Abstract:
An experiment was carried out to find suitable ratio of inorganic fertilizer and compost,
which could give an economic yield of onion (cv. Jaffna Local). This experiment was
designed in a Randomized Complete Block Design with four replicates. Treatments were
recommended dosage of inorganic fertilizers as a control (T1), ¾ fold of the control treatment
+ compost (2 t ha-1
) (T2), ½ fold of the control treatment + compost (4 t ha-1
) (T3), ¼ fold of
the control treatment + compost (6 t ha-1
) (T4) and the compost alone (8 t ha-1
) (T5). These
were applied as basal application of fertilizer in this experiment. The results of this study
revealed that there were significant (P<0.05) differences in the numbers of leaves and roots
between the different treatments during the early stage of growth. Relatively higher yield
(5.03 t ha-1
) was obtained from the plants treated with inorganic fertilizers alone (T1),
whereas compost alone (T5) produced the lowest yield (3.43 t ha-1
). It was also noted that
there were no significant (P>0.05) differences in the yields between T1 and T2 as well as T1
and T3. The inorganic fertilizers appear to have compensated with slow release of nutrients
from the compost and their combined effects would have increased the yield. From this study,
it could be stated that half fold of the inorganic fertilizer and compost at the rate of 4 t ha-1
(T3) could give profitable yield (4.75 t ha-1
) and this combination could possibly reduce the
cost of production in the cultivation of onion.
