Yield, Quality, Antioxidants and Elemental Composition of New Leek Cultivars under Organic or Conventional Systems in a Greenhouse

Abstract

Leek (Allium porrum) is known for its high antioxidant activity and the ability to accumulate significant amounts of potassium and iron. We assessed yield, quality indicators, antioxidants and elemental composition of nine leek cultivars grown in greenhouses under organic or conventional systems in the Moscow region. The management system did not affect yield, which attained the highest value with the cultivar Giraffe and the lowest with Premier and Cazimir. Pseudo-stem dry matter and sugars were higher with organic management, whereas nitrate concentration was higher with conventional management. The cultivars Vesta and Summer Breeze showed the highest dry matter and total sugar content, whereas Goliath had the highest antioxidant, selenium and potassium concentrations. Among the antioxidants, ascorbic acid attained higher values with organic management. The antioxidant system of leek was characterized by highly significant positive correlations between: Se and polyphenols, Se and ascorbic acid, Se and K, ascorbic acid and polyphenols, ascorbic acid and K, polyphenols and K (r = 0.94, 0.94, 0.95, 0.94, 0.95, 0.96, respectively, at P ≤ 0.001). Negative correlations were recorded between leaf and pseudo-stem Se and between leaf and pseudo-stem polyphenols (r = −0.922 and −0.976, respectively, at P ≤ 0.001). Among the mineral elements, only K was significantly affected by the management system, showing a higher content in organically grown pseudo-stems. Varietal differences in pseudo-stem element composition showed strong positive correlations of: Al with As, Co, Li, Pb and V; Cr with I, Mg, Si, Ca; V with As, Co and Fe; negative correlations of Se with Cr and I. Compared to related species such as garlic (A. sativum), leek accumulated levels equal to garlic of K, Mg, P, Cd, Cu, Mn, Se, Zn, lower levels of Si and significantly higher amounts of Ca, Na, Al, As, Cr, Ni, Pb, Sr, V, Sn, B, Co, Fe, I, Li. The strong relationships between quality, antioxidant and mineral components in leek plants may give wide possibilities in breeding programs for both conventional and organic management systems in greenhouses.

Yield and Nutritional Quality of Vesuvian Piennolo Tomato PDO as Affected by Farming System and Biostimulant Application

“…Two out of the three variables characterizing the colour (a* and b*) were higher under conventional management compared to the organic one; conversely, the organic acids malate, oxalate and isocitrate attained higher concentrations in the organically grown berries ( Table 2). In the present research, both tomato fruit dry matter percentage and soluble solids were not significantly affected by farming management, whereas in previous investigations asparagus spears [47] and leek pseudo-stems [48] organically grown in southern or northern Europe respectively showed higher dry matter and sugar content than those managed conventionally. Regardless of the farming system, the soluble solids, fruit brightness and redness as well as the target organic acids malate, oxalate, citrate and isocitrate were significantly higher than untreated plants by 10.1%, 16.1%, 19.8%, 18.9%, 12.1%, 13.5% and 26.8%, respectively, with no significant differences between the PH-and PE-based biostimulants ( Table 2).…”

Yield, Growth, Quality, Biochemical Characteristics and Elemental Composition of Plant Parts of Celery Leafy, Stalk and Root Types Grown in the Northern Hemisphere

“…The peculiarities of the celery antioxidant system, reflected in the strong relationships between ascorbic acid, flavonoids, phenolics, antioxidant activity and Zn, were shown in celery in the present study. In a previous research [34], highly significant relationships between ascorbic acid, phenolics, antioxidant activity, Se and K, but not Zn, were recorded in leek. The latter phenomenon may be explained by the fact that, unlike celery, leek belongs to secondary accumulators of selenium.…”

Mineral Biofortification of Vegetables as a Tool to Improve Human Diet

“…Tuber species such as potato, showed a 13-fold average increased in I content, while root vegetables such as carrot presented a much higher average increase (greater than 100-fold). Biofortification of I through repeated foliar spray has been successfully performed in carrot and mustard plants [ 76 , 77 ]. Higher efficacy of lettuce iodine biofortification was noted Smolèn et al [ 71 ] after foliar application, rather than adding the element to the nutrient solution.…”