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Foxtail millet (Setaria italica L.) is a critical grain with high nutritional value and the potential for increased production in arid and semiarid regions. The foxtail millet value chain can be upgraded only by ensuring its comprehensive quality. Thus, samples were collected from different production areas in Shanxi province, China, and compared in terms of quality traits. We established a quality evaluation system utilizing multivariate statistical analysis. The results showed that the appearance, nutritional content, and culinary value of foxtail millet produced in different ecological regions varied substantially. Different values of amino acids (DVAACs), alkali digestion values (ADVs), and total flavone content (TFC) had the highest coefficients of variation (CVs) of 50.30%, 39.75%, and 35.39%, respectively. Based on this, a comprehensive quality evaluation system for foxtail millet was established, and the quality of foxtail millet produced in the five production areas was ranked in order from highest to lowest: Dingxiang > Zezhou > Qinxian > Xingxian > Yuci. In conclusion, the ecological conditions of Xinding Basin are favorable for ensuring the comprehensive quality of foxtail millet.

Foxtail millet (Setaria italic [L.] P. Beauv.) is an important food and fodder crop that is cultivated worldwide. However, weeds severely inhibit the growth of spring foxtail millet, and no suitable herbicide or method is available for weed control in foxtail millet fields. Field experiments were conducted to evaluate the efficacy of various herbicides and their safety toward hybrid foxtail millet, that is, ‘Zhangzagu 10’. The present study was conducted using seven herbicides applied by precision orientation spraying between plastic mulches in a foxtail millet field. All herbicide treatments exhibited no significant difference on foxtail millet shoot and root biomass. No difference in grain yield was observed among herbicide treatments, including MCPA (2-methyl-4-chlorophenoxyacetic acid), mesotrione, acetochlor, trifluralin, and pendimethalin, at the recommended dosage in field efficacy evaluation trial. For the same herbicide, the tendency of weed control increased with the increase in herbicide concentration. Following this finding, all herbicides applied at the highest dosage controlled weeds by 92.06% compared with the other treatments utilizing lower concentration. At the same concentration level, mesotrione controlled all weed populations was the highest observed among all herbicides, followed by prometryne and MCPA. Mesotrione controlled all weeds by at least 76.85%, exhibiting the highest weed injury among the herbicides and satisfying the requirement for weed species control. Finally, comprehensive analyses showed that mesotrione at 0.8 L ha-1, yielded the highest comprehensive evaluation value in foxtail millet field. Thus, this herbicide can be a good option in controlling weeds in foxtail millet field. This new model can aid in protecting hybrid ‘Zhangzagu 10’ foxtail millet seeds or seedlings against herbicide damage and is a good option in expanding the application range of herbicide in foxtail millet.

Low-temperature stress limits the growth and development of foxtail millet. Freezing stress caused by sudden temperature drops, such as late-spring coldness, often occurs in the seedling stage of foxtail millet. However, the ability and coping strategies of foxtail millet to cope with such stress are not clear. In the present study, we analyzed the self-regulatory mechanisms of freezing stress in foxtail millet. We conducted a physiological study on foxtail millet leaves at −4 °C for seven different durations (0, 2, 4, 6, 8, 10, and 12 h). Longer freezing time increased cell-membrane damage, relative conductance, and malondialdehyde content. This led to osmotic stress in the leaves, which triggered an increase in free proline, soluble sugar, and soluble protein contents. The increases in these substances helped to reduce the damage caused by stress. The activities of superoxide dismutase, peroxidase, and catalase increased reactive oxygen species (ROS) content. The optimal time point for the response to freezing stress was 8 h after exposure. The transcriptome analysis of samples held for 8 h at −4 °C revealed 6862 differentially expressed genes (DEGs), among which the majority are implicated in various pathways, including the starch and sucrose metabolic pathways, antioxidant enzyme pathways, brassinolide (BR) signaling pathway, and transcription factors, according to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. We investigated possible crosstalk between BR signals and other pathways and found that BR signaling molecules were induced in response to freezing stress. The beta-amylase (BAM) starch hydrolase signal was enhanced by the BR signal, resulting in the accelerated degradation of starch and the formation of sugars, which served as emerging ROS scavengers and osmoregulators to resist freezing stress. In conclusion, crosstalk between BR signal transduction, and both starch and sucrose metabolism under freezing stress provides a new perspective for improving freezing resistance in foxtail millet.