Abstract:
Evolution of plant growth techniques has increased demand for growth substrates such as peat,
zeolite, perlite, pumice and vermiculite but supply has been decreasing while the prices are
escalating. The aim of this research was to study die potential utilization of an alternative potting
media developed from agricultural waste compost in combination with coir dust on the growth
and development of leafy vegetable Ipomoea aquatica (L).
Agricultural waste compost was prepared by heap method with poultry litter, sawdust, rice straw,
gliricidia and cow dung. Seven different potting media were prepared by mixing compost at the
rates of 0%, 10%, 25%, 50%, 75%, and 100%with coir dust at 100%, 90%, 75%, 50%, 25%, and
0%, respectively. Another treatment was used as a control which had 100% coir with
recommended chemical fertilizer by the department of Agriculture, Sri Lanka.
Physical (bulk density, true density, water holding capacity, porosity, particle distribution, and
coarseness index) and chemical properties (electrical conductivity, PH, total nitrogen, available
phosphorous) of the all potting media were analyzed. Pot experiment was conducted in a
greenhouse using Ipomea aquatic to determine the impact of developed potting media on the
growth and the development of the plant. Height, fresh and dry weight of the plants were
determined. Two harvests were done. Experimental design was completely randomized design
with five replicates. Obtained data were subjected to analysis of variance to determine the
treatment effects. Duncan’s multiple comparison range test was used to determine significant
differences between the means using SAS package.
Developed potting media showed adequate physical and chemical properties for Ipomea aquatica
cultivation. First harvest showed significant differences among all treatments and treatment
containing 100% compost gave the best growth and yield parameters. But second harvest did not
show significant difference between 100% compost treatment and 90% compost in combination
with 10% coir. The highest plant height, shoot fresh weight and shoot dry weight obtained from
the 100% compost were increased by 2.70, 18.07 and 18.02 times in comparison to the 100% coir
with chemical fertilizer as the control. 100 % compost treatment had bulk density 0.632gcm , true
density 1.62 gem'3, water holding capacity 167.11 mLL ', porosity 60.98%, total nitrogen 1.14%,
available phosphorous 0.38 mgL'1, EC 0.22 dSm'1 and pH 6.75 was the best among all other
treatments and it gave a profit of Rupees 3142.00 for 10 m2. Compost in the potting mixture did
not show any toxic effect on plant growth and development. Utilization of compost derived from
different agricultural compost can be considered as alternative potting media for leafy vegetable
Ipomoea aquatica.
