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Research has been increasingly focusing on the preservation of the biodiversity of vegetable crops under sustainable farming management. An experiment was carried out in southern Italy on Brassica oleracea L. var. botrytis, landrace Gigante di Napoli, to assess the effects of two transplanting times (9 September and 7 October), in factorial combination with five nitrogen–potassium ratios (0.6; 0.8; 1.0; 1.2; and 1.4) on plant growth, yield, and quality of cauliflower heads. A split-plot design was used for the treatment distribution in the field, with three replications. The earlier transplant and the 1.2 N:K ratio led to the highest yield, mean weight, and firmness of cauliflower heads which were not significantly affected by both transplanting time and N:K ratio in terms of colour components. The 1.2 N:K ratio led to the highest head diameter with the earlier transplant, whereas the 1.0 ratio was the most effective on this parameter in the later crop cycle. The highest nitrate, nitrogen, and potassium concentrations in the heads were recorded with the earlier transplanting time. Antioxidant activity, ascorbic acid, and polyphenol content increased with the rise of the N:K ratio. The element use efficiency was constantly negative with the N:K increase for nitrogen and was augmented until the 1.2 ratio for potassium. The results of our investigation showed that the optimal combination between transplanting time and N:K ratio is a key aspect to improve head yield and quality of the cauliflower landrace Gigante di Napoli, under the perspective of biodiversity safeguarding and valorisation.

The tomato industry has been searching for new genotypes with improved fruit production, both in the field and industrially processed, together with high-quality performance under sustainable management conditions. This research was carried out in Southern Italy with the aim of assessing the effects of industrial processing on the yield and quality of four tomato hybrids grown according to organic farming methods and addressed at dicing. MAX 14111 and HMX 4228 showed the highest values of field and processing yield as well as reduced sugars and fructose. MAX 14111 had the highest values of total solids and soluble solids, titratable acidity, fiber, energetic value, polyphenols, and also rutin, though not significantly different from Impact. HMX 4228 performed best in terms of sugar ratio, color and naringenin. Concerning the diced products, the sensorial qualities of the four hybrids differed significantly. Total polyphenols, naringenin and rutin in the tomato fruits were higher in the processed than in the raw product. The appreciable fruit yield and quality resulting from both field and processing phase represent a promising perspective for identifying improved tomato genotypes addressed at dicing.

Research was carried out on onion landrace (Ramata di Montoro) for seed production in southern Italy, with the aim to evaluate the effects on yield and quality of four bulb planting times in factorial combination with four densities, using a split plot design with three replicates. The number of flower stalks per plant, their height and diameter, and the inflorescence diameter decreased with the bulb planting delay and density increase. The highest plant leaf area and LAI (leaf area index), seed yield, number, and mean weight were recorded with the earliest planting time, with the lowest bulb density eliciting the highest plant leaf area but the lowest LAI and seed yield per hectare. The ratio between seeds and inflorescence weight, and seed germinability, decreased with the planting delay and density increase. Seed oil, protein, and antioxidant content (polyphenols and selenium) were highest with the last crop cycle. The polyunsaturated fatty acids, predominant in oil, increased with planting time delay, whereas the monounsaturated fatty acids decreased. Linoleic, oleic, and palmitic acid prevailed among polyunsaturated, monounsaturated, and saturated fatty acids, respectively. Planting from 20 December to 10 January with 3.3 cold-stored bulbs per m2 was the most effective combination in terms of seed yield per hectare, whereas seed oil content and quality were the best, with the last crop cycle starting on 21 February, independent of bulb density.

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.