Articles
A study on different micro-irrigation techniques for mitigating water stress of immature rubber (Hevea brasiliensis) plants
Authors:
S. A. Nakandala ,
Rubber Research Institute of Sri Lanka, Dartonfield, Agalawatta, LK
N. M. C. Nayanakantha,
Rubber Research Institute of Sri Lanka, Dartonfield, Agalawatta, LK
P. Seneviratne,
Rubber Research Institute of Sri Lanka, Dartonfield, Agalawatta, LK
M. N. de Alwis,
Rubber Research Institute of Sri Lanka, Dartonfield, Agalawatta, LK
D. L. N. de Zoysa
Rubber Research Institute of Sri Lanka, Dartonfield, Agalawatta, LK
Abstract
The Intermediate and Dry Zones of Sri Lanka have been targeted in expanding the rubber plantations with a view to expand the extent under planting to achieve national targets in natural rubber production. However, climatic conditions of these regions are suboptimal for growing of rubber. The mid-year dry period in these areas extends from June to September and as a result, plants experience a severe water stress especially in nursery and immature period. Therefore, this study was carried out in the Kilinochchi District, which belongs to the Agro-ecological Zone, DL3 in order to assess the performance of micro-irrigation techniques for immature or young rubber plants. Two micro-irrigation systems; viz. drip and spray jet were tested under three soil moisture depletion levels; 30, 50 and 70% of available soil moisture.
Results showed that the growth of immature young rubber plants were highly responsive to moisture depletion levels and micro-irrigated systems. It was found that both drip and spray jet irrigation systems performed well in supplying water at 30% depletion level when compared to the depletion levels of 50 and 70%. Water stress is created by 70% depletion level with decreased chlorophyll content, stomata closure and increase in leaf temperature. Adequate irrigation at 30% depletion level in both systems resulted significant increment of chlorophyll content (p< 0.05). There was significant increment in chlorophyll content in plants which were irrigated with spray jet system when compared to drip system. Plants which were irrigated at 30% depletion level regulated higher stomatal conductance even under higher temperatures during mid-day period.
How to Cite:
Nakandala, S.A., Nayanakantha, N.M.C., Seneviratne, P., de Alwis, M.N. and de Zoysa, D.L.N., 2019. A study on different micro-irrigation techniques for mitigating water stress of immature rubber (Hevea brasiliensis) plants. Journal of the Rubber Research Institute of Sri Lanka, 99, pp.87–94. DOI: http://doi.org/10.4038/jrrisl.v99i0.1891
Published on
30 Dec 2019.
Peer Reviewed
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