Eucalyptus hybrid plants:-
INTRODUCTION | ||||||||||||||||||||||||
Eucalyptus is a fast growing tree which is among one of the best species for agro-forestry. Clonal plants are vegetatively propagated plants from a single mother tree having most desirable genetic qualities. Clonal plants have same genetic qualities as the mother plant. Trees raised from each superior clone will be uniform, true to type and fast growing. Productivity of clones is higher compared to normal seedlings of eucalyptus. Eucalyptus trees are harvestable within 8 to 10 years of short rotation for production of timber. Alternately, eucalyptus plantations can be raised for poles and paper pulp at 5-6 years rotation. | ||||||||||||||||||||||||
USES OF WOOD AND MARKETING | ||||||||||||||||||||||||
Wood of eucalyptus is suitable for constructional timber, furniture, plywood, ply-board, poles, paper pulp and packing cases etc. Due to its multiple uses, demand of eucalyptus wood is increasing day by day. The clonal eucalyptus trees yield more, clear, straight and knot free timber in comparison to normal seed rooted eucalyptus and fetches better market price of the wood. | ||||||||||||||||||||||||
SELECTION OF SITE | ||||||||||||||||||||||||
Well drained, fertile and rich soils in organic matter, loamy to sandy loam in texture are most suitable for better growth of clonal eucalyptus plants. Match the most adaptable clones to specific types of soil e.g. normal ph soils, high ph soils, irrigated and non irrigated lands etc. based on the soil tests. It is desirable to have assured source of irrigation to ensure higher survival and better growth of eucalyptus. However, rain-fed plantations can also be planted during rainy season. | ||||||||||||||||||||||||
SUITABLE CLONES | ||||||||||||||||||||||||
Almost all clones are suitable for normal soils having rich organic matter and texture loamy to sandy loam e.g. Clone nos. 1, 72, 105, 286, 288, 316, 405, 407, 411, 413, 469, 492 and 526 etc. and Hybrid Clone nos. 2004, 2012, 2045, 2049, 2069, 2070, 2136, 2155 and 3020 etc. But for alkaline soils separate set of clones like 413, 411, 526, 316, 288, 105 and 72 etc. are recommended. Hybrid clones 2004, 2012, 2045 and 2049 are also tolerant to mild alkaline soils. For ph 9 -9.5 plant only clones 413 and 411. Clones have to be tested on very sandy, saline or water logged soils before taking up large scale plantations. | ||||||||||||||||||||||||
SUITABLE TIME of PLANTING | ||||||||||||||||||||||||
In irrigated lands, transplanting can be done anytime during the year except very hot months of May- June. For rain-fed plantations, best time of transplanting is early part of monsoon rains so that plants take full advantage of rains for establishment and growth. | ||||||||||||||||||||||||
PLANTING DISTANCE/ SPACING | ||||||||||||||||||||||||
Each clonal eucalyptus tree needs approximately 8-10 square meter space for its optimum growth. Spacing, generally adopted by the growers for raising clonal eucalyptus under Agro-forestry system in block plantations are: | ||||||||||||||||||||||||
4 m x 2 m; 3 m x 3 m; 4 m x 2.5 m; 5 m x 2 m | ||||||||||||||||||||||||
Thus, 400- 500 saplings per acre can be planted for timber production at 8-10 years rotation. | ||||||||||||||||||||||||
Alternately adopt spacing of 3 m x 1.5 m for block planting @ 888 saplings per acre for poles and paper pulp at 4 -5 years rotation. | ||||||||||||||||||||||||
Farmers have the option to cut 50% trees for poles and paper pulp at 4-5 years and retain balance 50% for timber production to be harvested at 8- 10 years rotation. | ||||||||||||||||||||||||
Plant to plant distance is kept as 2 meters or 6 feet apart for single line or field boundary plantations. | ||||||||||||||||||||||||
SITE PREPARATION, LAYOUT AND DIGGING OF PITS FOR TRANSPLANTING | ||||||||||||||||||||||||
To study the soil profiles get the soil samples tested particularly for NPK status, PH, E.C. and hard pans in sub soil. With deep ploughing get the fields free from weeds and apply phosphatic and potassic fertilizers as basal dose as per the recommendations of soil testing report. Dig irrigation channels 45 cm. wide and 30 cm. deep in north to south direction based on pre determined spacing or 4 m apart (depending upon spacing to be adopted). It will result wider spacing in the east to west direction ultimately ensuring better sunlight to the trees as well as intercrops. Planting pits should be 45 to 60 cms. deep at 2 m apart. Lower portion of pits to be refilled and depth of planting to be maintained between 20 cms. to 30 cms. depending upon height of clonal plants. |
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FIELD PLANTING | ||||||||||||||||||||||||
After lifting the plants from nursery, provide light irrigation to plants in trays twice a day during mild season and thrice a day during hot summer months, till the planting is over. A light irrigation to plants in trays may be provided about one hour before planting, enabling to lift the plants from the tray through gentle push and pull along-with ball of vermiculite and roots. Apply adequate irrigation to the root zone of the plants after planting. Do not use fertilizers or saline/ alkaline water for irrigation.Apply Lindane or Chloropyriphos @ 2 ml. per litre of water per plant as prophylactic treatment against termites. over dose of Chloropyriphos may cause damage to the plants. However, application may be repeated from time to time in case of need.
Match clones to specific sites based on soil tests. To maintain clonal identity, plant each clone in separate block and keep the record. |
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IRRIGATION | ||||||||||||||||||||||||
Need based light but frequent irrigations to be provided for proper establishment and growth of plants depending on soil type & season and ambient climatic conditions. Apply first irrigation immediately after field planting and make sure that adequate moisture reaches the root zone of each and every young transplanted sapling. Three to four light irrigations per month during summer and two irrigations per month during winter will ensure excellent growth. Provide irrigation only through irrigation channels during first two years. Avoid heavy compaction of soil at the time of planting as it may put barrier in providing adequate moisture to the rooting zone of young transplanted saplings during initial irrigation, ultimately resulting mortality. Avoid heavy flood irrigation even during subsequent years too as it may result lodging of trees with strong winds. |
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APPLICATION OF FERTILISERS | ||||||||||||||||||||||||
It is better to apply Nitrogenous, Phosphatic and Potassic fertilizers as basal doses and top dressing as per the recommendations of soil testing report. In the absence of soil tests; following general recommendations about fertilizers may be followed:(1)DAP @ 100 kgs. per acre and Potash @ 50 kgs. per acre as basal dressing per year at the time of sowing of intercrops preferably in two split doses.(2)Urea @ 25 kgs. per acre thrice a year during first year and @ 50 kgs. per acre with irrigation at nearly 3 months interval i.e. total four times in a year from second year onwards.(3)10 kgs each of Zinc Sulphate and Ferrous Sulphate per acre per year.Apply fertilizers when the field is free of weeds. Apply light irrigation after application of fertilizers. Never apply Zinc and Phosphatic fertilizers together. Fertilizers should normally be applied to the whole field. Never apply fertilizers close to the stem or roots of young trees– keep a distance of 25-30 cms. otherwise the young plants may die because of dehydration.Never apply basal doses of any chemical fertilizer in the pit at the time of planting of clonal plants. otherwise, it may cause damage to plants. Usually apply chemical fertilizers after about three months of planting the plants. |
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INTERCROPPING | ||||||||||||||||||||||||
Intercrops like wheat/ peas / potato or any vegetables can be grown in 4 mt wide strips. Avoid heavy feeder crops or those growing extremely fast like, maize, pearl millet, sorghum, sugarcane and sunflower etc., which will suppress young clonal plants. Keep at least 2 feet space on all sides of the eucalyptus plants free of intercrop. Use of Weedicides for control of weeds in intercrops is prohibited, as many of these are very harmful to eucalyptus saplings. |
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MAINTENANCE OF PLANTATIONS | ||||||||||||||||||||||||
(1) Effective protection of plantations must be provided against abnormal damage by fire, cattle or physical injuries by implements/ tractors during inter-cultivation operations. Large numbers of birds like crows may rest on apical tips and damage the leading shoots. Scare the crows away with crackers around sunset time. Any injuries to bark or stem should be dressed with Bordeaux paste.(2) Timely weeding and soil working should be carried out to keep the plants free of weeds, which compete for moisture and nutrients.
(3) Most eucalyptus clones are self-pruning. Leaf canopy is essential for photosynthesis and good diameter growth. Hence no pruning is normally recommended for eucalyptus. Forked leaders can be carefully singled. (4) Judicious application of farm yard manure and fertilizers, based on soil test reports, will be required every year to take care of the deficiencies of major nutrients and micro nutrients and for ensuring optimum growth rates. (5) Many soils are deficient in zinc and iron. If Chlorosis or yellowing of leaves persists despite application of NPK as above, then address the iron and zinc deficiencies. Apply 10 kg Zinc Sulphate and 10 kg Ferrous Sulphate per acre followed by irrigation. Never apply Zinc and Phosphatic fertilizers together. |
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TIPS TO ENSURE BETTER SURVIVAL AND GROWTH OF PLANTATIONS | ||||||||||||||||||||||||
• More than 90 % survival of planted saplings can be achieved if improved package of practices is followed. major causes for mortality of plants after transplanting are as follows which can be prevented with good care:-(1) Improper and careless handling of plants before transplanting – please handle plants carefully & do not throw the root trainers while loading, unloading, transporting and carrying for planting.
(2) Lack of irrigation of plants before transplanting – irrigate plants adequately in trays twice a day during winter and thrice a day during summer. Irrigate the plants in root zone and avoid irrigation over the leaves. (3) Damage by termites – termites can cause heavy mortality. The symptoms are drooping of apical shoot followed by drying of leaves and sudden death of plant. Leaves do not fall and plant roots or underground stem are damaged by termites. Ensure effective preventive and control measures against termites. Use dependable brands of Chloropyriphos like Tricel, Durmet, Radar, Lithal and Dursdban or Lindane. Repeat Chloropyriphos application in deep crowbar holes around the stem on need based basis depending upon the infestation of termites. (4) Improper or excessive application of Chloropyriphos – apply lindane or Chloropyriphos @ 2 ml. per litre of water per plant. The treatment can be repeated with Chloropyriphos once a month in areas infested with termites. Excessive dose or application on the leaves may cause mortality. Inadequate dose may also prove ineffective. (5) Excessive fertilizers or application of chemical fertilizers close to the stem and roots of young saplings will kill the plants. Plants will dehydrate and die quickly after drooping of apical shoot and drying of leaves. Avoid basal application of chemical fertilizers at the time of planting. Even later on never apply fertilizers close to the stem or roots. If labour applies fertilizers close to stem by mistake, give deep hoeing, mix the dug soil well with surrounding soil and provide good irrigation. (6) Inadequate irrigation and moisture stress after transplanting – ensure good deep irrigation in channels so that adequate moisture reaches the root zone particularly with first two irrigations. Repeat irrigations at 5 to 7 days interval during summer and hot months and twice in a month during winter season. (7) Water logging and impeded drainage- prevent water logging and improve drainage of fields as stagnating water will also kill the plants. In low laying fields, improve drainage and transplant the plants on raised ridges preferably after rainy season where irrigation facilities are available. (8) Use of Weedicides – never use Weedicides as most of them are toxic to eucalyptus and may cause mortality. (9) Suppression by fast growing crops like Sugarcane, Maize, and Bajra etc. – avoid fast growing intercrops during first year. (10) Injuries by cattle, tractors and bullocks / implements during ploughing and weeding operations. (11) Excessive competition from weeds. Carry out regular weeding and soil working. (12) Protect your plantations from damage by fires. Burning of crop residues in adjoining fields should also be under controlled conditions. (14) Leaf spot diseases or root fungi can also lead to premature leaf fall and mortality in case of severe infection. however, the plants will die slowly and symptoms will be different (15) Mortality because of fungi is rare in eucalyptus clones and very often the blackening of stems and leaves of dead saplings is because of saprophytic fungi which grow on plants killed by other reasons.
Height of plants The girth of plant should be measured at 1.4 meter height above the ground level
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