Field sampling of quinoa (Chenopodium quinoa) was conducted at different growth stages to measure changes in major agronomic traits, dry matter accumulation, and nutrient element content. The results indicated that dry matter accumulation in quinoa followed an S-shaped curve, with a critical period between 60 and 90 days after emergence. There were significant differences in the dry matter allocation ratio and nutrient uptake rates among different parts of quinoa (roots, stems, leaves, panicles) at various growth stages. Notably, the uptake of nitrogen (N), phosphorus (P), and potassium (K) peaked between 60 and 80 days of growth, with K having the highest absorption rate, followed by N, and then P, at a ratio of 4.88:1.00:11.00. The distribution of nutrients in quinoa exhibited dynamic change regularity over time, and nutrients were mainly concentrated in leaves and stems during the early growth stage and shifted more towards the panicles in the later stage. Additionally, the agronomic traits of quinoa were also found to be significantly correlated with dry matter accumulation. Root weight, stem weight and panicle weight were positively correlated with plant height, stem diameter and leaf length.

To clarify the alleviating effect of auxin regulators on low-temperature stress at seedlings stage of soybean, the variety Kennong 18 was used as the test material, and seed coating with sodium naphthaleneacetic acid (NAA-Na), potassium indolebutyrate (IBA-K), and their mixture were adopted as the treatment. From the perspectives of morphological phenotype, antioxidant defense and osmotic regulation, the alleviating effect of NAA-Na and IBA-K on the growth and yield of soybean under low temperature stress was investigated. The results showed that the coating treatment with NAA-Na and IBA-K could reduce the accumulation of reactive oxygen species and the production rate of superoxide anion (O₂^-. ), and significantly decrease the accumulation of hydrogen peroxide (H₂O₂) and malondialdehyde. The osmotic regulation ability of soybean seedlings was enhanced, and the contents of soluble sugar, soluble protein, and proline increased. The activities of antioxidant enzymes such as superoxide dismutase, peroxidase, and catalase were enhanced, and the ascorbic acid-glutathione (AsA-GSH) cycle was promoted, thereby alleviating the damage of low-temperature stress to soybean seedlings. The dry matter accumulation in the aboveground and root parts of soybean seedlings increased. The adverse effects of low temperature stress on soybean yield were mitigated, and the number of pods per plant, the number of seeds per plant, 100-seed weight, and the seed weight per plant were significantly increased.

In order to explore the appropriate keeping way of tea plants before closing the garden, using “Baojinghuangjincha 1” as the test material, two autumn management treatments were set up, topping before garden closing (T) and no topping (CK). Samples were collected at germination stage, bud head stage as well as one bud and one leaf stage in spring, and the hormone content was determined. The amino acid components and related gene expression levels at one bud and one leaf stage were determined, and the correlation between hormone content and main amino acid components was analyzed. The results showed that budding density, 100-bud weight, and yield of tea plants in T treatment were extremely significantly increased compared with CK treatment. The determination of endogenous hormones in three periods showed that T treatment mainly affected the contents of auxin and cytokinin, the contents of auxin and cytokinin were positively correlated with the content of major amino acids, and the contents of theanine and aspartic acid were significantly positively correlated with the content of IAA-Ala. T treatment was beneficial to the accumulation of auxin and cytokinin in new shoots of tea plants in spring, promoted the germination and growth of lateral buds of tea plants, increased the yield, and T treatment was also beneficial to the accumulation of major amino acid components, such as theanine, aspartic acid, glutamate, serine, and improved the quality of tea.

To understand the effects of different fertilization rates and planting densities on yield and economic benefit of Zhuangtang 6, and to determine the optimal fertilization level and planting density, field experiments were carried out in Longʼan cane area of Nanning and Jiangzhou cane area of Chongzuo. A two-factor split-block design was conducted, with the main treatment (A) of fertilization. Three levels of 42% compound fertilizer 3750 (high fertilizer, A1), 2250 (medium fertilizer, A2) and 1125 kg/ha (low fertilizer, A3) were set. For secondary treatment (B), five planting densities were set: low density B1 (60 000 buds/ha), medium- low density B2 (75 000 buds/ha), medium density B3 (90 000 buds/ha), medium-high density B4 (105 000 buds/ha), and high density B5 (120 000 buds/ha). The results showed that the yield of Zhuangtang 6 sugarcane increased with the increasing planting density; however, there was no significant difference between yield and fertilization level. The correlation analysis showed that the yield and tillering rate were negatively correlated in the two cane areas (significantly in Longʼan and extremely significantly in Jiangzhou), and yield was significantly positively correlated with the number of productive stalks. The economic benefit of A3B5 treatment was the highest. The yield of A3B5 treatment in Longʼan area of Nanning was 91.44 t/ha, with an economic benefit of 35 419.5 yuan/ha, which was 6.75% higher than that of A2B4 treatment with the highest yield of 92.32 t/ha. The yield of A3B5 treatment in Jiangzhou area of Chongzuo was 74.88 t/ha, with an economic benefit of 27 190.2 yuan/ha, which was 27.15% higher than that of A1B4 treatment with the highest yield of 77.40 t/ha. Considering the different water and fertilizer conditions and management levels of the two sugarcane areas, the suitable fertilizer application rate for high-yield and high efficiency planting of Zhuangtang 6 is 1125-2250 kg/ha, and the reasonable planting density is 10 500-12 000 buds/ha.

Microbial agents are a novel type of fertilizer that can promote the growth and development of plant roots, and they have an important impact on improving nutrient absorption and yield formation in crops. However, their effects on rice grain quality remain unclear. This study used two conventional japonica rice varieties, Nanjing 9108 and Huaidao 5, as experimental materials to investigate the effects of two microbial agents of Bacillus subtilis (BS) and Trichoderma harzianum (TH) on rice grain quality under field cultivation conditions. The results showed that compared with the treatment without microbial agent (CK), the application of the BS and TH had no significant effect on the processing quality of rice. However, the BS treatment reduced the chalkiness rate by 5.5%-5.7% in Nanjing 9108 and 6.3%-7.2% in Huaidao 5, with a slightly decrease in chalkiness degree. The TH treatment significantly reduced the chalkiness rate by 7.7%-12.0% in Nanjing 9108 and 9.3%-11.1% in Huaidao 5, while the chalkiness degree decreased significantly by 10.3%-10.6% and 12.4%-12.5%, respectively. In a two-year experiment, the BS treatment decreased the taste value of two varieties to varying degrees, while the TH treatment increased it, reaching a significant level in 2022. Additionally, after microbial agent application, the amylose content of the rice decreased, while gel consistency and protein content increased. The peak viscosity and breakdown value of rice flour increased, whereas the setback value decreased. In conclusion, the application of B. subtilis and T. harzianum microbial agents contributed to improving the appearance and nutritional quality of rice. Furthermore, T. harzianum also enhanced the taste value of rice.

To clarify the physiological mechanism of graphene oxide (GO) acting as a herbicide safener to alleviate the phytotoxicity of nicosulfuron (NIF) on sweet corn, a pair of sweet corn sister lines, HK301 (NIF-tolerant) and HK320 (NIF-sensitive), were used as experimental materials. Using water treatment as a control, the effects of GO-NIF nanocomposite on key enzymes and non-enzymatic substances involved in sugar-starch metabolism in the leaves of sweet corn seedlings were investigated. The results showed that GO-NIF treatment significantly promoted the conversion of sucrose and starch in sweet corn seedlings compared with GO and NIF treatments alone. In HK320, the root to shoot ratio and the contents of sucrose, soluble sugar, and starch under GO-NIF treatment were significantly higher than those under NIF treatment at seven days after treatment, increasing by 30.19%, 71.80%, 79.29%, and 67.87%, respectively. Furthermore, compared with NIF treatment, GO-NIF treatment significantly increased the activities of sucrose phosphate synthase, sucrose synthase, α-amylase, and β-amylase in HK320. A comprehensive evaluation of the effects of different treatments on physiological indicators revealed that HK301 exhibited moderate responses and minimal fluctuations under both NIF and GO-NIF treatments. In contrast, HK320 showed significant physiological regulatory advantages under GO-NIF treatment, particularly manifesting a synergistic enhancement in key enzyme activities of sugar metabolism and the accumulation of saccharides. In conclusion, GO as a safener for NIF can effectively promote the sugar metabolism process as well as the distribution and transport of saccharides in sensitive sweet corn.

To determine a suitable nutrient solution for rapid propagation of virus-free sweet potato seedlings, four nutrient solutions at two concentrations each were tested using virus-free seedlings of Longshu No.9 in substrate culture to explore the effects of different treatments on the growth of virus-free seedlings. The results showed that both nutrient solution type and electrical conductivity significantly affected morphology and physiology of the virus-free seedling. The Longjiu treatments showed the best growth performance and root vitality, particularly Longjiu 2 resulted in superior stem vine length, stem node number, and aboveground fresh and dry weights compared with other treatments. These results indicated that Longjiu 2 was a suitable nutrient solution for rapid propagation of virus-free Longshu No.9 sweet potato seedlings.

Using ʻHongnuo 16ʼ sorghum as the experimental material and under equivalent nutrient input conditions, six treatments were established: no fertilization (CK), conventional fertilization (HF), and nitrogen organic fertilizer substitution ratios for nitrogen of 25% (NF25), 50% (NF50), 75% (NF75), and 100% (NF100). The results showed that compared with CK treatment, increasing the ratio of organic fertilizer substitution led to varying degrees of improvement in soil organic matter, total nitrogen, alkaline hydrolyzed nitrogen, available phosphorus, and available potassium contents. The activities of alkaline phosphatase, urease, and sucrase in soils treated with organic manure substitutions were significantly increased by an average of 40.8%, 13.6%, and 61.6%, respectively. Sorghum yield could be well fitted with a quadratic equation, with the highest yield obtained when applying cow manure at a nitrogen rate of 92.5 kg/ha theoretically. In this experiment, the treatment NF50 not only improved soil physicochemical properties and enhanced soil enzyme activity but also maintained sorghum at high productivity. Considering the responses in terms of sorghum yield and soil fertility as well as soil enzyme activity under different levels of organic manure substitution, it was suggested that an organic nitrogen substitution ratio of 50% was suitable for optimal application rates.

To investigate the species and pathogenicity of wheat root rot pathogens, diseased plants with symptoms of wheat root rot were collected from 16 sampling sites in six prefecture-level cities in Heilongjiang Province during 2022-2023. A total of 432 fungal isolates were obtained using the tissue isolation method. By combining morphological identification and molecular identification based on 5.8S rDNA-ITS or β-tubulin gene sequence analyses, the pathogens were identified as four species: Bipolaris sorokiniana, Fusarium avenaceum, Fusarium equiseti, and Fusarium proliferatum. The number of isolates for each species was 334, 24, 12, and 3, respectively, with B. sorokiniana being the most frequent, accounting for 77.31% of the total. Verification of Koch’s postulates demonstrated significant differences in pathogenicity among the four species, with both the disease index and disease incidence of B. sorokiniana being higher than those of the three Fusarium species. In summary, B. sorokiniana is the dominant pathogen of wheat root rot in Heilongjiang Province, with the three Fusarium species acting as secondary pathogens.

To explore the impact of soil moisture variation on the relationship between soil organic carbon (SOC) and color characteristic parameters, and to construct quantitative SOC prediction models based on color parameters, soil sample images under different soil moisture content (SMC) conditions were acquired by simulating continuous changes of farmland soil moisture to extract color characteristic parameters. Various mathematical transformation methods were employed to optimize these parameters. Combined with correlation analysis and regression models, the influence of soil moisture on the relationship between color characteristics and SOC was quantified, and SOC quantitative estimation models under different moisture conditions were established. The results indicated that SOC was significantly and negatively correlated with color characteristic parameters in RGB, HSV, and CIELab color spaces, with R, L, and V components showing the highest correlation. Reciprocal and logarithmic transformations enhanced these correlations. Soil moisture affected color component values; as SMC increased, most color parameter values decreased, and their correlation with SOC gradually weakened. Critical moisture contents were identified as SMC=15%. Color parameters such as 1/b*, lnb*, 1/S, and lnS effectively mitigated the impact of moisture on SOC prediction models. Under different moisture conditions, the BP neural network regression model outperformed the linear regression model, demonstrating superior predictive capability. This study demonstrates that the color characteristic parameters of digital images can be effectively utilized for the quantitative analysis of SOC.