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.

Fertigation is considered an efficient alternative to the enhanced use of chemical fertilizers. Since most of the fertigation systems rely on a theoretical electrical conductivity value of the nutrient solution, we tried to evaluate if this is the real need of the plants as well as if all the nutrients are needed at once. Therefore, we analyzed the electrical signals of the nutrients applied individually or in different mixes, correlating the electrical signals with the leaf gas exchange processes, studying the relation between the electrical signals and different plant phenological stages and the influence of the treatments on the lycopene content, nutritional composition, and antinutritional factors as well as the mineral bioavailability of tomato fruits cv. Brillante F1. The study was carried out in a greenhouse under controlled conditions. Ten different treatments consisting of MaEs (major elements) (V1—MgSO4, V2—KNO3, V3—K2SO4, V4—Ca(NO3)2, V5—KH2PO4, V6—KCl, V7—MgSO4 + KNO3 + KH2PO4, V8—K2SO4 + Ca(NO3)2 + KCl, V9—the mix of V1 to V6, commonly used in agricultural practices, V10—one nutrient each day) were applied daily when plants were 42 days old. The results showed that the values of the electrical signals varied depending on the treatment and the plant phenological stage. Five different trends of the electrical signals were identified. In addition, the shape of the signals varied during the day in accordance with the photosynthesis and the amount of CO2 registered. The results of the treatments’ influence on the nutritional composition and lycopene content of tomato fruits suggested that plants do not need all the nutrients at once; the highest values are registered for K2SO4 fertilization. However, this fertilizer also had the highest registered tannin, saponin, and trypsin inhibitors content, constituting a disadvantage considering the high nutritional values and lycopene content. Regarding the bioavailability of zinc, calcium, and iron for the human diet, regardless of the treatment applied, phytic acid did not affect the availability of zinc and calcium, but it had a negative impact on iron availability; also, the amount of oxalate could impair the bioavailability of calcium. The study suggests that tomato plants do not need all nutrients at once for quality fruits. However, further studies are needed in order to develop a fertigation scheme based on a smart nutrient use that provides an improved nutritional composition and mineral bioavailability. In addition, it is necessary to evaluate the influence of treatments on yield.

The research consisted of an experiment applying unconventional stimulators to tomato crop, as a measure against chemical stimulators, known as having negative effects on human health. In our research there have been used four unconventional stimulators (Ecostim, AuCl4-50μg, AuCl4-30μg and Chitosan) and a conventional stimulator BNOA, all compared with the untreated control.Application of stimulators in unconventional farming determined lower productions compared to conventional farming, but is an alternative because determined healthy products. In three of the four unconventional variants, the content of macro- and microelements in plants was higher.

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