INTER-CULTIVATION OF AGRICULTURAL CROPS

INTER-CULTIVATION OF AGRICULTURAL CROPS

Any traditional crops except paddy can be grown reasonably well in between the lines of poplars during the first 2 years. Subsequently shade tolerant crops like ginger, turmeric and colocasia can be raised as less sunlight penetrate to the ground during active growth period of poplars because the crowns cover most of the canopy. Short duration winter vegetables or rabi crops like wheat, lentils, toria etc. can also be raised as most poplar clones are leafless during autumn. However intercrop yield decreases with the increase in age of poplars. Care should be taken to avoid physical injuries to the stem of poplars during inter-cultivation operations.

However, inter-cultivation of sugarcane be preferred for first two years as it is more profitable. Third year onwards cultivation of wheat, cabbage, chilly, tomato, barley, coriander, turmeric, ginger, strawberry, oats, berseem, sarson etc. can be raised throughout the rotation.


Plant Protection Measures :

Certain insects and pathogens are known to damage the poplars. Among the important ones are the following :
  • Leaf defoliator : These are active during the rainy season particularly Pygaera species. The caterpillar of these moths feed on leaves. The insect can be controlled by collecting and destroying the infested leaves. Spray of Monocrotophos 36 SL @ 600 ml (Monocil / Monolik / Nuvacron / Corophos / Luphos) per acre is followed.
  • Termites : The risk of termite damage is likely where irrigation and inter cultivation operations are inadequate. The soil should be treated with Aldrin or Gammexene ( BHC ) (0.15%) and frequent irrigation arranged.
  • Stem and shoot borer : These can be controlled by pushing a small wick of cotton dipped in any liquid fumigant in the holes through which frass is being pushed out by the borer. All holes must be closed with mud paste after such treatment.
  • Leaf Webber : The young larvae scrap the leaf surface along with veins and feed on epidermis of leaves by webbing 2 and 3 leaves with silken threads. The pest is active from April to November with peak period from July to October. For controlling the same measures as indicated under leaf defoliators can be adopted.
  • Bark Eating Caterpillar : Nocturnal feeding larvae make L-shaped holes and wet silken threads entangled with fecal pallets. Pest is active throughout the year. Prune severely infested branches and spray suspension of 100 g Carbaryl 50 WP ( Sevin / Hexavin ) in 10 litres of water during September to October at feeding sites.
  • Case Worm : The pest is active throughout the year. The caterpillars feed on bark from December to March, on leaf buds during March and April and on leaves from April to November. For controlling this a spray of Carbaryl 50 WP ( Sevin / Hexavin ) @ 1 Kg per acre is recommended.
  • Leaf Hopper : The leaf hoppers are active from April to November with peak period of their activity from July to October. A spray of Oxydemeton-methyl 25 EC (Metasystox) @ 300 ml or dimethoate 30 EC @ 250 ml per acre is recommended.
  • Rot of cuttings : Black dots appear on the cuttings at ground level and decay of bark takes place. Dip the cuttings for 15 minutes in 0.5 percent solution of Emisan-6 before planting.
  • Leaf Spots : Brown to dark brown leaf spots of variable sizes appear on leaves. Severe infections lead to premature defoliation. Spray the crop with 0.25 percent Copper Chloride (Biltox 50) or Indofil M-45 at 15-20 days interval starting with first rain. Two to three sprays may be given.
  • Pink Disease : Girdling of branches in young plants leads to death of parts. The height of tree is stopped due to repeated death of the leaders. Pink to Salmon colored mycelial growth appears on branches. Use resistant varieties or two to three prophylactic spray of Bordeaux mixture during two to four years of age at the beginning of the summer monsoon.
  • Sunscald canker : Bark is killed due to insolation by heat and canker develops on the southern side of the stem. Protect from insolation and other injuries by white washing the main stem upto two meters from the ground level.
  • Bark Bursts and Canker : Water oozes out through the wounds resulting in cankers. Avoid injury and high water table sites. Clean the wounds and apply Bordeaux paste or Emisan-6.
9. Yield and Returns
  • Under reasonably good care poplars can attain 90 cm girth at breast height and mean annual increment of 20m3/ha (under bark) at 8 years rotation.
10. Utilization
  • Populus deltoides has a medium hardwood which is light, free from knots, easy to saw and work.
  • The wood has good nail holding power and strength coefficient of Populus deltoides is comparable to well known woods used in packing cases and hence can be used for making cases for fruit and food stuffs.
  • High yield pulps (71-80 percent) having excellent strength properties for newsprint could be prepared.
  • Young poplars of 2-3 years age group are an excellent source of cellulose fibre for making various grades of fine paper, packing paper, newsprint, etc.
  • An experiment conducted at Forest Research Institute, Dehradun indicates that Populus deltoides wood is suitable for preparation of hardboards, and that bark to the extent of 20 percent helps in improving the physical and mechanical properties of board compared to boards prepared alone with wood.
  • Most of the poplar wood is used in the match and plywood industry.
  • The species is suitable for making general purpose plywood, marine plywood, concrete shuttering plywood. It is also considered suitable for the manufacture of artificial limbs, sports goods and for structural uses such as false ceilings, partition and almirah shelves, etc.
  • It has also been found suitable as line supports for overhead power and telecommunication lines.
  • The white furniture made out of poplar wood is becoming popular in towns of Punjab.

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Source: Report of the task force on greening India for livelihood security and sustainable development. Planning Commission, Government of India, July-2001.
Last modified: Tuesday, 22 May 2012, 8:24 AM