No abstract

The plastic mulch has raised a disposal issue, which has been diverting the research focus on biodegradable film as an alternative. Research was carried out in southern Italy in 2016–2017 and 2017–2018 in order to assess the effects of three crop cycles (autumn-winter, winter, spring) in factorial combination with three soil mulching types (a MaterBi biodegradable black film; a brown photoselective low density polyethylene (LDPE) film; a black-standard LDPE film) and a non-mulched control, on leaves yield, quality and antioxidants of greenhouse grown Diplotaxis tenuifolia (L.) D.C. The spring cycle was the shortest and best enhanced plant growth and yield. The non-mulched control caused an 11% yield reduction compared to the mulching treatments average (12.4 t ha−1). The soil temperature was highest under photoselective and standard LDPE films. The Soil Plant Analysis Development (SPAD) index was 17.4% higher in the leaves grown in mulched soil. Winter season and biodegradable mulch led to higher leaf dry residue and organic acids. Leaf nitrate content was highest in winter and under mulching. The spring cycle, the biodegradable and photoselective LDPE film resulted in the highest antioxidant compound content and activity. The biodegradable polymer improved leaf quality, showing suitable features for sustainable production.

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).

The practice of organic agriculture represents an essential requirement for conserving natural resources and for providing the food necessary for a growing population, on a sustainable basis. Tomatoes are considered to be one of the most important crops worldwide. In this context, the organic production of tomatoes should be taken into more consideration. The use of microorganisms-based commercial products is an alternative to chemical fertilizers. Anyway, the results of their use are still variable because of various factors. The aim of this study was to test the effect of inoculation with AMF, PGPR and fungi-based products (Rizotech plus®) on the morphological (length of the plants), biochemical (lycopen, polyphenols, antioxidant activity), and number of fruits and yields of four tomato cultivars (Siriana F1, HTP F1, Minaret F1, Inima de Bou) in two different water regimes used for irrigation (200 m3 or 300 m3 of water/hectare) under a protected area. The results showed that the efficiency of Rizotech plus® application is dependent on the cultivar and the amount of water used. Also, it was clearly demonstrated that the microorganism inoculation significantly increased the yield of Minaret F1, Siriana F1 and HTP F1 cultivars as compared to the uninoculated plants, regardless of the water amount used in the experiment. Moreover, it was observed that for the irrigation of all four cultivars, inoculated with Rizotech plus®, a lower amount of water (200 m3·ha−1) can be used to get the same length of plants, number of fruits and yield as in the case of a higher amount of water (300 m3·ha−1). In the case of lycopene, polyphenols and antioxidant activity, the results varied with the cultivar and the water amount used. This study gives new information about the functionality and performance of the microorganisms from Rizotech plus® product when applied to different tomato cultivars grown in a tunnel, in the condition of two different water regimes, contributing to a better characterization of it and maybe to a more efficient use in agriculture to achieve optimum results.

No abstract

Conventional management of sweet pepper is based on farming practices characterized by the use of chemicals with harmful environmental impact. In order to investigate innovative production, research was carried out in order to assess the effects of two pepper cultivars (‘Brillant’ and ‘Yolo Wonder’) in combination with four farming systems (Conventional control-C; Conventional with microorganism-enriched fertilization-CMF; Organic control-O; Organic with microorganism-enriched fertilization-OMF) on plant physiological parameters, yield and fruit quality. Conventionally grown plants showed higher values of assimilatory pigments and of photosynthetic rate compared to the Organically ones. The CMF resulted in the highest early and total yield, followed by the OMF, due to higher fruit number. Higher values of carotenoids, ascorbic acid and α-tocopherol were recorded in ‘Yolo Wonder’ red fruits compared to ‘Brillant’ yellow berries. The highest total polyphenols concentration was recorded under the CMF, whereas OMF resulted in the highest flavonoids concentration and antioxidant activity.

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.

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.