Ideal Shade Tree Species
The species used as shade trees should have a canopy which allows sufficient light to pass through to fall on the bush surface and do not compete with the tea for moisture and nutrients. So in selecting the species the following criteria should get due consideration.
(a) Suitability to the soil and climate of the area.
(b) Economic life, i.e. the life span should be long.
(c) Size and shape of the canopy- it should be spreading but not dense.
(d) Leaflet size and duration of leafless period-Leaflet size should be small and short leafless period.
(e) Root depth, deep rooted species is ideal.
(f) The species should be resistant to pests and diseases.
(g) Species should be resistant to storm damage.
Shade Tree Species
The trees which are used as shade trees in tea plantations in N.E. India are of two types viz., temporary and permanent shade trees.
Temporary shade tree
Temporary shade trees are fast growing and are kept in the plantation for the initial 5-6 years. The species used as temporary shade tree are -Indigofera teysmanii, Albizzia moluccana, Albizzia procera, Dalbergia sisos, Melia azadarach, Leucaena lecucephala, Gliricidea maculeata etc.
The temporary shade trees are initially planted at a closer spacing and later thinned out and then removed completely when the permanent shade trees take over. Initially these are planted at a spacing of 2 m x 2 m and later on thinned out to 4.5 m x 4.5 m. Some of the temporary shade tree species like Indigofera can be vegetatively propagated. One year old stump of 1.5 m length can directly be planted in the field.
As the temporary shade trees are fast growing, thinning out of the branches and selected loppings are necessary.
Permanent Shade Tree
The species used as permanent shade trees are generally slow growing. They are with longer life and taller canopy and can be kept in the plantation for 30 to 40 years.
The recommended permanent shade tree species grown in tea plantations of N.E. India are as follows:
|Albizzia odoratissima||End December to end February|
|Derris robusta||Mid December -February|
|Acacia lenticularis||December -march|
|Adenanthera pavonina||January -March|
|Dalbergia sericea||December -March|
In the vicinity of elephant infested areas, shade trees like Acasia lenticularis, Derris robusta and Melia azadarach are normally preferred.