Plasma activated water (PAW) can represent an alternative to chemical fertilizers in agriculture. The effects of PAW treatment applied in two concentrations (1.5 or 3.0 mg L−1 NO3−) on some morphological, physiological, biochemical parameters and yield of Lactuca sativa L. grown in two different pot volumes (400 or 3200 cm3) were investigated in this study. The results showed that both PAW concentrations did not influence the germination, once the process was initiated. Positive effects of the treatments were registered on the length of radicle and hypocotyls of lettuce at a concentration of 1.5 mg L−1 NO3− (PAW I), the chlorophyll content was significantly increased at a concentration of 3.0 mg L−1 NO3− (PAW II) and bigger pot volume, also the foliar weight and area. No significant differences between the treated and untreated plants were recorded for the root weight, leaf length and width. The dry weight was significantly higher for the lettuce treated with PAW I and II grown in big volume pots at 57 days after transplanting (DAT) and small volume pots at 64 DAT. The nitrites content of the lettuce grown in big pots was lower than of the lettuce grown in small pots, regardless of the PAW treatment. Contrary, the nitrates content was higher in the lettuce grown in big pots (up to 36.4 mg KNO3/g DW), compared to small pots (under 0.3 mg KNO3/g DW).

In recent years, rhubarb is being increasingly cultivated, as it provides early yields when the vegetables supply to market is deficient and shows high levels of both polyphenols content and antioxidant capacity in edible parts. In 2017, we investigated crops of the rhubarb cultivar Victoria to the fifth year of production. Comparisons were performed between three root phase fertilizations—chemical (NPK 16-16-16®), organic (Orgevit®), and biological (Micoseeds MB®)—plus an unfertilized control. The determinations of polyphenols, the antioxidant capacity, and the yield indicators from the stalks (petioles) of rhubarb were made at each out of the 10 harvests carried out. The highest yield (59.16 t·ha−1) was recorded under the chemical fertilization. The total polyphenols content and antioxidant capacity varied widely from 533.86 mg GAE·g−1 d.w. and 136.86 mmol Trolox·g−1 d.w., respectively in the unfertilized control at the last harvest, up to 3966.56 mg GAE·g−1 d.w. and 1953.97 mmol Trolox·g−1 d.w. respectively under the organic fertilization at the four harvest. From the results of our investigation, it can be inferred that the chemical fertilization was the most effective in terms of yield, whereas the sustainable nutritional management based on organic fertilizer supply led to higher antioxidant compounds and activity.

Salinity and alkalinity are two of the main causes for productivity losses in agriculture. Quinoa represents a better alternative for global food products such as rice and wheat flour due to its high nutritional value and abiotic stress tolerance. Three cultivars of quinoa seeds (Titicaca, Puno and Vikinga) originating from Denmark were used in the experiments. The seeds were germinated under the action of three different salts (NaCl, Na2SO4, Na2CO3) at 0–300 mM for five days and the germination rate was calculated. Biometric measurements (radicle and hypocotyls lengths) andbiochemical determinations (proline) were performed in order to quantify the tolerance and the effects of salt and alkali stresses on the three quinoa cultivars. The germination rates showed that all cultivars were affected by the presence of salts, especially at 300 mM. The most sensitive cultivar to salts was Titicaca cultivar which evinced the lowest germination rate, regardless of the salt and the concentration used. On the other hand, Puno and Vikinga cultivars showed the best tolerance to the saline and alkaline stresses. Among the salts used, Na2CO3 had the most detrimental effects on the germination of quinoa seeds inhibiting the germination by ~50% starting with 50 mM. More affected was the growth of hypocotyls in the presence of this salt, being completely inhibited for the seeds of the Puno and Titicaca cultivars. Vikinga cultivar was the only one able to grow hypocotyls at 50 and 100 mM Na2CO3. Also, this cultivar had a high adaptability to NaCl stress when significant differences were observed for the germination rates at 200 and 300 mM as compared to 0 mM NaCl, due to the proline production whose content was significantly greater than that of the untreated seeds. In conclusion, the tolerance of the three quinoa cultivars to saline and alkali stress varied with the salt type, salt concentration and tested cultivar, with the Vikinga and Puno cultivars showing the best potential for growing under saline conditions.

Rhubarb is a perennial vegetable crop well adapted to the temperate climate but it is not well known and cultivated as a traditional crop. The aim of the present study is to highlight the influence of the rhubarb cultivar and crop density on the content of some organic acids (malic, tartaric, oxalic, citric, ascorbic) in an organic crop. The highest content of organic acids was determined in a local population from Moldova at a density of 9090 plants•ha-1; the following quantities of acids for 100 g fresh weight (FW) were determined: tartaric -486 mg, oxalic -343 mg, citric -41 mg, malic -686 mg and ascorbic -437 mg.In this present paper, we have demonstrated that content of organic acids from edible rhubarb parts varies according to crop density and cultivars, except for malic acid.

Tomato is considered one of the most important crops worldwide from nutritional and economic standpoints, and, in this respect, sustainable production should be a prime objective, particularly in terms of fertilization and irrigation management. The aim of this study is to compare the effects of two fertilization types (chemical or organic) and two irrigation regimes (67% or 100% of evapotranspiration replenishment) on biometrical, biochemical, and yield parameters of three indeterminate cultivars of tomato grown in a greenhouse. The results showed that the effect of organic fertilization was better compared to chemical fertilization for lycopene accumulation and antioxidant activity, as well as for the lower concentrations of any of the macroelements in the tomato fruits; therefore, organic fertilization can be used as an alternative to chemical fertilization in sustainable horticulture. In each cultivar under the same fertilization type, the effect of irrigation was significant on yield and the number of fruits, but the 100% evapotranspiration restoration did not enhance the fruit concentration of all the macroelements and microelements compared to 67% irrigation regime. Higher concentrations of macro- and microelements in the chemically fertilized fruits compared to the organic ones, regardless of the cultivar and the irrigation regime, suggest that the inorganic substances are more easily absorbed by plants under a protected environment. Organic fertilization positively affected the lycopene and antioxidant activities of tomato fruits, thus proving to be a valuable alternative to chemical fertilization in sustainable agriculture, although the product premium quality also depends on the cultivar used.