Effects of Irrigation-Fertilization and Irrigation-Mycorrhization on the Alimentary and Nutraceutical Properties of Tomatoes

Tomato, a key vegetable in the Italian Mediterranean diet, has recently gaining been attention in relation to the prevention of some human diseases. This interest is due to the presence of carotenoids and particularly lycopene, which is an unsaturated alkylic compound, that appears to be an active compound in the prevention of cancer, cardiovascular risk and in slowing down cellular aging, owing to its high antioxidant and antiradical power (Gerster 1997; Giovannucci et al. 1995). Lycopene is found in fresh, red-ripe tomatoes as all-trans (79-91 %) and cis(9-21%) isomers (Boileau et al., 2002; Shi et al., 1999; Stahh & Sies, 1992).


Introduction
Tomato, a key vegetable in the Italian Mediterranean diet, has recently gaining been attention in relation to the prevention of some human diseases.This interest is due to the presence of carotenoids and particularly lycopene, which is an unsaturated alkylic compound, that appears to be an active compound in the prevention of cancer, cardiovascular risk and in slowing down cellular aging, owing to its high antioxidant and antiradical power (Gerster 1997;Giovannucci et al. 1995).Lycopene is found in fresh, red-ripe tomatoes as all-trans (79-91 %) and cis-(9-21%) isomers (Boileau et al., 2002;Shi et al., 1999;Stahh & Sies, 1992).
In this paper, lycopene was used as a measure of the nutraceutical quality, while flavour volatiles, soluble sugars, organic acids, dry matter and pH as expression of the nutritional quality.
Soluble sugars and organic acids play an important role in the characterization of the tomato taste.Sugars (glucose, fructose and traces of sucrose) and organic acids (citric, malic and oxalic) represent half of the total dry matter of tomato fruit (Silvestri & Siviero, 1991).
The irrigation and the potassium (K) fertilization are two among the agronomical factors that mostly influence the alimentary and nutraceutical quality of tomato.Full irrigation regimes enhance the crop yield, however, cause a reduction of total and soluble solids and less colourful and firmness of fruits (Branthôme et al., 1994;Colla et al., 1999;Colla et al., 2001;Dumas et al., 1994;Favati et al., 2009).Among the several studies, Veit Kohler et al. (1999) reported that the higher levels of sugars, titratable acidity, aroma volatiles, and vitamin C are responsible for the higher tomato fruit quality under conditions of limited water supply.Taking into account the effects of irrigation on agronomic performances, a negative trend in response to increasing soil water deficit was observed for fruit yield and size (Candido et al., 2000;Patanè & Cosentino, 2010).Pernice et al. (2010) have also shown that the effects of irrigation on yield and unitary weight of berries are genotype-dependent.Finally, some studies demonstrated that irrigation generally reduces green fruit yield and blossom-end rot (Candido et al., 2000;Warner et al. (2007).
The nutritional quality of tomatoes may be affected by the amount of water applied, regardless of fertilizer management, and their irrigation system.For example, heavy rainfall may reduce the oxygen concentration in the soil, and indirectly affect the nutritional value of fruit (Dorais et al., 2008).Considering the effect of irrigation on ascorbic acid content of fruit, depending on cultivar, low soil water tension generally could decrease the content of this antioxidant compound (Rudich et al., 1977).Zushi & Matsuzoe (1998) also showed that the effects of soil water deficits on the vitamin C content (fm basis) may be positive or null, depending on the cultivar.
The effects of water availability on the synthesis of carotenoids have been studied, but results are sometimes contradictory, and the data often incomplete.Dumas et al. (2003) reviewed several studies that looked at agronomic and environmental factors that influenced lycopene concentrations in tomatoes and reported that moisture stress, for example, reduced lycopene content in some tomato varieties but increased it as well as -carotene content in others.On the other hand, it is reported that the increase of abscisic acid, induced by limited water supply, may affect the ethylene production and then the carotenoids synthesis (Dorais et al., 2008).Serio et al. (2006) confirmed the increase of lycopene (and ascorbate) content at moderate levels of water stress.In recent studies performed on two tomato ecotypes, Pernice et al. (2010) found an higher amount of total carotenoids content of fruits under no irrigation conditions, nevertheless no variation for antioxidant activity of carotenoids extracts were detected.Furthermore, this behaviour was also ascertained after canning process.
In soilless culture, however, higher plant water availability provided by a capillary system did not reduce the lycopene content or the antioxidant activity, compared to tomato plants grown either on rockwool or sawdust and irrigated according to solar radiation (Dorais, 2007).However, Dorais (2007) also found that lycopene content of fruit from plants grown in sawdust andpeat at low levels of moisture stress was less than that of fruit grown on rockwool and irrigated according to solar radiation.No effect of irrigation treatment on antioxidant activity detected.
In general, increasing the water supply increased tomato fruit yield but reduced fruit quality attributes, because of high fruit water content (Dorais et al. 2001).Consequently, on a fresh weight basis, vitamin, mineral and carotenoid contents were generally lower under higher water supply although not all nutraceutical compounds responded to soil moisture variation (Dorais et al., 2008).
Mineral nutrients (nitrogen, phosphorous, potassium and calcium) and their supply through fertilization can affect yield and quality of tomato crops.K is needed in stomatal movement for water regulation in the plant.It activates enzymes and is required for carbohydrate metabolism and translocation, nitrogen metabolism and protein synthesis, and regulation of cell sap concentration.This essential nutrient helps in vigorous growth of tomato and stimulates in early flowering and setting of fruits, thereby increasing the number and production of tomato berries per plant (Bergmann, 1992;Ruiz & Romero, 2002).
In tomato, as well as in other fruit and vegetables, K improves fruit quality: its levels are positively correlated with a good fruit shape, a reduction in ripening disorders (puffiness, gray-wall, blotchy ripening, green back and yellow shoulder), while it simultaneously plays an important role as a counter-ion to organic acids, maintaing electroneutrality in fruit (Dorais et al., 2001).Several studies have shown that K-fertilization increased several quality parameters in tomato fruit such as marketable yield, total and soluble solids contents (°Brix), sugars, acidity, red colour and leads to a reduction of the sugar/acid ratio (Ghebbi Si-smail et al., 2007;2005;Oded & Uzi, 2003;Wuzhong, 2002).Wright and Harris (1985) pointed out that flavour scores indicated that increasing N and K fertilization had a detrimental effects on tomato flavour.An increase in titratable acidity and soluble solids was found with increasing fertilization.Concentrations of hexanal, 2hexanone, benzaldehyde, phenylacetaldehyde, -ionone and 6-methyl-5-hepten-2-one increased with increasing N+K levels.Trudel and Ozbun (1970;1971) reported that K enhanced the colour of the fruit, increasing the lycopene content and reducing that of -carotene.The positive effect of K fertilization on lycopene content, has been confirmed more recently by other authors (Oded & Uzi, 2003;Serio et al., 2007), as it is shown that K deficiency can lead to a reduction in the synthesis of carotenoids, particularly lycopene (Dumas et al., 2003).With regard to accumulation of this antioxidant compound in tomato fruits, Taber et al. (2008) have found that the response to high fertilizer dose of K is cultivar-dependent.
The vesicular-arbuscular mychorrhizae (VAM) are most common in nature but also more interesting for application in agriculture, as they can colonize most cultivated plants.
In addition to improving plant mineral nutrition (mainly phosphate) (Elia et al., 2006;Conversa et al., 2007), VAM fungi can promote photosynthetic activity, improve resistance to root pathogens and drought stress-saline and soil properties too (Turk et al., 2006).Besides, VAM are largely beneficial to crops, since they increase absorption of micro elements (van der Heijden et al., 2006) and water use efficiency (Davies et al., 2002) in the plant.
The importance of mycorrhizal symbiosis for plant growth and health is raising a growing interest in the use of these fungi as bio-fertilizers, bio-regulators and bio-protectors (Akhtar et al., 2008), thus reducing the input of fertilizers and pesticides (Gianinazzi et al., 2003).
Many studies conducted to evaluate the use of VAM fungi in vegetable crops have provided for the distribution fungal inoculum at transplantation time near plant roots; the need to www.intechopen.comproduce the fungal inoculation of host plants through breeding, is still an obstacle for wider application in the field.
The most promising method of VAM application in vegetable crops is represented by inoculation of seedlings (pre-inoculation) during their nursery growth in containers (Azcona-Aguilar & Barea, 1997).The pre-inoculation of VAM fungi reduced the mortality of seedlings, resulted in greater uniformity of crop growth (Waterer & Coltman, 1988) and increased yields too (Sorensen et al., 2008).
Although most vegetables (except Brassicaeae and Chenopodiaceae) are colonized by VAM fungi, it is known that the effectiveness of mycorrhization much depends on the specificity of fungus-host plant (species and/or cultivars) (Sensoy et al., 2007); sometimes VAM colonization does not improve growth and nutritional status of the plant but also a negative effect of the symbiosis may occur (Gosling et al., 2006).Some studies have also found that VAM influence positively some quality yield parameters, such as essential oils in aromatic plants (Copetta et al., 2006).
VAM fungi colonize the same area of root tissue and therefore often occur together in the rhizosphere and roots of plants.This contemporary occurrence raises a number of reciprocal interactions between these two groups of organisms, among which also a VAM suppressiveness against phytoparasitic nematodes populations (Gera & Cook, 2005).Competition for nutrients or induction of morphological changes or systemic resistance in root tissues were suggested as mechanisms for the nematicidal effect of VAM (De la Peña et al., 2006;Elsen et al., 2008).
Identification of VAM species is difficult because they do not possess a sexual stage and do not grow in host absence.The identification is generally based on morphological characters, in particular, those of spores (Morton & Bentivenga, 1994) which are, however, very similar and result not useful for reliable identification to species level (Jacquot et al., 2000).Molecular techniques (PCR, Nested-PCR analysis of nucleotide sequences, RFLP, RAPD) were used to identify and groped distinguish different species of mycorrhizal fungi in planta and in soil (van Tuinen et al., 1998).These methods have proved much more rapid and sensitive in identifying the species with respect to classical techniques.
The soil of the experimental plots was clay loam (43.8% sand, 27.8% silt, 28.3% clay), with poor organic matter content (1.4%) and very low salt concentration.Cationic exchange capacity was high (C.E.C. of 20,5 meq/100 g of soil).With regard to K, exchangeable and available fractions were very high (345 ppm and 0.72 meq/100 g of soil) too.
The two tomatoes studied, Corbarino (C) and Vesuviano (V), were ecotypes originating from Campania region (Italy), respectively from plain of Corbara (Agro Sarnese-Nocerino area) and slopes of Vesuvius Volcano.They were different in many morphological: the first one showed oval fruits tending to an extended shape (ratio between two diameters of 1.52) with unitary weight of approximately 13-18 g.; the latter, instead, was characterised by elongated, pearshaped fruits (ratio between two diameters of 1.85) with a clearly pronounced mucro (pointed shape at blossom end) and a weight of about 20-25 g (Parisi et al., 2006).
Transplant was performed, on May 16 th , in single rows with a density of 4.0 plants/m 2 .Microirrigation was started from fruit-setting (40 days after transplanting) adopting two different water regimes: "reduced" irrigation (I 1 ) (total irrigation volume 300 m 3 /ha) and "normal irrigation" (I 2 ) (total irrigation volume 1500 m 3 /ha).These established water regimes were applied in quantities of 50 m³/ha for I 1 level or 250 m 3 /ha for I 2 level, once a week for six weeks.
Regard to K-fertilization, to the natural endowment of land (K 0 ) was compared K 1 level (200 kg/ha of K 2 O, added to soil before transplant).
Each parcel was made up of 5 rows having an extension of 7 m.The main morphophysiological surveys were conducted for the plants of all the parcels; while, at harvesting, the main productive and qualitative aspects of the berries were estimated on the plants of the central row (Giordano et al., 2000).
Fruit harvest was performed at full ripening on August 20 th and September 24 th ; productive data were submitted to analysis of the variance with the program Mstat-C using the scheme "Randomized Complete Block Design for Factor A (watering regime), with Factor B (ecotype) as a Split Plot on A and Factor C (K-fertilization) as a Split Plot on B".Means were evaluated with Duncan's test.

Irrigation-Mycorrhization trials
The experimental trial was carried out using a split-plot scheme with 3 replicates, in the plain of Metaponto (Matera, South Italy 40° 24'N; 16° 48'E; 10 m a.s.l.), during springsummer of 2009, aimed to compare 3 watering regimes in combination with two different mycorrhization systems on Faino (Syngenta) F1 hybrid.
The soil of the experimental plots had a mixed composition, containing 51.3% of silt, 29.0% of sand and 19.7% of clay, with a slight alkaline reaction (pH 7.68), poor in total N (0.8 g /kg), with average organic matter (9.2 g / kg) and well equipped in exchangeable P (21.2

Agronomical and morphological data
The main agronomical and morphological results are reported in Table 1.The lack of natural rainfall during the period from flowering to harvest, together with the adoption of irrigation schemes of medium and small-scale to the needs of the tomato crop have been the main cause of low yields for both ecotypes (26.5 t/ha for Corbarino and 27.3 t/ha for Vesuviano tomato). (1)value from 1 (worst) to 5 (best).** P=0.01; *P=0.05;n.s.= not significant Table 1.Effects of irrigation/K-fertilization on agromical and qualitative traits of Corbarino and Vesuviano tomato.

Yield
Indeed a previous research in the same area indicated better agronomic performance for these local varieties (Parisi et al., 2006).
In this research, yields were highly influenced by the water regime; in particular moving from no irrigation to normal irrigation condition, increases in total production of 41.5% for Corbarino and 64.4% for Vesuviano tomato were found.For the first local variety the results were in agreement with those of Pernice et al. (2010).
No significant effects of ecotype and K-fertilization on total yield were recorded; instead, the interactions genotype x irrigation x K-fertilization and that between water regime x Kfertilization were significant for total yield and waste percent, respectively.The incidence of ripe fruit with defects (such as cracking, virus infections and damage by other biotic agents) seemed to have decreased with K-fertilization (from 17.6% to 12.6%), moreover the interactions between irrigation ×genotype and between irrigation × K fertilization were significant.
Increasing in water supply resulted in better values of size homogeneity and, according to Pernice et al., 2010, in worsening of fruit firmness.

Alimentary quality
The most of volatiles substances were found in both genotypes, while their concentrations, expressed as µg/100 g d.m., seemed to be influenced by both agronomical treatments (Table 2).
(  Different letters indicate significant difference (ρ≤ 0.05).Small letters concern the statistical analysis within the same genotype, keeping as fixed variable the K-fertilization levels, while the capital letters concern the statistical analysis within the same genotype, keeping as fixed variable the watering regimes.
In order to better estimate the effects of two agronomical methods on the tomato flavour, all the identified volatile compounds were distinguished in the volatile characteristic compounds (hexanal, 2(E)-hexenal and 2-isobutylthiazole), responsible of the tomato impact aroma, and the contributor volatile flavour such as alcohols, carbonyl compounds (aldehydes and chetones), phenolic derivatives and terpens.Fig. 1 showed that this effect was more evident for the volatile characteristic compounds and particularly for 2isobutylthiazole in the sample treated with the highest watering volumes and Kfertilization.On the contrary, in Vesuviano genotype, the volatile characteristic compounds had the highest concentration in the control.In fact the increasing watering volumes and Klevels caused a decrease of the values of the three compounds respect of the control, especially for 2-isobutylthiazole.The negative effects of the two cultural methods on the characteristic volatile compounds found in Vesuviano tomato were in accord to Veit-Khöler et al. (1999), who noted that an increase of watering regimes caused a decrease of six carbon atoms aldehydes as hexanal, 3(Z)-hexenal and 2(E)-hexenal in tomato samples.
Fig. 2 showed the influence of agronomical treatments on the contributor volatile compounds.In the Corbarino tomato, the increase of watering levels, with or without Kwww.intechopen.comfertilization, caused a decrease of alcohols, an enhancement of carbonyl compounds and terpens; while the content of phenolic derivatives were quite similar in all the samples.In Vesuviano genotype, the unirrigated sample had the highest values of all the classes of contributor substances, especially of the alcohols.Besides, the K-fertilization caused a decrease of contributor compounds and this behaviour was more evident in the sample irrigated with the highest watering regime, except of carbonyl compounds.
Small letters concern the statistical analysis within the same genotype, keeping as fixed variable the Kfertilization level, while the capital letters concern the statistical analysis within the same genotype, keeping as fixed variable the watering regimes.In Table 3 the other parameters of alimentary quality of two genotypes were reported.Dry matter was always similar in all the samples of Corbarino genotype, but it decreased in the Vesuviano samples irrigated with the highest water levels, according to Fontes et al (2000) and Helyes et al. (2009), who observed a positive effect of K-fertilization at different watering regimes.The pH of both genotypes was not modified by different watering regimes and K-fertilization, according to Ghebbi Si-smail et al. ( 2007), even if Fontes et al. (2000) reported a decrease of pH with increasing K-levels.As concern the soluble sugars, glucose decreased in the samples irrigated with the highest levels only in Vesuviano genotype, according to Parisi et al. (2006) and Mitchell et al. (1991).On the contrary fructose was not affected by the two cultural methods in both genotypes.
As regards the organic acids, oxalic acid was not influenced by the cultural techniques in both genotypes, citric acid did not show any variation in all the Corbarino samples, while it was positively influenced by fertilization in Vesuviano genotype, according to Mitchell et al. (1991).Malic acid was negatively affected only by watering irrigation.
Small letters concern the statistical analysis within the same genotype, keeping as fixed variable the Kfertilization level, while the capital letters concern the statistical analysis within the same genotype, keeping as fixed variable the watering regimes.Different letters indicate significant difference (ρ≤ 0.05).Small letters concern the statistical analysis within the same genotype, keeping as fixed variable the K-fertilization level, while the capital letters concern the statistical analysis within the same genotype, keeping as fixed variable the watering regimes.
Table 3. Effects of irrigation and K-fertilization on chemical-physical parameters of two tomato genotypes.

Nutraceutical quality
Fig. 3 showed the content of total lycopene in two treated genotypes.In both Corbarino and Vesuviano tomato, the lycopene content increased in samples treated with the highest watering regimes, with or without K-fertilization.So the lycopene content in both genotypes seemed to be mainly influenced by watering regimes than fertilization.In literature, contrasting results about total lycopene in relation with irrigation regimes and Kfertilization are reported.
Achilea & Kafkafi (2003) evaluated, in a series of experiments performed in different countries, the specific contribution of potassium nitrate to yields and quality parameters of processing tomatoes.They noted that potassium nitrate was found to be the best form for maximum lycopene concentration in the fresh fruit.
In another experiment, Fontes et al. (2000) studied the effect of K-fertilizers rates on the fruit size, mineral composition and quality of the trickle-irrigated tomatoes.Lycopene and other analytical parameters in the fruits were not affected by K-rates.
On the contrary, Serio et al. (2007) determined the influence of K-levels in the nutrient solution on lycopene content of tomato plants grown in a soil-less system using rockwool slabs as substrate.Two growing seasons were studied with the aim of comparing three Klevels: low, medium and high (corresponding to 150, 300 and 450 mg K t-1 in the nutrient solution).The lycopene content increased linearly with increasing K-level in the nutrient solution.
Fig. 3. Total lycopene in irrigated and K-fertilized Corbarino and Vesuviano tomato genotypes.Different letters indicate significant difference (ρ≤ 0.05).Small letters concern the statistical analysis within the same genotype, keeping as fixed variable the K-fertilization level, while the capital letters concern the statistical analysis within the same genotype, keeping as fixed variable the watering regimes.
Ghebbi Si-smail. et al. (2007) studied the effect of three levels of K-supply on the total lycopene content of two tomato cultivars, during two seasons in open field.The plants were grown in loamy soil poor in organic matter (1.18%) and in K (75 ppm K 2 O).Results about lycopene concentration seemed to be negatively affected by K-fertilization.Zdravković et al. (2007), in order to research whether lycopene production depended upon mineral macro-nutrient, used industrial tomato cv.Narvik SPF as a material.The content of lycopene regarding the fertilizer formulation was from 33.69 mg/kg in control to 56.92 mg/kg in plants treated with increased content of potassium.Taber et al. (2008), studying the response of tomato cultivars with fruit of average and high lycopene to increased K-fertilization, demonstrated that K-fertilization could affect carotenoids biosynthesis, and the response of tomato to an high K-rate was genotype dependent.
Finally, Helyes et al. (2009) in an open field experiment, studied the effects of irrigation (regularly irrigated, irrigation cut-off 30 days before harvest, and unirrigated) and two Ksupplementation (454 and 555 kg ha -1 respectively) on lycopene and other analytical parameters of tomato fruit.The high K-rate increased the lycopene content of tomato in the irrigation cut-off and unirrigated treatments.
In our research, the scarce influence of K-fertilization on the lycopene biosynthesis, in contrast with other authors (Achilea & Kafkafi, 2003;Helyes et al., 2009;Serio et al., 2007;Zdravkovic et al., 2007;), could be explained with the high natural content of K in the soil, where the tested tomatoes were grown, as reported in materials and methods.On the other hand, this behaviour is in accordance with other authors (Dumas et al., 2003;Panagiotopoulos & Fordham, 1995;), who found a positive response of the lycopene content to fertilization levels only in tomato grown in soil treated with excessively high dose of fertilizers, in contrast to the modern cultural management, whose target is the reduction of the crops chemical input.
Besides, our researches showed that the lycopene content seemed not to be genotypedependent because Corbarino and Vesuviano showed the same trend in relation with Kfertilization, in contrast with Taber et al. (2008).
The effect of watering supply on lycopene content of tomato was investigated by other authors.Brandt et al. (2003) found that the lycopene content of tomato harvested in greenhouse, supplied with 50% of optimal water intake, was higher than that of fruits supplied with 100% of optimal intake.Riggi et al. (2008) studied the influence of two watering regimes (a fully irrigated treatment receiving 100% of evapotranspiration for the whole growing season and an unirrigated control watered up to plant establishment only) on lycopene and -carotene accumulation during fruit ripening in a field-grown processing tomato.Higher amounts of lycopene were measured in the well watered treatment.On the contrary, Favati et al. (2009) in a two-years research found an higher fruit content of carotenoids (lycopene and -carotene) under water deficit irrigation respect to well irrigated processing tomatoes.In other studies, on the effects of four irrigation regimes (40, 50, 60 and 70% depletion of the available soil moisture) on three tomato cvs, Naphade (1993) ascertained that the lycopene content decreased in response to moisture stress, whereas Matsuzoe et al. (1998) in red and pink cherry tomato cvs found that lycopene increased when there were soil water deficits.In red and pink large-fruited tomatoes, soil water deficits also tended to increase the amount of lycopene in the region of the outer pericarp (Zushi and Matsuzoe, 1998).However, the effects of water availability seemed to need further studies, particularly in relation with the fruit environmental conditions (Dumas et al., 2003).

Agronomical and morphological data
Table 4 showed that the watering regimes had positively influenced the commercial yields.
In fact, the total yield had highlighted an increase of 36.1 t/ha and 59.6 t/ha respectively for V 50 and V 100 .The higher productivity levels of the watered thesis were also accompanied by a significant increase in weight of the berries.Besides, the increase of water volumes caused an increase of waste berries, from 12.6% of the control (V 0 ) to 15.1% and 16.7% respectively in V 50 and V 100 .The yields of the mycorrhized thesis with Micosat F and VAM did not show significant differences and the yields of the two mycorrhizae had similar values in comparison with unmycorrhized and irrigated samples (V 50 ).

Yield
Take into account the interaction between irrigation × mycorrhization, the agronomical parameters had not statistically significant differences.As concern firmness, the reported values were similar among all the studied theses, irrigated, mycorrhized and irrigated/mycorrhized samples.

Alimentary quality
Table 5 showed the composition and the values (µg/100 g d.m.) of tomato aromatic profiles treated with different watering regimes and mycorrhizae.The single volatile compounds were identified in all the analyzed thesis and the influence of the agronomical treatments were only ascertained for their content.Even in this section, as for the irrigation/K fertilization one, the volatile compounds were subdivided in characteristic and contributor volatile compounds of the tomato aroma.As concern the characteristic volatile compounds, Fig. 4 showed that hexanal had the highest value in unmycorrhized samples V 50 and V 100 with respect to the untreated sample (V 0 ).A constant content of 2(E)-hexenal was noted for unmycorrhized and irrigated samples.2-isobutylthiazole, among the same samples, had the highest concentration in V 50 and the lowest in V 100 .In the irrigated and treated with two different kinds of mycorrhization samples, a decrease of all the characteristic volatile compounds was noted, especially for M 2 treatment.If the total content of characteristic volatile compounds was considered, the sample with the highest content was V 50 , while M 1 V 0 and M 2 V 0 showed the lowest levels.
Fig. 5, concerning the contributor volatile compounds, showed that in the unmycorrhized irrigated samples alcohols, carbonyl compounds and terpenes had the highest content in V 50 and V 100 , except for phenolic derivatives, only in V 50 .Besides, in the irrigated and mycorrhized samples, contributor volatile compounds were always lower than unmycorrhized and irrigated samples.This trend was more evident when the total content of contributor volatile compounds was considered.
Different letters indicate significant difference (ρ≤ 0.05).www.intechopen.com The other alimentary quality parameters were reported in Table 6.
The dry matter (d.m.) showed similar values in the irrigated and unmycorrhized samples.Among the samples treated with M 1 , the value of M 1 V 0 was slightly higher than the other samples (M 1 V 50 and M 1 V 100 ), but with little statistically significant differences.Among all examined thesis, M 2 V 0 had the highest d.m. value, while M 2 V 100 the lowest one.So, a light positive influence of mycorrhization system, and particularly of M 2 , was noted in the unirrigated samples.
Among the unmycorrhized samples, V 0 had the lowest value of pH, while V 100 the highest A similar trend was observed for irrigated and mycorrhized samples.Among all the samples, the lowest pH was noted for M 2 V 0 , while the highest values in V 100 and M 1 V 100 .
Since pH is the expression of the organic acids content, the same table showed that to higher organic acids content corresponded lower pH, as demonstrated for M 2 V 0 .These two parameters are very important in processed tomatoes, because a pH=4.3ensures a microbiological stability during the conservation in the sterilized products (Silvestri & Siviero, 1991).
As concern soluble sugars, both glucose and fructose showed the highest content in the unirrigated sample (V 0 ) and mycorrhized samples (M 1 V 0 and M 2 V 0 ).Furthermore, their content was always higher in mycorrhized sample than untreated one.Table 6.Effects of mycorrhization and irrigation on chemical-physical parameters of Faino F 1 tomatoes.

Nutraceutical quality
From Fig. 6 it could be deduced that in unmycorrhized and irrigated samples (V 50 and V 100 ) the total lycopene content significantly increased, in comparison with the control, respectively of 6,58% and 18,54% and this increase was directly proportional to the watering volume.Among the unirrigated samples, M 1 V 0 presented the same content respect of V 0 , while M 2 V 0 showed a deep decrease (-31%).Utilizing the mycorrhizae with a watering regimes corresponding to 50%, the lycopene content decreased both in M 1 V 50 (-18%) and M 2 V 50 (-45%) with respect to V 50 .In the full irrigated samples (V 100 ), the lycopene content in M 1 V 100 and M 2 V 100 showed a decrease of about -53% in comparison with V 100 .
From reported data, it could be deduced that the highest concentration of lycopene was obtained in fully irrigated samples without mycorrhization.This trend was more evident for M 2 mycorrhized samples.
Fig. 6.Effects of irrigation and mycorrhization on total lycopene content of Faino F 1 tomatoes.
Recent studies pointed out that lycopene, as well as other carotenoids, are synthesized from isoprenoids that are products of mevalonic acid (MVA) and methylerythritol-4-phosphate (MEP) pathway (Botella-Pavia & Rodriguez-Concepcion, 2006).The use of M 1 and M 2 mycorrhizae could most likely decrease the action of enzymes involved in these pathways such as deoxyxylulose-5-phosphate synthase.This hypothesis seems to be the most plausible to explain the negative interaction of mycorrhization vs. lycopene synthesis, because of the scarce available literature about this behaviour.
However our results about the negative effect of mycorrhization on lycopene content were in contrast with other authors.Ordookhani & Zare (2011) investigated the effects of inoculating tomato (Lycopersicon esculentum F1 Hybrid, Delba) roots with plant growthpromoting rhizobacteria (PGPR) and Arbuscular Mycorrhiza Fungi (AMF) on lycopene and other parameters of tomato fruit.PGPR treatments were inoculated with Pseudomonas putida, Azotobacter chroococcum and the AMF treatment was inoculated with Glomus mossea.In comparison to the untreated sample, lycopene of fruit was increased by PGPR and AMF treatments.In the PGPR × AMF treatment maximum lycopene were found in plants of the Pseudomonas + Azotobacter + AMF treatment.In the PGPR treatment maximum lycopene were found in plants of the Pseudomonas + Azotobacter treatment.Data showed that lycopene increased when AMF added to PGPR treatments.Probably, the different behaviour of lycopene vs. Mycorrhization could depend on different composition of the mycorrhizae.
On the other hand, a positive effect of high watering regimes on lycopene content was in accordance with the other authors, as reported in the section relative to the Irrigation/ K-fertilization.

Conclusion
It can be deduced that agronomic parameters (yields, waste %, fruit weight etc.) are influenced by agronomic treatments when are separately analysed.Irrigation gives a better commercial yield and higher weight of berries in all examined genotypes.A different behaviour is showed by the other experimental treatments (K-fertilization and mycorrhization).Besides, poor effects on the same parameters were observed for the interactions between the different agronomical treatments and even in this case they seem not to depend on the genotype.
The influence of the agronomical treatments on the biochemical parameters can be detected from Fig. 7 and Fig. 8, where these parameters are compared against the control (I 1 K 0 for fig. 7 and V 0 for Fig. 8) equal to 100.In Corbarino and Vesuviano tomato, the irrigation and irrigation/K-fertilization can reduce the flavour synthesis; this effect is more evident in Vesuviano tomato.
In Faino (F1) tomato hybrid, the irrigation enhances the volatile compounds content, while, in combination with mycorrhization, it cause a decrease of the volatile substances, especially with M2 (VAM).
Autochthon tomato varieties, as Corbarino and Vesuviano, are already adapted to the arid climate of the Vesuvius volcano slopes, characterized by low rainfall and difficulties in water supply.In this case, organoleptic characteristic are enhanced when they are cultivated in soil where the lonely water support is represented by rainfall.Besides, in new genotypes, as well as Faino hybrid tomato, the same characteristic are enhanced by high watering regimes.The interaction, as irrigation/K-fertilization and irrigation/mycorrhization, seems to have poor effects on aromatic profiles.A correlation among agronomical treatments and their effects on sugars and organic acids is very difficult.However, the lonely positive effect, on sugar and organic acids content, due to mycorrhization, is evident only in rainfall watered fields.As concern the nutraceutical quality, high watering regimes can cause an increase of lycopene in three genotypes.Moreover, in Corbarino and Vesuviano tomato, irrigation x Kfertilization considerably enhances the lycopene content in the theses with the highest level of both irrigation and fertilization.On the contrary, a considerable decrease of the lycopene content is noted in the Faino tomato in the theses with irrigation x mycorrhization.
In conclusion, the irrigation seems to be the best agronomical treatment to enhance the organoleptic, nutraceutical and agronomical characteristics of tomatoes, regardless of genotype and origin countries.Besides, the interactions of irrigation with K-fertilization and mycorrhization cause poor effects on biochemical and agronomical characteristics.

Fig. 4 .
Fig. 4. Effects of irrigation and mycorrhization on characteristic volatile compounds of Faino F 1 tomatoes.

Fig. 7 .
Fig. 7. Comparison of alimentary and nutraceutical parameters of "Corbarino" and "Vesuviano" tomatoes cultivated with different watering regimes and different Kfertilization levels.The percent changes with respect to the control (I 1 K 0 ), assumed equal to 100%, are reported.

Fig. 8 .
Fig. 8.Comparison of alimentary and nutraceutical parameters of " Faino F 1 tomatoes.The percent changes with respect to the control (V 0 ) ,assumed equal to 100%, are reported.

Table 2 .
Quali-quantitative composition of identified volatile components.

Table 5 .
Quali-quantitative composition of identified volatile components in Faino F 1 tomatoes.n.d.= not detected.