Introduction. Cien. Inv. Agr. 43(1): DOI: /S Abstract

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1 Cien. Inv. Agr. 43(1): crop production DOI: 1.467/S reserch pper The effect of folir pplictions of io-stimulnt derived from lge extrct on the physiologicl ehvior of lulo seedlings (Solnum quitoense cv. Septentrionle) Jhon J. Díz-Leguizmón, Oscr F. Chingté-Cruz, Alefsi D. Sánchez- Reinoso, nd Hermnn Restrepo-Díz Deprtmento de Agronomí, Fcultd de Ciencis Agrris, Universidd Ncionl de Colomi. Crrer 3 No 45-3, Bogotá D.C., Colomi. Astrct J.J. Díz-Leguizmón, O.F. Chingté-Cruz, A.D. Sánchez-Reinoso, H. Restrepo-Díz The effect of folir pplictions of io-stimulnt derived from lge extrct on the physiologicl ehvior of lulo seedlings (Solnum quitoense cv. Septentrionle). Cien. Inv. Agr. 43(1): Seweed extrcts re used s nutritionl supplements, iostimulnts, or iofertilizers in griculture nd horticulture to increse plnt growth nd yield. In this experiment, folir pplictions of io-stimulnt derivte from seweed extrct were tested on plnt growth, lef gs exchnge properties, nd proline ccumultion in lulo seedlings cultivted under greenhouse conditions. Lulo plnts were split into four tretments: (i) plnts with soil fertilizer; (ii) plnts treted only with folir io-stimulnt sprys; (iii) comintion of soil fertilizer plus folir io-stimulnt ppliction; nd (iv) control tretment (without nutrient ppliction). Lulo plnts treted with soil fertilizer nd folir io-stimulnts incresed growth, s this group of plnts showed higher totl plnt dry weight, stem dimeters, nd solute growth rte. Lulo plnts without soil fertilizter nd treted with folir io-stimulnt ppliction hd lower lef gs exchnge (photosynthesis, stomtl conductnce, nd plnt trnspirtion) nd lef chlorophyll content. Folir iostimulnt sprys enhnced the prtitioning of dry mss in florl cushions. In conclusion, the ppliction of folir io-stimulnt pplictions s complement to soil fertilizer is technique tht cn e employed in the cultivtion of lulo ecuse folir sprys of these kinds of grochemicls cn enhnce dry mtter ccumultion nd looming. Key words: Folir sprys, growth rtes, proline, PSII efficiency, soil fertilizer Introduction Lulo (Solnum quintoense L.) is ntive fruit species from the rin forests of the South Americn Andes nd is minly found in countries such s Received August 1, 215. Accepted Ferury 26, 216. Corresponding uthor: hrestrepod@unl.edu.co Colomi, Ecudor nd Peru. In Colomi, the production of this fruit for the yer 213 ws 68,748 tons in totl of 7,327 hectres (Agronet, 215). The plnt yield is especilly influenced y fertiliztion supplied during its growth nd development (Mengel et l., 21). Additionlly, soil fertiliztion is the principl method y which crops re

2 26 cienci e investigción grri provided with essentil nutrients (Mschnner, 212). Moreover, crop plnts cn uptke nutrients nd/or other growth-promoting sustnces (hormones, crohydrtes, nd mino cids) through leves under pproprite concentrtions (Fgeri et l., 29). Consequently, the folir ppliction of fertilizers nd io-stimulnts is complementry technique tht cn: (i) promote growth (Ardeili et l., 212); (ii) increse crop production (Fgeri et l., 29); nd/or (iii) reduce the negtive effects cused y iotic stress conditions in specific periods during crop development (Clvo et l., 214). Generlly, it hs een reported tht the use of sustnces such s mino cids, vegetle extrcts, nd/or io-stimulnts hve shown positive effects on plnt growth nd yield (Brown nd S, 215). Applictions of plnt iostimulnts hve enhnced growth, yield nd fruit qulity in tomtoes (Zodpe et l., 211; Hernández-Herrer et l., 214), incresed net photosynthesis, trnspirtion rte, nd the intercellulr concentrtion of CO 2 in mize (Anjum et l., 211), nd triggered erly flowering nd fruit set in numer of crop plnts (Khn et l., 29). Mesurements of free mino cid contents (lnine, sprgine, or proline) my reflect chnges in the nutrition conditions of these plnts (Al-Krki et l., 1996). In this regrd, the ccumultion of free proline in plnts is n indictor of the degree of cclimtion to iotic stress conditions (Clussen et l., 26). Furthermore, the determintion of proline hs lso een used s n indictor of plnt responses to minerl nutrition tretments (Neuerg et l., 21). Al-Krki et l. (1996) found tht sorghum leves showed n incresed proline ccumultion when supplied with higher level of phosphorus. Additionlly, n increse of this free mino cid ws oserved in tomto nd pepper plnts under conditions of oron toxicity (Ersln et l., 27). In contrst, the collection of growth rtes llows quntittive pproch to understnd the growth of plnt or popultion of plnts under different cropping prctices such s the fertilizer ppliction method or the effect of fertilizers (Gil nd Mirnd, 27). Growth rtes such s the solute growth rte, reltive growth rte (RGR) nd/or the lef weight rtio (LWR) hve een used to model the effectiveness of the fertiliztion tretments (Neuerg et l., 21). In generl, the studies tht hve een developed in lulo crops (S. quintoense) in Colomi hve een focused minly on the res of post-hrvest, plnt pthology, nd gro-industril processing (Medin et l., 29). However, studies on the physiologicl ehvior of this species with regrds to minerl nutrition hve een poorly documented. Additionlly, the studies on the response to folir fertiliztion using iostimulnts or mino cids, s well s reports on the gronomic performnce of the use of these products in horticulturl crops in tropicl res, especilly S. quitoense, re scrce ecuse the ville literture is minly gered towrds understnding the response of lulo plnts to the effect of folir nitrogen pplictions (Prr-Corondo et l., 215; Florez-Velsco et l., 215). Consequently, these kinds of studies with iostimulnts derived from seweeds nd/or mino cids ecome highly vlule ecuse they hve n importnt influence on crop productivity. Additionlly, dt on the effects of plnt iostimulnt use on proline ccumultion in leves of this species is not ville in terms of iotic stress effects such s, in this cse, nutritionl deficiencies. Therefore, the ojective of this study ws to evlute the effect of folir ppliction of iostimulnt derived from seweed s supplement of the soil fertiliztion in lulo plnts (S. quitoense cv. Septentrionle) on physiologicl processes such s photosynthesis, stomtl conductnce, trnspirtion, growth rtes, nd iochemicl processes such s proline production.

3 VOLUME 43 Nº1 JANUARY APRIL Mterils nd methods Plnt mteril nd growth conditions The present work ws conducted in the unheted greenhouses of the Fculty of Agrrin Sciences of the Universidd Ncionl de Colomi, Bogotá (ltitude north nd longitude west) for 15 dys. Sixty-dy-old lulo seedlings cv. Septentrionle were trnsplnted into 4-L plstic pots contining pet snd mixture (in 2:1 reltionship (v/v)) s sustrte. In ddition, the spce etween pots ws 25 cm. In generl, the experiment re used ws pproximtely 8 m 2 in the greenhouse. Finlly, the growing conditions in the unheted greenhouse during the test were n verge temperture of 22 C, reltive humidity 6% to 9%, nd nturl photoperiod of 12 h. Tretments Lulo seedlings hd n cclimtion period of 15 dys fter trnsplnting (DAT) during which time they were irrigted weekly with 4 ml of distilled wter throughout the experiment. After this period of cclimtion, plnts were sujected to four different nutrition tretments. Fertilizer tretments consisted of: (i) group of plnts with soil fertilizer; (ii) plnts treted only with io-stimulnt through folir sprys; (iii) comintion of soil fertilizer plus folir io-stimulnt ppliction; nd (iv) control tretment (without nutrient ppliction). The soil fertiliztion consisted in supplying compound fertilizer (TRIAN 15 Yr, Colomi) s source of nitrogen, phosphorus, nd potssium t dose of 5 g per plnt. In ddition, compound fertilizer with microelements t dose of 1 g per plnt (Agrimins, Colingro, Colomi) ws dded. The Agrimins composition ws 8% totl nitrogen (1% mmoni N nd 7% ure N), 5.% ssimille phosphorus (P 2 O 5 ), 18% clcium (CAO), 6% mgnesium (MgO), 1.6% totl sulfur, 1% oron,.75% copper,.5% molydenum, nd 2.5% zinc. Soil fertilizer ws pplied t, 34, nd 75 DAT. For the folir ppliction tretments, io-stimulnt derived from lge (Ascophyllum nodosum) ws used (Msi, Colingro, Colomi) t dose of 3 ml L -1 H 2 O. The io-stimulnt hd concentrtion of 139 g of orgnic cron per liter of nutrient solution. Seven folir pplictions were mde t 22, 44, 66, 88, 11, 132, nd 147 (DAT), respectively. Folir pplictions were crried out etween 8:.m. nd 1:.m. using hndheld spryer (Grden, Royl Condor, Colomi) on oth the surfce nd the underside of leves. The folir sprys were crried out during those dy hours to gurntee higher contct of solution with the lef surfce. Likewise, the spry volume pplied per plnt during iostimulnt ppliction ws 1 ml. Lulo seedlings were spryed until solution rn off the leves, ut pots were covered with plstic to prevent excess run-off from entering the sustrte. For the tretment in which soil fertilizer plus folir io-stimulnt ws pplied, method comining the two techniques descried in the two previous tretments (soil fertiliztion nd folir ppliction of io-stimulnt) ws performed. Dry weight, lef re, specific lef re, stem dimeter, nd shoot length Totl dry plnt weight (TDPW), lef re, nd shoot length were determined t 36, 59, 97, nd 15 DAT. TDPW ws otined y hrvesting six plnts per tretment t ech smpling dte. Then, plnts were dried in compressed dry ir oven (Mod 27 Thelco, Chicgo, USA) t 8 C for 48 h in order to otin dry weight. Lef re ws lso recorded from the plnts hrvested in TPDW using lef re meter (Li31, Li- Corinstruments, Nersk, USA). At the end of the experiment (15 DAT), the specific lef re ws clculted y the rtio of the lef re nd lef dry weight (cm 2 g -1 ). The stem dimeter ws lso determined t 15 DAT, nd it ws tken in the stem segment tht ws locted 8 cm ove the sustrte surfce.

4 28 cienci e investigción grri Growth components Photosystem II Efficiency (F v ) To determine the growth components, solute growth rte (AGR), reltive growth rte (RGR), nd net ssimiltion rte (NAR) were determined t 36, 59, 97, nd 15 DAT using the following equtions descried y Crrnz et l. (29): ( ); 1 To determine the efficiency of photo system II (F v / F m ), continuous excittion fluorometer (Hndy PEA, Hnstech Instruments, Kings Lynn, UK) ws used t 145 DAT. Two full-grown leves (the sme leves used to determine photosynthesis) were used to determine the F v rtio y using clips in order to ensure the cclimtion of portion of lef in totl drkness for 1 min. 1 ) ( ); 1 1 ( 1 ) ( ); 2 1 ( W = totl dry weight (g); L A = lef re (cm 2 ); dw = dry weight (mg or µg); nd dt = time (d). Lef chlorophyll content (SPAD units) Three redings were conducted on fully extended lef from the upper middle portion of cnopy using SPAD chlorophyll meter (SPAD- 52, Konic Minolt Sensing, Inc., Rmsey, NJ, USA). In generl, two mture leves were used to determine the chlorophyll content per replicte. Lef SPAD redings were estimted t 97 nd 145 DAT. Finlly, the SPAD vlue represents the men of six redings. Photosynthesis nd stomtl conductnce Photosynthesis (P n ) nd stomtl conductnce (g s ) of leves were estimted using portle photosynthesis system (Li-Cor 62, Lincoln, Nersk, USA) nd porometer (SC-1, DecgonDevices, Pullmn WA, USA) etween 145 nd 15 DAT, respectively. P n nd g s mesurements were determined in fully expnded leves from the upper middle prt of the plnt. P n nd g s dt come from group of mesurements tken for 5 dys, etween 1:.m. nd 4: p.m. Trnspirtion nd Wter Use Efficiency Totl plnt trnspirtion ws estimted on the sme dtes of P n nd g s using the grvimetric technique descried y Florez-Velsco et l. (215), which consists of mesuring the difference in the weight of the plnts in their pots every 24 h. Wter use efficiency (WUE) ws determined using the Rviv nd Blom (21) method, which consists of otining the rtio of the totl dry weight of the plnt versus the totl mount of wter tht ech plnt received throughout the experiment. Proline content Proline determintions were mde t 148 DAT y collecting pproximtely 1 g of fresh lef tissue. The plnt mteril ws then processed with liquid nitrogen in order to preserve the plnt tissue until nlysis. Bsed on the method descried y Btes nd Wldren (1973), smple of.3 g of tissue ws homogenized in 1 ml of 3% queous solution of sulfoslicylic cid (Merck Millipore, Drmstdt, Germny). Then, this preprtion ws filtered through Whtmn #2 filter pper. Two milliliters of the filtered sustnce were then rected with 2 ml of ninhydrin cid (Pnrec, Cstellr del Vlles, Spin) nd 2 ml of glcil cetic cid (J.T. Bker, Mexico, Mexico). This mixture ws plced in wter th (B-48, Buchi, Postfch, Switzerlnd) for one hour t 9

5 VOLUME 43 Nº1 JANUARY APRIL C, nd the rection ws quenched with dry ice. Then, the rection mixture ws extrcted with 4 ml of toluene (J.T. Bker, Mexico, Mexico), gitting the test tues vigorously with vortex mixer. The sornce ws mesured t 52 nm using spectrophotometer (SpectronicBioMte 3 UV - Vis, Thermo, Mdison, WI, USA). The proline content ws determined using stndrd curve, nd it ws clculted on fresh weight sis with the following eqution in the entire experiment: [(µg proline/ml ml toluene) / µg µmoles -1 ] / [(g smple) / 5] = µmoles proline/g fresh weight of the mteril. n increse of ~24% compred to the tretment without nutrient pplictions (control tretment). In plnts treted only with soil fertilizer dry mtter incresed pproximtely ~14% with respect to the control tretment. Plnts with folir io-stimulnt pplictions showed no significnt chnges in dry mtter ccumultion compred to plnts without fertilizer pplictions throughout the experiment (Totl Plnt Dry weight in oth tretment did not exceed 2 g t the end of the study). Finlly, shoot length ws higher in lulo plnts treted with soil fertilizer nd soil fertilizer + folir io-stimulnt (Figure 1B). Experimentl design nd sttisticl nlysis A completely rndom design ws used in order to nlyze dt. Six plnts were rndomly smpled for ech tretment t ech smpled point. A totl of twenty four plnts per tretment were used for four mesurements in the whole experiment. When significnt differences were found, the test for comprison of tretment mens ws performed using the Tukey test. Dt were nlyzed using the progrm Sttistix v 8. (nlyticl softwre, Tllhssee, FL, US). Results TPDW (g) Shoot lenght (cm) A B No ppliction Soil Folir Soil + Folilr Accumultion of dry mtter, shoot length, lef re nd distriution of ssimiltes Results of the ccumultion of dry mtter nd totl shoot length in lulo seedlings sujected to different fertiliztion tretments re presented in Figure 1 (A nd B, respectively). Figure 1A shows tht significnt differences were found etween tretments t 97 nd 15 DAT. Lulo plnts under the tretment of soil fertilizer nd soil + folir io-stimulnt sprys hd greter ccumultion of dry mtter t the end of the experiment. At 15 DAT, the gretest iomss ccumultion occurred in plnts treted with soil fertilizer + folir io-stimulnt pplictions, with Dys fter trnsplnting Figure 1. The effect of soil fertilizer nd folir iostimulnt pplictions on Totl Plnt Dry Mtter (A) nd Shoot Length (SL); B) in lulo seedlings (S. quitoense vr. Septentrionle). For ll tretments, vlues re the men of six replictes ± stndrd error. In contrst, significnt differences were oserved etween fertiliztion tretments on dry mtter ccumultion in the leves, root, nd flower cushions, which were differences not oserved in the stems. Tle 1 summrizes the results of dry mtter ccumultion in different orgns of lulo seedlings sujected to different tretments

6 3 cienci e investigción grri of fertiliztion t the end of the experiment. The tretment of soil fertilizer + folir io-stimulnt showed the highest dry mtter ccumultion in ll of the orgns of the plnt, followed y the soil, folir, nd control tretments, respectively. With regrd to lef re, specific lef re, nd stem dimeter, similr trends to those oserved in the dry weights of the orgns re oserved. Seedlings treted with soil fertilizer nd soil fertilizer + folir io-stimulnt pplictions were the ones tht hd etter folir nd stem dimeter; menwhile, the specific lef re ws higher in plnts treted with folir io-stimulnt sprys. Significnt differences were lso found etween fertiliztion tretments on dry mtter distriution percentge mong the different orgns of lulo seedlings (Figure 2). The two tretments tht received no soil fertilizer (control nd only folir io-stimulnt ppliction) were ssigned the highest mount of dry mtter to root production (~41.4%, nd ~44.6%, respectively) compred to soil tretments (soil nd soil + folir), which hd ~23.2% nd 24.8% of their dry weight to roots, respectively. Growth rtes Tle 2 summrizes the effects of different fertiliztion tretments on growth rtes of lulo seedlings. Significnt differences etween tretments from 36 DAT were oserved in AGR. Plnts treted with oth soil + folir ppliction showed higher vlues in AGR until 97 DAT. Then, non-significnt differences were otined for AGR etween tretments with oth soil + folir ppliction nd soil ppliction t 15 DAT. However, RGR showed significnt differences only t 15 DAT. The seedlings sujected to soil fertilizer nd soil + folir io-stimulnt lso showed higher vlues in RGR. NAR lso presented significnt differences from 36 DAT. Plnts without ny kind of nutrition, either folir or soil, showed the highest vlue during the experiment. Tle 1. The effect of soil fertilizer nd folir io-stimulnt pplictions on Dry Mtter Accumultion in orgns nd whole plnt, Lef Are, Specific Lef Are, nd Stem Dimeter of lulo seedlings (S. quintoense vr. Septentrionle) t 15 dys fter trnsplnting. Tretment Root (g) Stem (g) Leves (g) Florl cushions (g) Totl plnt (g) Dry weight in plnt orgns No ppliction c c Soil Folir c c Soil + Folir Significnce ** ** *** * ** Tretment Lef re (cm 2 ) Specific lef re (cm 2 g -1 ) Stem dimeter (mm) Lef re, specific lef re nd stem dimeter No ppliction c Soil c Folir c Soil + Folir c Significnce *** ** ** 1 Mens within column followed y the sme letter re not significntly different y Tukey test (P.5). **, *** significnt t P.1 nd.1, respectively.

7 VOLUME 43 Nº1 JANUARY APRIL Proportion of totl iomss (%) Proportionl of totl iomss (%) Proportion of totl iomss (%) Proportion of totl iomss (%) c d c Leves Roots Stems Florl cushions No ppliction Soil Folir Soil + Folir Figure 2. Effect of soil fertilizer nd folir io-stimulnt pplictions on the distriution of totl iomss in lulo seedlings (S. quitoense vr. Septentrionle); (. leves,. roots, c. stem, nd d. florl cushions). For ll tretments, vlues re the men of 6 replictes. Mens with different letters represent sttisticlly significnt differences ccording to Tukey s test (P.5). c Efficiency of PSII (F v ) nd SPAD redings The F v rtio ws higher when plnts hd etter nutritionl sttus, minly those which were soil fertilized (Tle 3). In generl, ll vlues of fluorescent chlorophyll otined during the experiment were within the optimum rnge (.7-.8). Similrly, Tle 3 shows the results of SPAD redings. In line with this trend, seedlings treted with soil fertilizer + io-stimulnt or only soil fertilizer showed the highest redings t 97 nd 15 DAT, respectively. Photosynthesis, trnspirtion, stomtl conductnce, nd WUE Seedlings treted with soil fertilizer nd soil fertilizer + folir io-stimulnt showed the highest CO 2 ssimiltion vlues. Plnts with these tretments hd ~75% higher photosynthetic rte compred to the control seedlings. However, the folir io-stimulnt tretment did not show vrition in the photosynthesis rte compred to unfertilized plnts (Figure 3A). Likewise, ehvior similr to tht descried for photosynthesis ws lso oserved for the vriles stomtl conductnce, trnspirtion, nd WUE (Figure 3B, C nd D). Proline contents An incresed ccumultion of this free mino cid ws otined on lulo plnt leves tht received soil fertilizer, showing proline contents of 21.4 μmol g -1 FW. Additionlly, plnts treted with soil nd folir methods showed lef concentrtion of 12.3 μmol proline g -1 FW. Finlly, plnts without soil fertilizer (control nd only folir ppliction) hd the lowest levels of this mino cid in the lef, 2.3 μmol proline g -1 FW (Figure 4).

8 32 cienci e investigción grri Tle 2. The effect of soil fertilizer nd folir io-stimulnt pplictions on the solute growth rte (AGR), reltive growth rte (RGR), nd net ssimiltion rte (NAR) in lulo seedlings (S. quintoense vr. Septentrionle). Tretment 36 DAT (mg d -1 ) 59 DAT (mg d -1 ) 97 DAT (mg d -1 ) 15 DAT (mg d -1 ) AGR No ppliction c c 79.4 Soil c Folir Soil + Folir Significnce *** *** ** *** Tretment 36 DAT (mg g -1 d -1 ) 59 DAT (mg g -1 d -1 ) 97 DAT (mg g -1 d -1 ) 15 DAT (mg g -1 d -1 ) RGR No ppliction Soil Folir Soil + Folir Significnce NS NS NS * Tretment 36 DAT (µg cm -2 d -1 ) 59 DAT (µg cm -2 d -1 ) 97 DAT (µg cm -2 d -1 ) 15 DAT (µg cm -2 d -1 ) NAR No ppliction Soil Folir Soil + Folir Significnce *** * ** ** 1 Mens within column followed y the sme letter re not significntly different y Tukey test (P.5). NS, not significnt t =.5. *, **, *** significnt t P.5,.1 nd.1, respectively. Tle 3. The effect of soil fertilizer nd folir io-stimulnt pplictions on mximum yield of PSII (F v / F m ) nd Lef Chlorophyll Content (SPAD redings) in lulo seedlings (S. quintoense vr. Septentrionle). Tretment F v 97 dt 145 dt SPAD No ppliction c Soil Folir Soil + Folir Significnce *** ** *** 1 Mens within column followed y the sme letter re not significntly different y Tukey test (P.5). **, *** significnt t P.1 nd.1, respectively.

9 VOLUME 43 Nº1 JANUARY APRIL P n [µmol CO2 m -2 s -1 ] No ppliction Soil Folir Soil + Folir A E [g H 2 O dy -1 plnt -1 ] B 3 C 1 D g s [mmol H 2 O m -2 s -1 ] 2 1 c c WUE [g dry mtter L -1 H 2 O] Tretments Tretments Figure 3. The effect of soil fertilizer nd folir io-stimulnt pplictions on A. Photosynthesis; B. Perspirtion; C. stomtl conductnce; D. Wter Use Efficient (WUE). For ll tretments, vlues re the men of 6 replictes. Mens with different letters represent sttisticlly significnt differences ccording to Tukey s test (P.5) No ppliction Soil Folir Soil + Folir Proline ( mol g -1 FW) c c Tretments Figure 4. The effect of soil fertilizer nd folir ppliction of io-stimulnt on Proline content in lulo seedlings (S. quitoense vr. Septentrionle). For ll tretments, vlues re the men of 6 replictes. Mens with different letters represent sttisticlly significnt differences ccording to Tukey s test (P.5).

10 34 cienci e investigción grri Discussion Lulo seedlings treted with soil fertilizer plus folir io-stimulnt pplictions hd higher dry mtter ccumultion compred to the other tretments. Additionlly, folir io-stimulnt pplictions in plnts receiving soil fertilizer fvored looming ecuse this group of plnts flowered erlier (dt not shown) nd hd higher ccumultion nd distriution of dry mtter in flower cushions (Tle 1 nd Figure 1A nd 2d). This is consistent with the results presented y Clvo et l. (214) in which iostimulnt pplictions lso stimulted greter flower formtion per plnt in grpevines, nd mize plnts. Additionlly, the ctivity of mny of the growth regulting hormones involved in the formtion of florl orgns is relted to n increse of mino cid synthesis y the plnt. These, when pplied to leves s free mino cids, my reduce the numer of dys to full loom nd increse the percentge of flowering nd performnce prmeters of the fruit (Seif El-Yzl et l., 214). Furthermore, in our study, we found tht plnts sujected to soil fertilizer nd soil + folir io-stimulnt hd significnt increses in the height of the shoot (Figure 1B). Similr results were reported y Clvo et l. (214), where the use of plnt iostimulnts enhnced the growth of plnts in per nd whet. The Net Assimiltion Rte decresed over time in ll fertiliztion tretments with oth soil nd folir io-stimulnt pplictions (Tle 2). According to Crrnz et l. (29), this reduction is closely relted to the shding tht occurs on the lower leves s n effect of the growth nd cretion of new leves t the top of the plnt, generting lower interception of photosyntheticlly ctive rdition. Moreover, poor soil nutrition cused reduction of vriles, such s the mximum efficiency of PSII (F v ) nd SPAD redings (Tle 3). In generl, plnts deprived of nutrients vi soil fertiliztion showed vlues in the F v rtio of pproximtely.7, indicting tht this group could hve ltertions in photosystem II (Gore nd Cltyud, 213). It should e noted tht the determintion of the efficiency of PSII is useful tool to identify erly stges of nutritionl deficiencies in strwerries (Osorio et l., 214), tomtoes, nd corn (Klji et l., 214), where the lowest vlues of F v re ssocited with plnts with nutrient indequcies. Similr trends were lso oserved in the SPAD redings where chlorophyll content ws higher in the group of lulo plnts with soil fertilizer. Additionlly, the properties of lef gs exchnge were conditioned y the different nutrition tretments. Hence, seedlings treted with soil fertilizer nd soil fertilizer + folir io-stimulnt showed the highest vlues of CO 2 ssimiltion, trnspirtion, stomtl conductnce, nd WUE (Figure 3) compred to tretments tht consisted only of folir ppliction of io-stimulnt or control. Similr oservtions were reported y Neri et l. (22) in strwerry crops where folir pplictions of humic cids stimulted pigment production nd wter use efficiency nd mintined photosynthetic rtes. Additionlly, Afrousheh et l. (21) reported tht nutritionl deficiencies in Pistci ver resulted in lower photosynthesis, trnspirtion, nd stomtl conductnce rtes. The highest proline concentrtions were present in lulo seedlings sujected to soil nd soil fertilizer + folir io-stimulnt (Figure 4). Furthermore, proline production is relted to the stress response fctors in plnts, including toxicity nd/or nutrient deficiency (Ahmed nd Hsn, 211; Ftim et l., 211). However, in our results, the increse of the proline content ws not relted to stte of stress in lulo seedlings. In conclusion, the ppliction of folir io-stimulnt pplictions s complement to soil fertiliztion is technique tht cn e employed in the cultivtion of lulo ecuse it shows the highest rtes of dry mtter ccumultion, stem length, lef re, growth, nd florl cushion numer. Additionlly, supplying only folir io-stimulnt s fertiliztion pln in lulo plnts is not recommended ecuse it does not meet the nutritionl demnds required y the plnts, which is reflected in the rte of net photosynthesis, wter use efficiency, flower cushion numer, nd growth.

11 VOLUME 43 Nº1 JANUARY APRIL Resumen J.J. Díz-Leguizmón, O.F. Chingté-Cruz, A.D. Sánchez-Reinoso y H. Restrepo- Díz Efecto de l plicción folir de un iostimulnte de extrcto de lgs mrins sore el comportmiento fisiológico de plántuls de lulo (Solnum quitoense cv. Septentrionle). Cien. Inv. Agr. 43(1): Extrctos de lgs mrins son usdos como Fuente de nutrientes, iosetimulntes o iofertilizntes in l gricultur y horticultur con el propósito de increment el crecimiento y rendimiento de l plnt. En este experimento, se evluron ls plicciones folir de un ioestimulnte se de un extrcto de lgs mrins sore el crecimiento de l plnt, propieddes de intercmio gseoso de l hoj y producción de prolin en plántuls de lulo cultivds jo condiciones de inverndero. Ls plnts de lulo fueron dividids en cutro trtmientos: i) plnts con fertilizción edáfic; ii) plnts trts solmente ví folir con el iostimulnte iii) un cominción de fertilizción edáfic y plicción folir de ioestimulnte y iv) plnts control (sin ningun plicción de fertiliznte y ioestimulnte). Ls plnts de lulo trtds con fertiliznte edáfico más plicciones folires del ioestimulnte mostrron un myor ltur de plnt, peso seco totl, diámetro del tllo y ts solut de crecimiento. Plnts control presentron un menor ts fotosintétic, conductnci estomátic y trnspirción. Asimismo, plicciones folires del ioestimulnte fvoreció l prición de otones florles. Los resultdos otenidos permiten concluir que el uso de un ioestimulnte se de extrctos de lgs mrins puede ser considerdo como un complemento l fertilizción edáfic, y que puede fvorecer l cumulción de mteri sec y florción. Plrs clve: Eficienci del PSII, fertilizción edáfic, fertilizción folir, prolin, tss de crecimiento. References Afrousheh, M., M. Ardln, nd H. Hokmdi. 21. Nutrient deficiency disorders in Pistci ver seedling rootstock in reltion to eco-physiologicl, iochemicl chrcteristics nd uptke pttern of nutrients. Scienti Hort. 124: Agronet Producción de Lulo en Colomi, Estdístics Agronet. Ministerio de Agricultur y Desrrollo Rurl, Colomi. Aville online t: estdistics.spx (Wesite ccessed: July 215). Ahmed, J., nd M. Hssn Evlution of seedling proline content of whet genotypes in reltion to het tolernce. Bngldesh J. Bot. 4: Al-Krki, G.N., R.B. Clrk nd C.Y. Sullivn Phosphorus nutrition nd wter stress effects on proline ccumultion in sorghum nd en. Journl of Plnt Physiol. 148: Anjum SA, L. Wng, M. Frooq, L. Xue, nd S. Ali Fulvic cid ppliction improves the mize performnce under well-wtered nd drought conditions. J. Agron. Crop Sci. 197: Ardeili, Z., A. Moghdm, N. Ardeili, nd A. Pshie The induced physiologicl chnges y folir ppliction of mino cid in Aloe ver L. Plnts Omics Journl 5: Btes, S., nd R. Wldren Rpid determintion of free proline for wter-stress studies. Plnt Soil 39: Brown, P., nd S. S Biostimulnts in griculture. Front Plnt Sci. 6:671. Clvo, P., L. Nelson, nd J.W. Kloepper Agriculturl uses of plnt iostimulnts. Plnt soil 383(1-2):3-41. Crrnz, C., O. Lnchero, D. Mirnd, nd B. Chves. 29. Análisis del crecimiento de lechug (Lctuc stiv L.) Btvi cultivd en

12 36 cienci e investigción grri un suelo slino de l Sn de Bogotá. Agron. Colom. 27: Clussen, W., B. Brückner, A. Krumein, nd F. Lenz. 26. Long-term response of tomto plnt to chnging nutrient concentrtion in the room environment the role of proline s n indictor of sensory fruit qulity. Plnt Sci. 168: Ersln, F., A. Inl, A. Gunes, nd M. Alpsln. 27. Boron toxicity lters nitrte reductse ctivity, proline ccumultion, memrne permeility, nd minerl constituents of tomto nd pepper plnts. JPN 3: Fgeri, N., M. Bros, A. Moreir, nd C. Guimrães. 29. Folir fertiliztion of crop plnts. JPN 32: Ftim, N., N. Ahmd, nd M. Anis Enhnced in vitro regenertion nd chnge in photosynthetic pigments, iomss nd proline content in Withni somnifer L. (Dunl) induced y copper nd zinc ions. PPB 49: Flórez-Velsco, N., H.E. Blguer-López nd H. Restrepo-Díz Effects of folir ure ppliction on lulo (Solnum quitoense cv. Septentrionle) plnts grown under different wterlogging nd nitrogen conditions. Scienti Hort. 186: Gil, A.I., nd D. Mirnd Efecto de cinco sustrtos sore índices de crecimiento de plnts de ppy (Cric ppy L.) jo inverndero. RCCH 1: Gore, E., nd A. Cltyud Applictions of chlorophyll fluorescence imging technique in horticulturl reserch: review. Scienti Hort. 138: Hernández-Herrer, R. M., F. Sntcruz-Ruvlc, M.A. Ruiz-López, J. Norrie, nd G. Hernández- Crmon Effect of liquid seweed extrcts on growth of tomto seedlings (Solnum lycopersicum L.). J. Appl. Phycol. 26: Klji, H., A. Oukrroum, V. Alexndrov, M. Kouzmnov, M. Brestic, M. Zivck, I.A. Smorsk, M.D. Cetner, S.I. Allkhverdiev, nd V. Goltsev Identifiction of nutrient deficiency in mize nd tomto plnts y in vivo chlorophyll fluorescence mesurements. PPB 81:1-1. Khn, W., U.P. Ryirth, S. Surmnin, M.N. Jithesh, P. Ryorth, D.M. Hodges, A.T. Critchley, J.S. Crigie, J. Norrie, nd B. Prithivirj. 29. Seweed extrcts s iostimulnts of plnt growth nd development. J. Plnt Growth Regul. 28: Mrschner, P Mrschner s minerl nutrition of higher plnt. Londres: Acdemic Press.Third edition. Elsevier. Sn Diego, USA. Medin, C., M. Loo, nd E. Mrtínez. 29. Revisión de estdo del conocimiento sore l función productiv del lulo (Solnum quintoence Lm.) en Colomi. Corpoic Cienc. Tecnol. Agropec. 1: Mengel, K., E. A. Kirky, H. Kosegrten, nd T. Appel. 21. Nitrogen. p In: Mengel, K., E. A. Kirky, H. Kosegrten nd T. Appel (eds.). Principles of plnt nutrition (Fifth edition). Kluwer Acdemic Pulishers. Springer, The Netherlnds. Neri, D., M. Lodolini, G. Svini, P. Stini, G. Bonmomi, nd F. Zucconi. 22. Folir ppliction of humic cid on stwerry (cv. Ond). Act Hort. 594: Neuerg, M., D. Pvlíková, M. Pvlík, nd J. Blík. 21. The effect of different nitrogen nutrition on proline nd sprgine content in plnt. Plnt Soil Environ. 56: Osorio, J., M.L Osorio, P.J. Corei, A. Vrennes, nd M. Pestn Chlorophyll fluorescence imging s tool to understnd the impct of iron deficiency nd resupply on photosynthetic performnce of strwerry plnts. Scienti Hort. 165: Prr-Corondo, A., G.H. Ardil-Ro, nd H. Restrepo-Díz The physiologicl response of lulo plnts (Solnum quitoense vr. Septentrionle) to soil nd folir pplictions of nutrients. Int. J. Fruit Sci. 15(2):1-13. Rviv, M., nd T.J. Blom. 21. The effect of wter vilility nd qulity on photosynthesis nd productivity of soilless grown cut roses. Scienti Hort. 88: Seif El-Yzl, M.A., nd M.M. Rdy Exogenous onion extrct hstens ud rek, positively lters enzyme ctivity, hormone, mino cids nd

13 VOLUME 43 Nº1 JANUARY APRIL phenol contents, nd improves fruit qulity in Ann pple trees. Scienti Hort. 169: Zodpe, S. T., A. Gupt, S.C. Bhndri, U.S. Rwt, D.R. Chudhry, E. Eswrnnd, nd J. Chikr Folir ppliction of seweed sp s iostimulnt for enhncement of yield nd qulity of tomto (Lycopersicon esculentum Mill.). J. Sci. Ind. Res. 7:

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