Evaluating Root Distribution Pattern of Selected Coconut Cultivars at Seedling Stage Under Different Climatic and Soil Conditions
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Date
2013
Journal Title
Journal ISSN
Volume Title
Publisher
Uva Wellassa University of Sri Lanka
Abstract
Coconut is one of the main commercial plantation crops in Sri Lanka. Annual National Coconut
Production (ANCP) in Sri Lanka is more or less stagnant or with only a slight increase during
last two decades. Human inhabitation and climatic change are the main contributory factors that
affected on reducing extent of coconut growing lands in traditional areas and led to promote
coconut cultivation in non-traditional areas. Therefore, identification of a coconut cultivar/s
with putative drought tolerance is of a paramount importance.Strong and well distributed root
system is of extremely important in withstanding frequent dry spells experienced in marginal
areas especially in dry zone. This led to the present investigation on root distribution pattern of
selected, improved coconut cultivars grown under different climatic and soil conditions. The
experiment was conducted (i) to identify the root distribution pattern of CRISL 98 (a cross
between Tall and San Ramon) and Kapruwana (a cross between Dwarf Green and San Ramon)
cultivars at seedling stage under different climatic and soil classes and also (ii) to identify their
active root zones and their variation under different environments.
Methodology
Experiment was conducted as a three factor factorial using around 3 year old coconut seedlings
of Kapruwana and CRISL 98cultivars under intermediate zone (IZ) and wet zone (WZ) in S1/S2
and S3/S4 land suitability classes (LSC). Soil core samples were taken from different distances
(50, 100 and 150 cm) from the base of the seedling and at five depths in two opposite directions
(20, 40, 60, 80 and 100 cm). They were separated in to two groupsviz. primaries and
secondariesafter washedthe root samples.Then, number, dry weight, total root length (Tennant,
1975) and root volume (Herath, 2004) were measured for primary and secondary roots
separately. Data were analyzed using ANOVA and means were separated using Duncan’s new
multiple range test (DNMRT) using SAS (version 8) computer software.
Description
Keywords
Agriculture, Export Agriculture, Crop Production, Coconut, Plantations