Ailanthus

Ailanthus excelsa Roxb. is a fast growing tree species belongs to the family of Simaroubaceae. The genus, Ailanthus derived from “Ailanto” an Ambonese word probably meaning “Tree of Gods” or “Tree of Heaven”. It is native from South East Asia, South to Northern Australia. In India, it comes very well almost all the states It is common in West Bengal, Bihar, Odisha, Rajasthan, Tamil Nadu and Andhra Pradesh. It is widely cultivated in semi arid and subtropical areas. A.excels is a medium to large tree, growing to 25-45 m height, with spreading branches. The species can grow in altitudes of 0-1500MSL, precipitation (500-1900mm) and temperature between 4ºC and 47ºC.

Botanical Description

A.excelsa have small whitish trunk, branches are thick and spreading with a massive spreading crown. The bark is greenish or grey and smooth in young trees. While in old trees the bark is rough having large conspicuous leaf scars. Leaves are pinnate, alternate or sub opposite, coarsely and irrugularly serrate, oblique at base; petioles 5-8 cm long. The leaves with 15-41 long pointed leaflets, the terminal leaflet normally present. The leaves have an unpleasant smell when touched. The leaves are shed during the cold season and the new leaves appear in March-April. The flowers appear in the large open clusters among the leaves, the male, female and bisexual flowers being intermingled on the same tree. The flowers are small in size, starts blooming during February to March in Central India and in the month of April in north India. Yellow to greenish flowers are borne on branched panicles they turn reddish later in the year and eventulally brown they stay on the tree for long time. The male flowers have a strong odour. Calyx lobes 1.5x1 mm, ovate triangular. Corolla petals 5, 4 mm long, ovate lanceolate reflexed, glabrous, stamen 10 in the male flower and 0 in the female flower; filaments glabrous. Ovary 2-5 partite. Fruits samara, 4-7 x 1-1.2 cm lanceolate, acute at ends, multiveined, twisted near base, reddish brown. The fruits are formed soon after flowering. The fruit ripen in May-June, just befor the onset of south west monsoon.

Economic Importance

1. A. excelsa wood is extensively used for making matchwood boxes and match splints. The wood is used in pencil slate, making wooden toys and low quality cricket bats. A. excelsa wood is used for light timber (0.45g/cm3); the timber is valued as grade III and grade IV type substitute for veneering. The wood is used for packing cases, fishing floats and sword sheaths. The wood pulp is used for paper industry as a substitute for aspen pulp. It improves the surface quality of paper. The plywood industry in Rajasthan widely uses and the wood of Ailanthus. Stem and branch are used for fuel wood as it gives poor quality and it burns quickly and does not sustain heat for long time. It is also grown for fodder production. Ailanthus excelsa is also has several medicinal properties, the bark of the tree is bitter, astringent, febrifuge, antispasmodic, antiseptic and as expectorant, is also used in treating asthma and bronchitis.

Image: Selected Superior tree of A. exelsa

Edaphic and climatic conditions

It grows in a wide range of soil types, however, it grows well-aerated soil and thrives best in well-drained alluvium and does not tolerate clayey soil and water logging. It can grow even on shallow dry soils but the growth is poor. Halics has given better performance as compared to other species in lateritic soils.

A.excelsa is a strong light demanding tree and it requires high light intensity of better growth and development. It grows well MSL 0 to1500 m with the rainfall of 500-1900 mm. It can grow in temperature varied from 4ºC to 47ºC and relative humidity of 40-90%. It has been found to be a suitable species for planting in dry areas of Rajasthan with annual rainfall of about 400mm. It avoids moist areas having high monsoon rainfall.

Nursery Techniques

Collection of seeds

The quality seeds were collected from the superior trees of Seedling Seed Orchard and Clonal Seed Orchards. Otherwise collected from identified seed stands or selected seed stands with good population. The seeds are generally available in April-June and natural regenaration comes up in July. The seeds are very light, winged and are easily dispersed far and wide by wind. The fruit bunches at the end of the branches should be cut with long handled tools as soon as they show sign of ripening. The seeds are dried on a clean floor so as to prevent seed to be blown away by winds. The seeds are then separated and stored in sealed air tight tins after being thoroughly dried. Seeds normal viablity is 4-5 months. The seeds lose viability fast but under proper storage conditions they can remain viable for up to 240 days. The number of seeds in one kg is about 8,000 to 10,000. From one kg of seeds about 3,000 healthy seedlings can be obtained.

For nursery establishment the soil should be light, porous and well drained. The mother beds should be well raised to allow free drainage. Sowing of seeds in beds is carried out in the month of July - August. The seeds are sown in the motherbeds covered with soil. The seeds may also be sown directly in the polybags. About 15 grams of seeds are required for sowing 1 sq.m of bed.

The seed germination is epigeous, it starts 8-10 days after sowing and completed in about 40-45 days. No pre treatment is required for seeds. Mixing of seeds with ash or pulverized soil ensures uniform growth. The germination percentage is nearly 60-70%. The nursery bed to be irrigated regularly they also require gentle and light irrigation as seedlings are susceptible to diseases such as damping off with heavy irrigations. Over require watering causes damping off and root rot in the plants. The young seedlings in the nursery stage regular weeding to control the weeds and secure the seedlings. After 45 days the seedlings from mother beds are ricked out and transplanted into plastic containers and kept till they become fit for planting.

Image: Collected Seeds

Image: Seedlings of A. excelsa

Clonal propagation

Clonal propagation methods play an important role for mass multiplication of selected superior trees. It is one of the most simple and less expensive methods. In Ailanthus excelsa selected as superior trees are cut at above ground level and applied antifungal treatment (1 g of Lead+ 1 g of copper carbonate 1000 ml or blue copper) for production of healthy coppice shoots. The quality of cutting plays a pivotal role in success of rooting. After 35-40 days the emergence of young shoots are suitable for harvest. The shoots should be green and fleshy with 5-10 cm height, and it’s collected either early morning or evening. The collected shoots treated with 0.05% of bavistin solution to prevent the fungal disease. Vermiculite has been used as rooting media, the cuttings were treated with 1000-6000 ppm Indole 3 - Butyric Acid (IBA) in the powder tip method and planted in the root trainers filled with vermiculite. The root trainers are placed inside the poly tunnel or mist chamber 3-4 weeks for rooting. The initial temperature should be maintained at 26-36°C and humidity 80-100%. Dried and dead cuttings are regularly removed to avoid fungal attack. The treated cuttings were rooted 15-20 days after planting. The rooted cuttings were periodically kept for hardening and after 3 month, old rooted cuttings are suitable for establishing field clonal trials.

Image: Coppice shoot induction

Image: Cuttings for rootings

Image: Rooted cuttings

Land preparation

A.excelsa prefers sandy and porous soil. It comes up on slopes and also on stony patches under suitable moisture conditions. After selecting the site remove bushes and plough the field 2-3 times at the depth of 50-60 cm with tractor drawn disc plough or victory plough and soil made fine until.

Planting

The seedling or cuttings are planted in a pit of 30cm2 or 45 cm2 with a spacing of 3mx3m to 5mx5m. The seedlings which attain height of 50-100 cm are suitable for planting. The root shoot ratio of 1:2 is considered good for stump planting.

Application of fertilizers

A.excelsa is fast growing and requires application of organic or inorganic feritlizers in plantations. In the arid regions of the country and in sandy soils, nitrogenous fertilizer application has given good response for the first year growth, in this plantation causing improvement in plant height around 24% when urea was applied at the rate of 20g/plant. The effect and response of nirogen applicaton gradually diminishes in the second year. The effect of phosphorus before planting in pits at the rate of 40g per plant in single does leads to increase in collar growh in sandy soils.

Irrigation

Normally watering is not necessary in moist areas. Irrigation should be used as an arid and semi-arid area, if the rains are not received within one week of planting. Planting should be stopped in no rains are expected for few days afterwards.

Weeding

The regular weeding for the first two years to stimulates the plant girth and plant growth. In heavy soils three weeding in four month intervel may be required in the first year, subsequently one weeding per year upto 3-4 years is stimulate A. excelsa growth and development.

Pruning

Pruning is an important practice in the cultivation of A. excelsa in farmland. Pruning favour the good growth, clear bole and intercropping ability. Removal of side branches, dead and insect/pest/disease affected shoots in every six months.

Thinning

Thinning is generally required under block planting and also it enhances the production of saw log. The first silvicultural thinning may be carried out in the 3rd or 4th year when the tree attains at the height of 6 to 8 m. Fencing is also needed in areas where the goats and sheep have become accustomed to eating it.

Agroforestry system

Agroforestry research in the country has been accepted and emphasized by the researchers, policy makers and farmers for its apparent ability to contribute significantly to economic growth, poverty alleviation and environmental amelioration. Growing of A. excelsa in agroforestry model is a commercial practice in India. Farmers get more yields of crops and revenue from A. excelsa, various popular agroforestry models practiced in India given below

1. excelsa+ wheat, Aexcelsa + millet, Aexcelsa + barely, Aexcelsa + mustard

Harvest and Yield

There is no specific period for harvesting the tree. Six to eight year old trees can be used for safety matches splints.Above 15 cm girth of all branches of the grown up tree is utilized for safety matches production. The tree has to be cut by saw slantingly just half feet above the ground. It allows the tree for coppicing for the second harvest. Withing three days of harvest the tree has to reach the industry in order to avoid the weight loss. At any cost the harvested material shold reach the industry with in 15 days. Further delay will lead to change in colour and misfits for the industry.

Image: A.excelsa field trial

A comparative estimation of Approximate yield and Income /ha under Rainfed and Irrigated condition

	Year (Rotation)	No. of Trees	Wood Yield (Tons)	Sale Price / Tons (Rs.)	Income (Rs.)
Rain Fed	6	997	200 - 250	1,600	4,00,000
Irrigated	6	1055	315 - 360	1,600	5,76,000

Insect/Pests/Diseases/ Deficiencies and its Control methods

S.No	Affected Plant Parts	Name of the insect / pest	Part of the tree affected	Disease Intensities	Control Measure
1	Defoliator	Atteva fabriciella (Ailanthus webworm)	Fruits, seeds and leaves	Major	0.01-0.02% Formothion and Fenvaluate DDT, BHC, Aldrin, Dieldrin, Endosulphan and Malathion
2	Defoliator	Atteve niveigutta	Leaves	Major	Authio and Chloridimefrorm Sevin 0.01-0.02% Sumicidin 0.01-0.02%
3	Defoliator	Eligma narcissus	Leaves	Low	Manual
4	Bores (Young Stem)	Batocera rufomaculata	Bores in the young stem	Major	Kerosene
5	Bores	Diboma proura	Bores in the young shoot	Moderate	0.05% Phosphamidori or Monochrotophos
6	Leaf spot	Cercospora ailanthiola, C. glandulosa, C.simarrubacienses and Alternaria sp.	Necrotic spots on the leaves	Low	Foliar spray of Bavistin or Dithane M-45 or Fytolan (0.2%)
7	Leaf spot	Alternaria sp.	Leaves	Low	Blitox 0.02% monthly intravel
8	Powdery mildew	Ovulariopsis and Oidium sp.	Leaves	Low	0.05% calixin karathane E.C. 0.05% (20 days interval)
9	Leaf	Oidium ailanthi	Leaves	Low	Very rare occurrence
10	Leaflets	Phome medicogines	Light brown leaf spots with red halo	Low	Cu based fungicides