Abstract:
An experiment was conducted 'at the Instructional Farm attached to the
College of Agriculture, Vellayani, during November 1998 to February 1999
with objectives to find out the effect of different sources and levels of organic
manures on the yield and quality of amaranthus and to assess the optimum
quantity of these sources in sustaining the productivity of amaranthus. The
experiment consisted of twenty six treatments and three replications laid out in
RBD. The organic manures used were coir pith compost, FYM, neem cake,
poultry manure and vermicompost. Five levels of these organic manures (50, 75,
100, 125 and 150 per cent of POP) were tried on nitrogen equivalent basis.
The results of the study revealed that the growth characters as well as
yield were significantly influenced by different levels and sources of organic
manures. Regarding growth characters vermicompost, FYM and poultry manure
performed well throughout the growth period. Highest level of FYM and
vermicompost (150 per cent POP) maintained their superiority at all growth stages
regarding plant height, number of leaves, number of branches and LAI. Maximum
plant height of 67.22 cm was recorded at 45 DAP by highest level of FYM.
Vermicompost @, 25 t ha" (150 per cent of POP) recorded maximum number of
leaves (100.78) at 45 DAP but it was on par with highest dose ofFYM. Maximum
LA! was noted in the highest dose of FYM and no other treatment was on par with it.
High yield was obtained from 100, 125 and 150 per cent levels of FYM,
vermicompost, poultry manure and neem cake. All the coir pith compost
treatments recorded lower yield than POP. The lowest yield was recorded by
lowest dose of coirpith compost. The same trend was obtained in the case of
marketable yield also. Higher levels gave better yield in general. Total dry matter
production showed an increasing trend with increasing dose of manure. Highest
dose of FYM recorded maximum DMP of 11.41, 25.7 and 28.27 g respectively at
15, 30 and 45 DAP.
Variation among different organic manures was significant in the case of
biomass production also. Through out the growth stages 125 and 150 per cent
levels of all manures except coir pith compost recorded superior biomass
compared to POP. Vermicompost at highest level (25 t ha-I) recorded
maximum biomass during three harvests. Variation was less in the case of NAR
and dry matter partitioning at different stages.
Quality of amaranthus improved with varIOUS organic manures.
Maximum vitamin C content was recorded by highest level of vermicompost.
Maximum fibre content was registered by neemcake at 100 per cent level of
POP (4.8 t ha-I). Highest dose of poultry manure (25 t ha") gave highest
protein content. Vitamin C and protein contents increased with increasing
doses of manure. Highest moisture content was noted by highest dose of FYM.
In the case of residual nutrients high soil NPK values were registered by
higher levels of organic manures irrespective of source. No treatment was
inferior to POP with respect to nitrogen content. Uptake of nutrient was poor
from all coir pith compost treatments. Uptake of N increased with increasing
levels of manures. P uptake was more for FYM treatments. Vermicompost at
highest dose (17 5 I ha-I) gave maximum n C ratio