The GesCoN model was evaluated for its capability to simulate growth, nitrogen uptake, and productivity of open field tomato grown under different environmental and cultural conditions. Five datasets collected from experimental trials carried out in Foggia (IT) were used for calibration and 13 datasets collected from trials conducted in Foggia, Perugia (IT), and Florida (USA) were used for validation. The goodness of fitting was performed by comparing the observed and simulated shoot dry weight (SDW) and N crop uptake during crop seasons, total dry weight (TDW), N uptake and fresh yield (TFY). In SDW model calibration, the relative RMSE values fell within the good 10-15% range, percent BIAS (PBIAS) ranged between -11.5 and 7.4%. The Nash-Sutcliffe efficiency (NSE) was very close to the optimal value 1. In the N uptake calibration RRMSE and PBIAS were very low (7%, and -1.78, respectively) and NSE close to 1. The validation of SDW (RRMSE = 16.7%; NSE = 0.96) and N uptake (RRMSE = 16.8%; NSE = 0.96) showed the good accuracy of GesCoN. A model under- or overestimation of the SDW and N uptake occurred when higher or a lower N rates and/or a more or less efficient system were used compared to the calibration trial. The in-season adjustment, using the "SDWcheck" procedure, greatly improved model simulations both in the calibration and in the validation phases. The TFY prediction was quite good except in Florida, where a large overestimation (+16%) was linked to a different harvest index (0.53) compared to the cultivars used for model calibration and validation in Italian areas. The soil water content at the 10-30 cm depth appears to be well-simulated by the software, and the GesCoN proved to be able to adaptively control potential yield and DW accumulation under limited N soil availability scenarios and consequently to modify fertilizer application. The DSSwell simulate SDW accumulation and N uptake of different tomato genotypes grown under Mediterranean and subtropical conditions.

The objective of this research was to evaluate the effect of the conventional and organic farming on the bio-physical, physiological and some nutritional aspects of ready-to-use ‘Riccia di San Marzano’ and ‘Cima grande’ cima di rapa genotypes, at harvest (T0) and after 7 (T7) and 14 (T14) days of cold storage. At harvest, the organic product had better overall appearance, higher chlorophyll and β-carotene concentrations and lower glucosinolate levels compared with the conventionally grown product. During the storage period the weight loss was lower in the organic product likely due to reduced respiration activity, particularly in ‘Riccia di San Marzano’. The lower respiratory rate of the organic sprouts could had been involved in a better color retention during the shorter storage time, however after 14 days they showed a sharper loss of visual quality and, in particular, the development of off-odors. These differences were probably due to a higher N:S ratio in plant nutrition under the organic cultivation system. Vitamin C, ascorbic acid, dehydroascorbic acid and flavonol concentrations as well as tissue electrolyte leakage were all affected by the storage time and not by cultivation systems. Vitamin C concentration dramatically slowed down during the T0-T7 period, while flavonols progressively increased by 1.5 times during storage, thus leading to an enhancement of total antioxidant capacity of the product. ‘Riccia di San Marzano’ compared to ‘Cima grande’ was richer in antioxidant compounds and, under organic cultivation system, also in nitrates. Stored ‘Riccia di San Marzano’ showed a decrease in nitrate concentration and an increase in antioxidant activity. With the organic farming, cima di rapa visual quality resulted improved both at harvest and after 7 days of storage, while after 14 days a high development of off-odors occurred. The choice of cultivation system seems not to have modified the antioxidant proprieties of raw or processed product.

Content of bioactive compounds in broccoli head varies with genotype, environmental, agronomical, processing, and postharvest conditions. A study was planned to characterize and evaluate changes in fresh (FW) and dry (DW) weight, in antioxidant capacity (AC) and total phenolics (TP) content, in fresh-cut processed florets in seven broccoli cultivars after 7 (T7), 14 (T14), and 21 (T21) days of storage at 5°C in OPP packaging. Head were harvested in early spring from a commercial farm located in Foggia province (southern Italy). Results indicate that at harvest cultivars cv1, cv2, cv3, cv4, cv5, and cv6 showed the highest floret DW content, followed by cv 7. Postharvest storage was stopped on day 14 for cv1, cv2, cv3 and cv4, because of strong off-odors produced. At T14, floret DW concentration decreased much more in cv4 than in cv7. Fresh weight loss (WL) was negligible, however cv5 and cv7 showed the lowest values. The main component of total weight loss during storage was the respiratory component being not significant that connected with transpiration. Differences in AC and TP content were detected in raw material. Compared with T0 AC decreased at T7 and increased at T14, particularly in cv1 and cv2. After 7 days of storage TP content was unchanged (except cv3 and cv6), while at T14 increased (except in cv7). No relationship seems to exist between AC and TP, whereas it is possible to suppose that the higher the initial AC the longer the shelflife of fresh-cut florets.

Dry weight (DW) accumulation and partitioning, and N uptake and allocation for two broccoli cultivars ('Parthenon' and 'Montecarlo') grown in a Mediterranean environment, were studied. Transplanting was done on 25 September 2008 (3.5 plants/m2) and harvesting on 29 January 2009. Plants were fertilized with 130 kg ha-1 of N. Starting from 21 days after transplanting up to commercial maturity of corymbs, eight destructive samplings were performed. At each sampling, fresh and dry weight of leaves, stems and corymbs were recorded. Kjeldahl-N concentration was also determined on dried aerial parts of the plant. Nitrogen uptake data for each cultivar were used for modeling the decrease in N concentration in the aboveground plant DW as affected by plant DW increase, by using the exponential curve: %N=aDW-b. In 'Montercarlo' maximum aerial DW accumulation occurred 15 days before the harvest (5.3 t ha-1), while in 'Parthenon' DW continuously increased up to the end of the growing cycle (5.0 t ha-1). The maximum corymb DW accumulation was reached earlier in 'Montecarlo' that in 'Parthenon'. 'Montecarlo' compared with 'Parthenon' showed higher stem DW and an earlier leaf senescence. No difference was observed in the harvest index (0.26) and in the corymbs fresh yield. Partial factor productivity index indicates that 85.7 kg of fresh product was obtained for each kilogram of N fertilizer. Nitrogen dilution curve fitted for 'Montecarlo' had a and b parameters slightly higher compared with 'Parthenon' curve. Total N uptake was higher in 'Montecarlo' than in 'Parthenon', while corymb N uptake was 74 and 71 kg ha-1, respectively. Total plant nitrogen use efficiency (NUEtotal), showed by the total aerial DW accumulation per unit of up-taken N (NUE total), was similar for both cultivars, whereas 'Parthenon' exhibited higher nitrogen efficiency in head production per unit of up-taken N (NUE yield) than 'Montecarlo'.

Peat is the most common substrate used in nurseries despite being a very expensive and a non-renewable material. Peat replacement with biochar could be a sound environmental practice, as it is produced from waste biomass, but evaluation of biochar as a potting substrate is needed. Ratios of peat:biochar of 100:0, 70:30, 30:70 (BC0, BC30, and BC70, respectively), two fertilizer rates (FERT1, FERT2), and arbuscular mycorrhizal fungi (AMF) inoculation were tested on potted Pelargonium plants. Plant growth, flowering, bio-physiological and nutritional responses, and root mycorrhization were evaluated. The BC30 mixture did not affect plant growth compared with pure peat. However, BC30 in combination with FERT2 treatment was more effective in enhancing nitrogen (N) and chlorophyll (CHL) leaf concentrations, and leaf and flower numbers. The BC70 mixture depressed plant growth, flowering traits, and root mycorrhization. Leaf N concentration was below the sufficiency range reported for Pelargonium growth. Leaf concentration of phosphorous (P) was adequate in pure peat and in BC30 but it dropped close to sub-optimal values in BC70. The pH value of the mixtures lowered P availability, though in BC30 the mycorrhizal activity could have allowed adequate P plant uptake. In BC70 plants, the deficiency of both N and P might be a reason for the observed growth reduction. The inoculation of the substrate with selected AMF improved plant growth (higher dry biomass, greater floral clusters, larger and more abundant leaves) and quality resulting in unstressed (lower electrolyte leakage and higher relative water content values) and greener leaves (low L∗ and C∗, high CHL content) and in more intensely colored flowers. We conclude that biochar can be applied in nursery/potted plant production provided that the proportion in the peat mixture does not exceed 30%. Furthermore, AMF inoculation contributed to achieving the best plant performance in 30% biochar amended medium.

Carnation is a valuable crop for the cut flower industry and is gaining importance as potted plant. Carnation is produced through America and Europe, mainly under temperate climate. Its production in the Mediterranean area is constrained by the low quantity and quality of water supplied for irrigation. The present work aims at investigating the effect of different electrical conductivity (EC) values (1, 3, and 6 dS m−1) of irrigation water on growth, quality and mineral concentrations of potted carnation plants inoculated or not with different strains of Glomus intraradices (GiI and GiII), growing in a commercial substrate (peat). The highest mycorrhizal colonization (26%) was reached in plants inoculated with GiII and irrigated with fresh water, whereas with the increase of salinity in the irrigation water, both strains proved less successful in enhancing mycorrhizal colonization. Results show that salt tolerance in carnation is increased when roots are colonized by G. intraradices. Moreover, the ornamental value of the potted carnation (plant growth, number and size of flowers, leaves and flower color) is increased by combining the mycorrhizal inoculation with a moderate salinity (3 dS m−1) in the irrigation water. Better performance was related to a lower Cl− concentration in flower and stem tissues (improving the ornamental quality) and an increased concentration of NO3− in leaves (maintaining plant growth) and of Ca2+ in roots (maintaining cellular homeostasis and plant growth).

Abstract BACKGROUND: Baby spinachwas cultivated under spring orwinter conditions to investigate the effect of azoxystrobin and, only in the winter cycle, of nitrogen fertilisation (0, 80 and 120 kg ha−1 of N) on yield and product morphological traits at harvest and on the physical, visual, bio-physiological, nutritional and anti-nutritional characteristics change during cold storage. RESULTS: The yieldwas 37% higher in spring than in the overwinter cycle. Spring grown plant had leaves of lighter colour, lower in dry matter content, higher in ascorbic acid, nitrate, and total phenol content. They had higher weight loss during storage than the winter product. Fresh weight was favoured by azoxystrobin only in the non-fertilised plants. During storage azoxystrobin reduced leaf dehydration, contrasted weight loss and the increase in phenols in leaves from fertilised plants. N supply positively affected yield, and greenness of raw and stored leaves. N fertilisation lowered weight loss due to respiration and showed a protective effect onmembrane integrity during storage. Azoxystrobin proved effective in reducing nitrate leaf content. CONCLUSION: Azoxystrobin, especially in fertilised crop, is useful in improving the physiological quality, the safety, and the nutritional quality of baby spinach. A rate of 80 kg ha−1 can be suggested as optimum N fertilisation.

We have evaluated the effectiveness of arbuscular mycorrhizal fungi (AMF) inoculation (+M and –M) at 0, 60 and 120 kg ha-1 of P fertilizer on crop growth (IEg), plant P nutrition and yield (IEy), and on mycorrhization occurrence in a processing tomato crop. Two experiments were carried out in calcareous soil under field conditions. Phosphorus fertilization had no effect on crop growth and yield. At harvests, +M plants showed higher aerial dry weight (DW), fruit fresh weight (FW), and P concentration. Inoculated plants produced larger inflorescences, higher flower number, and total and marketable fruit number compared with –M plants. At P0 and P60, plants associated with exogenous AMF were able to enhance P recovery, nevertheless factors other than the P uptake improvement concurred to make the inoculation effective. In both years, P fertilization enhanced IEg and IEy, and the application of 60 kg ha-1 of P in inoculated soil was enough to reach high production level (134 Mg ha-1). In the first trial, due to earlier root mycorrhization in inoculated and P fertilized soil, higher IEg and IEy were obtained compared with the second experiment. In the latter, during the initial phase, plant growth was more affected by P fertilization than by soil AM inoculation. Root mycorrhization by native AM fungi indicates that the intensive management of the investigated agro-system did not depress fungi infectivity, however it caused the selection of less effective AMF. The application of selected AMF as a biofertilizer may represent an innovative eco-sustainable practice for improving the crop profitability for growers while reducing the need for P fertilization.