium nitrate, 5. potassium sulphate and, 6. wood ash, arranged in a complete randomized block design. The seeds were subsequently planted in plastic pots and placed in a greenhouse. Germination was characterized by the number of seedlings emerging per pot, root length, leaf number and leaf area, stem diameter and plant height recorded weekly over three months. Data were analyzed using the Statistical Analysis System (SAS) where analysis of variance and mean separation were based on Least Significant Difference at P≤0.05. The results showed that priming with potassium solutions improved seed germination capacity and subsequent seedling growth.