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1. IntroductionThe ITC Limited-Paperboards and Specialty Papers Division (PSPD), Bhadrachalamunit uses 0.6 Mt yr-1 wood from eucalypt along with other woods for manufacturingthe pulp and paperboards. A plan to grow 10,000 ha yr-1 of plantations was drawnto meet the raw material requirements of the mill on a continuous and sustainablebasis.
In the first phase, the company promoted social and farm forestry plantationsby distributing nearly 30 M seedlings and covered 9,441 ha with eucalyptplantations from 1982 to 1995. These plantations showed high genetic variations,poor survival and productivity. At that time the prevailing scene of eucalypt seedroute plantations was grim as the foliar blight disease caused by Cylindrocladiumspp. was quite prevalent in plantations. Apart from that, termites caused large-scale seedling mortality in plantations of young age. The outcome was that thesurvival of trees in plantations at harvest stage was 30 to 50 per cent andproductivity of 4 to 6 t ha-1 yr-1. Due to low yields, the plantations were noteconomical to the farmers as an alternative farming option. The other reasons forpoor productivity were hybrid break down, non-availability of quality seeds,primitive nursery practices, mismatch of species and provenances to site, closespacing, lack of follow up of correct package of practices (Kulkarni, 2001). Becauseof eucalypt controversy (Rajan, 1987), farmers were scared to take up plantations.
Therefore, two decades ago, farm forestry plantations were becoming unpopularin spite of the incentives, subsidies and National Bank for Agriculture and RuralDevelopment (NABARD) loans to the farmers. This adverse scenario changed, overa period of four to five years, from the year 1989 when the company decided tolaunch tree improvement programme (TIP) and promoted clonal technology basedplantations (Kulkarni and Lal, 1995).
ITC PSPD, Bhadrachalam unit launched a major plantation programme withtwo-fold objectives:
Eucalypt Improvementat ITCH.D. Kulkarni
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1. Achieve self-sufficiency in wood based fibre requirements on a continuousand sustainable basis, and
2. provide agri-farmers a viable alternative land use option by improvingproductivity and returns.
The objectives of tree improvement programme set were:h Increase plantation productivity by at least three times,h reduce plantation harvest period,h adopt suitable spacing for better growth,h develop disease resistant, wind and drought tolerant and site specific clones,h improve silvicultural and fibre traits,h improve package of practices for raising plantations,h develop models and package for social and farm forestry to take tree,
improvement research to the field, andh make eucalypt farming a farmer friendly viable alternative option.
2. TIP LocationThe experimental site and Clonal Research Station is located at 17o 40' N latitude and81o E longitude. The altitude of the place is 100 m above mean sea level. The climateis sub-tropical with annual rainfall of 1,033 mm, mostly from southwest monsoon.The maximum temperature recorded is 49oC and minimum 10oC. The predominantsoils are red sandy and black cotton. Soils are either normal or alkaline. Saline soilsare also found.
3. TIP Strategies and MethodsEucalypt seeds were imported from CSIRO (Australia) in the years 1986, 1990, 1994and 1995 to raise provenance trials. Candidate plus trees (CPTs) of E.tereticornisSmith and E. camaldulensis Dehnh. were mainly selected from government and farmforestry plantations. Selected plus trees were propagated vegetatively from coppicecuttings in mist chambers. Root trainer technology was adopted for the productionof plants. The successful ramets were planted in gene banks known as clonalmultiplication areas (CMA) at a spacing of 1 m x 1 m. The clonal testing areas (CTA)were planted at 3 m x 2 m spacing in RBD with three replications. Ploughing of theplots was carried out annually. No fertilizers and irrigation was provided to the trialplots. Periodic measurements were recorded for girth, height and occurrence ofpests and diseases and promising clones were short-listed. Clonal seed orchards(CSOs) adopting the permutated neighbourhood design (Sekar et al., 1984) wereestablished in 3 ha area. Clonal demonstration plots (CDPs) were raised under theextension scheme. Inter- and intra-specific hybridization was carried out betweenselected best clones and other species of Eucalyptus. Half and full-sib progeny
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trials were laid out. Promising hybrids were cloned and planted in multi-locationtrials. Genotype x site interaction studies for various clones were carried out onnormal and refractory sites. A gene repository was also established for conservingclonal material. The wood morphology, proximate chemical analysis and strengthproperties of wood for pulp and paper and DNA finger printing studies were carriedout.
At the beginning of the programme, the main handicap faced was the non-availability of a wide genetic base for the improvement of eucalypt. Therefore, ‘breedthe best with the available best’ strategy was followed.
3.1. Gene ResourceThe genetic base deployed for improvement of eucalypt is based on the speciesE. tereticornis as it is most suited to this zone. However, other species ofEucalyptus such as E. alba, E. camaldulensis, E. citriodora, E. grandis, E. pallita,E. torelliana, E. urophylla, etc. were also involved for selection and hybridisation(Fig.1).
3.2. Candidate Plus Tree SelectionThe selection of the most desirable tree with characteristics such as straightness ofstem, annual growth rate, disease resistance, crown structure, wood density, fibremorphology, cellulose/lignin balance, bark: solid wood ratio, under-bark relation-ships, etc. were considered. Starting with the cloning of 64 CPTs during 1989, morethan 1,000 CPTs and 500 full sib CPTs have been selected and cloned. Out of 1,500selections, 107 promising clones were shortlisted and 63 per cent have come fromprovenance seeds source obtained from CSIRO (Australia) and 37 per cent fromlocal land race Mysore gum. The provenances that gave maximum clones are 8 KMNW Black Mountain and 1 KM N of Laura.
3.3. Vegetative PropagationFor most of the clones, the percentage of rooting of juvenile coppice shoots underintermittent mist conditions with 70 per cent relative humidity and 35oC temperature,was more than 70 per cent except for clone 6 which was less than 40 per cent. Roottrainer technology employed for growing the cuttings ensured low handling andtransportation cost in comparison to traditional polybag nurseries. Besides, the plantswere transported without any damage over long distances. Thus, ITC became the firstcompany in India to introduce root trainer technology on large scale.
3.4. Clonal Testing and Promising ClonesClones were evaluated from CTAs for comparative genetic superiority and G x Einteractions. Nearly 159 trial plots in 36 ha area have been established since 1989 in
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various soil types under rainfed conditions. As many as 107 promising clones wereshort-listed from the above trials. In the beginning of the programme, clones wereplanted without due regard to site. After a gap of three to four years, it was discoveredthat some clones were doing well and some were not in a given site. In general, blacksoils (normal, alkaline and saline) require specific ITC clones 1, 10 and 130 whichadapt well. But clone 10 does not tolerate saline sandy soils and it led to highmortality (up to 90%) in a two-year-old plot at Tangutur in Prakasam District of
H.D. Kulkarni
Fig. 1. Eucalypt improvement at ITC.
Base Population
E. tereticornisBlack Mount - 60Kennady River - 5Mt. Molley - 26Ruthcreek - 31Mysoregum - 299
E. simulateLaura - 44Kennady - 39
E. camaldulensisKatherine River - 19Maxwelton - 8Petford - 32Kennady River - 32
E. urophylla - 12E. grandis - 2E. alba - 1E. pellita - -C. torelbana - 1
1000 CPTs
CTACMAGXESILVI TRIALS
107 Promising Clones
Hybridization
CSO-7 Intraspecific-217 Interspecific-30
Hybrid Clones
New Eucalypt Forests
ProductionPopulation
BreedingPopulation
Wood ProductionPopulation
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Andhra Pradesh. However, in the same plot ITC clone 411 and 413 were performingwell with high productivity and survival. Normally, CPTs selected from black soil areto be tested first on black soil itself and later on other soil types as clones exhibit astrong affinity to the site of their origin. For example, ITC clone 351 that was selectedfrom black soil gave a yield of 22 t ha-1 yr-1 on similar site compared to 6 t ha-1 yr-1 onred soil (Table 1).
Eucalypt improvement at ITC
Clone 3: Origin from red soil Clone 351: Origin from black soil.
Table 1. Performance of two clones on red and black soilsRed soil Black soil CAI/MAI (under bark tha-1)
Clone 3 Clone 351 Clone 3 Clone 351 CAI at age 1 14.2 7.9 4.6 4.0 2 24.7 4.9 9.0 13.3 3 11.7 5.7 25.2 33.2 4 14.8 5.4 37.0 37.4 MAI at 4 years 16.3 6.0 18.9 22.0
The clonal testing method was later modified as testing was directly taken-up inthe farmers’ field by providing irrigation and fertilization. As a result, the woodvolume production went up by 10 to 40 per cent and harvesting was done at 2 to 3years period. The site-specific and commercial clones shortlisted are:
The most important commercial clones are:- ITC-3, 6, 7, 10, 27, 71, 72, 99, 105, 115,122, 128, 130, 223, 265, 266, 271, 272, 273, 274, 175, 277, 284, 285, 286, 288, 290, 292, 316,319, 405, 411, 412, 413, 417, 439 and 470.
The most adaptable clones for alkaline soils are:- ITC-1, 10, 27, 71, 99, 105, 115, 116,122, 128, 130, 158, 223, 266, 271, 272, 273, 274, 277, 290, 316, 318, 328, 410, 411, 412, 413and 417.
The plastic clones are :- ITC-27, 71, 83, 99, 105, 116, 128, 130, 147, 271 and 285.
3.5. Disease ResistanceThe outbreak of diseases caused by various fungi on eucalypt in nursery and fieldrevealed main pathogens as Cylindrocladium spp. and Alternaria spp. causing foliarblight disease. The resistant clones short-listed are ITC-1, 3, 6, 7, 288 and 316.Eucalyptus gall (Kulkarni, 2010a) caused by Leptocybe invasa (Fig. 2) created havocin nursery and plantations in the year 2008-09. ITC - clones 1, 320, 411, 413, 513, 612,2145, 2253, 2254 and 2306 were identified as gall resistant. Parasitoid Quadrastichusmendeli as a biological control agent was introduced from Israel. The gall is now under
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control. Clones such as ITC 10 and 27 are found to be highly susceptible. Little leafdisease (Kulkarni, 2010b) caused by thrips (Fig. 3) was found on all the clones. Theother insect Batocera rufomaculata (mango beetle) caused wide spread damage tothe growing shoot of three-month to one-year-old plants (Kulkarni, 2010c).
3.6. Productivity of ClonesThe survival percentage for majority of clonal plantations is more than 95 (Kulkarniand Lal, 1995). The productivity of ITC-Bhadrachalam clones thus range from 20 to 58t ha-1 yr-1. compared to 6 to 10 t ha-1 yr-1 from seedling origin plantations (Fig. 4). Apartfrom increase in productivity by four to six times, the rotation period has reduced by
H.D. Kulkarni
(a) Leptocybe invasa (b) Leaf gall
(c) Resistant clone (413) (d) Susceptible clone (27)Fig. 2. Eucalypt gall. (a) The insect pest, (b) the symptom, (c) the resistant and(d) susceptible genotype.
155Eucalypt improvement at ITC
Fig. 3. Vector (a-b), symptom (c) and causal organisim (d) of little leaf disease.
Fig. 4. Annual increment in CTA 21 at the age of six years at Bhadrachalam.
(a) Nymph (b) Thrips
(c) Little leaf (d) MLO
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half (Fig. 5). The root system invariably has a depth of 1.5 to 2.5 m with surface feederand anchor roots (Fig. 6). Therefore, farmers are now harvesting plantations at fouryears instead of seven years with uniform premium timber.
H.D. Kulkarni
Fig. 5. Clonal plantations from one to four years.
Fig. 6. Root system from one to four years.
157Eucalypt improvement at ITC
3.7. Volume Table for ClonesThe regression equation developed for eucalypt seedling based plantations (Rajan,1987) did not suit clonal plantations as the rhythm of growth was quite different.The regression equation and volume table for eucalypt clones was prepared(Chaturvedi, 1995).
Volume (over bark) V = 0.00352 + 0.0341 G2HVolume (under bark) V = 0.00258 + 0.0281 G2H
3.8. Yield AssessmentOne hundred plantations were felled in different districts to assess woodproduction for authenticating the CTA trial results. The farmers obtained the MAI(t ha-1) of 23 in Khammam, 28 in Prakasam, 21 in Guntur, 24 in Krishna and 39 inWest Godavari was obtained. The average MAI (t ha-1) works out to 27. Further,the farm forestry plantation average IRR per acre in different districts worked outto 40 in West Godavari, 48 in Khammam, 32 in Prakasam, 26 in Guntur and 30 inKrishna (MANAGE, 2003).
3.9. Clonal Multiplication Areas (Gene Bank)Since 1989, 33 ha gene bank has been raised with 0.22 million ramets in blocks at1 m x 1 m spacing in the mill premises. The CPT material was first planted in thegene banks. Gene banks are regularly coppiced at two years age for obtainingthe propagules for multiplication. Each stump has given 180 to 200 ramets withthree harvests and annually nearly 10 M plants are produced for planting.Recently, mini cutting area (MCA) has been developed and apical shoots areharvested for propagation which gives continuous supply of shoots throughoutthe year.
3.10. Clonal Demonstration PlotsClonal demonstration plantations (CDPs) raised by the company resulted in large-scale adoption of genetically superior ITC-Bhadrachalam clones of eucalypts by thefarmers and state forest departments/forest development corporations. Since 1989,more than 50 ha of CDPs have been established at various places in Andhra Pradesh.As ‘seeing is believing’, farmers’ meetings were regularly held in these plots whichenabled them to pick and choose the clones most suited for their land.
3.11. Clonal Seed OrchardsBest clones were planted in 3 ha area in (CSO). Fresh CPTs are now being selectedfrom the CSO based plantations as selections with new recombinations are givingnext generation clones. The major problem encountered in raising CSO was that theneighbouring fast growing clones suppressed the slow growing clones. Thus,
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planting in a mosaic design did not serve the purpose. Another problem encounteredwas non-synchrony in flowering of clones resulting in restricted gene exchange.
3.12. HybridizationThe hybridization programme was initiated in 1994. A breeding orchard was set upwith cleft grafted plants of E. tereticornis, E. camaldulensis, E. alba, E. urophyllaand E. grandis. The selected material was multiplied in large numbers by cleft grafting.The graft union was successful between E. tereticornis root stock and scion materialderived from E. alba, E. camaldulensis and E. urophylla. Graft incompatibility,however, was noticed in the case of E. torelliana. At seven years of age, the graftsin the breeding orchard have attained a maximum GBH of 58 cm and height of 10 m.The best results of grafting were obtained in the months of August to November.Almost all the grafts flowered at two to three years age.
Inter-specific hybridization was attempted to combine desirable complementaryattributes of promising clones and eliminate defects keeping in view the customers’(grower/mill) viewpoint, viz., high yields (volumetric productivity), felling cycle ofthree to five years (economic rotation), adaptability to sites, superior wood qualityand uniformity of raw material. The clones with well-defined traits (Table 2) wereincluded in the breeding programme.
Development of inter-specific hybrids such as E. tereticornis x E. urophylla.;E. tereticornis x E. grandis; E. tereticornis x E. camaldulensis; E. tereticornis xE. alba and E. tereticornis x E. torelliana; E. urophylla x E. grandis was attempted.One of the major problems encountered in breeding E. urophylla is that the floweringcoincides with the rainy season (August) leading to flower drop (before and afterfertilization). Therefore, E. urophylla is considered to be the male donor parent asthe pollen is collected in the month of August and is stored and used for pollinationin the months from October to January. Teretigrandis and Urograndis hybrids haveadapted well to drought conditions and producing maximum volume of wood. Thesehybrids are now planted on large scale. Recently, E. tereticornis x E. globulus andE. grandis x E. globulus hybrids have been successfully grown in the plots. By
H.D. Kulkarni
Character ITC clone number* Clear bole 1, 4, 6, 7, 27, 122, 223, 265, 266, 272, 274, 275, 284, 286, 288, 290,
292, 316 and 319.
High productivity 3, 6, 7, 10, 105, 130, 265, 266, 272, 274, 284, 290, 292, 316 and 319.
Adaptable to refractory sites 1, 10, 71, 105, 115, 116, 128, 130, 223, 266, 271, 272, 274, 285, 290, 316, 405, 411 and 413.
Disease resistance 1, 3, 6, 7, 288 and 316.
Table 2. Clonal characters for hybridization
*Species details not disclosed.
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controlled pollination between the best 32 clones of E. tereticornis, the derivedfull-sib hybrids have shown good heterosis at two years age. The full-sib progenytrial showed a maximum of 33 per cent improvement over the parents for productionof wood volume. Based on the performance of full-sibs, elite full-sib trees wereselected and cloned. Nearly 358 full-sib hybrid trees have been cloned. Thesehybrid clones have been tested on various sites. Heterobeltioisis studies on 18hybrid clones showed 82 per cent improvement in wood volume production overthe best parent. A few hybrid clones from the crossing of clone ITC-6, 10 and 27gave hybrid clones ITC-2011, 2014, 2045, 2050, 2052, 2053, 2120, 2121, 2149, 2155and 2156 which are totally devoid of the defects and surpassed in growth. Inaddition, some of the clones showed a narrow crown which is required for closerplanting at a spacing 3 x 1.5 m enabling harvesting of trees at three to fouryears age.
4. DNA Fingerprinting of Eucalypt ClonesThe advent of DNA fingerprinting has opened new vistas in molecular biologyas this technique has the ability to detect differences between individualsat the level of DNA. Nearly 90 ITC Eucalyptus clones were subjected to PCRbased randomly amplified polymorphic DNA (RAPD) technique and genetic mapsbased on DNA markers were prepared. The 90 clonal compositions included 44parental clones, 39 hybrids and seven clones of different Eucalyptus speciesand 12 primers were used for DNA amplification (Paramathma and Kulkarni,2005).
The amplified products varied in number and intensity among the clones(Table 3). Among 12 primers, OPR 05 exhibited monomorphism. Altogether 247amplified products were observed in the profiles of both parents and hybridsand out of which 224 products (90.70%) were polymorphic (Fig. 7).
Eucalypt improvement at ITC
Parents Hybrids Primers No. of
bands No. of
polymorphic bands
Per cent polymorphism
No. of bands
No. of polymorphic
bands
Per cent polymorphism
OPS 01 14 14 100.00 13 11 84.62 OPAL 03 15 15 100.00 17 16 94.12 OPAB 04 9 9 100.00 8 7 87.50 OPAB 05 9 8 88.90 15 15 100.00 OPAK 10 7 6 85.70 10 7 70.00 OPH 19 9 6 66.70 10 8 80.00 OPR 10 9 8 88.90 8 8 100.00 OPR 11 8 8 100.00 8 8 100.00 OPT 03 8 8 100.00 13 13 100.00 OPR 08 15 15 100.00 17 17 100.00 OPR 09 10 9 90.00 8 8 100.00 OPR 05 3 0 0.00 4 0 0.00
Table 3. Polymorphism observed in different primers
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4.1. Scoring of Amplified Products and Genetic Similarity MatrixIn case of parents, 15 amplified products were observed in the profiles (Fig. 8) while,in hybrids 17 amplified products with same primers (Fig. 7) were observed. Geneticsimilarity matrix for all pair-wise combination of parental clones revealed that thelowest coefficient value of 0.44 (highest genetic distance 0.56) was observed betweenITC-105 and 1 as well as ITC-45 (636) and 286. The highest similarity co-efficient of0.83 (lowest genetic distance 0.17) was observed between ITC-10 and 9. Similarly, forhybrid clones, the matrix revealed that the lowest 0.53 coefficient (highest geneticdistance 0.47) was observed between ITC-2135 and 2156 as well as ITC 2188 and2183. The highest coefficient value of 0.85 (lowest genetic distance 0.15) wasobserved between hybrids ITC-2153 and 2045 as well as ITC-2155 and 2053.
Fig. 8. RAPD profile generated by the primer OPR 08.
Fig. 7. RAPD profile generated by the primer OPAL 03.
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Fig. 9. Hierarchical clustering pattern of parents based on RAPD markers.
Eucalypt improvement at ITC
4.2. Cluster AnalysisBased on genetic similarity matrix of 12 oligonucleotide arbitrary decamers, phenetictrees were constructed (Fig. 9 and 10). Two major clusters were delineated (Fig. 9).Cluster-A had 23 ( ITC 99, 130, 128, 526, 417, 122, 157, 158, 147, 223, 272, 271, 292, 316,319, 266, 413, 632, 72, 273, 45 (636), 124, and 405) parental clones at coefficient levelof 0.57. Majority of clones in cluster-A belong to the local landrace Mysore gumshowing closer affinity. While, cluster-B had 21 (ITC 1, 3, 4, 7, 9, 10, 27, 83, 105, 285,288, 286, 115, 495, 274, 275, 277, 284, 290, 71 and 548) parental clones. Interestingly,clones ITC-1, 3, 4, 7, 9 and 10 belong to Australian provenance – 8 KM MW BlackMountain and the rest belong to Mysore gum.
For hybrids (Fig. 10), at a coefficient level of 0.67 cluster A had only five clones(ITC-2118, 2132, 2120, 2154 and 2124) while, in cluster B 34 (ITC-2011, 2014, 2151,2160, 2125, 2052, 2045, 2153, 2156, 2121, 2198, 2202, 2136, 2189, 2188, 2228, 2053, 2155,2149, 2069, 2147, 2152, 3017, 2019, 2149, 2023, 2144, 2139, 2135, 2204, 2169, 2183, 2207
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and 2040) hybrid clones occurred. The clustering pattern revealed that the hybridswith common parents were grouped together.
4.3. ApplicationBased on the RAPD finger printing studies, ITC 105, 1, 45(636) and 3 which expressedmaximum genetic distance were selected for further breeding and improvement. Theclones ITC-9 and 10 with maximum similarity and high wood yield are also consideredfor breeding with other clones. The DNA finger printing is also being used to registerthe clones as well as to maintain genetic purity in the gene banks.
5. Wood PropertiesThe wood morphological studies on 98 Eucalyptus clones and four seedlingscontrol grown at varied sites with differences in age, espacement and culturalpractices and there influences on various wood properties are presentedbelow:
Fig. 10. Hierarchical clustering pattern of hybrids based on RAPD markers.
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5.1. Factors Influencing Wood PropertiesIn order to identify the most suitable clone amongst from the widely representedfour clones for further development of pulpwood plantations, adjusted mean valuesof various parameters which varied considerably fitting into the model are representedin Table 4.
Table 4. Estimated adjusted means of clones with regard to selected wood properties
* Significantly lower value, ** significantly higher value
5.1.1. Tree size/volumeThe effect of the factors, viz., clone, location, age and spacing were examined. Allthe factors had significant effects on tree size. As number of trees per hectareincreased with closer spacing, tree size/volume decreased. However, with the increasein age, the tree volume has also increased. The adjusted mean value of ITC-6 wassignificantly lower than ITC-7, indicating that the ITC clone 7 may yield the highestvolume per tree with faster growth rate.
5.1.2. Basic density and moisture contentThe initial espacement alone did not explain significant variation in basic densityof wood. By and large wood density increased with age up to nine years in all theclones studied. ITC clone 4 displayed densest wood (710 kg m-3) which wassignificantly different from clone 6 with lightest wood. As the basic density valuehigher than 600 kg m-3) is not desired in eucalypts, for better pulp yield trees,clones such as ITC - 3, 6 and 7 are better compared to ITC 4. Among 98 clonesstudied, ITC 10 (699 kg m-3) and ITC 433 (676 kg m-3) also have high density. Bhat(1990) reported that aiming at faster growth does not necessarily affect the wooddensity. Although the initial moisture content in wood increased with age neitherthe espacement nor the particular clone had any effect.
5.1.3. Heartwood and bark percentageThough not related to espacement, heartwood percentage increased with age (forclone 3 at three years: 16 per cent; six years: 40 per cent and nine years: 56 per cent),after initiation at the age of three years in clone 3. No significant difference wasnoted among the clones. Bark per cent varied from clone to clone and increasedslightly with age (for clone 7 at three years: 12 per cent and nine years: 15 per cent),but the fitted model itself was not significant to explain the variation.
Eucalypt improvement at ITC
Clone no.
Tree vol. (m³ tree-1)
Basic density (kg m-3)
Moisture content (%)
Heart wood (%)
Fibre length (μm)
Fibre dia. (μm)
Lumen width, μm
2 x fibre wall thickness (μm)
Vessels (per mm²)
Vessel dia. (μm)
3 0.238 575.8 31.8 20.3 0.88** 19** 8** 10** 2.2* 131 4 0.169 613.9** 18.8 34.8 0.81* 16* 7 9* 2.6 136 6 0.138* 573.1* 21.4 32.2 0.86 16* 7* 9 2.5 144 7 0.346** 580.7 30.4 17.8 0.84 18 8 10 2.7** 141
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5.1.4. Fibre length, diameter, lumen width and double wall thicknessAll the factors had significant effects on the fibre length though the overall differencesamong the four clones were not statistically significant. It increases with the increasein number of trees per hectare with closer spacing and age of the trees. The fibrelength varied from 0.7 to 1 ì m and with age (for ITC-3 at three years: 0.82 and nineyears 1ì m). The fibre diameter varied from 13 to 20 ìm. All the factors had significanteffects on the fibre diameter and it decreased with the increase in number of trees perha. As age increases fibre diameter also increases. The adjusted means of clonesITC-3 vs 4, 3 vs 6 and 4 vs 7 differed significantly. Lumen width varied from 6 to 9.74ìm. Neither the number of trees per ha nor age had significant effects on fibre lumendiameter. With widest fibre lumen, clone 3 was significantly different from fibrelumen width of ITC 6. The fibre double wall thickness varied from 6.66 to 10.98 ì m.All the factors had significant effects on fibre wall thickness as it decreased with theincrease in number of trees per hectare and increased with tree age. The adjustedmean of ITC-3 was significantly different from ITC-4.
5.1.5. Tissue percentageThe percentages of vessels, fibres and parenchyma were not influenced by theclone age and espacement.
5.1.6. Number of vessels per mm² and vessel diameterThe vessel frequency varied from 1.38 to 3.28 per mm². Vessel frequency (number ofvessels) per mm² area decreased with age although espacement had no effect. Theadjusted mean of clone ITC 3 was significantly different from ITC 7. The vesseldiameter varied from 107 to 163 ì m . As number of trees per hectare increased, thevessel diameter also increased although the adjusted means of clones were notsignificantly different.
5.2. Between-Species DifferencesSpecies to species comparison revealed that wood of E. camaldulensis clone wassignificantly denser than E. tereticornis and Eucalyptus hybrids. Wood was also denserwith longer fibres in E. tereticornis than in Eucalyptus hybrids. Wood was also denserwith longer fibres in E. torelliana than in E. urophylla at the age of five years. Thelongest fibres were found in E. torelliana and E. urophylla while the densest woodwas in E. camaldulensis which is not the most preferred species for pulping.
5.3. Clonal ComparisonThe general comparison of the wood properties and tree size among clones revealedthat there could be significant differences in certain properties such as basicdensity, heartwood and bark contents, fibre dimensions (length, width, wall
H.D. Kulkarni
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thickness) and vessel frequency (number per mm²). As a single factor, neither theclone, nor the age and espacement (number of trees per hectare) influenced thepercentages (volume) of vessels, fibres and parenchyma. This implies that theclones sampled in the study are quite uniform in wood composition in terms oftissue proportions (Fig. 11).
Clone ITC-3: (a) 1-year-old (x80); (b) 3-year-old and (c) 9-year-old trees (x40)Clone ITC-7: (d) 1-year-old (x80); (e) 3-year-old and (f) 9-year-old trees (x40)
Fig. 11. Transverse section of clones showing anatomical changes with age.
Eucalypt improvement at ITC
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5.3.1. Basic densityHowever, if basic density is considered as selection criterion with an averagevalue remaining within the threshold value of 600 kg m-3, two clones, viz., cloneITC-3 and 7 are the most desirable ones for pulping in view of their relatively longfibres (with a range of 0.77 to 0.97 mm from one to nine years) among the clonesstudied. If the rotation age of three years is to be fixed, ITC 3 appears to the mostpotential one as it merits most desired features such as growth rate (wood volume),basic density and fibre length. ITC 10 (699 kg m-3) and ITC 433 (676 kg m-3) appearto be the densest woods among the clones sampled. The density and structure ofhardwoods in relation to paper surface characteristics and other properties aresimilar to the studies conducted by Higgins et al. (1973). Comparison of woodproperties of clones ITC- 3 and 7 in three age groups indicates that clone 3 issuperior in tree size, basic density, fibre length at the age of three years althoughdifference at the age of four and five years were not of practical value althoughoverall growth was greater in ITC-7.
5.3.2. Fibre shape factorCross-sectional fibre shape (fd2-ld2/fd2+ld2) value was almost the same for allclones as clone 3 has value of 0.69 as against 0.67 of other three clones (ITC 4, 6and 7). This implies that cross sectional shape is almost similar among the variousclones.
5.3.3. Runkel ratioNone of the clones had Runkel ratio value <1 as clone ITC-3 and 7 displayed valueof 1.25 as against 1.28 by clones ITC-4 and 6. If this ratio is critical, clonal eucalyptsof young age may not meet the required fibre bonding in pulping.
5.3.4. Age effectAmong the various factors considered, age seems to be most crucial factorinfluencing the pulpwood quality of the clones up to nine years. Basicdensity, heartwood percentage and fibre morphology (length, diameter andwall thickness) improved with age from one to nine years in all clones whiletissue proportions and vessel diameter did not vary significantly. Basic densityand fibre length showed linear relationship with age increasing consistently.However, vessel frequency per mm2 area decreased accompanying a small increasein vessel diameter with age during the initial years of growth. Generally heartwood content increased and bark content decreased with age although variationwas very high depending on the site conditions. Trees in Jangareddygudemsites showed a tendency of higher percentage of heartwood as seen in ITC-3,115, etc.
H.D. Kulkarni
167Eucalypt improvement at ITC
5.3.5. Effect of rotation ageIn order to ascertain the wood quality difference between three and five year rotationsof most potential clones, wood properties were compared between clones ITC-3 and7. Expecting a small difference in tree size, no significant difference was noticed inprime wood properties. This result implies that there is no economic advantage ofextending the rotation age from three to five years in terms of wood qualityimprovement in these conditions.
5.3.6. Site effectThe comparison of clone ITC-2011 and 2021 at the age of four years between fertileand poor sites revealed that wood property differences were not significantexpecting lower moisture content and wider fibre lumen in wood from fertile site(moisture: fertile = 24.4 per cent and poor = 20 per cent; lumen: fertile = 8.87 andpoor = 6.96 ì m).
5.3.7. Soil type and wood qualityWhen clones ITC-3, 7, 115, and 413 were compared at the age of four to six yearsbetween the sites with black soil and red soil, the former promoted GBH with highermoisture and heartwood contents with wider fibre lumen and thinner fibre walls.This suggests that black soil condition is more favourable for better tree growth andthinner fibres although higher heartwood and moisture contents are not desired bythe pulping industry. Similar earlier studies by Purkayastha et al. (1979) and Singhet al. (1986) on five different plantation sties of E. tereticornis in India indicatedinfluence of locality factor in the variation in wood specific gravity and fibre/vesselcharacteristics and their influence on surface properties of hard sheets. Majority ofclones have shown site specificity (areas with black soil and red soils) in respect ofgrowth, adaptability and productivity. Hence, in the first phase, the site-specificclones are shortlisted and then clones with best wood properties are promoted forlarge scale plantations (Kulkarni, 2004).
5.3.8. Irrigation/fertilization effectsClones ITC-3 and 7 were sampled from three to four years old plantations to comparethe wood properties from irrigated and rainfed conditions. As a response to irrigation,clones showed higher vessel percentage with larger vessels, for better conductionefficiency, and greater moisture content in the wood although the difference wassignificant only in ITC-3 for the former and ITC-7 for the latter due to small numberof samples studied. This tendency of higher vessel percentage is in agreement withthe index suggested by Carlquist and Hoekman (1985) with vulnerability ratio (vesseldiameter/vessel frequency per mm2) value being lower towards the drought condition,as it decreased from 59 to 56 from the irrigated to rainfed plantations in ITC-3. In
168
three years old ITC-3 from Jangareddygudem locality, the trend was clear forincreased tree height, GBH, basic density, fibre lumen width, vessel percentage,vessel diameter and vessel frequency in irrigated condition. Bhandari et al. (1988) intheir studies on kraft pulps of E. tereticornis bought out effect of locality on fibre/vessel characteristics and strength/surface prosperities of paper.
5.3.9. Coppice vs main cropTesting of three years old trees of clones ITC-3 and 7 indicated that the differenceswhere significant only for fibre with thinner walls with higher moisture content incoppice crops of ITC-3 while ITC-7 had longer fibres and higher percentage of bark.The study needs to be continued with testing larger number of clonal samples tosupport the current indicative figures.
5.3.10. Influence of tree heightWithin the tree, tissue proportions did not show consistent variation from the baseto the top. However, basic density, fibre length and heartwood percentage variedsignificantly. As shown in clone ITC-3, basic density increased initially from thebase upto 50 per cent of the tree height before it started decreasing to the top whilefibre length increased only upto 25 per cent of tree height level and then decreasedtowards the crown. Heartwood percentage decreased consistently from the base totop.
5.3.11. Superiority of clones over seedling controlThe comparison of ITC-3 with seedling crop at the age of three years indicates thatclones have gained superiority in pulpwood quality over the seedlings in Sarapakasite. Basic density was higher by 13 per cent and fibre length by 17 per cent withincrease in fibre diameter and wall thickness in clones ITC-3 and 7, respectivelywhile other parameters of fibre morphology were not significantly affected. At age ofsix years, the superiority was seen clearly in ITC-3 with longer fibres and less densewood having density value of 520 kg m-3 than the seedling crop having densityvalue of 648 kg m-3.
5.3.12. Wood basic density and fibre dimensions have long been accepted as themost crucial quality indicators of pulpwood. Low density and longer fibre woods aremostly preferred for pulping process for eucalypts. The basic density is generally anindicative of pulp yield of any species for raw material production as it is a measureof the mass of wood on oven dry basis. Fibre length is known to determine thetearing strength of paper. If low density aids impregnation due to a more open woodstructure, longer fibres promote higher tear index (Banham, et al., 1995). The studiessuggest that in eucalypts, the optimum basic density is around 480 to 520 kg m-3 and
H.D. Kulkarni
169
above the upper limit of 600 kg m-3 (Dean, 1995). The other crucial parameter of fibremorphology that favours the pulping properties is the ratio of double wall thicknessof fibre/lumen width of fibre and the value of upper limit is 1; the desired Runkel ratioof 2 x fibre wall thickness/lumen diameter is < 1. The pulpwood demand and qualityassessment studies are reported by Singh and Naithani (1994). Further, a detailedaccount of eucalypt for pulp and paper making are also given by Sharma and Bhandari(1983) and Tewari (1992). Hence, it is concluded that:
a. clones gained considerable superiority over seedling crop with optimalbasic density and longer fibres. Wood quality is significantly influencedby various factors such as clone, age, site/soil type, spacing, irrigation,etc. Age seems to be the most crucial factor that determines the pulp woodquality up to the age of 9 years,
b. among the 98 clones tested clones ITC-3, 4, 6, and 7 merit attentions inshortlisting the clones as most potential ones for commercial multiplicationbecause of their relatively modest wood density, longest and widest fibreswith wider lumen and thicker walls. However ITC-4 has denser wood (>600kg m-3 and shorter fibres making it the least favoured among the fourpotential clones identified,
c. clones with denser wood showed the tendency of having shorter fibresd. two clones, viz., ITC-3 and 7 are the most desirable ones for pulping in view
of their relatively long fibres and desired wood basic density around 576 to581 kg m-3, and
e. clone ITC-7 yields more wood per tree (greater growth rate).
5.3.13. Based on the wood morphology, site/soil and silvicultural practices out of98 clones studies, 31 potential clones (ITC-3, 6, 7, 10, 27, 99, 105, 122, 130, 222, 226,265, 271, 272, 273, 274, 285, 286, 288, 316, 405, 411, 412, 413, 501, 2045, 2069, 2070,2135, 2253 and 2254) of superior pulp and paper qualities are shortlisted for commercialcultivation in clonal plantation programme.
6. Improvement for Pulp and Paper Quality
6.1. Pulp AnalysisProximate chemical analysis and strength properties for 213 E. tereticornis clonesrevealed wide variation (Table 5). The ash content ranged from 0.37 to 4.2 per centwith a mean of 1.3 per cent. Clone ITC-319 showed minimum ash content while, ITC-2231 gave 4.2 per cent. The alcohol-benzene (A-B) extractive content ranged from1.24 (for clone 2294) to 8.4 per cent (for clone 266) with a mean of 3.3 per cent.Presence of more extractive content tends to increase the consumption of chemicalsduring pulping and reduce pulp yield.
Eucalypt improvement at ITC
170
6.2. LigninIn respect of lignin, ITC-2396 showed lowest lignin (24.7%) while, ITC-2324 had highestlignin content (35.7%). Out of 213 clones analyzed, 71 clones fall under 28 to 30 percent class intervals while, 9 clones in 34-36 per cent and 10 clones in 24 to 26 per centclass intervals (Fig. 12). The unbleached brightness of pulp varied from 24.4 to 39 percent and the average brightness was observed at 32.8 per cent. More lignin contentmeans high chemical consumption in cooking and bleaching of wood. Moreover,higher lignin has significant impact on refining and paper properties. Lignin ishydrophobic and contains chromophoric groups, therefore, pulp has poor swellingcharacteristics (Singh and Rawat, 2000). Hence, low fibre bonding results in low strengthproperties. Kappa number, a measure of residual lignin, varied from 19.1 to 29.7 withaverage value of 22 indicating variation in lignin content in the 213 clones analyzed inthe study. More bleaching chemicals are required to bleach higher amount of lignin.Sharma et.al. (1987) opined that more lignin has to be removed to produce easilybleachable grade pulp of satisfactory brightness by increasing active alkali chargeand pulp yield and kappa number decrease with increased chemical charge.
6.3. Cellulose and PentosansFor holocellulose content, the readings varied from 54.3 to 70 per cent with a meanvalue of 63.7 per cent. Out of 213 clones, nearly142 clones occurred in 61 to 66 per
H.D. Kulkarni
Parameter Unit Minimum Maximum Mean
Ash % 0.37 4.20 1.3 A-B extractives % 1.24 8.40 3.3 Lignin % 24.70 35.70 29.4 Holo-cellulose % 54.30 70.00 63.7 Pentosans % 9.00 17.20 13.9 Screen pulp yield % 44.00 53.00 47.9 Rejects % 0.23 4.10 1.2 Kappa no. 19.00 29.70 22.0 UBV cps 11.90 22.80 14.8 Brightness % 24.40 39.00 32.8 R.A.A. gpl 3.10 13.30 6.9 Solids % 11.00 19.20 14.4 Organics % 51.50 62.0 56.8 In-organics % 38.00 48.50 43.0 Bulk cc gm-1 1.34 1.97 1.7 Burst factor - 26.00 58.00 34.9 Tear factor - 44.00 78.00 54.3 Breaking length m 3900 8000 5194 Strength index - 20.00 85.00 41.0
Table. 5. Variation in pulp and paper properties for E. tereticornis clones
171
cent class interval followed by 41 clones in 66 to 70 per cent class interval (Fig. 13).The lowest holocellulose content of 51-56 per cent was shown by ITC-411 and 417which is not a desirable property. The highest holocellulose content of 70 per centwas shown by ITC-343. More cellulose content means better property for papermaking. The pentosans percentage varied from 9 to 17.2 with a mean value of 13.9.
6.4. Screened YieldThe important parameter for pulp properties is the screened yield. Eucalypts requireless chemicals (17%) to obtain 46 to 48.8 per cent pulp yield at kappa number 22 to20. The screened pulp yield for 213 clones ranged from 44 to 53 per cent with a mean
Eucalypt improvement at ITC
Fig. 12. Variation in lignin content in E. tereticornis clones.
Fig. 13. Variation in holocellulose content in E. tereticornis clones.
10
49
71
53
21
9
0
10
20
30
40
50
60
70
80
24‐26 26‐28 28‐30 30‐32 32‐34 34‐36
Lignin (%)
No.
of c
lone
s (n
=213
)
2
28
142
41
0
20
40
60
80
100
120
140
160
51‐56 56‐61 61‐66 66‐70
Holocellulose (%)
No.
of c
lone
s (n
=213
)
172
value of 47.8 per cent. Highest number of clones (51 clones) gave 49 per cent pulpyield (Fig. 14). The best performance at 53 per cent was shown by ITC-2129 while theleast performance at 44 per cent of pulp yield was shown by ITC-147, 319, 433, 2069,2261, 2262, 2264 clones.
6.5. Rejects, UBV and RAAThe clone 2008 showed higher per cent of rejects at 4.10 per cent while lowest valueof less than 0.5 per cent was recorded in 11 clones. The average value of 1.2 per centwas recorded for 99 clones out of 213 clones. Dadswell and Wardrop (1959) linkedrejects with that of density and opined that with increase in density of wood pulp,rejects also increase as well as tear and tensile indices decline. Unbleached viscosity(UBV) varied (range 11.9 to 22.8 cps) considerably with a mean value of 14.8 cps.Similar trend was also observed for other parameters like R.A.A, solids, organicsand inorganics.
6.6. BulkThe eucalypt clones showed higher bulk of 1.7 cc gm-1 (range 1.34 to 1.97). Stifffibres of eucalypts give more bulk due to which more open sheet and goodstrength in the wet state is obtained where eucalypt pulp show distinct advantagecompared to other hardwoods. The bulkier sheets with increased porosity givebetter drying on higher machine speed reducing the drying costs considerably.Therefore, higher bulk gives better printability on coated board with goodrunnability. Sharma and Bhandari (1983) reported that eucalypt that pulp withhigher bulk formed bulkier sheets than those with less bulk. In the present studyalso clones with high bulk values gave bulkier sheets. Bulk and stiffness arecritical to paperboards manufacture and is an important property of eucalypt
H.D. Kulkarni
Fig. 14. Variation in pulp screened yield for E. tereticornis clones.
7 9
23
45 4751
18
7 51
0
10
20
30
40
50
60
44 45 46 47 48 49 50 51 52 53
Screened yield (%)
No.
of c
lone
s (n
=213
)
173
clones which is employed for production of paperboards in ITCs mill atBhadrachalam. However, during a trial run with only eucalypt wood it wasobserved that there is high amount of fluff generation and fines are on higherside (4.5 to 4.7%) which creates problems at paper machine level. Blendingeucalypt fibre with other pulp wood species appears to be an answer to thisproblem.
6.7. Paper PropertiesStrength properties in respect of burst and tear factor and breaking lengthvariation was significant and indicated in the form of strength index which rangedfrom 20 to 85 with a mean at 41. The maximum breaking length of 8,000 m wasrecorded for ITC-2385 while the average breaking length was at 5,194 m.There are 40 clones showing strength index above 50 which are preferredfor paperboard making (Fig. 15). A strong and significant trend of low pulpyield and strength index with high content of lignin, rejects, kappa numberand AB extractives is observed with respect to ITC-7 of E. tereticornis(Table 6).
Eucalypt improvement at ITC
Fig. 15. Strength index for E. tereticornis clones.
6.8. Eucalyptus spp.Results of proximate chemical analysis and strength properties (Table 7 and Fig.16 to 19) indicate that the screened pulp yield was higher (49 to 52.8%) forclones of E. globulus, E. grandis, E. torelliana, E. urophylla and Urograndishybrids while it was on lower side (46%) for E. alba and E. camaldulensis. Thestrength index was high (above 50) for E. globulus, E. grandis and Urograndishybrid whereas, E. alba, E. camaldulensis, E. torelliana and E. urophyllashowed considerably lower strength index. Breaking length was invariably high
17
22
17
41 42
34
24
4 3 3 2 2 2
0
5
10
15
20
25
30
35
40
45
20‐25 25‐30 30‐35 35‐40 40‐45 45‐50 50‐55 55‐60 60‐65 65‐70 70‐75 75‐80 80‐85
Strength index
No.
of c
lone
s (n
=213
)
174 H.D. Kulkarni
Clone no. A-B extractives (%)
Lignin (%)
Holo-cellulose (%)
Kappa (no.)
Rejects (%)
Screen pulp yield (%)
Strength index
147 3.30 32.2 62.3 23.6 1.40 44 20.0 319 4.10 29.2 65.2 21.3 0.53 44 29.6 433 4.50 27.1 64.5 21.4 1.38 44 39.2 2069 2.86 31.3 61.4 25.0 2.21 44 29.9 2261 2.48 31.2 62.4 23.9 3.82 44 29.5 2262 3.20 28.3 67.0 24.8 0.94 44 42.3 2264 3.80 30.1 62.1 22.3 1.50 44 51.5
Table. 6. Low pulp yielding E. tereticornis clones with other properties
Fig. 16. Comparison among Eucalyptus species/hybrid clones for lignin.
26 26 27 2728 29 29 29 29 30
31 3133
0
5
10
15
20
25
30
35
E. torellina455
E. globulus (Ooty)
E. urophylla347
Urograndis2254
E. alba Urograndis2253
Urograndis (BCM)
E. grandis643
(HNL)
E. teriticornis(BCM
Clones)
E. grandis (Ooty)
Urograndis 283
(HPL)
E.urophylla348
E. camaldulensis678
Lign
in (%
)
Eucalyptus species/hybrid clones
Fig. 17. Comparison among Eucalyptus species/hybrid clones for holocellulose.
6060 61 61
6364
64 64 64 64
66
6868
54
56
58
60
62
64
66
68
70
E. grandis (Ooty)
E. alba E.urophylla348
E. camaldulensis678
Urograndis (BCM)
E. teriticornis(BCMClones)
E. torellina455
E. grandis643
(HNL)
E. urophylla347
Urograndis 283
(HPL)
Urograndis2253
Urograndis2254
E. globulus (Ooty)
Holo
-cel
lulo
se (
%)
Eucalyptus species/hybrid clones
175Eucalypt improvement at ITCU
nit
Mea
n Pa
ram
eter
U
225
3 U
225
4 U
(B
CM
) U
283
(H
PL)
E.u.
347
E.
u. 3
48
E.t.
455
E.g.
643
(H
NL)
E.
g
(OO
TY)
E.c.
67
8 E.
gl.
(Oot
y)
E.a.
Ash
%
0.
98
1.18
1.
59
1.10
0.
98
1.96
1.
89
1.79
2.
87
0.98
0.
74
0.40
A
-B ex
tract
ives
%
4.
10
2.69
3.
10
3.20
6.
20
4.90
4.
00
3.79
3.
11
4.60
3.
70
2.50
Li
gnin
%
28
.50
26.9
0 28
.90
31.0
0 26
.50
31.3
0 26
.10
28.9
0 29
.60
32.9
0 26
.10
27.9
0 H
olo-
cellu
lose
%
66
.40
67.7
0 62
.80
64.4
0 64
.20
60.7
0 64
.00
64.1
0 59
.80
60.8
0 68
.20
60.3
0 Pe
ntos
ans
%
15.6
0 16
.40
18.7
0 16
.60
13.8
0 11
.90
16.5
0 15
.79
11.6
0 15
.90
16.4
7 14
.10
Scre
ened
pul
p yi
eld
%
49.4
0 50
.18
49.0
0 47
.90
45.0
0 50
.40
51.7
0 52
.80
51.0
0 45
.67
49.0
0 46
.00
Reje
cts
%
0.70
1.
59
1.60
0.
90
0.70
1.
60
0.30
1.
16
1.10
0.
54
1.00
1.
40
Kapp
a
No.
22
.80
21.1
0 22
.00
23.0
0 24
.60
24.0
0 22
.00
22.2
0 21
.20
21.9
0 22
.00
21.0
0 UB
V
%
19.2
0 14
.20
15.1
0 17
.40
15.7
0 14
.80
17.2
0 20
.66
18.5
0 13
.00
15.0
0 14
.50
Brig
htne
ss
%
34.0
0 30
.00
32.1
0 35
.00
34.0
0 36
.00
34.0
0 36
.50
36.1
0 26
.90
35.0
0 36
.00
R.A.
A.
gpl
7.60
7.
10
6.80
9.
20
8.80
7.
90
8.60
9.
40
9.80
4.
00
9.50
8.
60
Solid
s %
13
.10
12.5
0 13
.50
14.2
0 13
.00
12.2
0 13
.70
14.1
0 13
.90
17.2
0 20
.00
18.4
0 O
rgan
ics
%
60.5
0 55
.40
56.0
0 61
.20
61.9
0 64
.50
63.7
0 54
.60
53.5
0 56
.80
55.0
0 53
.00
Inor
gani
cs
%
39.5
0 44
.60
44.0
0 38
.80
38.1
0 35
.50
36.3
0 45
.40
46.5
0 43
.20
45.0
0 47
.00
Bulk
cc
gm
-1
1.45
1.
68
1.80
1.
60
1.70
1.
70
1.61
1.
62
1.50
1.
80
1.40
1.
60
Burs
t fac
tor
- 44
.00
37.0
0 40
.00
41.0
0 35
.00
31.0
0 38
.00
44.1
0 49
.00
29.0
0 43
.00
38.0
0 Te
ar fa
ctor
-
63.0
0 63
.00
55.0
0 66
.00
51.0
0 55
.00
54.0
0 72
.00
65.0
0 42
.00
58.0
0 48
.00
Brea
king
leng
th
m
5980
56
90
5680
55
42
4900
48
00
5250
56
21
6420
39
00
6970
49
40
Stre
ngth
inde
x -
66.8
0 56
.90
51.8
0 62
.42
35.0
0 34
.00
44.5
0 72
.31
78.2
0 10
.00
70.7
0 35
.40
U =
urog
rand
is; E
.u.=
E. u
roph
ylla
; E.t.
= E
. tor
ellia
na; E
.g. =
E. g
rand
is; E
.c. =
E. c
amal
dule
nsis;
E.g
l. =
E. g
lobu
lus a
nd E
.a. =
E. a
lba
Tabl
e 7.
Pul
p an
d pa
per
and
stre
ngth
pro
pert
ies
for
clon
al E
ucal
yptu
s sp
ecie
s
176 H.D. Kulkarni
Fig. 18. Comparison among Eucalyptus species/hybrid clones for pulp screened yield.
Fig. 19. Comparison among Eucalyptus species/hybrid clones for strength index.
for E. globulus, E. grandis, E. urophylla and Urograndis hybrids indicating thatthe fibres are longer and stronger in comparison to E. alba, E. camaldulensisand E. tereticornis. Apart from the above, wide variation in lignin content isalso recorded between species while other parameters remained the same withless variation. The above results clearly show that best fibre for paper makingcan be derived from species such as E. globulus, E. grandis, E. torelliana,E. urophylla and Urograndis and other hybrids than pure species E. alba,E. camaldulensis and E. tereticornis. Seventeen clones of E. grandis from 643
4546 46
48 48
49 49 4950 50
5152
53
40
42
44
46
48
50
52
54
E. urophylla347
E. camaldulensis678
E. alba E. teriticornis(BCMClones)
Urograndis 283
(HPL)
Urograndis (BCM)
E. globulus (Ooty)
Urograndis2253
Urograndis2254
E.urophylla348
E. grandis (Ooty)
E. torellina455
E. grandis643
(HNL)
Scre
en y
ield
(%)
Eucalyptusspecies/hybrid clones
10
34 35 3541
45
5257
6267
71 7278
0
10
20
30
40
50
60
70
80
90
E. camaldulensis678
E. urophylla348
E. urophylla347
E. alba E. teriticornis(BCMClones)
E. torellina455
Urograndis (BCM)
Urograndis2254
Urograndis 283
(HPL)
Urograndis2253
E. globulus (Ooty)
E. grandis643
(HNL)
E. grandis (Ooty)
Stre
ngth
inde
x
Eucalyptusspecies/hybrid clones
177Eucalypt improvement at ITC
to 659 numbers showed high pulp yield of 50 to 53 per cent but did not performwell at Bhadrachalam location. These E. grandis clones however, are performingwell at Hindustan Newsprint Limited (HNL), Kottayam, Kerala. E. globulus (bluegum) is not adaptable to Bhadrachalam site as it requires higher elevation andtemperate climate. The clones of above species gave excellent properties withrespect to pulp and paper properties and similar results are recorded by Tewari(1992) for eucalypt kraft pulps which give a unique combination of strength,bulk and opacity. This combination together with excellent sheet formationcaused by extremely small fibres makes Eucalyptus pulp as an ideal raw materialfor fine papers.
6.9. Age FactorThe data in Table 8 indicate that the proximate chemical compositions and strengthproperties of eucalypts are highly influenced by age. The lignin per cent increasedwith age from 23.4 to 27 and 28.4 to 31.3 for ITC-3 and 7, respectively. Similar trendwas also recorded for screened pulp yield 48.4 to 50.4 per cent for ITC-3 and 47.44to 49.8 per cent for ITC-7. Strength index increased from 30.33 to 46.38 for ITC-3and 37.8 to 46 for ITC-7 suggesting that the fibre strength is less at young agewhile the required strength in fibre is attained at four years. Other parameters didnot vary drastically.
Table 8. Age-wise analysis of ITC-3 and 7 for pulp and paper propertiesClone ITC-3 Clone ITC-7 Parameter Unit
1 Yr 2 Yr 3 Yr 4 Yr 1 Yr 2 Yr 3 Yr 4 Yr
Ash % 1.03 1.00 1.74 1.04 1.31 1.11 1.28 0.92 A-B extractives % 3.48 2.35 2.99 3.71 4.33 2.98 3.20 3.67 Lignin % 23.40 24.60 24.10 27.00 28.40 30.40 31.40 31.30 Holo-cellulose % 65.10 65.50 62.30 61.20 63.00 64.90 63.30 64.20 Pentosans % 14.39 14.57 14.54 15.54 15.28 16.44 15.70 16.90 Screened pulp yield % 48.40 49.30 50.40 51.00 47.44 47.60 48.40 49.80 Rejects % 1.10 1.12 1.46 1.87 0.59 0.69 0.86 1.11 UBV cps 13.70 14.50 14.90 16.00 14.10 14.20 15.50 14.90
Brightness % 35.30 35.20 35.30 35.20 28.40 31.40 33.50 35.90 R.A.A. gpl 7.00 5.30 7.00 5.60 6.30 7.00 7.60 8.10 Solids % 13.70 12.60 13.80 12.40 12.50 13.60 12.60 13.50 Organics % 54.60 55.40 56.20 56.80 54.00 55.60 56.80 57.90 In-organics % 45.40 44.60 43.80 43.20 46.00 44.40 43.20 42.10 Bulk cc gm-1 1.70 1.70 1.70 1.80 1.70 1.70 1.63 1.71 Burst factor - 29.50 30.50 35.00 37.00 30.00 31.00 33.20 35.60 Tear factor - 54.50 54.50 53.00 55.00 53.00 55.00 54.00 57.60 Breaking length m 4633 4661 5378 5438 5480 4986 5203 5280 Strength index - 30.33 31.61 41.78 46.38 37.80 35.86 39.2 46.00
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6.10. HybridsThe hybridization between best clones ITC-6, 10 and 27 was carried out in order toobtain hybrids with superior pulp and paper properties. Perusal of Table 9 reveals thathybrids clones ITC-2120, 2121 and 2156 have shown improvement with regard to screenyield and strength properties while marginal improvement in other parameters is alsoseen. Many hybrids have outperformed in the field as well as with pulp and paperproperties and are being planted on large scale in the catchment area of the company.
H.D. Kulkarni
Table 9. Comparison between parent and hybrid progeny for improvement of pulpand paper traits in ITC Bhadrachalam clones of Eucalyptus
Rao et.al. (1999) rated five Bhadrachalam clones of eucalypt (clone ITC-3, 4, 6,7 and 10) as high pulp yielding clones with high holocellulose content (66.64 to71.44 %), lignin of 24.92 to 30.17 per cent and pulp yield of 48.3 to 53.3 per cent.
Supply of fibre is the key issue facing the pulp and paper industry in India. Rawmaterial and processing costs raise serious concerns over competitiveness of theindustry. While considering the entire production chain from wood procurement topaper products, with optimum wood density (550 to 600 kg m 3), higher pulp yieldallows reduction in wood requirement and savings on wood cost. The unit cost ofthis extra pulp is the variable cost of bleaching and drying. Wood with high pulpwoodyield will have a lower chemical demand. Higher pulp yield with improved pulpstrength has cost advantage. Improved pulp yield reduces fixed costs (e.g. capitalcost per tonne of production). It is estimated that less alkali consumption, less useof bleaching chemicals, less power consumption, less wood requirement, moredigester productivity and more steam generation from lignin lead to sizable costsavings. The economics of harvesting, transport and processing are greatly improvedwhen the pulp yield is high. Pulp yield has a multiplier effect on costs for growing,harvesting, transport and processing (Dean, 1995). Therefore, breeding programme
Parent Hybrid clone
(at 6 years age) (at 3 years age)
2120 2121 2156
Properties Unit
6 10 27
10x6 10x27 10x27
Lignin % 30.40 31.10 28.20 32.80 29.60 26.70
Holo-cellulose % 64.20 63.00 68.50 66.70 67.10 70.10
Pentosans % 11.40 9.50 16.10 11.80 13.90 14.10
Prox
imat
e
chem
ical
pr
oper
ties
Screened pulp yield % 48.90 49.50 46.00 50.20 50.80 50.60
Bulk cc gm-1 1.50 1.50 1.90 1.70 1.50 1.60 Burst factor - 39.20 39.80 31.20 43.00 43.80 40.00 Tear factor - 66.00 64.00 57.50 78.00 80.00 62.00
Breaking length m 5520 5350 4425 6000 6400 5400 Stre
ngth
pr
oper
ties
Strength index - 60.40 57.30 33.00 81.00 87.80 56.00
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should consider cost of pulp production and accordingly plan clonal developmentand deployment.
Eucalypt wood has been an important raw material for pulp production. Itscontribution to the world market of pulp is continuously growing (Kulkarni, 2008,2013). It is a very good wood source for the paper mills as the yield of many speciesof eucalypts is high and pulps are very easy to bleach to high brightness. Fibre ofeucalypts is highly valued in the world market as the fibres are small, in diameter, andhave relatively thick wall for their size. This fibre property leads to less flocculationand good sheet formation (Dean, 1995). The small fibre enhances opacity due toextra surface area for bonding and adds to visual appearance and better performanceduring processing and in end product (Tewari, 1992). The wall thickness impartsincreased porosity and better drying on higher machine speed. Further, the stifffibres of eucalypt give high bulk, more open sheet and good strength in wet state.Higher bulk gives better printability on coated board and good runnability.
Wood raw material quality sets the quality of pulp and paper. Within the 225eucalypt Bhadrachalam clones analyzed for proximate chemical analysis andstrength properties, there are wide differences in pulp and paper makingproperties. Pulp yield and strength properties are the important characteristicswhich are financially rewarding and advantageous to the paper mills. Top 25 clonesare ranked according to the pulp yield and strength properties index– ITC-3, 6, 7,10, 27, 158, 273, 274, 279, 286, 288, 411, 412, 2014, and hybrids 2050, 2121, 2129,2135, 2140, 2143, 2156, 2294, 2306, 2315, 2401 and are recommended for large scalemultiplication and planting under farm forestry programme (Venkatesh and Kulkarni,2002). Amongst them, eight clones have shown highest strength index (ITC-10,274, 288, 2129, 2140, 2143, 2306 and 2401).
Eucalypt clones with high productivity, best pulp and paper properties not serveany purpose if they are affected by gall disease caused by Leptocybe invasa insect.Clones resistant to gall (Kulkarni, 2010a) along with pulp and paper properties arerequired to be promoted in the plantation programme. Hence, clones ITC-1, 7, 320, 411,413, 513, 612, 2008, 2145, 2253, 2254 and 2306 now with moderately high pulp yield andstrength properties are being recommended for planting on large scale.
7. Clonal Nursery InfrastructureFor a successful clonal forestry programme, a good nursery is a pre-requisite. Amodern clonal nursery with an annual production capacity of 20 million Eucalyptusramets was established with indigenous technological know-how. Presently, theinfrastructure for clonal propagation includes 120 mist chambers covering an area of12,000 m2, hardening area of 5,000 m2 and 0.1 M m2 for open nursery. The clonaltechnology with root trainers has given considerable improvement in the productionof quality planting stock. The root development is better than seedlings raised in
Eucalypt improvement at ITC
clone
s age)
1 2156
27 10x27
0 26.70
0 70.10
0 14.10
0 50.60
0 1.60 0 40.00 0 62.00
0 5400 0 56.00
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polypots as multiple roots seldom form in the root trainers and root coiling is totallyavoided. The outplanting results were quite high, thereby increasing survival andproductivity.
8. Package of PracticesApart from the superior genetic quality of the planting stock, site quality,adaptability of the clones to specific sites, implementation of the improved packageof practices and effective protection of plantations from damage by pests, diseasesand cattle are also important factors which determine the overall productivity ofthe plantations. Therefore, the company developed an improved package ofpractices for rising and maintenance of clonal eucalypt plantations anddemonstrated the benefits of the same to the farmers. Study of soil profiles andanalysis of soil samples was carried out to match adaptable clones to the plantingsites. Deep ploughing of the soil with disk ploughs or mould-board ploughs inboth directions is recommended for preparing the fields for transplanting of clonalsaplings. Spacing of 3 m x 2 m and 3 m x 1.5 m is recommended for the productionof poles and pulpwood, and larger spacing is desirable for production of timber(Table 10 and Fig. 20). Transplanting in 30 cm3 pits is carried out during the earlyparts of the monsoon rains so that plants establish and grow well benefiting fromthe good moisture availability throughout the monsoon rains. Soil in and aroundthe planting pit is treated with 2 ml of chlorpyriphos in one litre of water to preventdamage to the young clonal saplings by termites during the critical establishmentstage. Application of bio-pesticides like kodesa (Clistanthus collinus) forcontrolling termites was introduced as an eco-friendly replacement to chemicalpesticides. Cultural practices recommended include timely weeding and soilworking, protection against damage by insect pests and cattle and raising ofleguminous crops in between the 3 m wide rows for green manuring. In addition,inter-cultivation (agroforestry) with cotton, chilli, tobacco, pulses, vegetables,and horticulture plants was encouraged during the first year of planting whichgives additional earnings to the farmers. As most of the soils in India are deficientin nitrogen and phosphorous, application of fertilizers to supplement availability
H.D. Kulkarni
Table 10. Result of spacing trials of clone ITC-3 at the age of four yearsSpacing (m2) No. of trees GBH (m) Height (m) Volume (m3)
1X1 10,000 0.1500 10.30 0.009 1X1.5 6,666 0.1734 11.55 0.012 1X2 5,000 0.1957 12.25 0.016 1X3 3,333 0.2180 13.85 0.021
1.5X2 3,333 0.2069 13.05 0.018 1.5X3 2,222 0.2436 14.45 0.027 2X2 2,500 0.2537 14.57 0.029 2X3 1,666 0.2832 16.15 0.039 3X3 1,111 0.3213 18.00 0.055
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of these deficient plant nutrients is recommended. Soil and water conservationmeasures like raised field boundaries and staggered trenches are recommended inwell-drained planting sites for holding the rainwater. However, in low-lying areasor poorly drained heavy black cotton soils, drainage has to be improved duringthe rainy season. It was found that eucalypt plantations with Pisolithus tinctoriusecto-mycorrhizae showed excellent growth. Hence, this symbiotic association wasused in the clonal propagation wherein the rooting media was inoculated with thespores and it became part of nursery package of practices.
9. Clonal PlantationsThe company distributed more than 145 M clonal saplings to growers from 1992to 2013. More than 65,114 ha (Fig. 21) of clonal plantations have emerged over aperiod of 21 years under farm forestry programme promoted by ITC, which hascreated an estimated wood asset worth Rs. 16 billion* (US$ 290 million**).However, the all India figure of clonal plantations today is more than 0.2 Mha.These clonal farm forestry plantations are also acting as carbon sinksremoving an estimated 9.5 Mt of carbon dioxide from the atmosphere. Theseplantations have generated estimated 29.25 million person days of employmentopportunities over one felling cycle to the rural masses bringing in socio-economic prosperity.
* Green wood: per tonne value Rs. 3,000**1 US$= Rs. 55
Eucalypt improvement at ITC
Fig. 20.Tree volume observed in spacing trials of clone ITC-3 at the age of four years.
0.0090.012
0.016
0.021
0.029
0.039
0.055
0.018
0.027
0
0.01
0.02
0.03
0.04
0.05
0.06
1X1 1X1.5 1X2 1X3 1.5X2 1.5X3 2X2 2X3 3X3
Spacing (m2)
Vol.
(m3 )
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AcknowledgementThe author is grateful to Mr. Sanjay Singh, Divisional Chief Executive of ITC PSPD forencouragement and support of plantation research and development. Thanks are dueto the research, production, marketing and extension team of plantation departmentfor active support and encouragement. Thanks are also due to Dr. M. Parmathma andDr. K.T. Parthiban of TNAU, Mettupalyam and Dr. (Late) K.M. Bhat of KFRI, Peechifor undertaking wood properties and DNA finger printing studies, respectively.
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