Corea, A.S.L.E. <br/><br/>
Comparison of different low cost manure's in Aponogeton crispus culture  

 - Sri Lanka,  NARA,  2003, 
 - 1p. 
 - Proceeding of the Ninth Annual Sessions of the Sri Lanka Association for Fisheries and Aquatic Resources .
<br/><br/> Export of wild collected Aponogeton species has caused a threat to its natural <br/>existence. Therefore, present regulations insist on permitting only cultured stock for <br/>the export markets. However there is a popular belief that this species can be <br/>propagated only through vegetative methods, especially by using parts of the tuber. <br/>The plants that are exported are approximately 15cm in size. Earlier tubers were <br/>exported separately. However, presently export of tubers has been prohibited.<br/>Present study was undertaken to investigate the possibility of propagating <br/>Aponogeton crispus by seeds and to compare the low cost different types of manure <br/>that could, be used for culture purposes.. Fifteen plants were used for each plot and 3 <br/>plots vyere used fo r each treatment. The study was carried out for a period of 165 <br/>days. Manure was applied at commencement of the experiment and every 50 days <br/>thereafter. Nitrate and Phosphate levels were monitored weekly and levels were <br/>maintained for each manure throughout the experiment.<br/>Seed germination showed a 100% success rate. And the plants took an average of 4 <br/>months to grow to the exportable size; (16.1±3.01 cm. In 126 days) The plants had <br/>developed a tuber of 0.7± 0.002cm in 165 davs.<br/>The types of manure used were cow dung, chicken manure, compost and a <br/>commercial liquid manure. The results showed no significant difference in the specific <br/>growth or final length of plants between the different treatments and the control <br/>(P<0.05) when analyzed using Analysis of Variance.<br/>proceedings or me iMincn annual .bessions or me b'ri LanKa association ror i-isneries ana 5 Aquatic Resources, 30th.June 2003, NARA Auditorium, Colombo (Abstract)<br/>However, a .significant difference was observed in survival rate of plants between the <br/>different treatments (P>0.05). Plants cultured using cow dung and chicken manure <br/>.showed ’ lower survival (72% and 60% survival respectively compared to 100% <br/>survival in other treatments). The quality of plants was not acceptable for export <br/>when plants were-cultured using cow dung and chicken manure.<br/>According to- this study, compost is the best low cost manure that can be <br/>recommended Tor Aponogetoh crispus culture.