YOON P. K.(2 ), TROGLIA M., TASIAS J. V., RODRIGUEZ J. N., AND FRUTOS D. T.
TECNAGRIND S. L., El Rebato, s/n� Finca Moli Coloma, 08739 Subirats, Barcelona, Spain
(1) This demonstration project in Murcia has been possible thanks to an European Union
financial contribution under Rules 4256/88 art. 8 of the General Direction VI
-Agriculture.
(2 ) 2 - P. K. YOON is the Vetiver consultant to Tecnagrind S. L. Contact Address: No.69
Jalan SS 3 / 39, Sungai Way Subang, 47300 Petaling Jaya, Selangor, Malaysia.
The establishment and growth of VGHR were tested in the hostile, aerial and edaphic
environment of Murcia, Spain. The climatic condition consists of hot summer, cold winter
with sub-zero temperatures, low precipitation and negative water balance over more than
half a year. The soil is calcareous, mostly clayey. Hilly topography is common with
serious erosion rate of more than 5000 Tm / km2 per annum.
The experimental sites were El Chopillo and Lorca. 5 trials were carried out to study the
establishment and growth of Vetiver grass and the potential uses of VGHR for soil
protection and moisture conservation under different conditions. Despite cold winter with
frost, trials established by container plants from winter to early spring, had overall
transplanting success of 95.9 %.
Plant growth during the growing season was good to vigorous. Harvesting of plant tops in
El Chopillo, produced 1030 and 1388 gm per plant after 14 and 15 months respectively. In
Lorca, the Malaysian Accession produced 305 and 489 gm per plant after 9 and 10 months
respectively, while the American Accession produced 377 and 560 gm per plant respectively
over the same two periods. In all cases, the cut-tops regenerated rapidly showing vigorous
growth in autumn conditions.
Excavations showed that the root system in El Chopillo had reached a depth of 2.6 m after
14 months growth. In Lorca, the Malaysian and American Accessions had produced roots
reaching down to 2.1 metres and 1.7 metres respectively after 9 months growth. In all
cases, the major root masses were at the top 0.4 - 0.5 metres level.
In a 320 Highway slope of 11 metres height, 2 blocks of 20 metres were planted with VGHR
at 1 metre vertical intervals in January 1995. The in-between block, left unplanted as
control, suffered severe erosion by September 1995 despite the low rainfall. Significant
cant soil had been trapped by the VGHR
Sub-zero temperatures in winter killed exposed tops but the buried crowns survived. In
early spring, new tillers were formed, followed by good and vigorous growth in summer and
autumn. The plant's response to the seasonal weather condition suggests 4 distinct phases
1. Frost Injury and Dormancy
2. Awakening and Tillering (Regeneration or Multiplication)
3. Rapid Growth and Biomass Production
4. Slow Growth or Sustenance period.
The tropical to sub-tropical Vetiver grass adapted well to the weather conditions and
appeared to behave like a temperate plant. This, plus easy establishment, good growth and
good root system suggest potential uses for Vetiver in the Mediterranean Regions. It also
suggests that VGHR could be established for useful gains, in the cold highlands of the
tropics and the subtropics.INTRODUCTION
In this project, an attempt was made to test the establishment, growth and potential uses
of Vetiver grass hedgerows ( VGHR) in the hostile aerial and edaphic environments of
Murcia, Spain. Two sites were selected for testing , viz. El Chopillo (Latitude 38� 22'
08" N Longitude 10 48' 06" E) and Lorca (Latitude 37� 42' 36" N Longitude
37� 37' 28" E). The climatic conditions consist of a long dry summer with absolute
maximum temperatures reaching of 42�C in Lorca and 47�C in El Chopillo, and a cold
winter with absolute minimum temperatures of - 4�C in Lorca and - 14�C in El Chopillo
Precipitation is low with averages of 27.51 cm per annum in Lorca and 40.45 cm per annum
in El Chopillo, and with few rainy days. The relative humidity is consistently low with
high evapotranspiration. Negative water balance occur over 6 months in El Chopillo and 10
months in Lorca. The soil type is quite calcareous, mostly clayey but sometimes alluvial
with negligible nutrient. Hilly topography is common with serious yearly erosion rates of
more 5,000 Tm / Km2. The aim of the project is to use VGHR to minimise soil erosion and to
enhance soil moisture. If successful, it will be tested as a means to improve crops,
protect highway slopes and other embankments, as a source of biomass production and other
applications.
MATERIALS AND METHODS
Planting Materials used for Various Look - See Trials
i. Planting Materials for El Chopillo
A small consignment of 300 bare-root tillers was obtained from Malaysia and sent directly
to El Chopillo in May 1994. They were raised in 12.5 cm x 17.5 cm polybags in a glasshouse
for 11 weeks before being planted into the ground in El Chopillo on 29 July 1994.
ii. Planting Materials for Lorca
Large consignments of tillers were obtained from Malaysia in June 1994 and America in July
1994. They were planted in plastic planting trays of 37 x 30 cm; with 20 containers, of
22.5 cm deep and each container holding 800 cc of standard potting mixture (Composition
25% peat + 65% pine bark and other forest materials + 10% rice husk. Fertilization
Osmocote 1.5 kg / m3, 16-8-12-2, 6-8 months). The plants were kept in a glasshouse near
Barcelona with the controlled environment maintained at 180� C to 350� C and 60% - 80%
R. H. Plants were irrigated for 5 to 10 minutes with a overhead mist for 1 - 3 times per
day depending on the prevailing climatic conditions. They were also flooded with nutrient
solution of "10-1 0-20-oligoelements" at a rate of 0.5 gm./1 once every 3 days.
The bare-root tillers produced roots within 2 weeks. After 3 1/2 months, the roots had
enmeshed the core of the potting mixture with the tops having 2 - 5 tillers newly produced
in-site. The plants were cut to. 20 cm height before sending it to Lorca (Photo 1). They
were then reconditioned in an open air container nursery (Photo 2). These container plants
were used in all the field trials in Lorca.
Irrigation and Fertilization System Used In The Look - See Trials.
In Phase I of the project, the main concern was to ensure establishment of the Vetiver
plants in the hostile environments of Murcia. It was therefore decided from the onset to
reduce the stresses from water deficit and low nutrients by adequate supplies. Irrigation
and fertilizer were applied as follows
i. Ground Nursery in El Chopillo.
The plants were drip-irrigated every 1, 2 or 3 days depending on the season. Water
consumption was equivalent to 6,670 m3/ha from February to October 1995. Soluble
fertilizer was distributed regularly through irrigation water; from February to October
1995; the total amount used was 170 kg/ha KNO3 + 70 kg/ha H3P04 75% + 500 kg/ha KN03 59%.
ii. Container Nursery in Lorca.
Irrigation was supplied by overhead sprinklers at a rates of 2 l/m2 day to 9 l/m2/day,
adjusting it according to the climatic conditions. Fertilizer was applied at rates of
0.156 gm./m2/day, KNO3.
iii. Ground Nursery in Lorca.
Irrigation was by flooding. The amount of water used was equivalent to 700 m3/ha over 10
occasions from February to October 1995. Fertilizer was applied by adding the equivalent
of 500 kg/ha N15P15K1, before planting; and 500 kg/ha KNO3 distributed with the irrigation
water over the 10 applications.
iv. Highway Slope
Irrigation was by drip-irrigation at rate 4 l/hr/m of VGHR. The total amount of water
applied from February to October 1995 was 948 l/m of hedgerow. Fertilizer was through the
irrigation pipes, using a total of 151 gm/m KNO3 over the recorded period. This area was
not linked to the farm's irrigation system. The pipe system was connected to a mobile tank
of 6,000 litres placed at a higher level. Drip-irrigation was by gravity, at a rate of 4
l/hr/m of VGHR. The amount of water used was about 500 l/m from April to October 1995.
Fertilizer, at a rate of 180 gm/m of KNO3 was distributed in the irrigation water over the
same period.
Design For Look - See Trials.
Our main concern at the begining of the project was the establishment of the Vetiver
plants; we were not even sure whether the plants would grow!! Thus only observational
trials were set up.
i. Ground Nursery in El Chopillo
204 polybag plants were planted in a single block of 4 rows on 29 July 1994. The planting
distance was 1 metre between rows and 0.33 metres between plants.
ii. Ground Nursery in Lorca.
The total trial consisted of 2 blocks of 2,917 and 2,478 plants of Malaysia Accession, and
3 blocks of 2,587 ; 2,685; and 2,745 plants of American Accession. They were planted into
the ground nursery on 5 - 19 December 1994. The block size was about 0.1 hectare and the
planting distance was 0.33 metres with 1.00 metre between rows. Because the blocks were of
irregular shape, the number of rows varied from 12 - 16 per plot and the number of plants
per row varied from 150 - 200.
iii. Highway Slope.
A trial was undertaken to test the effect of VGHR to prevent soil erosion on the Highway
slope of 12 m vertical height and with 320 gradient. The slope construction used a rocky
gyspic base covered with very irregular, unstable, not consolidated, clay soil. 3 blocks
of 20 metres width were selected with the outer blocks planted with VGHR and the central
block as control. Vetiver container plants were planted at 5 cm between plant distance and
the VGHR were at 1.0 metre vertical intervals . 12 full length VGHR were planted in each
block and the total plants used were 10,258. The VGHR were planted on 4 - 9 January 1995.
iv. Almond Plots.
Three VGHR of 90 metres length were planted between blocks of four almond rows on 7 April
1995. The between-plant distance was 5 cm and a total of 6006 container plants were used.
i. Serial photos of the container nursery in Lorca were taken weekly, while for all
the other ground trials, photos were taken at approximately monthly intervals. Qualitative
assessment of plant performance were from examining these collections of photos.
ii. Quantitative count of tiller production and dry weight production were done by
harvesting the tops as follows :-
a) Ground Nursery El Chopillo 4 groups of 6 - 8 plants each were cut at 20 cm from the
ground. The fresh weight was measured and numbers of tillers of each top were taken.
Sub-samples were taken to obtain oven - dry weights.
b) Ground Nursery, Lorca To remove boundary effect, the boundary rows were topped by a
mechanised grass cutter to facilitate sampling in the immediate adjacent rows. 3 groups
are randomly selected and the plants were cut manually at heights of 20 cm. For the
Malaysian Accession, 15 plants were sampled per group per row of each of the 2 blocks. For
the American Accession, 10 plants were sampled per group per row of each of the 3 blocks.
The fresh weight and tiller number of each top were noted in the field. Sub - sample's
were taken to obtain oven - dry weights.
iii. Root Examination Excavations to examine the root systems were carried out in
September 1995. A back-hoe was used to dig a large pit next to a group of plants ranging
from 4 plants in El Chopillo to 7 plants in Lorca. To ensure the roots were not damaged, a
gap of at least 20 cm were left between the hole and VGHR. A pressure pump, linked to a
water tank, was used to wash away the soil and expose the roots.
iv. Meteorological Data were obtained from the official stations near the trials sites.
For this paper, we concentrated on the maximum and minimum temperatures and rainfall as
given in Appendices 1 and 2.
1. Establishment and Growth of Plants in Ground Nursery, El Chopillo
This was essentially our first observation block. The 11 week old polybag plants were
transplanted into the ground in July 1995 in the warm weather of summer with very good
transplanting success of 99.5%. Growth was good between August - September 1994 ( Photo 3
) with very vigorous growth from October to early December 1994. Subzero temperatures
occurred between 23 - 28 December 1994 and the frost killed all the exposed tops. However,
the buried crown-portion survived and by early February 1995 new tillers started to
emerge. ( Photo 4 ) From then to May 1995 there were rapid tiller productions. A census
taken in June 1995 showed that 81.8% of the plants have fully recovered from the winter
frost. Good growth was observed in June 1995 ( Photo 5 ) followed by very vigorous growth
rates from August to November 1995.
( Photo 6 )
Harvesting of the tops were carried out on two occasions. ( Photo 7a ) The results are
summarised below:
Date No. of Tillers Dry Weights ( gm per plant)
29/09/95 54.5 +/- 5.0 1030.6 +/- 132.0
04/11/95 66.7 +/- 8.7 1387.5 +/- 250.2
The differences between the dry weights obtained in the 2 harvests suggested rapid biomass
production in autumn 1995. This was confirmed by the very rapid regeneration of the cut
tops. (Photo 7b + 7c).
Excavation showed the root system to have reached 2.6 metres deep, with very dense root
mass on the first 0.5 metre depth. ( Photo 8 )
2. Establishment and growth of Container Plants in Lorca.
The plants in planting trays, in the glasshouse in Barcelona, were cut back to 20 cm
height and transplanted on 2 occasions viz.: 27 October 1994 and 10 November 1994, to a
open air container nursery in Lorca ( Photo 2 ). The plants transported well with no sign
of transporting shock and practically no casualty. They stayed a healthy green colour but
with little growth; the young tillers barely increased in height over the next few weeks.
With the decreasing cold temperature in December 1994, the matured green leaves became
bleached, turned yellowish and finally after sub-zero minimum temperature over 7 days in
end December; they were killed and turned straw colour. Throughout this period, the young
tillers continued to retain the green colour and turned dull green only after the sub-zero
minimum temperature. On site examination showed that, whereas the matured leaves were
killed, the young tillers and the crown region was alive. The dull green colour of the
young tillers persisted through to March 1995, when, with the warmer weather, a healthy
green colour was re-attained and growth resumed. Then, new tillers were also noted.
Container plants were taken out for planting at various times, into the ground starting
from 5 December 1995 and ending 7 April 1995. Towards the end, each container plant had a
few actively growing tillers. The overall establishment success of field planting 32,498
container plants was 95.9 %.
3. Establishment and growth of plants in Ground Nursery, Lorca.
At the time when the container plants were taken out, the cold weather had already turned
the matured leaves to bleached yellow colour, but the young tillers were still green.
After the transplanting and after the frost in late December 1994, the matured leaves
dried up into straw colour ( Photo 9a ); even the young tillers turned a purplish-green to
straw colour. This condition persisted into the cold period of January - March 1995. With
warmer weather in April 1995, the young tillers regained a healthy green colour and there
were new tillers. By May 1995, there were good tiller production, followed by growth in
June and July 1995. Very rapid growth was observed from August 1995 onwards (Photo 9b +
9c). Census taken on 4 July 1995 showed the overall establishment success to be 89.1 %. On
two occasions, assessments of growth were carried out by topping the plants (Photo 10a)
Date No. of Tillers Dry Weights (gm per plant)
Malaysia American Malaysia American
30/09/95 45.2 +/- 3.2 79.0 +/- 4.9 304.7 +/- 36.6 376.9 +/- 23.8
03/11/95 46.6 +/- 3.4 65.0 +/- 3.2 488.8 +/- 50.6 559.8 +/- 42.9
The dry weights between the 2 harvests were substantially different indicating vigorous
growth. Observations of rate of regeneration of cut tops confirmed this view (Photo 10b).
Excavation of roots were carried out. The roots of the American Accession has reached a
depth of 1.7 m while those of the Malaysian Accession was 2.1 m (Photo 11). However, the
main and pronounced root mass was in the upper 0.4 metres, and there was no apparent
difference between the 2 accessions.
4. VGHR to protect Highway slope
Planting was done on 13 - 17 January 1995, at which time the plants in the containers was
suffering from the cold December weather; the mature tillers were dead and the young
tillers were dull green in colour (Photo 12). However by late March, the young tillers had
turned a healthy green colour and by April / May, new tillers were being formed. Very
rapid tiller formation and good growth occurred between April and July followed by
vigorous growth from August 1995 onwards (Photo 13). The overall establishment success was
98.8%. Observations in late September 1995 showed that the VGHR had effectively reduced
soil erosion in the planted plots (Photo 13). Severe erosion had occurred in the control
plots despite the low rainfall of 740 mm over 24 days since the establishment of the trial
(Photo 14a + 14b).
5. VGHR to improve Almond Plots
At the time of planting in April 1995, the container plants had fully recovered from the
frost injury; the young tillers were actively growing with healthy green colour and there
were also new tillers being formed (Photo 15a). The plants established very fast with a
good success of 99.3 %. From the beginning of transplanting new tillers were produced and
by July, useful hedgerows had been formed. Growth from August 1995 was rapid (Photo 15b).
In this trial, it is hoped that the VGHR will serve to slow down the surface rain wash
thus improving infiltration and conserving moisture. There were also plans to cut the tops
of the VGHR to mulch the almond plants. The effect of VGHR on almond production will be
studied using the 2 adjoining plots as controls.
6. General Field Observations.
In the field, some interesting observations were made
( i) Both the Malaysian and the American Accessions had not flowered though plants had
many morphologically matured culms with distinct nodes.
(ii) The morphology of the Malaysian Accession in Spain seemed to be different from the
same Accession in Malaysia. The culms of plants in Spain were clearly bigger and taller
than the same Accession grown in Malaysia. However, the internodes were surprisingly
shorter. In addition, there were very few culm-branches in the plants grown in Spain.
( iii) Plants in the boundary of blocks of Vetiver grass tended to be less vigorous and
showed more stress symptoms of dying of the leaf tips, when compared with plants growing
in the centre.
There do not appear to be any documented record of Vetiver grass having been successfully
grown in Mediterranean climate. Dr. Francoise Dinger reported his failed attempt to grow
Vetiver in Draix ( Haute-Provence Alps, France ) in the Vetiver Newsletter # 6. We are
happy to have successfully established Vetiver grass and to be able to study the
performance of VGHR in Murcia.
Field Establishment of VGHR Under Mediterranean Climate
Due to various logistic requirements, the large number of container plants were
transplanted to the ground beginning 5 December 1994 and ending 7 April 1995. This,
fortuitously, allowed the study of plant development stages on the transplanting success,
establishment and growth under different weather conditions. It also permitted observing
container plants over a longer period. Observations from the various trials in Lorca
showed that new tillers were largely produced in May regardless of the time of the first
transplanting into the field. The same time of new tiller production also occurred in the
container plants. In addition, there was a distinct trend that plants taken out during the
warmer weather have better establishment success. This ranged from 89.1% in the Ground
Nursery (planted December 1994) through 98.8% in the Highway slopes (planted January 1995)
to 99.3% in the Almond Plot Trial (planted April 1995). Therefore, it would appear that
plants should not be taken out too early. In addition to better establishment success, the
plants would be easier to irrigate and maintain in the container nursery. Based on this
first set of results, it appears that the best time to take out container plants may be in
the spring months of March / April. However, this gain in ease of management and less
water usage must be weighted against the advantage of winter planting with its least
competition for labour; spring planting is normal for the main crops.
Growth and Biomass Production
A most interesting field observation was that the plants in the boundary rows were smaller
than those in the central rows and showed more stress symptoms. This occurred in all 5
ground nursery blocks and in the 2 Highway slope blocks. This is different from
observations noted in the tropics where the central rows consistently performed poorer
because of the shade sensitivity of Vetiver. This new observation may be due to the high
solar intensity and the long sunlight hours during the growth period of May - September
1995 and the negative stress effect of low relative humidity. If so, moisture and water
stress have become a stronger limiting factor when compared with light effect. Due to the
growth pattern, biomass determination of the tops were not done until the plants have gone
through some months of the active growth period. Active growth of plants in ground
nurseries started in May 1995 in El Chopillo, but commenced in June / July in Lorca. This
difference was most likely due to the different times of planting. Though the El Chopillo
plants were damaged by winter frost, they already had an established root - system, and
plant growth can take off faster. On the other hand, plants in the ground nursery in Lorca
were only transplanted to the ground just before the winter 1994-5 and the plants will
take time to establish first. Harvesting of plant tops in El Chopillo produced 1030 gm and
1388 gm per plant after 14 and 15 months respectively. For the same 2 periods, the number
of tillers per plant were
55 and 67 respectively. In reality, as the tops of plants were killed during the frost of
winter
1994-5, this biomass production was over a growth period of 5 and 6 months. These values
were high and showed good growth of the Vetiver plants.
In the ground nursery in Lorca, the Malaysian Accession produced 45 and 47 tillers after 9
and 10 months growth respectively. Over the same periods the dry matter were 305 gm and
489 gm per plant respectively. The American Accession yielded 377 gm with 79 tillers and
560 gm with 65 tillers after 9 and 10 months respectively. After deducting for
establishment time, the growth periods were only 4 and 5 months. It would appear that the
American Accession was more vigorous than the Malaysian Accession but it must be noted
that the trials were not designed for such comparisons; also the plants were rather
variable as there were no stringent selection of container plants used for field planting.
In both El Chopillo and Lorca, the cut tops regenerated rapidly confirming the good growth
of Vetiver grass m autumn. Whether the impressive growth during the growing seasons is
sufficient to compensate for negligible growth during the dormant and sustenance seasons
to give good annual biomass production, will be the subject of future investigation.
The good growth of Vetiver grass and the rapid regeneration of cut tops point to
potentially abundant in-site mulch to improve the main crops; this will be tested in the
almond plots. Also the toppings may be considered for fuel, fodder, animal bedding, etc.
The fast establishment of quality VGHR could be used to prevent surface soil erosion, as
was clearly demonstrated in the observation trial on Highway Slopes.
Root System And The Need For Irrigation.
Excavation to study the root systems showed that the roots of the plants in El Chopillo
had reached a depth of 2.6 metres after 14 months in the field. In Lorca, the Malaysian
Accession and the American Accession had produced roots reaching down to 2.1 metres and
1.7 metres respectively after only 9 months. However, m all 3 cases the massive root
system was at the top 0.4 - 0.5 metres. The root Systems observed were not inferior to the
condition experienced in Malaysia.
In this project, there was an attempt to grow Vetiver grass in the Mediterranean climate
of Murcia. Vetiver grass originated mainly from the humid tropics and it will therefore be
most challenging to try to establish it in such an alien and hostile aerial conditions.
For the first Phase of the project, Vetiver grass was irrigated to allow it to have a
better chance of establishment so that its growth performance may be studied. However,
irrigation is expensive and m certain locations, water may not be readily available. The
ultimate economic success may ultimately be determined by its tolerance to water stress.
With the good root system produced, the plants may be able to tap into the sub-soil
moisture during drought and that VGHR, once established, may be tolerant of dry weather
conditions. This is a very important speculation as the need for continued irrigation may
make VGHR not economically viable. Therefore, more experience is needed in order to
confirm this key aspect of the project. Phase II Trials will be targeted to achieve this
objective.
Plant Response to Climatic Conditions.
Since there is no easy nor economical way to modify the temperature in the field, we
decided, in Phase I of the project, to concentrate on studying its effect on the
establishment and growth of Vetiver plants. The responses of the plant to the seasonal
weather conditions showed very interesting results. With plants established in the ground
in El Chopillo, frost killed the tops but the crown-portions were not injured. With the
coming of the warmer weather, new tillers were formed. In the Container Trial in Lorca,
the cold winter killed the matured tillers but not the newly emerged ones. This recovery
from cold damage was not surprising as the Vetiver Newsletter had carried such
observations made in China, U.S.A., South Africa, Zimbabwe, etc. The plants in El Chopillo
recovered from frost injury and cold weather much faster and produced tillers earlier than
the plants in Lorca. The main reason may be, that the plants in El Chopillo were well
established with a good root system while the plants in Lorca were being established in
the field or were in containers exposed to the aerial environment. The depth of root in
the warmer ground could be of importance in the plant's tolerance to cold as well as water
stress. These observations, documented by serial photos, suggest that there seem to be
distinct plant performance periods (at least under irrigation) viz.
1. Frost injury and dormancy
2. Awakening and tillering (regeneration or multiplication)
3. Rapid growth and biomass production
4. Slow growth or sustenance period.
The last period need to be verified during the coming 1995 - 6 late August to early winter
months. If these observations were correct, the tropical to sub-tropical Vetiver Grass is
behaving more like a temperate plant, adapting to the prevailing climatic conditions. This
adds on to the documented great range of adaptabilites of Vetiver Grass, a very unusual
plant indeed. It also points to the possibility of using VGHR in the Mediterranean regions
as well as up m the cold highlands of the tropics and sub-tropics.