Infrared Thermography Monitoring of Durum and Common Wheat for Adaptability Assessing and Yield Performance Prediction.

Wheat is one of the most cultivated cereals thanks to both its nutritional value and its versatility to technological transformation. Nevertheless, the growth and yield of wheat, as well as of the other food crops, can be strongly limited by many abiotic and biotic stress factors. To face this need, new methodological approaches are required to optimize wheat cultivation from both a qualitative and quantitative point of view. In this context, crop analysis based on imaging techniques has become an important tool in agriculture. Thermography is an appealing method that represents an outstanding approach in crop monitoring, as it is well suited to the emerging needs of the precision agriculture management strategies. In this work, we performed an on-field infrared monitoring of several durum and common wheat varieties to evaluate their adaptability to the internal Mediterranean area chosen for cultivation. Two new indices based on the thermal data useful to estimate the agronomical response of wheat subjected to natural stress conditions during different phenological stages of growth have been introduced. The comparison with some productive parameters collected at harvest highlighted the correlation of the indices with the wheat yield (ranging between p < 0.001 and p < 0.05), providing interesting information for their early prediction.

Integrating Smart Greenhouse Cover, Reduced Nitrogen Dose and Biostimulant Application as a Strategy for Sustainable Cultivation of Cherry Tomato.

Fruit yield and quality of greenhouse tomatoes are strongly influenced by light conditions and nitrogen (N) availability, however, the interaction between these factors is still unclear. We evaluated the effects on cherry tomatoes of two tunnel plastic covers with different optical properties and three N doses, also in combination with a biostimulant treatment. We compared a diffuse light film (Film1) and a conventional clear film (Film2), and three N levels, corresponding to 50% (N50), 75% (N75) and 100% (N100) of the optimal dose, with and without a microbial plus a protein hydrolysed biostimulant, compared to a non-treated control. The three experimental treatments significantly interacted on several yield and quality parameters. In control plants (untreated with biostimulants), the early yield was higher at reduced N doses compared to N100, with greater increments under the diffusive Film1 compared to the clear Film2 (+57.7% and +37.0% vs. +31.7% and +16.0%, in N50 and N75 respectively). Film1 boosted the total fruit production at all the N rates and with or without biostimulants, compared to Film2, with stronger effects under sub-optimal N (+29.4% in N50, +21.2% in N75, and +7.8% in N100, in plants untreated with biostimulant). Total yield decreased with decreasing N levels, while it always increased with the application of biostimulants, which counterbalanced the detrimental effects of N shortage. Quality traits were mainly affected by the cover film and the biostimulant treatment. The diffusive film increased the content of carotenoids, lycopene and total phenols compared to the clear one, and the biostimulants increased texture, soluble solids, phenols and ascorbic acid compared to the untreated control. It is worth noting that in plants fertilized at 75% of the reference N dose, the biostimulants determined higher yield than the N100 untreated control, under both the covers (+48% in Film1 and +20% in Film2). In conclusion, the diffusive film improved the fruit yield and quality of greenhouse tomatoes in the spring-summer period, presumably avoiding plant stress due to high-intensity direct light. Reduced N rates limited the plant productivity, however, the biostimulant application was effective in compensating for the detrimental effects of sub-optimal supply of N synthetic fertilizers.

Biodegradable Mulch Films and Bioformulations Based on Trichoderma sp. and Seaweed Extract Differentially Affect the Metabolome of Industrial Tomato Plants.

The use of biostimulants and biofilms in agriculture is constantly increasing, as they may support plant growth and productivity by improving nutrient absorption, increasing stress resilience and providing sustainable alternatives to chemical management practices. In this work, two commercial products based on Trichoderma afroharzianum strain T22 (Trianum P®) and a seaweed extract from Ascophyllum nodosum (Phylgreen®) were tested on industrial tomato plants (Solanum lycopersicum var. Heinz 5108F1) in a field experiment. The effects of single and combined applications of microbial and plant biostimulants on plants grown on two different biodegradable mulch films were evaluated in terms of changes in the metabolic profiles of leaves and berries. Untargeted metabolomics analysis by LC-MS Q-TOF revealed the presence of several significantly accumulated compounds, depending on the biostimulant treatment, the mulch biofilm and the tissue examined. Among the differential compounds identified, some metabolites, belonging to alkaloids, flavonoids and their derivatives, were more abundant in tomato berries and leaves upon application of Trichoderma-based product. Interestingly, the biostimulants, when applied alone, similarly affected the plant metabolome compared to control or combined treatments, while significant differences were observed according to the mulch biofilm applied.

Biodegradable Mulching Film vs. Traditional Polyethylene: Effects on Yield and Quality of San Marzano Tomato Fruits.

Mulching is a common practice for improving crop yield and obtaining an out-of-season production, but when made using plastic materials it can bring environmental problems due to the management and the disposal of films at the end of the cropping seasons. To increase the sustainability of this practice, recently, mulching films made with biodegradable organic materials have become more widely used. Our aim was to evaluate the effect of a biodegradable mulching film on yield and qualitative traits of the San Marzano tomato fruits over two years (2014 and 2015). Two different types of mulching were tested: (i) black biodegradable film (MB12) and (ii) black low-density polyethylene (LDPE) were compared to bare soil (BS). Both mulching films elicited a 25% increase in yield, mainly due to the significantly higher number of fruits per square meter, compared to BS. Both mulching films also elicited a 9.9% increase in total soluble solids and a 57% increase in carotenoid content, while firmness showed the highest value in BS fruits. MB12 determined the highest value of the Hunter color ratio a/b of tomato fruits, followed by LDPE, while the lowest value was recorded in BS fruits. Both mulching films elicited an increase of 9.6%, 26.0%, and 11.7% for flavonoids, polyphenols, and AsA, respectively. In 2014, the MB12 degradation started at 71 days after transplant (DAT); in 2015, at 104 DAT. Therefore, replacing polyethylene with biodegradable film would seem to be an agronomically efficient and environmentally sustainable practice.

Effects of Plant Biostimulation Time Span and Soil Electrical Conductivity on Greenhouse Tomato 'Miniplum' Yield and Quality in Diverse Crop Seasons.

Biostimulants help plants cope with environmental stresses and improve vegetable yield and quality. This study was conducted to determine the protein hydrolysate (PH) effect of three different durations (weekly applications: three, six, or nine times plus an untreated control) in factorial combination with four soil electrical conductivities (EC: 1.5, 3.0, 4.5, or 6.0 mS·cm-1) on yield, fruit quality, and elemental composition of tomato 'miniplum' grown in a greenhouse. Fruit yield was best affected, during the summer, by six and nine biostimulant applications at EC 3.0 mS·cm-1, and in the same season, the six treatments led to the highest fruit number with no difference compared to nine applications; during the winter, the three and six treatments improved the mentioned variables at each EC level. Fruits' dry residue and Brixo were positively affected by biostimulation both in summer and winter. In summer, the 6.0 mS·cm-1 EC led to the highest dry residue and Brixo values, though the latter did not show any significant difference compared to 4.5 mS·cm-1; in winter, the best results corresponded to 4.5 and 6.0 mS·cm-1. A higher beneficial effect of PH on fruit antioxidant status, i.e., lycopene, polyphenols, ascorbic acid levels, and lipophilic (LAA) and hydrophilic (HAA) activity, was recorded in winter compared with summer. Positive correlations between polyphenols and LAA, as well as ascorbic acid content and HAA were found for all EC and PH treatments. Most of the mineral elements tested demonstrated concentration stability, whereas the highest EC decreased P, Mg, Cu, and Se accumulation. The opposite effect was shown by PH application on Se and Mn levels, with P tending to increase. The concentrations of Fe, Zn, and Cu were the lowest under the longest duration of PH supply. These results further confirm the essential role of plant biostimulation in enhancing tomato yield and quality, with a particular focus on the treatment duration.

Assessing Yield and Quality of Melon (Cucumis melo L.) Improved by Biodegradable Mulching Film.

Low-density polyethylene (LDPE) plastic mulching films have an important function, but at the end of their lifetime pose an economic and environmental problem in terms of their removal and disposal. Biodegradable mulching films represent an alternative to LDPE with the potential to avoid these environmental issues. In this preliminary study, we employed a biodegradable film based on Mater-Bi® (MB) in comparison with low-density polyethylene to assess their effect on the yield and particular quality traits (organoleptic and nutraceutical composition of the fruits) of muskmelon (cv Pregiato) grown on soils with different textures (clay-loam-CL and sandy loam-SL) in two private farms in South Italy. Soil temperature under the mulch was also measured. During the monitored periods, mean soil temperature under LDPE was higher (about 1.3 °C) than that under the biodegradable film and was higher in SL soil than in CL soil, at 25.5° and 24.2 °C, respectively. However, the biodegradable film was able to limit the daily temperature fluctuation, which was 1.7 °C in both soils compared with 2.3 °C recorded for LDPE. Fruit yields were higher with MB film than LDPE (+9.5%), irrespective of soil texture. MaterBi® also elicited increases in total soluble solids, polyphenols, flavonoids, and antioxidant activity compared with LDPE films: 13.3%, 22.4%, 27.2%, and 24.6%, respectively. Color parameters of flesh, namely brightness, chroma, and hue angle were better in fruits grown on LDPE. Our findings suggest that Mater-Bi® based biodegradable mulching film is a potentially valid alternative to traditional LDPE, particularly for obtaining the agronomical benefits outlined above and for promoting environmental sustainability due to its favourable biodegradable properties.

Bioactive Compounds and Antioxidant Properties of Wild Rocket (Diplotaxis Tenuifolia L.) Grown under Different Plastic Films and with Different UV-B Radiation Postharvest Treatments.

Rocket species are rich in nutrients with well-known bioactive activity, but their content depends on several factors, such as plant-UV radiation interaction. In this work, we measured the production of nutritional elements in wild rocket (Diplotaxis tenuifolia L.) leaves as a function of exposure to UV-B radiation by adopting a combined approach. The wild rocket plants were grown under three greenhouse cover films (A, B, and C) having different transmittivity to UV-B and the fresh-cut leaves were exposed to UV-B in postharvest for 45, 150, 330, and 660 s. The content of chlorophyll, carotenoids, phenolic compounds, ascorbic acid, and the antioxidant activity were determined. Chlorophyll, carotenoids, and total phenolic content were significantly increased by the combination of Film C and treatment with UV-B for 45 s. The predominant phenolic compounds were kaempferol, isorhamnetin, and quercetin. Film C also elicited an increase in ascorbic acid (the most abundant antioxidant compound in the range 374-1199 per 100 g of dry matter) and antioxidant activity. These findings highlighted an increase in bioactive compound content in the wild rocket when it was cultivated under Film C (diffused light film with a tailored UV-B transmission dose) and treated with UV-B radiation for 45 s postharvest, corresponding to an energy dose of 0.2 KJ m-2.

Stand-Alone and Combinatorial Effects of Plant-based Biostimulants on the Production and Leaf Quality of Perennial Wall Rocket.

Modern agriculture is facing many difficulties due to a rapidly changing climate, and environmental damage from agricultural production. The commitment of scientists and farmers to increase environmentally sustainable agricultural practices is one way to help mitigate environmental impacts. Among these practices, the use of biostimulants could be beneficial for increasing fertilizer efficiency and reducing excessive use in agriculture, and as plant growth regulators capable of increasing both production volume and quality of crops. In our study, rocket plants were grown in a greenhouse and treated with two biostimulants (protein hydrolysates or tropical plant extract), either individually or combined, to assess the effect on yield, dry biomass, mineral content, qualitative parameters as well as on economic profitability of foliar biostimulant applications. Total yield and dry biomass of the plants treated with the three biostimulant combinations on average increased by 48.1% and 37.2% respectively compared to untreated plants, without significant differences between treatments. Biostimulant application increased the content of chlorophyll, K, Mg and Ca, compared to the untreated plants. Furthermore, a biostimulant synergistic effect was detected concerning the content of total ascorbic acid. Our results confirmed that the biostimulants are eco-friendly products, able to boost plant growth and product quality and thus increase growers' profitability.

Shading Affects Yield, Elemental Composition and Antioxidants of Perennial Wall Rocket Crops Grown from Spring to Summer in Southern Italy.

Shading nets have been increasingly drawing research interest, as they allow us to improve the environmental conditions for greenhouse-grown crops. The effects of two shading nets (50% and 79% shading degree), plus an unshaded control, on yield, mineral composition and antioxidants of perennial wall rocket (Diplotaxis tenuifolia L.-D.C.) grown under tunnels in southern Italy were determined. The shading application resulted in a yield decrease, compared to the unshaded control, except for the highest production under 50% shading in July. The highest yield was recorded in the April-May and May-June and the lowest in July. Similar trends were recorded for plant dry weight, leaf number per rosette and mean weight, but the latter showed the highest value under 79% light extinction in July. The rocket leaves were brighter in the summer cycles than in the spring ones. Leaf nitrate was highest in spring and under 79% shading. Potassium, phosphorus, calcium and magnesium showed the highest values in spring and in the unshaded control. The lipophilic antioxidant activity showed the highest values under the 79% shading net in the spring cropping seasons, whereas in July it did not significantly differ from 50% light extinction. The hydrophilic antioxidant activity always attained the highest values in the unshaded control. The unshaded leaves had the highest total phenol accumulation when grown in April-May and the lowest in July. The total ascorbic acid content was always highest in the unshaded control leaves compared to the shading treatments. Fifty percent crop shading is, therefore, an effective sustainable tool for increasing the yield of perennial wall rocket leaves in July, when the light intensity under the plastic tunnel exceeds the plant requirements, also resulting in a mineral composition that is not significantly different from that of the unshaded crops.

Joint Selenium-Iodine Supply and Arbuscular Mycorrhizal Fungi Inoculation Affect Yield and Quality of Chickpea Seeds and Residual Biomass.

The essentiality of selenium (Se) and iodine (I) for the human organism and the relationship between these two trace elements in mammal metabolism highlight the importance of the joint Se-I biofortification to vegetable crops in the frame of sustainable farming management. A research study was carried out in southern Italy to determine the effects of the combined inoculation with arbuscular mycorrhizal fungi (AMF) and biofortification with Se and I on plant growth, seed yield, quality, and antioxidant and elemental status, as well as residual biomass chemical composition of chickpea grown in two different planting times (14 January and 28 February). The AMF application improved the intensity of I and Se accumulation both in single and joint supply of these elements, resulting in higher seed yield and number as well as dry weight, and was also beneficial for increasing the content of antioxidants, protein, and macro- and microelements. Earlier planting time resulted in higher values of seed yield, as well as Se, I, N, P, Ca, protein, and antioxidant levels. Se and I showed a synergistic effect, stimulating the accumulation of each other in chickpea seeds. The AMF inoculation elicited a higher protein and cellulose synthesis, as well as glucose production in the residual biomass, compared to the single iodine application and the untreated control. From the present research, it can be inferred that the plant biostimulation through the soil inoculation with AMF and the biofortification with Se and I, applied singly or jointly, proved to be effective sustainable farming tools for improving the chickpea seed yield and/or quality, as well as the residual biomass chemical composition for energy production or beneficial metabolite extraction.

Plant-Based Biostimulants Influence the Agronomical, Physiological, and Qualitative Responses of Baby Rocket Leaves under Diverse Nitrogen Conditions.

Nitrogen is the primary technical means responsible for food production increase, but on the other hand, wise management is needed because its excessive use can have a negative impact on the environment and on green leafy vegetable quality, such as that rocket. Rocket has the characteristics of accumulating nitrate in leaves with possible impacts on human health. In order to overcome this issue, researchers are focusing their attention on the use of alternative means, such as plant biostimulant application. The scope of this study was to assess the effect of legume-derived protein hydrolysate(LDPH) and tropical plant extract(TPE), combined with various doses of nitrogen (0 kg ha-1 non-fertilized; N0); 60 kg ha-1 (sub-optimal; N1); 80 kg ha-1 (optimal; N2); and 100 kg ha-1 (supra-optimal; N3)), in order to reduce nitrogen use, boost yield, and enhance the chemical and nutritional value of leaves without significantly accumulating nitrate. Both vegetal-based plant biostimulants enhanced plant growth, boosted the marketable yield (especially at N0 and N1 levels, by 38.2% and 28.2%, respectively, compared to the non-treated control), and increased the SPAD (Soil Plant Analysis Development) index and leaf pigments content, such as chlorophyll and carotenoids, especially in treated-LDPH rocket. The plant-based biostimulants also produced a major amplification in lipophilic antioxidant activity (+ 48%) and total ascorbic acid content (average + 95.6%), especially at low nitrogen fertilization levels, and maintained nitrate content under the legal European Comission limits.

Protein Hydrolysate or Plant Extract-based Biostimulants Enhanced Yield and Quality Performances of Greenhouse Perennial Wall Rocket Grown in Different Seasons.

Research has been increasingly focusing on the environmentally friendly biostimulation of vegetable crop performances under sustainable farming management. An experiment was carried out in southern Italy on Diplotaxis tenuifolia to assess the effects of two plant biostimulants (Legume-derived protein hydrolysate, Trainer®; Tropical plant extract, Auxym®) and a non-treated control, in factorial combination with three crop cycles (autumn-winter; winter; and winter-spring) on leaf yield, photosynthetic and colour status, quality, elemental composition, antioxidant content and activity. Both biostimulants prevalently contain amino acids and soluble peptides, showing the major effects on crop performances, though Auxym also has a small percentage of phytohormones and vitamins. The biostimulants enhanced plant growth and the productivity of perennial wall rocket. The winter-spring cycle led to higher leaf yield than the winter one. The two plant biostimulants enhanced leaf dry matter, oxalic and citric acids, Ca and P concentrations, phenols and ascorbic acid content as well as antioxidant activity, but did not increase nitrate content. A presumed mechanism involved in the enhancement of crop production could be attributed to the improvement of mineral nutrient availability and uptake. The winter-spring cycle elicited higher antioxidant content and activity than winter crops. Our current study shows that both the legume-derived protein hydrolysate and tropical plant extract represent an effective tool for boosting the yield, nutritional and functional quality of vegetable produce in the view of sustainable crop systems.