Abstract:
Presently, the tea industry in Sri Lanka, both in plantation sector and small holdings, mainly
in the low country are facing a shortage of labour for harvesting, especially during the heavy
cropping season. Harvesting is the most labour intensive agricultural practice in tea growing
and labour cost for plucking is about 30 to 40% of the total cost of production. In order to
enhance labour productivity, Tea Research Institute has introduced a selective tea harvester.
Hence this experiment was conducted at the Tea Research Institute, Low country station,
Ratnapura to study the characteristics of tea cultivars amenable for shear harvesting.
In order to study the different shoot growth characteristics, 42 tea cultivars (38 tea selections
and 04 tea clones) were chosen for the study and among these 15 cultivars were selected for
assessing the impact on growth, yield and quality of harvested crop. Manual and shear
harvesting were tested on these 15 cultivars separately. In this study, shoot characteristics
such as inter nodal length, leaf angle (apical and basal angle), leaf length, leaf area, active and
dormant shoots in the plucking table, plucking area of the bush, shoot density and percentage
of the dormant shoots in the plucking table were used to identify suitable cultivars for shear
harvesting.
Results showed that, total yield was not affected by method of plucking. Of the shoot
characteristics identified selections with longer inter nodes showed higher yield. Selections
with short leaf length showed lower percentage of dormant shoots left after plucking and
selections with wider basal angles incurred minimum damages and gave soft leaf pieces
under shear harvesting. Therefore, of the studied selections LVP 58-12, LVP 57-142, LVP
57-49 and LVP 57-133 are suitable for shear plucking and long inter nodal length, short
leaves and wider leaf basal angle can be used as key criteria for identifying cultivars suitable
for shear harvesting.
