Agronomic evaluation of different lettuce (Lactuca sativa L.) varieties under unheated plastic tunnel

In e na ional Jou nal o Ho icul u al Science 2022, 28: 50-56. h ps://doi.o g/10.31421/ijhs/28/2022/10314 Ag onomic e alua ion o di e en le uce (Lac uca sa i a L.) a ie ies unde unhea ed plas ic unnel Ko ácsné Mada , Á. & Takácsné Hájos, M. Uni e si y o Deb ecen, Facul y o he Ag icul u al and Food Sciences and En i onmen al Managemen , Ho icul u e Depa men , H-4032 Deb ecen, Böszö ményi S ee 138. Au ho o co espondence: mada .ago a@ag .unideb.hu Summa y: Among he lea y ege ables, le uce (Lac uca sa i a L.) is he mos widely g own species in he wo ld. Wide anges o physical p ope ies o he p oduc s a e used o assess he deg ee o ma u i y. In his s udy, di e en le uce a ie ies we e g own unde an unhea ed plas ic unnel in sp ing ime. We e alua ed he ag onomic p ope ies o di e en le uce a ie ies, e alua ed he condi ion o he plan s, and de e mined he bioac i e subs ances. La ge head weigh can be achie ed by he ‘King o May’ bu e head (259.31 g) and ‘G ea Lakes 659’c isphead (220.40 g) geno ypes. A e y s ong co ela ion ( = 0.995) was obse ed be ween he le uce head index, and lea index and bo h had a s ong posi i e co ela ion ( = 0.828 and 0.760) wi h NDVI. The highes SPAD alues we e measu ed o cos le uce ‘Romaine le uce’ (44.01) and icebe g le uce ‘G ea Lakes 659’ (42.71). Howe e , hese geno ypes showed he highes (9.52%; 8.74%) d y ma e con en , oo. The ed lea a ie y 'Lollo Rosso' had he highes o al polyphenol con en (181.53 GAE/100 g FW). Among he e alua ed p ope ies, icebe g le uce showed a o able mo phology, plan condi ion, and good d y ma e con en . In addi ion, be ween he loose-lea le uces, he ed lea lollo ype was ou s anding wi h bioac i e con en . Ko ácsné Mada , Á., Takácsné Hájos, M. (2022): Ag onomic e alua ion o di e en le uce (Lac uca sa i a L.) a ie ies unde unhea ed plas ic unnel. In e na ional Jou nal o Ho icul u al Science 28: 50-56. p. h ps://doi.o g/10.31421/ijhs/28/2022/10314 Key wo ds: le uce, NDVI, SPAD, mo phology, o al phenol con en , d y ma e con en In oduc ion Among he lea y ege ables, le uce (Lac uca sa i a L.) is one o he mos popula species in he wo ld. Acco ding o he FAO (2018) da a, he le uce and chico y p oduc ion was 27 million ons, and he ha es ed a ea was 1.3 million ha in he wo ld. Le uce is g own on all con inen s, bu he g ea es consume s and p oduce s a e in China (14 million ons) and he USA (4 million ons). In Eu ope, le uce p oduc ion was 2.9 million ons, and he ha es ed a ea was 123 housand ha. Le uce consump ion con ibu es p o i amin A, i amin C, i amin E, ca o enoids, and ibe o consume s' die (Agüe o e al., 2008). So, he impo ance o consuming ege ables is due o he many nu ien s hey con ain and he di e en bioac i e subs ances. They include bu a e no limi ed o, phy ochemicals (ca o enoids, phenols, and la onoids), mine als (calcium, magnesium, and po assium), i amins ( i amin C, olic acid, and p o i amin A), and die a y ibe (Oz & Ka kas, 2017; Liu, 2013). In le uce genus has mo e han 100 species and 6 ypes. Di e en ypes o le uce a e he ollowing – bu e head, c isphead (icebe g), omaine (cos), s em (aspa agus), lea (cu ing), and oilseed le uce (Mousa i e al., 2013; Křís ko á e al., 2008). Ma u i y o ha es is he s age o de elopmen in which a plan o plan pa possesses he condi ions o u iliza ion by consume s o a p ope pu pose. Wide anges o physical p ope ies o p oduc s a e used o assess he deg ee o ma u i y – changes in diame e , head leng h, head wid h, colou , i mness, compac ness and su ace. These pa ame e s a e used as gene al ipening indices (Ba g e al., 2009). The compac ness o he head, which can be comp essed wi h mode a e hand p essu e is conside ed op imal ma u i y. Depending on he des ina ion, di e en ipeness indica o s can be used. These di e en pu poses may be needed o he esh- cu p ocessing sec o . Head weigh is an impo an ac o o quali y e alua ion o he aw ma e ial o he esh-cu p oduce indus y. Fu he mo e, he ipe lea es and pe iole leng h a e g ea ma u i y indica o s o ensu e he quali y o he p ocessed p oduc (Gil e al., 2012; Jenni & Yan, 2009). In le uce cul i a ion, i appea s plan spacing is an impo an c i e ion o achie ing maximum ege a i e g ow h, he eby maximizing yield. In addi ion, op imum plan spacing helps o inc ease he numbe o heal hy lea es and oliage (Hasan e al., 2017; Maboko & Du Plooy, 2009; Zemichael e al., 2017). In ecen yea s, he ma ke o esh-cu , minimally p epa ed o “ eady o ea ” lea y ege ables ha e been con inuously inc easing. Consume accep ance is associa ed wi h lea y ege ables’ isual cha ac e is ics such as shape, colou , size and eshness, and ex u e and la ou (Fe an e e al., 2004; Nicola & Fon ana, 2014). The G een Seeke Model 505 measu ing de ice speci ies he NDVI alue om which we can conclude he c op co e o he ield and he ege a ion dis ibu ion. The NDVI is compu ed as (NIR - Red)/(NIR + Red) whe e NIR and Red a e he sum o nea -in a ed and ed ligh , e lec ed by he su ace. The g een lea es ha e g ea isible ligh abso p ion oge he wi h g ea nea -in a ed e lec ance, esul ing in posi i e NDVI 51 Ko ácsné Mada & Takácsné Hájos alues (Pe o elli e al., 2011). The ege a ion index can help assess ege a ion co e densi y, iden i y plan s, and moni o plan g ow h (Zhang e al., 2019). In addi ion, he ea ly de ec ion o pes in es a ion by non-des uc i e me hods is an impo an p e equisi e o accu a e and a ge ed con ol o pes s and diseases du ing c op p oduc ion (Sandmann e al., 2018). The Minol a SPAD-502 ins umen is used o quick and non-des uc i e de e mina ion o ela i e lea chlo ophyll concen a ion. The ni ogen con en o plan s can be in e ed om he chlo ophyll con en o he lea es since he amoun o chlo ophyll is closely, posi i ely and linea ly ela ed o he ni ogen con en o he lea es (Zeba h e al., 2002). Fu he mo e, based on he SPAD alues, we can conclude he chlo ophyll con en o he plan , which is co ela ed o he heal h o he plan and he yield (Duzs e al., 2019). Some epo s sugges ha SPAD is a dependable measu ing de ice o es ima ing ni ogen concen a ion in le uce plan s. Thus, ea ly e alua ion o chlo ophyll and ni ogen s a us can be used o mo e e ec i e and scheduled e iliza ion du ing he g owing season (Mendoza-Ta olla e al., 2019). Se e al ac o s in luence he accumula ion o ni a e in plan s such as he soil pH, he wea he condi ions (p ecipi a ion, ligh ), he ha es ime, he ype o a ie ies and he use o ni ogen e ilize s (Žnida čič & Kmecl, 2018). Based on he chlo ophyll con en , we can conclude he heal h s a us o he plan as i is one o he mos impo an indica o s o pho osyn he ic capaci y, nu i ional s ess and g ow h s a us o plan s (Kizil e al., 2012; Ba y e al., 2009) Ou esea ch aimed o e alua e he ag onomic p ope ies o di e en le uce a ie ies, o e alua e he condi ion o he plan s based on he NDVI and SPAD alues, and o de e mine he bioac i e subs ances. Ma e ials and me hods The expe imen was conduc ed a he Bo anical and Exhibi ion Ga den o he Fa m and Regional Resea ch Ins i u e in he Uni e si y o Deb ecen in an unhea ed plas ic unnel (in sp ing ime), on limes one che nozem soil. The soil es esul s o he expe imen al a ea a e gi en in Table 1, which was pe o med a he Ag icul u al Labo a o y Cen e o he Uni e si y o Deb ecen. In he expe imen , we e alua ed he ollowing ypes and a ie ies o le uce – non-heading ype (‘Lollo Rosso’, ‘Lollo Bionda’), heading ype (‘G ea Lakes 659’, ‘King o May’) and cos ype (‘Romaine le uce’). Rega ding he condi ions o he expe imen , sowing was pe o med in 84-cell ays on 9 Ma ch 2019. T ansplan s o 5– 6 lea es we e plan ed ou on 9 Ap il 2019 wi h ow and plan dis ances 25 cm unde unhea ed plas ic unnel. Fe ica e e ilize (24:8:16 + 3,8MgO + mic oelemen ) was applied in 0.75 % concen a ion 3 imes du ing he ege a ion pe iod. The ollowing mo phological pa ame e s we e measu ed a he ha es : • Head weigh (g) • S em leng h (cm) • Head i mness (1-5 scale) 1 – e y so  5 – ex a ha d • Closing o base (1-5 scale) 1 – open  5 – comple ely closed • Head shape index (heigh / diame e ) • Lea shape index (leng h / wid h) Du ing ins umen al measu emen s, he ollowing we e measu ed: Measu emen o pho osyn hesis ac i i y: • SPAD alue (Minol a SPAD-502) – easy non-des uc i e measu emen o he chlo ophyll con en o plan lea es wi hou damaging he lea es. • NDVI alue (G een Seeke Model 505) – can be used o ollow c op g ow h and de elopmen . Labo a o y measu emen s he ollowing we e measu ed: • To al d y ma e con en (%) – D y ma e was de e mined a e d ying in an o en a 105°C. • To al polyphenol con en (TPC) was analyzed by he Folin–Ciocal eu me hod. The esul s we e gi en in Gallic acid equi alen alue (Meda e al., 2005). Table 1: The soil analysis o expe imen al a ea. Measu ed pa ame e s (uni o measu emen ) Amoun pH (KCl) 7.35 Plas ici y index acco ding o A any (KA) 42 To al wa e -soluble sal (%) 0.10 CaCO3 (%) 4.20 Humus (%) 2.88 AL-soluble P2O5 (mg kg-1) 313.7 AL-soluble K2O (mg kg-1) 459 KCL-soluble NO3- (mg kg-1) 130 AL-soluble Na (mg kg-1) 69.7 KCL-soluble Mg (mg kg-1) 584 KCL-soluble S (mg kg-1) 98.7 EDTA-soluble Mn (mg kg-1) 135 EDTA-soluble Zn (mg kg-1) 35.9 EDTA-soluble Cu (mg kg-1) 9.514 S a is ical analysis The da a we e submi ed o analysis o a iance (ANOVA) and di e ences be ween means we e de e mined by pos hoc Duncan and Tukey’s es a he 5% (0.05) le el o signi icance (n=5). Pea son’s co ela ion coe icien be ween some da a pai s was also calcula ed (n=25). Co ela ion was signi ican a p ≤ 0.05 and p ≤ 0.01 le el (2- ailed). The analyses we e ca ied ou using IBM SPSS so wa e ( e sion 25). Resul s and discussion Rela ionship be ween esh weigh and s em leng h o he head by di e en le uce a ie ies The leng h o he s em can de e mine he numbe o lea es, in his way he weigh o he head. I is impo an because le uces a e also de e mined by hei head weigh . I can be s a ed ha a simila endency can be obse ed be ween he de elopmen o s em size and head weigh o di e en le uce ypes (Figu e 1). Among he cul i a s, he smalles (1.95 ± 0.27 cm) s em size was measu ed by he non-heading le uce ‘Lollo Rosso’. This geno ype also had he smalles head weigh (129.00 ± 14.05 g). D ăghici e al. (2016) ha e de ec ed a simila endency o lollo ype le uce a ie ies Ag onomic e alua ion o di e en le uce (Lac uca sa i a L.) a ie ies unde unhea ed plas ic unnel 52 (‘Lollo Bionda’: 201.33 g/plan ; ‘Lollo Rosso’: 187.25 g/plan ) by applying chemical e ilize (NPK a io o 4-1-2) o he g owing. The ‘King o May’ bu e head ype le uce has imp o ed he la ges s em size (4.22 ± 0.48 cm) and head weigh (259.31 ± 16.83 g). E alua ions o head i mness The head i mness was classi ied in o i e g oups om 1 o 5. In g oup 1 he e is le uce wi h e y loose heads, while in he g oup 5 had belonged he mos compac ed heads. Conside ing he ma ke accep ance, i mness and compac ness a e impo an equi emen s. Bu i is known ha he a ie ies wi h compac heads a e mo e sensi i e o physiological diseases, leading o quali y decline. Figu e 2 shows ha he highes head i mness (4.01 ± 0.32) was de ec ed by bu e head le uce ‘King o May’ (Figu e 3), while he looses head s uc u e (1.00 ± 0.00) was imp o ed by ‘Lollo Rosso’ (Figu e 4). Visual assessmen o he closing o base o le uce heads This pa ame e was classi ied in o i e classes – om open (1) o comple ely closed (5). Va ie ies wi h a well- closed base a e mo e esis an o Bo y is sp. and scle o ic diseases. The appea ance o his ungus (Scle o inia scle o io um) is e y equen by ield-g own le uce p oduc ion causing g ea p oblems wo ldwide (Cla kson e al., 2014). I can be seen in Figu e 5 ha he bu e head ype le uce has a signi ican ly mo e closed base (4.08 ± 0.41) compa ed o he o he le uce ypes, which is a a o able p ope y. Fo he lollo ype le uce (‘Lollo Rosso’) we ha e de ec ed a e y open (1.00 ± 0.01) base pa , o espond mo e sensi i ely o diseases. E olu ion o head shape and lea shape index by di e en le uce ypes and a ie ies Di e en le uce a ie ies ha e di e en head shape indexes ( a io be ween plan heigh and diame e ), which play a signi ican ole in he appea ance o diseases and de e mining he g owing a ea. Mo eo e , he up igh lea a ie ies a e a o able, because he lowe lea es nea ly ha e no o con ac wi h he soil, in his way, he occu ence o ungal in ec ion is a he less. Fo he plan ing design, i is majo o know he head size o he di e en le uce ypes because he la ge headed a ie ies need g ea e ow- and plan dis ance (25x30 o 30x30 cm), while he smalle ones a e enough 20x20 cm. The highe plan densi y can dec ease he head weigh and ea liness, while he oo la ge dis ance educes he p o i abili y o p oduc ion pe uni a ea. This ela ionship be ween he head- and lea shape index is a he clea (Figu e 6), he e is a s ong co ela ion ( = 0.955) o each le uce ype and a ie y. Highe head shape (Figu e 7) and lea shape (Figu e 8) we e de ec ed by ‘Roman le uce’ (cos le uce). Fu he mo e, he up igh lea es a e no in con ac wi h he soil su ace, in his way, he p obabili y o soil bo ne in ec ion is educed. Among he lollo ype a ie ies ‘Lollo Bionda’ showed (0.60 ± 0.03; 0.83 ± 0.01) he less head shape (Figu e 9) and lea shape (Figu e 10). This geno ype p oduced a ound lea shape, which is close o he soil, he e o e he lowe lea es ha e a highe isk o diseases. Figu e 1: Rela ionship be ween head weigh (g) and s em leng h. Means ollowed by he same le e s do no di e en acco ding o he Tukey es (P ≤ 0.05). Figu e 2: Le uce head s uc u e (1-5) by di e en ypes le uce a ie ies. Means ollowed by he same le e s do no di e acco ding o he Tukey es (P ≤ 0.05). Figu e 3-4: ’King o May’– compac head and ’Lollo Rosso’ – non-heading a ie y. Figu e 5: Closing o he base (1-5) by di e en ypes and a ie ies o le uce. Di e en le e s be ween cul i a s deno e signi ican di e ences (Tukey’s es , p < 0.05). c d b cd a ccc b a 0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0 0 50 100 150 200 250 300 Lollo Bionda Lollo Rossa G ea Lakes 659 Romaine le uce May King S em lengh (cm) Head weigh (g/plan ) Le uce a ie y/species Head weigh (g/plan ) S em lengh (cm) c d b c a 0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0 Lollo Bionda Lollo RossoG ea Lakes 659 Romaine le uce King o May Head compac ness (1-5) Le uce a ie y/species b c bb a 0 1 2 3 4 5 Lollo Bionda Lollo RossoG ea Lakes 659 Romaine le uce King o May Closing o he base (1-5) Le uce a ie y/species 53 Ko ácsné Mada & Takácsné Hájos Figu e 6: E olu ion o he shape index o le uce lea and heads by di e en ypes. Means ollowed by he same le e s do no di e acco ding o he Tukey es (P ≤ 0.05). Figu e 7-8: ’Romaine le uce’ – head shape and ’Romaine le uce’ – lea shape. Figu e 9-10: ’Lollo Bionda’ – head shape and ’Lollo Bionda’ – lea shape. Rela ionship be ween le uce heads shape index and NDVI alue Wi h he NDVI alue, we can conclude he ege a ion co e o he g owing a ea because i co ela es well wi h lea a ea index and biomass. This measu emen is sui able o c op- ela ed ield pheno ype de e mina ion (Baue e al., 2019). Figu e 11 shows ha he e is a s ong co ela ion ( = 0.828) be ween he head shape index o each le uce ype and he NDVI alue. Among he e alua ed le uce ypes, he highes head shape index (1.06 ± 0.06) was measu ed o he cos le uce (‘Romaine le uce’) and his ype also had he highes NDVI alue (0.72 ± 0.03). The lowes alues o his pa ame e we e shown in loose-lea le uces, ’Lollo Bionda’ and ’Lollo Rosso’. SPAD alue measu ed o di e en le uce ypes The chlo ophyll con en o he lea es di ec ly de e mines he e iciency o plan pho osyn hesis. Based on he colou in ensi y (g een) o he lea es o he plan s, he ni ogen supply o he plan can be concluded. Fu he mo e, chlo ophyll con en is an indica o o plan heal h, and i can be used o op imize he iming o nu ien supply and he amoun o supplemen al e ilize applica ion o achie e highe quali y and yield. Se e al s udies men ion ha in many species, he e is a high co ela ion be ween SPAD alue and ex ac able chlo ophyll con en (León e al., 2007). The highes SPAD alues we e measu ed o icebe g le uce (‘G ea Lakes 659’) and cos-le uce (‘Romaine le uce’), and hese geno ypes also had he mos in ense g een colou (Figu e 12). The e was no s a is ically signi ican di e ence be ween he wo ypes. The lowes SPAD alue was measu ed by he ‘Lollo Bionda’. Son & Oh (2013) ha e measu ed a highe SPAD alue by he ed lea ype ‘Sunmang’ (mo e han 20 SPAD alue) compa ed o he g een lea ype ’G and Rapid TBR’ (less han 20) unde a ious combina ions o ed and blue ligh -emi ing diodes (LEDs). Figu e 11: E alua ion o connec ion o shape index and NDVI alue by di e en le uce ype and a ie y. Means ollowed by he same le e s do no di e acco ding o he Tukey es (P ≤ 0.05). Figu e 12: SPAD alue o di e en le uce ypes and a ie ies. Means ollowed by he same le e s do no di e acco ding o he Tukey es (P ≤ 0.05). D y ma e con en (%) To al d y ma e con en is an impo an componen o ege ables. Among he a ie ies, we ha e ound highly signi ican di e ences in his pa ame e (Figu e 13). The ‘Romaine le uce’ (cos le uce) showed he highes (9.52 ± 0.12%) and he lea le uce ‘Lollo Bionda’ showed he lowes o al d y ma e con en (6.02 ± 0.30%) on he che nozem soil. In hei expe imen , Ba ickman e al. (2018) e alua ed wo ypes o Roman le uce (‘Sal ius’ and ‘Thu inus’). Fo he d y mass con en (DM) hey measu ed lowe alue o hese a ie ies – ‘Sal ius’ (5.26 %) and ‘Thu inus’ (6.21 %). c c b a c c bc b a bc 0,0 0,5 1,0 1,5 2,0 2,5 3,0 0,0 0,2 0,4 0,6 0,8 1,0 1,2 Lollo Bionda Lollo Rosso G ea Lakes 659 Romaine le uce King o May Lea sahpe index (1-5) Head sahpe index (1-5) Le uce a ie y/species Head shape index Lea shape index c c b a c cc aab b 0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 0,0 0,2 0,4 0,6 0,8 1,0 1,2 Lollo Bionda Lollo Rossa G ea Lakes 659 Romaine le uce May King NDVI Head shape index (1-5) Le uce a ie y/spacies Head shape index NDVI cb aa b 0 10 20 30 40 50 60 Lollo Bionda Lollo Rosso G ea Lakes 659 Romaine le uce King o May SPAD Le uce a ie y/spacies Ag onomic e alua ion o di e en le uce (Lac uca sa i a L.) a ie ies unde unhea ed plas ic unnel 54 To al polyphenol con en (TPC) Polyphenols a e seconda y plan me aboli es ha ha e a bene icial e ec on human heal h. The TPC alue o he i e selec ed le uce a ie ies (Table 2) has changed be ween 37.80- 181.53 mg gallic acid equi alen (GAE) pe 100g esh weigh . Among he di e en ypes o le uce, he ed lea a ie y (‘Lollo Rosso’) showed he highes TPC alue (181.53 ± 3.29 mg GAE/100 g FW). The lowes alue (37.80 ± 2.07 mg GAE/100 g FW) was measu ed by cos le uce (‘Romaine le uce’). Gan & Az ina (2016) e alua ed he TPC con en o di e en lea le uce species (icebe g, bu e head, omaine, g een co al and ed co al) by DPPH assay. Simila ly, hey also measu ed he highes alue in ed lea le uce, al hough hey ound a lowe alue (76.05 mg GAE/100 g FW) han ou esul s. Liu e al. (2007) e alua ed he o al phenolic con en and an ioxidan capaci y o le uce by Folin–Ciocal eu me hod and DPPH assay. The esul s p o ed he highes TPC con en (52.4 mg GAE/g d y mass) and DPPH sca enging abili y (es ima ed alue o 76.4%) o ed lea le uce compa ed o omaine (70.0%) and bu e head (51.7%) ype. Co ela ion analysis The e is a s ong, high co ela ion be ween he pa ame e s, which a e highligh ed (Table 3). Le uce head index and lea index had e y s ong co ela ions ( = 0.955) and s ong posi i e co ela ions ( = 0.828 and 0.760) wi h NDVI. The d y ma e con en is also highly co ela ed wi h he head index, lea index, NDVI and SPAD alue. Pe o elli e al. (2011) also men ioned ha NDVI measu emen s s ongly co ela ed wi h o al d y ma e accumula ion o he baceous o e an obse a ion pe iod. Ou expe imen p o ed a high co ela ion ( = 0.840) be ween NDVI and SPAD. Be ween he s em leng h and he head weigh , he e is a medium co ela ion ( = 0.664) and a signi ican ela ionship. Figu e 13: D y ma e con en (%) o di e en le uce ypes and a ie ies. Means ollowed by he same le e s do no di e acco ding o he Tukey es (P ≤ 0.05). Table 2: To al polyphenol con en (TPC) o di e en le uce a ie ies. Le uce a ie y/species To al polyphenol con en (TPC) ’Lollo Bionda' 45.40b ± 2.80 ’Lollo Rosso' 181.53a ± 3.29 ’G ea Lakes 659' 40.80b,c ± 2.58 ’Romaine le uce' 37.80c ± 2.07 ’King o May' 46.13b ± 2.48 Table 3: Pea son’s co ela ion coe icien s among physiological and biochemical pa ame e s by le uce Pea son co ela ion coe icien o a pa o pa ame e s. Co ela ion was signi ican a *p ≤ 0.05 and **p ≤ 0.01 (2- ailed). d c ba c 0 2 4 6 8 10 12 Lollo Bionda Lollo Rosso G ea Lakes 659 Romaine le uce King o May D y ma e con en (%) Le uce a ie y/species Pea son Co ela ions Head weigh (g/plan ) S em leng h (cm) D y ma e con en (%) Le uce lea index Le uce head index NDVI SPAD To al polyphenol con en (TPC) Head weigh (g/plan ) 1 0.664** 0.119 -0.294 -0.135 0.061 0.076 -0.584** S em leng h (cm) 1 0.389 0.239 0.266 0.312 0.317 -0.432* D y ma e con en (%) 1 0.738** 0.796** 0.896** 0.785** -0.273 Le uce lea index 1 0.955** 0.760** 0.612** -0.300 Le uce head index 1 0.828** 0.682** -0.442* NDVI 1 0.840** -0.385 SPAD 1 -0.339 To al polyphenol con en (TPC) 1 55 Ko ácsné Mada & Takácsné Hájos Conclusions The head weigh o le uce is an impo an ac o because he lowe le el can educe he e icacy o he p ocess o he esh cu indus y. A simila endency can be obse ed be ween he de elopmen o head size and head weigh by di e en le uce a ie ies. La ge head weigh can be achie ed wi h bu e head and c isphead geno ypes. Howe e , he lollo ype le uce wi h a smalle head weigh is asked, oo, o aw ma e ial o a ious salad mixes. The i mness o le uce heads is an impo an ac o , oo, because a ie ies wi h highe compac ness may be mo e sensi i e o ungal diseases and physiological diso de s. Fo designing he g owing a ea, i is impo an o know he head size o he le uce o achie e op imal plan ing space and p o i able yield. I is possible o apply a smalle g owing a ea by up igh lea le uces (cos le uce) a ie ies. Acco ding o ou esul s, we can conclude, ha he ege a ion co e o he g owing a ea (e alua ed wi h NDVI alue) s ongly co ela es wi h he head shape index. Wi h in ense g een colou (icebe g and cos le uce), le uce has a highe SPAD alue. The chlo ophyll con en is an indica o o plan heal h and can op imize e ilize applica ion o achie e highe quali y and yields. NDVI and SPAD alues showed a s ong co ela ion wi h d y ma e con en (%), oo. 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