Agroforestry Chapter 8 (Part 1): Khair, Shisham and Poplar
Agroforestry Notes · Chapter 8 · Part 1
Chapter 8 (Part 1): Khair, Shisham and Poplar
Identity, distribution, site, phenology, silvics, seed and nursery facts, planting, protection and uses of Acacia catechu, Dalbergia sissoo and Populus deltoides.
1. Khair (Acacia catechu Willd.)
| Feature | Khair |
|---|---|
| Family | Leguminosae: Mimosoideae |
| Common names | Khair, Katha tree, Cutch tree |
| Habit | Moderate-sized deciduous tree; light feathery crown, crooked bole, recurved thorns |
| Varieties | catechuoides, sundra, catechu (var. catechu: Sikkim, Terai, Bengal, Assam, Shiwaliks of HP, Punjab, Haryana; var. sundra: peninsular India and Burma) |
| Distribution | Throughout India except humid and temperate regions; mostly 900–1200 m from Jammu to Assam |
| Climate | Max 40–50 °C, min 1 °C; rainfall 500–2000 mm |
| Soil | Even shallow soils with murram or kankar; a riverain pioneer on new alluvium |
| Phenology | Leaf fall Jan–Feb; flowers Apr–Aug; fruits Sep–Oct; seed collection Oct–Dec |
Silvics
- Strong light demander
- Frost and fire hardy, wind-firm
- Browsed; grazing stops natural regeneration
- Strong coppicer: stumps up to 60 cm diameter coppice; no coppice under heavy shade
Seed and nursery
- Pods collected just before full ripeness (insects attack seed on the tree)
- Store no more than 6–8 months
- 30–40 seeds per gram; 0.5–2 kg seed per tree
- Sow Feb–Mar at 20 × 2 cm; damping-off with poor drainage and shade
Planting
- Direct sowing is best; also polybag seedlings and stumps
- Polybag plants in 30 cm³ pits at 3 × 3 m, planted in July
- Stumps from 12–15-month seedlings: root 23–31 cm, shoot 2.5–5 cm
Management and uses
- Best system: clear felling with artificial regeneration
- Root rot by Ganoderma lucidum after clear felling
- Heartwood gives katha and cutch; gum is the best substitute for gum arabic
- Fuel of very high calorific value (5142–5244 kcal/kg)
Growth: a 9-year coppice reaches about 20 cm girth and 3.4 m height. Over-mature trees coppice weakly.
2. Shisham (Dalbergia sissoo Roxb.)
| Feature | Shisham |
|---|---|
| Family | Leguminosae: Papilionoideae |
| Common names | Shisham, Sissu |
| Habit | Large deciduous tree up to 30 m and 2.4 m girth; thick grey bark peeling in woody strips |
| Distribution | Sub-Himalayan tract from the Indus to Assam, usually up to 900 m (occasionally 1500 m) |
| Habitat | Gregarious on fresh alluvium along streams, often with khair (riverain pioneer) |
| Climate | Max 40–50 °C, min 4 °C; rainfall 760–4600 mm |
| Phenology | Leaf fall Nov–Dec; flowers Mar–Apr; fruit ripe Nov–Dec |
Silvics
- Strong light demander
- Frost and drought hardy, wind-firm
- Sensitive to fire and browsing
- One of the easiest species to propagate
Seed
- Fertile seed from 3–4 years; 12–15 kg pods (4–5 kg clean seed) per tree
- Viability 12–18 months
- Lecture: about 530 seeds/g; seed-ID exercise: 18,500–35,000 pods/kg, 1–3 seeded
- Soaked seed germinates in 7–15 days; germination 80–90%, plant per cent about 45%
Planting
- Direct sowing in lines 3–4 m apart; about 56 kg seed per ha
- Entire transplants
- Stump planting is best: cheap and planting can run July–September
- Stumps 1.8 m apart in lines on trenches 3 m apart
Uses
- Premier furniture and construction timber
- Fuel and charcoal
- Leaf fodder
- Anti-erosion works on river banks
Memory trick: K-M, S-P: Khair = Mimosoideae, Shisham = Papilionoideae.
3. Poplar (Populus deltoides Bartr.)
| Feature | Poplar |
|---|---|
| Family | Salicaceae |
| Origin | Exotic, native to the USA (river bottom lands) |
| Habit | Straight cylindrical bole, conical crown; leafless in winter |
| Indian indigenous poplars | P. ciliata, P. laurifolia, P. gamblei, P. alba, P. glauca |
| Main clones | G-3, G-48 (Australian selections); D-121 (American selection); also D-61, D-67, S7C8, S7C15, L-34, L-49, L-52, Uday, Kranti, WSL-22/27/32, PL-1 to PL-7 |
| Where | Irrigated north-western plains (Punjab, Haryana, western UP); succeeds mainly above 28° N |
| Soil | Moist, well-drained, deep, medium-textured alluvium; very sensitive to zinc deficiency (ZnSO₄ 25 kg/ha) |
| Rotation | 8–10 years |
P. deltoides and its hybrids make up about 90% of the world’s cultivated poplars (FAO, 1979). Without irrigation it grows poorly and suffers from borers.
Propagation
| Material | Details |
|---|---|
| Seed | Rarely used; lab germination 5.25–19.25%; about 14,000 seeds/kg; first flowered in the Terai in May 1982 |
| Cuttings | 18–25 cm long, 1–2.5 cm thick, at least 4 buds; from main stem of 1-year wood; soaked 24 h |
| Sets | 1-year cut-back plants without roots, about 3.5 m long, in 75 cm–1 m deep pits |
| Stumps | 25 cm root + 3 cm shoot from 1-year plants |
| Bag plants | Do not give vigorous plants |
| ETPs (entire transplants) | Best method: 1–2-year plants, root cut at 25 cm, naked root, no foliage |
Nursery and planting
- Cuttings planted Jan–Feb, thin end up, 2 cm above ground; irrigation every 7–10 days.
- Nursery spacing for vigorous ETPs 80 × 60 cm; FYM 200–250 q/ha; singling in Apr–May; debudding up to 2/3 height Jun–Oct.
- Field planting Jan–Feb before bud burst with ETPs about 3 m tall.
- Per plant: 2 kg FYM, 50 g superphosphate, 5 g urea; later urea 75, 150, 250 g (Jun–Aug).
- Best agroforestry spacing: 5 × 4 m = 500 plants/ha.
- Intercrops: any crop except paddy; sugarcane most profitable in years 1–2; later wheat, berseem, toria, turmeric, ginger. Intercrop yield falls as poplar ages.
Pests
- Defoliator Clostera (Pygaera) in the rains
- Termites, stem borer, leaf webber
- Bark-eating caterpillar
Diseases
- Rot of cuttings: dip in 0.5% Emisan-6
- Pink disease: resistant clones or Bordeaux mixture
- Sunscald canker: whitewash stem up to 2 m
Yield and uses
- About 90 cm girth and MAI 20 m³/ha at 8 years
- Matchsplints and plywood, packing cases, sports goods
- Pulp yield 71–80% (newsprint)
4. Quick revision box
- Khair: Mimosoideae; 30–40 seeds/g; katha from heartwood; Ganoderma lucidum root rot; clear felling + artificial regeneration.
- Shisham: Papilionoideae; viability 12–18 months; stumps 1.8 m on trenches 3 m apart; furniture.
- Poplar: Salicaceae, exotic (USA); G-3, G-48 Australian, D-121 American.
- Poplar: ETPs best; cuttings 18–25 cm, 4 buds; 5 × 4 m = 500/ha; no paddy; sugarcane years 1–2.
- Poplar: ZnSO₄ 25 kg/ha; whitewash against sunscald; MAI 20 m³/ha at 8 years; matchsplints, plywood.
5. Interactive MCQ Quiz
15 questions. Tap an option to see the answer and explanation, then go to the next question.
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