Yield and quality of Amaranthus hypochondriacus grain amaranth under drought and salinity at various phenological stages in southern Italy.

BACKGROUND: Several studies have shown that grain amaranth (Amaranthus spp.) is tolerant to abiotic stresses such as drought and salinity. Irrigation applied only during sensitive growth stages can stabilize yield and improve water use efficiency. Given the increasing frequency of salinity and drought stress in European countries and the scarcity of information on grain amaranth responses to combined salt and drought stress, an open field trial was carried out in Italy in order to evaluate the response of one accession of Amaranthus hypochondriacus to various irrigation strategies. RESULTS: Grain amaranth yield components were not negatively affected either by different irrigation volumes or by irrigation time. Some differences in seed yield were caused by water quality; salinity significantly reduced seed yield. The combined effect of irrigation time and irrigation volume significantly influenced seed yield. The quality of amaranth seeds was preserved; no significant differences due to simple or combined stresses were found during the three-year field experiment. CONCLUSIONS: The overall results from this study suggest that A. hypochondriacus can be cultivated in a more sustainable way compared to other protein crops, thus reducing water use and using saline water. It could be introduced to marginal European environments where traditional crops cannot be cultivated. © 2021 Society of Chemical Industry.

Field phenotyping and quality traits of grass pea genotypes in South Italy.

BACKGROUND: Grass pea (Laithyrus sativus L.) is a rustic plant whose seeds are rich in polyphenols and antioxidants, and it has been consumed as food by human beings since ancient times. This study was conducted in Italy between 2017and 2019 to evaluate, under field conditions, the stability of seed yield, biomass and 1000-seed weight (THS) and to assess the antioxidant composition and activity of 11 grass pea accessions. RESULTS: Analysis of variance revealed significant effects of the environment, accession and accession × environment (A × E) on the yield, above-ground biomass and THS. We found that the environment (year) and A × E explained 52.61% and 23.76% of the total seed yield variation, respectively. No relationship was observed between the yield and the total protein of seeds. Most grass pea accessions showed sensitivity to frost conditions that occurred in the third growing season. The total phenolic content ranged from 50.51 to 112.78 mg 100 g-1 seeds and antioxidant activity ranged from 0.576 to 0.898 mmol Trolox equivalents 100 g-1 seeds and from 0.91 to 1.6 mmol Fe2+  100 g-1 seeds in 2,20-azinobis-3-ethylbenzothiazoline-6-sulfonic acid and ferric-reducing antioxidant power, respectively. Among the accessions, the 'Campi Flegrei' and 'di Castelcività' showed the best performance with the highest yield and stability, phenolic content and superior antioxidant activity. CONCLUSION: The results showed that the yield of grass pea was mainly influenced by different climate conditions. This variability in yield, phenolic content and antioxidant activity among different accessions could help breeders and farmers select high-performance accessions for cultivation. © 2020 Society of Chemical Industry.

Polyphasic OKJIP Chlorophyll a Fluorescence Transient in a Landrace and a Commercial Cultivar of Sweet Pepper (Capsicum annuum, L.) under Long-Term Salt Stress.

In a soilless long-term salt-stress experiment, we tested the differences between the commercial sweet pepper cultivar "Quadrato d'Asti" and the landrace "Cazzone Giallo" in the structure and function of PSII through the JIP test analysis of the fast chlorophyll fluorescence transients (OKJIP). Salt stress inactivated the oxygen-evolving complex. Performance index detected the stress earlier than the maximum quantum yield of PSII, which remarkably decreased in the long term. The detrimental effects of salinity on the oxygen evolving-complex, the trapping of light energy in PSII, and delivering in the electron transport chain occurred earlier and more in the landrace than the cultivar. Performance indexes decreased earlier than the maximum quantum yield of PSII. Stress-induced inactivation of PSII reaction centers reached 22% in the cultivar and 45% in the landrace. The resulted heat dissipation had the trade-off of a correspondent reduced energy flow per sample leaf area, thus an impaired potential carbon fixation. These results corroborate the reported higher tolerance to salt stress of the commercial cultivar than the landrace in terms of yield. PSII was more affected than PSI, which functionality recovered in the late of trial, especially in the cultivar, possibly due to heat dissipation mechanisms. This study gives valuable information for breeding programs aiming to improve tolerance in salt stress sensitive sweet pepper genotypes.

Agronomic Practices and Performances of Quinoa under Field Conditions: A Systematic Review.

Quinoa (Chenopodium quinoa Willd.) is one of the most popular emerging food crops in the Andean region. It is tolerant to environmental stresses and characterized by interesting nutritional traits. Thus, it has the potential to contribute to food and nutrition security in marginal environments. In this study, we conducted a systematic review integrated with a bibliometric analysis of cropping practices of quinoa under field conditions. The analysis is based on published data from the literature relating to the period 2000-2020. A total of 33 publications were identified, revealing that scientific research on the agronomic practices and performances of quinoa under field conditions is still limited. Africa, Asia, and Europe were the leading research production sites in this field and together provided over 81% of the total scientific production. There were no papers from the Australian continent. The number of papers screened dealing with tillage and weed control management was very limited. The keyword co-occurrence network analyses revealed that the main topics addressed in the scientific literature related to the effect of "variety" and "deficit irrigation", followed by "water quality", "fertilization", and "sowing date" on seed yield. Results from this study will permit us to identify knowledge gaps and limited collaboration among authors and institutions from different countries. Salinity, sowing density, and sowing date were the agronomic interventions affecting productive response the most.