Biomass currently supplies about a third of the developing countries’ energy varying from about 90% in countries like Uganda, Rawanda and Tanzania, to 45 percent in India, 30 percent in China and Brazil and 10-15 percent in Mexico and South Africa. The crucial questions are whether the two billion or more people who are now dependent on biomass for energy will increase. The fact that 90 percent of the worlds population will reside in developing countries by about 2050 probably implies that biomass energy will be with us forever.

Planting of more  trees in forest reserves for reducing global warming has been universally accepted, the idea being that carbondi-oxide absorption would continue until the trees mature say for 40 to 100 years. Although it is recognized that this is not a permanent solution this “carbon sequestration” strategy buy time to develop alternative energy sources.


Tropical deforestation is currently a significant

environment and development issue. At the global level,

according to recent estimates by FAO the annual tropical

deforestation rate for the decade 1981 to 1990 was about

15.4 million h (Mha) [1]. According to the latest data

published in 1994, for the assessment period 1989-1991,

the total area under forests is 64.01 Mha accounting for

19.5 percent of India’s geographic area [1].

At present there is hardly 0.4 percent forest below 25cm

rainfall zone and 1.3 percent above 30 cm rainfall zone.

There is rapid depletion of forest products and in order to

provide alternative energy sources a change is needed in

conventional forestry management.

Four broad categories of biomass use can be

distinguished – a) basic, e.g. food, fiber, etc.; b) energy,

e.g. domestic and industrial; c) materials, e.g.

construction and d) environmental and cultural, e.g. the

use of the fire. Biomass use through the course of history

has varied considerably, greatly influenced by two main

factors population size and resource availability.

Since the annual photosynthetic production of biomass is

about eight times the world’s total energy use and this

energy can be produced and used in an environmentally

sustainable manner, while emitting net CO2, there can be

little doubt that this potential source of stored energy

must be carefully considered in any discussion of present

and future energy supplies. The fact that nearly 90

percent of the worlds population will reside in

developing countries by a bout 2050 probably implies

that biomass energy will be with us forever unless there

are drastic changes in the world energy trading pattern.

Thus biomass is a scarce resource which should be used

sparingly from an ecological point of view. If biomass

should play a major role for CO2 reduction, the efficacy

of biomass use has to be increased. This can be achieved

by focusing on a “cascade utilization of biomass” the use

of biomass as raw material and as energy carrier should

be optimized in an integrated manner. The rationale

behind this is that if biomass is used for energy

generation which had been previously used for some

other, this will not contribute to an increase of NPP

appropriation. The development of optimal biomass

utilization cascades requires that conflicts of interest

have to be solved.

According to the widely held view of many

environmental experts, its utilization should be

encouraged for several purposes. Biomass should be used

instead of fossil energy carriers in order to reduce i) CO2

emissions ii) the anticipated resource scarcity of fossil

fuels and iii) need to import fuels from abroad.


A 50 ha bioenergy plantation demonstration project

centre has been established in the campus of the

University of Rajasthan to conduct the experiments on

large scale cultivation of selected plants with the

objective of developing optimal conditions for their

growth and productivity, besides conserving the

biodiversity. Considerable work has been carried out on

these plants

Certain potential plants were selected and attempts were

made to develop agrotechnology for their large scale

cultivation [2,3,4,5,6,7,8,9,10]. The potential plants could

be characterized under the following categories i)

hydrocarbon yielding plants ii) high molecular weight

hydrocarbon yielding plants, iii) non edible oil yielding

plants, iv) short rotation fast growing energy plants, vi)

hill plants growing on Aravallis.

(I) Hydrocarbon yielding plants included :

♦ Euphorbia lathyris Linn.

♦ Euphorbia tirucalli. Linn.

♦ Euphorbia caducifolia Haines.

♦ Euphorbia nerifolia Linn.

♦ Pedilanthus tithymalides Linn.

♦ Pedilanthus tithymalides Linn.

♦ Calotropis procera (Ait.). R. Br.

♦ Calotropis gigantea (Linn) R. Br.

(II) High molecular weight hydrocarbon yielding plant

♦ Parthenium argentatum Linn


2nd World Conference on Biomass for Energy, Industry and Climate Protection, 10-14 May 2004, Rome, Italy

(III) Non edible oil yielding plants

♦ Jatropha curcas

♦ Simmondsia chinenesis

(IV) Short rotation energy plants

♦ Tecomella undulata

♦ Prosopis juliflora

♦ Pithocellobium dulce

♦ Azadirachta indica

♦ Dalbergia sisso

♦ Acacia tortilis

♦ Holoptelia integrifolia

♦ Parkinsonia aculeata

♦ Cassia siamea

♦ Albizzia lebbek

♦ Acacia nilotica


3.1 Propagation

In general these plants are easily propagated through

cuttings. The optimum period for raising cuttings in June-

July and March-April. Cuttings from apical and middle

portions of E. antisyphilitica exhibit 100 percent survival

rate, while non of the cuttings from the basal portions

survived. Spacing among the planted cuttings is also a

crucial factor for survival of cuttings. It was noted that

initially up to a period of two months the survival

percentage was maximum in closest planting density.

Regarding environmental variations. March to October

period was best suitable for E. antisyphilitica because of

linear increase in growth was recorded in this period

[11]. Overall growth and productivity was lowest in the

winter months from November to February. Higher

accumulation of hexane extractable corresponded with

higher temperatures of summer season [12].

3.2 Edaphic Factors

Among different soil types, sand was best for the growth

of E. lathyris [13] and P. tithymaloides [14] while red

loamy soil was best for E. antisyphilitica. When different

combinations of these soil types were made biomass of

E. antisyphilitica was maximum in red+sand+gravel [15],

while red+sand combination in equal amounts was best

for P. tithymaloides [016,17]. A mixture of gravel + sand

favoured maximum increase in plant height, fresh weight

and dry weight in E. lathyris [13]. Environmental factors

influenced the growth and yield of Calotropis procera


3.3 Growth Curve

Maximum growth was observed during June-July to

October-November and also from February-March to

May-June. Increase in hexane extractable was recorded

upto 6-7 months; thereafter percent hexane extractable

(HE) did not increase significantly in E. lathyris, E.

antisyphilitica and P. tithymaoildes. Higher levels of HE

were recorded in leaves as compared to the stem in E.

lathyris, E. antisyphilitica and P. tithymaoildes. Higher

levels of HE were recorded in leaves as compared to the

stem in E. lathyris and in fruits of Calotropis procera.

Active phase of growth exhibited gretaer amounts of

hexane extractable.

3.4 Fertilizer application

Application of NPK singly of or various combinations

improved growth of all the selected plants. In general NP

combination gave better growth which was only slightly

improved by the addition of K for E. tirucalli [19,20].

When best doses of NPK were applied in different

combinations like NP, NK, KP) and NPK, the last

combination gave best results in the form of biomass,

latex yield, sugars and chlorophyll in E. lathyris [13] and

P. tithymalides [17]. In E. antisyphilitica however, NP

combination gave best results, followed by NPK, for

biomass production. Chlorophyll, sugars and latex yield

was best in KP combination [15]. Addition of FYM alone

and with combination of urea improved FYM+Urea

applications improved the productivity in comparison

with FYM increased the plant height, fresh weight and

dry weight to varying degrees. Hexane and methanol

extractable also increased [21,22].

3.5 Influence of Salinity

Salinity stress studies were also made of on Euphoriba

tirucalli [20]. Salinity was applied in the form of

irrigation water. Lower concentrations of salinity

improved plant growth of E. antisyphilitica [15]. But

higher concentrations inhibited further increase in

growth. Sugars however did not increase in any saline

irrigation. A slightly higher level of salinity impaired

chlorophyll synthesis also. At higher level of salinity,

leaves of E. antisyphilitica became yellow and fell off

but stem did not show any visible adverse effects. E.

lathyris could also tolerate lower salinity levels, but its

tolerance was higher than E. antisyphilitica. In E. lathyris

salinity adversely affected the root growth [23,13].

P. tiothymaloides also exhibited increases in biomass and

yield at lower salinity levels and higher concentrations

adversely affected the plants. Its underground part could

tolerate slightly higher salinity concentration [14].

3.6 Effect of growth regulators

Spray of growth regulators resulted in enhanced fresh

and dry weight production [24]. However biocrude

synthesis occurred more in auxins, NAA and IAA in E.

antisyphilitica. Out of all the growth regulators employed

on P. tithymaloides IAA supported maximum plant

growth in terms of fresh weight and dry weight of

aboveground and undergound plant parts. 2,4,5-T showed

minimum plant growth, besides, certaion nodular

structures were observed on the sterm of the plants

treated with 2,4,5-T. Biocrude yield was best in IAA

followed by 2,4,5-T, GA3, CCC, NAA and control.

Application of growth regulators on P. tithymaloides

resulted in slight decrease in chlorophyll over the control

plants. Whereas on E. lathyris they induced favourable

results, regarding chlorphyll [25].