Wa e 2015, 7, 4848-4857; doi:10.3390/w7094848
wa e
ISSN 2073-4441
www.mdpi.com/jou nal/wa e
A icle
Reclaimed Wa e Use in Bio uel P oduc ion
Ma ía del Pino Palacios-Diaz1,†,*, Vanessa Mendoza-G imón 1,†, Idai a He nández B i o 2,†,
Juan Ramón Fe nández-Ve a 2,† and José Manuel He nández-Mo eno 3,†
1 Dp o P oducción Animal, G upo In es igación GEOVOL, Uni e sidad de Las Palmas de G an
Cana ia, Fac. Ve e ina ia, A ucas 35013, Spain; E-Mail: .mendozag imó[email p o ec ed]
2 Labo a o io Ag oalimen a io y Fi opa ológico del Cabildo de G an Cana ia (Ag i-Food and
Phy opa hological Labo a o y); A ucas 35013, Spain;
E-Mails: ihe nandezb@g ancana ia.com (I.H.B.); j e nande[email p o ec ed] (J.R.F.-V.)
3 Depa amen o de Biología Animal, Eda ología y Geología, Uni e sidad de La Laguna,
San C is óbal de La Laguna 38200, Spain; E-Mail: [email p o ec ed]
† These au ho s con ibu ed equally o his wo k.
* Au ho o whom co espondence should be add essed; E-Mail: mp.pal[email p o ec ed];
Tel.: +34-928- 454-353; Fax: +35-928-451-142.
Academic Edi o : Ashok K. Chapagain
Recei ed: 13 Ap il 2015 / Accep ed: 6 Augus 2015 / Published: 4 Sep embe 2015
Abs ac : Ja opha cu cas L., a oxic species ha does no in e e e wi h he ood chain,
p oduces biodiesel o be e en i onmen al quali y han mine al oils. Howe e , in o de o
cul i a e i sus ainably, i is necessa y o op imize he limi ed esou ces used, mainly wa e
and soil. The e o e, in a id a eas, i is necessa y o cul i a e unde in ensi e condi ions,
i iga e wi h eclaimed wa e and cu p oduc ion cos s. To op imize wa e consump ion,
pa ial oo -zone d ying (PRD), which keeps a pa o he oo sys em d y, was used. This
wa e managemen s a egy, employed success ully in o he oil c ops, yielded less ui pe
bunch, bu mo e ui bunches pe plan . This ac will p obably allow o es ablish highe
plan ing densi y and, consequen ly, highe p oduc i i y pe su ace uni . This is one o he
ew a ailable op ions o imp o ing p o i abili y as p oduc ion pe ee is s able (1.25 kg
seed plan −1 yea −1 o he mos p oduc i e ees, wi h excellen clima e and soil, and no
limi a ions wa e use). A high pe cen age o ui lying on he g ound (24%) and
non-uni o m iming in ui p oduc ion (excep some specimens) g ea ly hinde i s
mechaniza ion. Al hough his c op’s en i onmen al and socio-economic bene i s a e no
aken in o accoun , i is e y di icul , wi h only he calcula ed wa e consump ion (15.5 m3
OPEN ACCESS
Wa e 2015, 7 4849
wa e pe L o oil o 5.6 m3 wa e pe L o oil acco ding o ou bes es ima ions), o
conside i a p o i able op ion.
Keywo ds: Ja opha cu cas; wa e consump ion coe icien ; pa ial oo -zone d ying
(PRD); biodiesel; subsu ace d ip i iga ion (SDI)
1. In oduc ion
Cul i a ing Ja opha cu cas L., a oxic species ha does no in e e e wi h he ood chain, can
p o ide enewable uel o he anspo sec o , a sec o ha accoun s o one hi d o ene gy
consump ion in Spain [1]. Howe e , in o de o o e a sus ainable solu ion, uncon en ional wa e
esou ces mus be used, which a oids compe i ion o “g een wa e ” (e ec i e ain all), and “blue
wa e ” (su ace and g oundwa e ). Soil, a limi ed, non- enewable esou ce, is ano he p oduc i e ac o
o be op imized i we wish o ind an en i o- iendly solu ion. The e o e, he in ensi e cul i a ion o
his species by using eclaimed wa e and i iga ion echniques o achie e op imized p oduc ion is he
only op ion ha has appea ed in de eloped coun ies. Ve y li le in o ma ion is a ailable abou how o
add ess Ja opha cu cas cul i a ion unde hese pa icula condi ions because i s high gene ic
a iabili y [2] makes ca ying ou such s udies di icul . None heless, some ecen publica ions ha e
p o ided in o ma ion on i s esponse o d ip i iga ion wi h eclaimed wa e [3,4] unde d y condi ions.
Cos -bene i s udies ha e es ima ed J. cu cas p oduc ion cos s o be be ween 3 and 10 imes he
e enue gene a ed by selling diesel in cul u al p ac ices in de eloping coun ies [3], so educing hese
cos s is essen ial. Ye he li e a u e o e s no s udies in o in ensi e p oduc ion cos s. Mo eo e , a
global analysis should in oduce he associa ed en i onmen al (pa icula es a e 80% cheape han hose
p oduced by mine al uels [5], ca bon emissions a e lowe , isk o e osion dec eases when soil is
cul i a ed, e c.) and economic ( inancial esou ces and economic ac i i y a e used and gene a ed in he
coun y, which lowe s he ade de ici ) bene i s.
Pa ial oo -zone d ying (PRD), a echnique ha has been de eloped based on knowledge o he
physiological mechanisms ha con ol plan anspi a ion and oo -shoo signaling unde wa e
sho age condi ions, consis s in i iga ing only one side o he oo zone so ha he plan can be
simul aneously exposed o bo h we and d y soil [6]. This echnology, which was de eloped in he
1990s in Aus alia, o e s h ee bene i s: inc eased wa e use e iciency wi h no loss o yield; educed
ege a i e g ow h (imp o ed ep oduc i e/ ege a i e balance); and imp o ed ui quali y [7,8].
Al hough he e a e no s udies ha ha e analyzed he esponse o PRD in Ja opha cu cas, he esul s
ob ained o ano he oil ui , oli e, and explained by he bes s oma a closu e when PRD [9] is used,
led us o conclude ha i would be possible o inc ease i s oil yield [6].
This pape analyzes he easibili y o using an i iga ion managemen echnique (PRD) o
imp o e wa e p oduc i i y by p o iding da a o ad ance he s udy o he economic iabili y o
Ja opha cu cas p oduc ion.
Wa e 2015, 7 4850
2. Me hodology
2.1. Expe imen al Design and I iga ion Sys em Desc ip ion
Fo his expe imen , a Ja opha cu cas plan a ion was used, which was se up 5 yea s ago on he
g ounds o he Ag icul u al Expe imen al Fa m o Cabildo de G an Cana ia (Cana y Islands), wi h a
plan ing ame o 3 m be ween aisles and 2.5 m be ween ees. In ea ly Feb ua y 2014, ees we e
p uned wi h a chainsaw, which le ee heigh a 1.30 m and a c own diame e o app oxima ely
0.75 m. Then new specimens we e plan ed be ween ees in he old aisles (a a dis ance o 1.5 m) o
lea e new aisles o 2.5 m. Howe e , his s udy only p esen s he da a o he ma u e ees. A he end o
Feb ua y 2014, a subsu ace i iga ion sys em was bu ied 0.2 m deep o eplace he p e ious su ace
d ip i iga ion. A se e e cochineal a ack mean wo pes icide ea men s had o be applied using
summe mine al oil. No mo e pes s o diseases we e obse ed abo e he ea men h eshold.
The soil o his land is classi ied as An h osol [10] (ISSS/ISRIC/FAO, 1998) o To ia en [11].
The o cha d has an au oma ic wea he s a ion, used o calcula e e e ence c op Penman-Mon ei h’s
e apo anspi a ion (ET0) wi h da a a ailable since 2000. A p oblem occu ed in his wea he s a ion
in 2014, which mean ha we we e only able o ob ain p ecipi a ion da a o 5 mon hs (Ap il–Augus ),
du ing which ime accumula ed ain all was low, and he a e age alue o 2000–2014 was no
dis inguished (26.6 L/m2) om he 22.7 L/m2 collec ed du ing his pe iod, while annual p ecipi a ion
was 196 L/m2. The 248 m2 plo was di ided in o h ee blocks (each line o ees cons i u ed one block),
in which he wo ea men s we e applied: a con ol (Tc), which consis ed in applying a daily dose o
2.6 L/m2; a second ea men (Ta), which ecei ed he same dose, bu was i iga ed al e na ely
(weekly) on ei he side o he ees. A line o i e ees wi h 12 emi e s/ ee was i iga ed in each
block; hus, each ea men i iga ed h ee lines o i e ees each, and each ea men consis ed in
15 ees dis ibu ed in o h ee lines: A, B and C (Tc) and D, E and F (Ta). A subsu ace i iga ion
sys em (SDI) wi h in eg al d ippe s, p essu e-compensa ing a ange 1.5–4.0 ba , an i-siphon and high
an i-d ain mechanism, spaced a 0.5 m wi h deli e y a es o 2.5 l hou −1, was used o apply eclaimed
wa e . I iga ion lines we e spaced a 1.2 m, which le ees in he cen e . I iga ion ime was adjus ed
o apply a cons an daily dose o wa e (wi h i iga ion wice daily) o ma ch he e e ence c op
e apo anspi a ion (ET0) a e age measu ed in he las 14 yea s. Then wo i iga ions/day we e
o ganized, and each i iga ion las ed 20 min o Tc ( he wo lines simul aneously i iga ed he same
ee) and 40 min o Ta, bu only one o he lines i iga ed each ee (pa ial oo d ying “PRD”). Each
subuni had one lowme e and eadings we e aken weekly.
2.2. Soil, Plan Analysis and Yield-Rela ed Pa ame e s
Composi e soil samples be ween 0 and 0.2 m deep we e aken, which coincided wi h he beginning
o he expe imen : 0.2 m apa om ee unks (in he we bulb, loc 1), be ween wo ees o each line
(loc 2) and in he aisles (loc 3). A d y combus ion echnique was used wi h a LECO CNS 2000
analyze o de e mine o ganic ca bon (CO, as a %) and o al ni ogen (N o ). Soluble sal s we e
es ima ed by elec ical conduc i i y (EC) a he 1:5 soil/wa e a io, exp essed in (dS/m) 1:5. A ailable
ni a e (mg/kg) was de e mined by ex ac ion wi h 0.01 M calcium chlo ide and was hen analyzed by
ion ch oma og aphy. A ailable phospho us (P, mg/g) was de e mined by he me hod o Olsen and
Wa e 2015, 7 4851
Somme s [12]. Exchangeable ca ions we e ex ac ed wi h an ammonium ace a e solu ion bu e ed o
pH 7. Ex ac ed ca ions (exp essed in meq/100 g), po assium (K), calcium (Ca), magnesium (Mg) and
sodium (Na) we e analyzed by op ical emission spec opho ome y (ICP_OES). Composi e samples o
young lea es we e aken om each ee line. N (%) was de e mined by he d y combus ion LECO
CNS 2000 echnique. Fo he o he analyzed elemen s P, K, Ca, Mg, Na (exp essed in %), B, Cu, Fe,
Mn and Zn (in mg/kg), he diges ion echnique was adop ed using ni ic acid in a mic owa e o he
ICP_OES and subsequen analyses.
The ipe ui s o each ee used in he di e en ea men s and he ui s ound on he soil we e
collec ed weekly o 15 weeks. The ollowing pa ame e s we e measu ed in he ield: numbe o
ma u e ui pe bunch and numbe o bunches wi h ipe ui ( e ile bunches), o each ee a each
collec ion ime. F om he ob ained da a, he ollowing pa ame e s we e calcula ed: numbe o
ha es ed ui pe ee (by adding hose collec ed om ees and hose ound on he soil). In he
labo a o y, he ipe ui s and seeds o each ee and each ha es we e weighed. Also o each ee,
wo new a iables we e calcula ed: accumula ed numbe o ui s pe bunch and accumula ed seed
p oduc ion o e ime.
2.3. S a is ical Analysis
An analysis o a iance (ANOVA) was ca ied ou wi h he SPSS s a is ical package ( e sion 22)
using he gene alized linea m. The dependen a iables we e ea men (PRD: Ta s. Tc), collec ion
da e and ee, including he analysis o he ollowing pe o mance pa ame e s: numbe o ui pe
bunch, numbe o bunches wi h ipe ui pe ee ( e ile bunch/ ee), o al numbe o ma u e ui
(including allen ui ) and numbe o ui collec ed om he ee op, weigh o he yield ob ained pe
ui and seed (exp essed in g DM/ ee), and amoun o wa e applied (Tc and Ta) and hei in e ac ion.
Mean sepa a ion was es ed by leas signi ican di e ence (LSD) a e se ing he signi icance le el a
α = 0.05. The esul s we e agg ega ed o cumula i e p oduc ion.
3. Resul s and Discussion
Ja opha is a species ha ole a es d yness, bu adequa e p oduc ion is no possible i i does no
ecei e enough wa e . I needs an annual minimum o 500–600 L/m2 o app op ia e lowe ing and
se ing [13]. As in all semia id egions, 196 L/m2 pe yea is insu icien , and i iga ion mus be used in
hese zones [14]. Annual ain all mus each 1000–1500 L/m2 o achie e accep able p oduc ion
wi hou i iga ion [15]. The amoun o wa e supplied du ing he expe imen al pe iod was
2.6 (L/m2·day−1), and wa e consump ion was measu ed om he lowme e eadings a 680 L/m2. The
mon hly amoun o wa e used, compa ed wi h mon hly e apo anspi a ion (ET0) om Feb ua y o
No embe 2014 (which was simila o he 14-yea a e age ET0), was 961 mm e sus 1015 mm, which
was highe in au umn, bu lowe in summe and au umn 2014 (Figu e 1). The applied dose (assuming
no p ecipi a ion) con ibu ed be ween 65% and 110% o he measu ed daily ET0 o 2014.
Rega ding he esponse o clima ic ac o s, he daily a e age minimum empe a u e o he a ailable
pe iod was always abo e 10 °C. The e o e, empe a u es coincided wi h op imal c op g ow h
condi ions (20–28 °C, [16]).
Wa e 2015, 7 4852
0
20
40
60
80
100
120
1.8
2.1
2.4
2.7
3.0
3.3
3.6
3.9
4.2
Jan
Feb
Ma
Ap
May
Jun
Jul
Ago
Sep
Oc
No
Dec
I iga ed wa e /ETo (%)
ETo (Lm-2)
Daily ETo Daily ETo_2014 I iga ed wa e /ETo
Figu e 1. A e age e e ence c op e apo anspi a ion (ET0) o a ailable 14 yea s (g een),
daily ET0 om he expe imen al pe iod 2014 ( ed) and i iga ed wa e /ET0 in % (blue).
The soil samples esul s a e p esen ed in Table 1. Signi ican di e ences we e ound in almos all
he pa ame e s acco ding o he sampling si e. In loc 1, a signi ican ly highe basici y was obse ed.
Signi ican ly highe Ca and Na con en s, bu lowe salini y, OM, C/N, P, K and Mg, we e also ound.
Despi e no being signi ican , he ni a e alues we e lowe in bulbs, which can be accoun ed o by
g ea e nu ien abso p ion om he oo s ha g ew p e e en ially in he a ea. The e o e, he soil
explo ed by oo s mos ly had a basic cha ac e , no salini y p oblems, a high OM con en and a e y
s able cha ac e .
Table 1. Means pH alues in wa e (1:2.5), elec ical conduc i i y 1:5 (EC in dS/m), lime,
o ganic ma e (OM, exp essed as a %), o al ni ogen (N o , exp essed as %), a ailable ni a e
(exp essed as mg N/kg), Olsen phospho us (exp essed as mg P/kg), ex ac ed ca ions
(exp essed as me/100 g): po assium (K), calcium (Ca), magnesium (Mg) and sodium (Na)
o he h ee sampling loca ions: (1) we bulb; (2) be ween lines; (3) be ween aisles.
Loc pH EC Limes one OM N o C/N Ni a e P K Ca Mg Na
1 med 8.52 0.31a 5.05a 5.29a,b 0.33b 9.38a 109.18a 53.42a 4.47a 24.80c 7.54a 3.35b
s d 0.037 0.08 0.17 0.18 0.01 0.16 136.86 4.38 0.26 0.48 0.12 0.19
2 med 8.37b 0.51a 5.91b 5.66b 0.34b 9.78a,b 384.1a 65.06b 8.40b 22.92b 9.33b 2.58a
s d 0.041 0.09 0.19 0.20 0.01 0.18 151.61 4.85 0.29 0.54 0.13 0.22
3 med 8.11a 1.08b 5.87b 4.87a 0.29a 9.97b 1261.05b 64.64b 8.93b 21.25a 9.1b 3.2b
s d 0.046 0.10 0.21 0.22 0.01 0.20 167.62 5.37 0.32 0.59 0.14 0.24
No e: Di e en le e s in supe sc ip ollowing alues (a, b, c) indica e s a is ical signi icance.
Rega ding lea pa ame e s, he Ta plan s exhibi ed signi ican ly highe con en han he Tc ones, bu
only o Na+. The mac onu ien con en s o he plan s used he ein ell wi hin he same ange as o he
au ho s ha e epo ed (Figu e 2). Do a-San os [4] s a ed ha no p oduc i i y cons ain s occu ed wi h
he nu ien con en s in he young lea es ha hey ob ained. Howe e , he K con en ob ained in ou
expe imen was below ha epo ed in [4] and [17], bu simila o ha ob ained by [18] and [19]), and
may be associa ed wi h p og essi e soil K deple ion in we bulbs (Figu e 2), in which no K e iliza ion
was applied. Do a-San os [4] ound ha he soil pa ame e s which mos ly in luenced seed p oduc ion
we e P and K. Gi en he ichness o ou soil P, K e iliza ion is ecommended.

Wa e 2015, 7 4853
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
N o P K
%This s udy
La iola and Dias, 2008 [18]
Chaudha y, 2008 [19]
Souza e al, 2011 [17]
de Miguel e al, 2013 [3]
Do a-San os e al, 2014 [4]
Figu e 2. Mac onu ien con en s in he lea es (%) ob ained he ein and hose epo ed by
o he au ho s.
When analyzing he esul s o ee a iables, we ound signi ican di e ences o numbe o
ui /bunch. This esul ag ees wi h hose ob ained by [20] and [2], who obse ed di e ences when
analyzing di e se Ja opha popula ions, al hough he ange o a ia ion indica ed by hese au ho s
(0.2–9 and 6.6–12.3, espec i ely) was much wide han ha ound in ou ees. Signi ican di e ences
we e also no ed in numbe o e ile bunch/ ee (pa ame e o which [2] ound no di e ences). A hi d
pa ame e , numbe o ui / ee, which mus be added o he o he wo pa ame e s, also p esen ed
signi ican di e ences, which again coincides wi h he indings o [20]. Howe e , no di e ences we e
ound by [2]. In con as , a e age ui weigh did no signi ican ly di e among ees, and his esul
also coincided wi h ha ob ained by [20], e en when a e age ui weigh (1.52 g/ ui ) was much
lowe han ha ob ained in his expe imen (4.82 g/ ui ). These esul s con as wi h hose ob ained by
Zegbe e al. [21], who s udied he in luence o PRD on yield, ui quali y a ha es , lesh i mness,
o al soluble solids concen a ion, and many o he pa ame e s in apple ees. These au ho s ob ained
he same alues be ween he con ol ea men and PRD, ye wa e use e iciency imp o ed by 120%
in PRD ees.
When he e olu ion o hese pa ame e s e sus ha es week (a e 15 weeks) was analyzed,
di e ences we e ound in ou pa ame e s: numbe o ui /bunch (and wi h he ee a iable); a e age
ui weigh (unlike ha ob ained o ees); and weigh / ee nu s and seeds, wi h highe yields ound
be ween weeks 3 and 9. The wide a iabili y among ees coincided wi h [2], who s a ed ha lack o
uni o mi y wi hin popula ions is one o he main p oblems o planning comme cial Ja opha
p oduc ion. Thus, as he di e ences be ween ees we e so ma ked, i was di icul o obse e he
e ec s o he s udied managemen p ac ices. Howe e , in his s udy we ound di e ences be ween Ta
and Tc o wo pa ame e s, numbe o ui pe bunch and numbe o e ile bunches pe ee. Al hough
Ta had signi ican ly less ui /bunch han Tc (2.5 s. 3.05, espec i ely), no signi ican di e ences
we e ob ained o weigh o ha es ed ui .
This esul ag ees wi h ha ob ained by [9] ia PRD echniques, who ound ewe , bu sligh ly
la ge , oli e ui s. Ta had a signi ican ly highe a e age (14.88 e ile bunches/ ee) s. Tc (11.77).
This indica es ha he smalle numbe o ui s pe bunch was compensa ed o by g ea e e ili y,
which esul ed in he equi alen o al p oduc ion. This inding is p omising as i sugges s ha i
Wa e 2015, 7 4854
plan ing densi y can inc ease, he ees i iga ed by an al e na e i iga ion me hod will be able o
p oduce he same yield as hey p oduce mo e e ile bunches/ ee, despi e ha ing less space. This
imp o emen in he balance be ween ege a i e g ow h and ep oduc i e de elopmen has al eady
been epo ed in he i s s udies conduc ed in cul u ed PRD ines [6,7], which is one o he easons o
imp o ed wa e e iciency in hese sys ems.
The mean alues ob ained o he o he pa ame e s we e: pe cen age o ui allen on soil, 24%;
a e age ui weigh , 4.82 g; weigh o p oduc ion ob ained o bo h ui and seed (148 and
63.66 g/ ee and ha es ing, espec i ely); and inally, 955 g seed/plan o 15 weeks, which coincides
wi h [2] o imp o ed a ie y.
Figu e 3 p esen s he cumula i e seed yield (exp essed as g DM/ ee) ob ained du ing he
p oduc ion pe iod. Wide a iabili y among ees was obse ed, which was also he case be ween he
less and mo e p oduc i e ees in he same line, and di e ences we e be ween 44% and 48% o Tc
and Ta, espec i ely.
Figu e 3b ep esen s he cumula i e p oduc ion o seeds o bo h ea men s. The ampli ude o he
boxes co esponded o he ma ked di e ence among ees on he same ea men . Excep o a ew
speci ic examples, we obse ed ha e y li le was ha es ed in mon h 1, and he same occu ed o he
las ew weeks. Due o he wide a iabili y ob ained be ween indi iduals, we we e unable o
dis inguish signi ican di e ences be ween Ta and Tc p oduc ion (1177 and 1173 kg/ha, espec i ely),
which was less han 1875 kg/ha ci ed by [22] and [20]. We also saw ha ewe g o seeds we e ini ially
ha es ed in Ta, bu he a e age ha es ed weigh since Oc obe was sligh ly g ea e . Whe he his
end con inued o he ollowing yea mus be moni o ed. Some au ho s ha e ci ed ha oil yield om
seeds was 28%, while Mo Fi [23] ci ed an oil yield o be ween 55% and 60% w/w, which coincided
wi h he 55%–58% ound in he Cana ies, because hey exp essed his yield in whi e seed pe o mance
e ms. When we ook he 35% /w alue as a e e ence, and assumed a densi y o 0.96 kg/L, i was
possible o es ima e he i iga ion wa e equi ed o p oduce 437.5 L o oil pe ha by conside ing
6800 m3/ha o wa e used. Thus Ja opha needed 15.5 m3 o wa e pe L o oil ob ained.
(a) (b)
Figu e 3. (a) cumula i e p oduc ion o seeds h oughou he collec ion pe iod (g/ ee) o
he h ee lines o each ea men (15 ees pe ea men ); (b) box-plo diag am o he
cumula i e p oduc ion o seeds o bo h ea men s.
Hence, he ob ained p oduc ion ha dly gua an ees p o i abili y o his c op. Indeed, by assuming a
p ice o 0.2 € and 0.7 €/ L o wa e and oil, espec i ely, wa e expendi u e would mul iply he
income ea ned om selling Ja opha by 4. Ye when we conside ed he p oduc ion o he bes ees
Wa e 2015, 7 4855
(1.25 kg/ ee and yea ), and by assuming ha young ees ecen ly ini ia ed p oduc ion (2667 ees/ha),
oil yield would be 1214 L/ha, which is he equi alen o 5.6 m3 wa e /L o oil, whe e wa e use would
ep esen 1.6 imes he income made om selling he oil. Only o yields abo e 5000 kg o seed/ha, o
i he p ice paid o he biodiesel was o e 0.7 €/kg, would Ja opha p oduc ion be in e es ing. Some
au ho s [24] ha e ci ed a sales p ice o 5 $/kg o seed, which would ensu e p o i abili y. The e o e, in
o de o imp o e p o i abili y, i is essen ial o educe he plan ing amewo k and inc ease he numbe
o p oduc i e ees pe hec a e. I emains o be e i ied whe he oil con en is highe o he al e na e
i iga ion me hod, as in oli es [6].
4. Conclusions
This s udy ob ained an a e age yield o 1200 kg seed/ha. Seed yield did no inc emen as a esul o
al e na i e i iga ion (PRD). The a o emen ioned wide gene ic a iabili y o Ja opha plan s was
e i ied, which makes conduc ing s udies in o op imizing ag onomic p ac ices di icul . Howe e ,
some pa ame e s we e a ec ed by he es ed wa e managemen as less ui pe bunch we e p oduced,
bu he mos e ile bunch pe ee occu ed when plan s we e i iga ed al e na ely. The e o e by PRD,
is i possible o inc ease plan ing densi y by main aining p oduc i i y/ ee since such managemen
p o ides a la ge numbe o e ile b anches pe ee, which inc eases o al p oduc ion. In ac in o de
o make Ja opha cu cas p oduc ion p o i able, educed spacing be ween ees is one o he ew
op ions as p oduc ion pe ee is e y s able (1.25 kg seed/ ee in he bes young ees in his
expe imen wi h excellen clima e and soil). Ano he ac o ha in luences p o i abili y is he la ge
pe cen age o ui ha alls o he g ound (24%), so i is necessa y o collec i . Excep o a ew
specimens, p oduc ion inc eased h oughou he p oduc ion pe iod, which made i e y di icul o
imp o e he ha es ing p ocess using machine y. Wi h he calcula ed 15.5 m3 o wa e consump ion
pe L o oil ob ained (5.6 m3 wa e /L acco ding o ou bes es ima ions once young ees s a ed
p oducing), i is e y di icul o make his c op p o i able i he en i onmen al and socio-economic
bene i s a e no conside ed.
Acknowledgmen
This wo k was suppo ed by Minis y o Economy and Finance (MINECO). Subp og am Basic
Resea ch P ojec s (CGL2012-39520-C03-03) and FEDER.
Con lic s o In e es
The au ho s decla e no con lic o in e es .
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