The Black Soldier Fly (Hermetia illucens (L.), Diptera: Stratiomyidae) is an insect whose larvae thrive on agro-industrial by-products. This study reports the first use of black soldier fly larvae processing residue (BSPR) as an innovative ingredient for growing media. BSPR was characterized and evaluated to partially replace commercial peat (CP) in the production of potted plants. Chemical and microbiological analysis showed the suitability of BSPR for soilless production. Hence, six growing media mixtures (CP 100% + slow acting synthetic solid fertilizer, CP 90% + BSPR 10%, CP 80% + BSPR 20%, CP 70% + BSPR 30%, CP 60% + BSPR 40% and CP 100% without fertilizer) were assessed for the production of baby leaf lettuce, basil and tomato potted plants. Using BSPR in a proportion up to 20%, all investigated crops showed values significantly greater than or comparable to those obtained using CP 100% + slow acting synthetic solid fertilizer. In general, BSPR used in a proportion up to 20% increased the crop growth of baby leaf lettuce, basil and tomato, recording a high total dry weight (+31%, compared to the total average) and the measured leaf parameters (+39% of leaf area, +14% of leaf number), without showing abiotic stresses. This study indicates that BSPR used in a proportion up to 20% might be a valid approach for soilless production of potted baby leaf lettuce, basil and tomato plants.

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The principal goal of the organic farming system (OFS) is to develop enterprises that are sustainable and harmonious with the environment. Unfortunately, the OFS yields fewer products per land than the non-organic farming system in many agricultural products. The objective of our study was to assess the effects of digestate and biochar fertilizers on yield and fruit quality of processing tomato produced under the OFS. The experiment was carried out in Po Valley, during the 2017 and 2018 growing seasons. Liquid digestate (LD), LD + biochar (LD + BC) and pelleted digestate (PD) were evaluated and compared to biochar (BC) application and unfertilized control. The results showed that plants fertilized with LD + BC recorded the maximum marketable yield (72 t ha−1), followed by BC (67 t ha−1), PD (64 t ha−1) and LD (59 t ha−1); while the lowest production (47 t ha−1) was recorded in unfertilized plants. Over the two cropping seasons, LD + BC, BC, PD, and LD, increased fruit number per plant (+15%), fruit weight (+24%), Brix t ha−1 (+41%) and reduced Bostwick index (−16%), if compared to the untreated control. Considering the overall agronomic performances, digestate and biochar can be useful options for increasing yield and quality of processing tomato production in the OFS. Hence, these fertilizers can be assessed in future research both on other crops and farming systems.

Agronomic and seed-quality traits in 17 quinoa (Chenopodium quinoa Willd.) accessions grouped according to seed colour (i.e. ochre and yellow) were investigated and compared with the white commercial cultivar Regalona-Baer. These accessions were previously selected from a range of accessions of diverse origin and seed colour for their potential value in a breeding program for cultivars adapted to the southern Italian environment. Field trials were conducted over 2 years in Foggia, southern Italy. The aim was to identify elite genotypes suited to the Mediterranean Basin in terms of high yields and seed quality, by using principal component analysis (PCA) and hierarchical cluster analysis. The genotype and year effects were statistically significant for most parameters investigated, whereas the genotype×year interaction was significant only for seed quality. There were significant differences between the two seed-colour groups for most of the investigated traits, but not for total dry weight, days to flowering, and soluble and insoluble fibre. The major difference between the accessions and cv. Regalona-Baer was lower seed yield for the ochre seed group (30% lower, on average); this was associated with increased plant height (13% higher, on average), greater number of days to maturity (+6 days, on average) and shorter panicle length (21% shorter, on average). These results were observed for both growing seasons. The seed yield of the yellow seed group was similar to Regalona-Baer. Focusing on individual accessions, PCA indicated that accessions Q12, Q18 and Q26 were similar to Regalona-Baer for seed yield, 1000-seed weight, seed area and seed perimeter, and accession Q4 had the highest protein and kaempferol contents for both years. Seed area and perimeter, harvest index, and 1000-seed weight showed positive associations with seed yield, whereas days to flowering, days to maturity and quality traits were negatively correlated with seed yield for both years. Cluster analysis carried out on all of the agronomic and seed-quality traits did not show clear clustering of the accessions based on seed colour alone. The results of this study confirm that both the ochre and yellow quinoa seed groups included elite accessions that can be used directly in future selection programs for the development of high-yielding varieties well adapted to the Mediterranean environment.

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