| dc.description.abstract | A study was conducted in the the Department of Agroforestry and Environment, Hajee
Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh during
October 2016 to March 2017. There were two experiments in the study. Experiment 1
was conducted to find out the effect of bark and stem exudates of Eucalyptus
camaldulensis on the three agricultural crops in laboratory condition. There were three
concentrations of bark and stem seperately viz., 10%, 25%, 50% and a control (only
water). Experiment 2 was conducted with 50% concentration of bark and stem exudates
in the field condition of 1m x 1m plot size. In both experiments three agricultural crops
namely Maize (Zea mays), Country bean (Lablab purpureus) and Bottle gourd
(Lagenaria siceraria) were taken to satisfy the objectives of the study. Designs of
laboratory and field experiments were CRD and RCBD with three replications,
respectively. Results of laboratory experiment showed that 50% concentration of both
bark and stem exudates of E. camaldulensis inhibited more in germination of all three
tested crops compared to other concentrations. Bark exudates of E. camaldulensis
showed germination percentage 24.74% in Maize, 31% in Country bean and 54.33% in
Bottle gourd over control and stem exudates of E. camaldulensis showed germination
percentage 35.36% in Maize, 37.33% in Country bean and 45.67% in Bottle gourd over
control. The results indicated that inhibition increases with the increase of concentration.
In case of field experiments, both bark and stem exudates of E. camaldulensis also
inhibited the germination of the three tested crop. Application of 50% concentration of
E. camaldulensis bark exudates showed germination percentage 52.0% in Maize, 34.33%
in Country bean and 50.0 % in Bottle gourd over control and 50% stem exudates showed
germination percentage 40% in Maize, 19.67% in Country bean and 40% in Bottle gourd
over control. Morphological parameters like plant height (cm), collar diameter
(mm),central root length (cm), no. of first order lateral roots showed significantly higher
growth in control over bark and stem exudates in all the tested crops at both the
laboratory and field experiments. Similar results were recorded for biomass allocation
like shoot dry weight (g), root dry weight (g), total dry weight (g), shoot/root ratio and
quality index. From the results of laboratory experiment it is also indicated that though
both bark and stem exudates inhibited the germination of Maize, Country bean and
Bottle gourd in different rates but inhibition by stem exudates is less compared to bark
exudates of respective crops except bottle gourd. In the field experiment, inhibition by
bark exudates is less compared to stem exudates of respective crops.Consequently,
germination speed of tested crops was more in control than bark and stem exudates of E.
camaldulensis due to the inhibitory effect. From the overall result it can be concluded
that in addition to the allelopathic effect of leaf and root of E. camaldulensis, bark and
stem have also allelopathic effect on the agricultural crops which inhibited more in
laboratory compared to field condition. This effect may be minimized through proper
management of the agroforestry field by removing the fallen bark and stem residues. | en_US |
