Delaying the application of plant growth retardants, such as ethephon, can increase kernel number in maize (Zea mays L.), primarily due to the enhanced assimilate allocation to the ear. However, the underlying physiological and molecular mechanisms remain unclear. To clarify this, we investigated the effects of ethephon application from the 8- to 15-leaf stages (E8-E15) on the physiological mechanisms of kernel development, including internode elongation, dry matter accumulation and partitioning, fertilization, and kernel set. RNA-seq analysis was further performed on E14-treated and control (water spraying) plants at the silking stage and 8 days after silking to elucidate the molecular mechanisms underlying the ethephon-mediated kernel number increase. Delaying ethephon application at E14-E15 significantly shortened internodes below (-26.3% to -23.5%), at (-33.9% to -41.2%), and above (-22.9% to -52.5%) the ear. Average whole-plant dry matter increased by 8.1% at E14-E15 compared with the control. While ear dry matter increased by 32.4% at E14, it remained unchanged at E15. Optimizing the timing of ethephon application at E14-E15 did not negatively affect spikelet number formation but allocated more assimilates to the ear by retarding stem growth, resulting in increased kernel number (+8.3%) and grain yield (+7.4%). In E14, elevated sucrose allocation to the ear at silking resulted in increased trehalose-6-phosphate (T6P) accumulation, which subsequently enhanced assimilate import and improved carbohydrate utilization after flowering. Consequently, ear sucrose levels at silking were significantly higher than those in the control, consistent with the enhanced sink capacity. This enhancement was related to the suppression of sucrose-non-fermenting1-related protein kinase (SnRK1) activity. In contrast, post-flowering sucrose content was lower in E14 due to the upregulation of T6P-SnRK1 interaction genes during the kernel differentiation stage, which promoted sucrose utilization. Taken together, delayed ethephon application increased maize kernel number by optimizing pre-flowering sucrose partitioning to the ear and promoting post-flowering sucrose utilization.

In this study, the effects of ozone treatment (O3), heat shock treatment (HS), and microwave treatment (MW) on sensory quality, physicochemical properties, and oxidation levels of sweet corn were systematically investigated during storage. The results demonstrated that three treatments prolonged the postharvest quality of sweet corn to varying degrees. Specifically, the O3 group demonstrated the best sensory and appearance characteristics, with its sensory score being 1.18 and 1.38 folds higher than the HS group and MW group, respectively, and significant retardation of color deterioration. In addition, the O3 group effectively maintained the stability and hardness of the starch structure. The weight loss rate of the HS group decreased 0.78-fold compared to the CT group after storage. Moreover, both HS and MW treatments maintained the antioxidant properties of sweet corn, but MW had the limitations of local scalding damage and accelerated deterioration in later quality. The results of this study provide a scientific basis for the optimization and application of postharvest preservation techniques for sweet corn.

Fresh corn is widely recognized for its outstanding nutritional value. However, the structural integrity of corn kernels is readily compromised by minimally processing operations, which triggers surface browning, nutrient loss, and a marked reduction in antioxidant activity, thereby impairing its edible quality and commercial market value. In this study, dielectric barrier discharge (DBD) low-temperature plasma (LTP) technology was employed to characterize the changes in sensory and nutritional quality of minimally processed corn across different storage durations (0, 4, 8, and 12 d) under standard commercial storage conditions (4 degrees C, 85% relative humidity, RH). Results demonstrated that the texture and color attributes of minimally processed corn were effectively preserved, and the degradation of nutritional compounds as well as lipid oxidation were significantly retarded by LTP. The optimal treatment power is identified as 50 W. After 12 d of storage, the alpha-amylase activity, total soluble solid, and total phenolic content of samples treated at this power are increased by 35%, 16%, and 37%, respectively, relative to the control group; the total antioxidant capacity is elevated by 32%, and antioxidant enzyme activities remain consistently higher than those of the control group throughout the entire storage period. This work holds critical scientific implications for enhancing the nutritional value and sensory quality of minimally processed corn, as well as for advancing the development of green, sustainable food processing technologies.

Efficient nitrogen management is crucial in developing sustainable strategies aimed at enhancing yield while mitigating negative environmental impacts. However, limited research has focused on this aspect in the production of fresh maize. Therefore, this study analyzed nitrogen application rates and yield for 40 sweet and 44 waxy maize varieties in Zhejiang Province, China from 2015 to 2019 across five sites. Nitrogen application rates were categorized as relatively high (RHN: >300 kg ha-1 for sweet maize, >320 kg ha-1 for waxy maize) or relatively low (RLN). An increase in nitrogen application rates for both sweet and waxy maize significantly reduced nitrogen fertilizer partial productivity (R2=0.616, P<0.01; R2=0.643, P<0.01), indicating that the optimum nitrogen application rate in this study might be the lowest values (160 kg ha-1 for sweet maize and 180 kg ha-1 for waxy maize). The kernel number per ear of sweet maize had a potentially more significant impact on fresh grain yield compared to the 1,000-fresh kernel weight both under RLN and RHN. In waxy maize, 1,000-kernel weight contributed more to fresh grain yield under RLN, and kernel number ear-1 and 1,000-kernel weight cooperatively affected yield under RHN. In this study, it was observed that sweet maize required taller plant and ear height, along with an optimal ear-plant height ratio, to enhance dry matter accumulation and increase source size, particularly under RLN, to achieve a higher fresh grain yield. In contrast, a lower ear height and ear-plant height ratio of waxy maize probably contributed more to increased kernel number and weight under RLN, likely due to a lower ear height can reduce the distance between sink and source, enabling more efficient photoassimilate allocation to the ear.

High temperatures impact sweet maize production; however, their specific effects on grain yield and kernel quality across different growing seasons remain unquantified. This study investigated high-temperature season effects, evaluated the yield and kernel quality responses in two sweet maize hybrids with different heat tolerance, and analysed the response mechanisms of dry matter accumulation (DMC), flowering, and grain filling in South China. Two contrasting sweet maize hybrids were planted annually in spring, summer, and autumn over a 2-year field experiment in Guangdong, South China. An evaluation of extreme degree days at different growth stages revealed that the sweet maize crops experienced high-temperature stress during their reproductive stages in the spring and summer growing seasons. In the high-temperature season, 'HMT8' showed heat sensitivity, with the grain yield significantly decreasing because of the lower kernel weight. The reduced grain-filling rates, especially in the early stages, contributed to lower kernel weight, which may be related to the decreased leaf area index (LAI) and post-anthesis DMC. Comparatively, 'GLT27' was heat-tolerant, with the grain yield slightly increasing because of the increased kernel number. However, it appeared cold-sensitive during the grain-filling stages in autumn. 'GLT27' exhibited stable or slightly increased pollen viability, LAI, post-anthesis DMC, and grain-filling rates. Furthermore, both hybrids showed reduced sucrose and elevated free amino acid content in the high-temperature seasons. Early grain-filling and post-anthesis DMC rather than reproductive organ viability may limit sweet maize during high-temperature seasons. Managing crops by selecting varieties and cultivation practices for different annual growing seasons is crucial.

The global production of crop straw has been steadily increasing as the demand for crops continues to grow, with current output reaching approximately 4 billion tons annually. Crop straw is a nutrient-rich resource, but if not properly managed, it can pose environmental risks. Effective utilization of straw remains a significant challenge in agricultural production. To address environmental issues such as pollution from straw burning, soil degradation, low crop germination rates, and the increase in soil-borne diseases, this study adopts the "organicinorganic granular fertilizer" method. By converting straw into granulated fertilizer and returning it to the field, this approach not only repurposes agricultural waste but also enhances soil quality and crop yields. A three-year field experiment (2020-2022) was conducted to investigate the effects of various application rates of SCMF (Straw Chemical Mixed Fertilizer) and optimal fertilization methods on the photosynthetic process, yield, soil nutrients, and sugar content of sweet corn. In 2020, SCMF and urea were applied to plots according to different fertilization methods and rates: S0, SUT0.5, SUT, SUB0.5, SUB, CK0, and CK. In 2021, based on the optimal fertilization rate identified in 2020, different fertilization methods were tested: SUT, SUB0.5UT0.5, SUB, CK0, and CK.In 2022, under the optimal fertilization method, SCMF application rates were adjusted according to a 10 % variation in nitrogen fertilizer content: S1.2UB, S1.1UB, SUB, S0.9UB, S0, CK0, and CK.Considering the chlorophyll content, leaf area index, dry matter accumulation, yield, soil nutrient status, and sugar concentration in sweet corn from 2020 to 2022, the SUB treatment demonstrated superior performance. Compared to CK (247.2 kg N ha(-1)), the SUB treatment (229.2 kg N ha(-1)) enhanced both the yield and quality of sweet corn, while SCMF applications led to an increase in sugar content. In 2022, the SUB treatment resulted in a 9.5 % increase in chlorophyll content, and the leaf area index at 10 days after planting (DAP) was the highest observed. This increase in leaf area index contributed to a higher accumulation of dry matter (6.3 %) and ultimately led to an 8.7 % increase in sweet corn yield and a 9.7 % increase in soluble sugar content. The findings suggest that the SUB fertilization rate and method are optimal for achieving higher chlorophyll content, leaf area index, yield, and soluble sugar concentration in sweet corn. Additionally, soil nutrient analyses indicated that SCMF applications improved soil pH, total nitrogen, and organic matter content.Therefore, the SUB treatment resulted in increased chlorophyll content and leaf area index, enhancing photosynthetic efficiency and providing a larger area for dry matter accumulation and yield. The application of SUB reduced nitrogen fertilizer input by 20 % while increasing sweet corn yield, contributing to higher agricultural productivity and offering an innovative strategy for the efficient management of crop straw residues. Further research is required to investigate the dynamics of straw decomposition products in enriching soil nutrients, their absorption rate by sweet corn, and their influence on soil enzyme activity and microbial community structure.

Context or problem: The prevalence of duckweed (Lemna minor L.) growth in paddy fields (DGP) has escalated in recent years, potentially due to climate warming and the eutrophication of irrigation water. However, limited attention has been paid to its significant impact on rice production, particularly with regard to rice quality. Objective or research question: A field experiment at two locations was conducted to evaluate the influence of DGP on grain quality and elucidate its possible reasons. Methods: Three rice cultivars (JFY2, NJ5055, and YY1540) were cultivated in both control and DGP plots throughout the entire rice growing seasons. The grain quality traits, as well as the pasting and thermal properties of rice flour, were assessed alongside ecological factors related to paddy water. Results: DGP notably enhanced the appearance quality of rice grains by reducing the chalky grain rate, chalkiness degree, and chalkiness area by 25.1 %, 34.4 %, and 13.1 %, respectively. Conversely, DGP reduced the breakdown, gel consistency, and Delta Hgel of rice by 10.0 %, 10.2 %, and 14.1 %, respectively, leading to an 8.0 % decrease in the taste quality of cooked rice. DGP had no significant effect on the processing and nutritional quality of rice grain, including protein and amylose contents, phytic acid, and the bioavailability of mineral elements, but increased the milled rice yield (7.8 %). DGP-induced reductions in daytime temperature (-0.94 degrees C), diurnal temperature difference (-0.88 degrees C), and pH (-0.4) of paddy water could enhance the appearance quality of rice. The significant deterioration in rice palatability may be primarily attributed to the latter two factors rather than the changes in protein and amylose contents. Conclusions: DGP significantly altered the ecological factors of paddy water, thereby improving the appearance quality of rice but greatly deteriorating its taste. Implications or significance: The findings support sustainable rice production through rice-duckweed collaboration, providing a basis for better understanding the response of paddy field ecosystems to future climate change.

In the waxy maize production of Zhejiang Province, China, conventional straw management often causes planting difficulties and nutrient competition. Although no-till with straw retention is known to benefit soil structure, its long-term impacts on local soil health and productivity remain poorly understood. Hence, a six-year field experiment (2016–2021) was conducted with four treatments, i.e., no-till with residue retention (NTRR), no-till with residue removal (NTR0), plow tillage with residue incorporation (PTRR), and plow tillage with residue removal (PTR0), to investigate the long-term effects of tillage and residue management. The results demonstrated that plow tillage (PT) significantly improved soil physical properties, reducing soil compaction and decreasing bulk density compared to no-till (NT) practices. Meanwhile, residue retention (RR) enhanced soil chemical fertility, increasing soil organic matter by 7.8–9.8% and substantially improving available potassium levels. The PTRR treatment achieved the most favorable soil conditions with the lowest compaction and bulk density values among all treatments. PTRR consistently yielded the highest maize production, showing a 1.7–6.9% advantage over PTR0 and a substantial 15.4% yield increase in spring maize compared to residue removal (R0) treatments. Correlation analyses revealed significant relationships between soil quality and productivity, with the Soil Quality Index (SQI) showing strong positive correlations with both yield (r = 0.74, p < 0.01) and economic returns (r = 0.67, p < 0.05). These findings demonstrate that PTRR represents an optimal agricultural management strategy for simultaneously enhancing soil health and ensuring sustainable crop production in fresh maize cultivation.

Duckweed growing in paddy fields (DGP) has substantially increased because of the effects of climate warming and/or eutrophication in irrigated water. Previous studies have primarily focused on investigating the effects of DGP as a nonchemical agent for enhancing rice productivity on nitrogen utilization in rice paddy fields. However, how DGP impacts rice yield remains poorly understood. Therefore, a field experiment with three representative rice cultivars was conducted to determine the effects of DGP on rice yield, considering ecological factors, photosynthetic capacity, spectral changes, and plant growth. The results showed that DGP significantly reduced the pH value by 0.6 and the daily water temperature by 0.6 °C, accelerated rice heading by 1.6 days and increased the soil and plant analyzer development (SPAD) and photosynthetic rate of leaves by 10.8% and 14.4% on average, respectively. DGP also markedly enhanced the values of various vegetation indices such as RARSc, MTCI, GCI, NDVI705, CI, CIrededge, mND705, SR705, and GM, and the first derivative curve of the rice canopy reflectance spectrum exhibited a ‘red shift’ phenomenon upon DGP treatment. Changes in the aforementioned factors may lead to average increases of 4.7% in plant height, 15.0% in dry matter weight, 10.6% in panicles m−2, 2.3% in 1000-grain weight, and ultimately a 10.2% increase in grain yield. The correlation observed suggested that the DGP-induced enhancement in grain yield can be achieved by reducing the pH and temperature of the paddy water, thus enhancing the SPAD value and photosynthesis of leaves and stimulating rice plant growth. These results could offer valuable theoretical support for the future sustainable development of agriculture and the environment through the biological synergy between rice and duckweed.

Crop growth and development can be impeded by salt stress, leading to a significant decline in crop yield and quality. This investigation performed a comparative analysis of the physiological responses of two maize inbred lines, namely L318 (CML115) and L323 (GEMS58), under salt-stress conditions. The results elucidated that CML115 exhibited higher salt tolerance compared with GEMS58. Transcriptome analysis of the root system revealed that DEGs shared by the two inbred lines were significantly enriched in the MAPK signaling pathway-plant and plant hormone signal transduction, which wield an instrumental role in orchestrating the maize response to salt-induced stress. Furthermore, the DEGs' exclusivity to salt-tolerant genotypes was associated with sugar metabolism pathways, and these unique DEGs may account for the disparities in salt tolerance between the two genotypes. Meanwhile, we investigated the dynamic global transcriptome in the root systems of seedlings at five time points after salt treatment and compared transcriptome data from different genotypes to examine the similarities and differences in salt tolerance mechanisms of different germplasms.

Background: Pesticide application before transplanting crops has been widely used in rice as an economical and effective method for reducing the use of chemical pesticides. This study focused on the feasibility of the application of pesticides before transplanting in a fresh corn nursery to control Spodoptera frugiperda. Methods: Three pesticides, including 35% Chlorantraniliprole WDG, 6% Spinetoram SC, and 3% Emamectin Benzoate WDG, combined with Polyorganosilicon (HTY-A8) or special flight additives (MF) as synergists were used and their toxicity was determined in the larvae of S. frugiperda feeding on sweet corn in the third leaf stage treated with 5 and 25 times the conventional field application concentration. The best combinations were tested in the field. The results showed that S. frugiperda exhibited high sensitivity to the three pesticides. The period of pest control validity of 35% Chlorantraniliprole WDG and 6% Spinetoram SC in the larvae was about 20 days, while that of 3% Emamectin Benzoate WDG was much shorter. The active component content of Chlorantraniliprole in the corn leaves was significantly higher than that of Emamectin Benzoate and Spinetoram. The pest control effects of Chlorantraniliprole were significantly promoted by HTY-A8 and MF. The field experiment showed that the control effect on S. frugiperda could last for 17 days by spraying Chlorantraniliprole or Spinetoram at 25 times the conventional concentration before transplanting, Furthermore, this method could reduce the amount of active ingredient to 4/5 or 3/4 of that found in a single field spray or seed coating treatment, respectively. Conclusions: This study puts forward a new method to effectively control S. frugiperda in the seedling stage of fresh corn.

为明确性比对草地贪夜蛾Spodoptera frugiperda(Lepidoptera:Noctuidae)成虫交配和繁殖的影响,为性信息素的应用提供理论基础,特设置雌雄性比为4∶1、3∶1、2∶1、1∶1、1∶2、1∶3和1∶4的7 个处理,通过解剖雌蛾卵巢的方法调查不同性比对成虫交配能力的影响,并采用生物学方法调查性比对成虫寿命,以及雌蛾产卵前期、产卵历期、产卵量与孵化率等的影响.结果表明,减少雄蛾比例可以显著(P<0.05)降低雌蛾的交配率,单头雌蛾的平均交配次数随着雌雄性比的降低而显著增加,从4∶1时的0.39 次增加到1∶4时的2.31 次.随着雌雄性比的增大,平均单头雄蛾的交配次数从4∶1时的1.56 次下降到1∶4时的0.50 次.当雌雄性比为1∶1时,雌、雄成虫的寿命均最长.当雌雄性比>1 时,单雌产卵量和卵孵化率均较低,随着雌雄性比的降低,二者显著增加,当雌雄性比降至1∶1时,二者分别为 949.48 粒和 73.68%,但若在此基础上继续增加雄蛾比例,这两个参数不再显著增加.不同性比下,雌蛾的产卵量和幼虫孵化量均集中在羽化后7d以内.随着雌雄性比的增大,产卵历期相对延长,但峰值相对降低.综上,当雌雄性比为1∶1时,草地贪夜蛾的雌蛾具有最长寿命,可充分交配,并具有最高的单雌产卵量和卵孵化率.在此基础上降低雄蛾比例,可降低交配率和雌蛾交配次数,进而降低单雌产卵量和孵化率.

Fertilization is a vital management practice to improve soil fertility and promote agricultural production. However, there is limited knowledge about the interactive effects between soil abiotic and biotic factors and soil multifunctionality after long-term fertilization. There has been little research on determining whether the application of organic fertilizers can improve the functional potential of microorganisms to maintain multifunctional stability. In this study, we integrated soil physicochemical properties, extracellular enzyme activities, bacterial community characteristics, and the abundance of functional genes related to carbon (C) and nitrogen (N) cycling to evaluate the mechanism of soil functional potential response to 13 years of fertilization management. Four treatments were compared, including no fertilizer (CK), conventional fertilization (CF), formulated fertilization by soil testing (SF), SF with organic fertilizer (SFO). The addition of organic fertilizer enhanced the soil electrical conductivity, N-cycling enzyme activities, contents of macroaggregate and associated C, and soil nutrients, while decreasing the content of microaggregates compared with other treatments. The coapplication of chemical and organic fertilizer led to significant increases in soil multifunctionality and the bacterial Shannon index compared with the CK and CF treatments. Soil abiotic factors are the key predictors for shaping soil multifunctionality. The addition of organic fertilizer could increase the abundance of functional genes related to C- and N-cycling mediated by the contents of nutrients and the aggregates associated with nutrients. Additionally, treatment with organic fertilizer can mitigate the decrease in genes for C-cycling function caused by the long-term application of chemical fertilizer (SF). In addition, the structural equation models revealed that the fertilization positively affected soil multifunctionality indirectly by changing the bacterial diversity and community composition, as well as the functional potential related to N-cycling. Overall, soil properties and microbial functional attributes jointly drive the response of soil multifunctionality to long-term fertilization management. These results suggest that the combination of organic and chemical fertilizer is worth popularizing to improve multifunctionality and its stability to maintain agricultural sustainability.

Context: Ideotype root system architecture is crucial for achieving high yields in maize by enhancing lodging resistance and nitrogen absorption, particularly under high planting densities. However, there is limited research on this topic in maize. Objective: The objectives of this study were to reveal the relative importance of different root system traits in root anchorage strength and nitrogen absorption, and to investigate their variations in response to increased plant density. Methods: To clarify this, a two-year field experiment was conducted in 2018 and 2019, involving four different lodging resistant maize genotypes and two plant densities. Root system traits including root crown architecture, root morphology per whorl, and root distribution in upper and lower soil layers were fully characterized. Root lodging resistance and nitrogen absorption capacity were quantified through artificial root lodging tests and 15N labeling, respectively, based on measuring root lodging rate and plant nitrogen content. Results: In comparison to lodging susceptible genotypes XY335 and XD20, lodging resistant genotypes LS1 and FM985 exhibited stronger root anchorage strength and lower root lodging risk. These characteristics were primarily attributed to their wider root crown width, larger projected root area, larger root angle, thicker brace roots, and wider distribution of the root system in the upper soil layer. However, LS1 was unfavorable for nitrogen absorption due to the larger root skeleton increased metabolic costs of soil exploration, which led to reduced root elongation, shallower rooting depth, and thus limited nitrogen acquisition from the soil. FM985 demonstrated a comparable nitrogen absorption capacity to XY335 (slightly higher than LS1) mainly because of the larger growth angle of the outermost crown root and greater specific root length of embryonic roots. With increased plant density, LS1and FM985 had larger reductions in root system traits, but maintained a larger root crown architecture than that of XY335 and XD20, leading to a lower lodging risk. XY335 and XD20 exhibited a stronger capacity for nitrogen acquisition at high plant densities, attributed to the increased root surface area, root volume and root dry matter of embryonic roots and root dry matter in the subsoil. Conclusions: Taken together, maintaining an optimized root crown architecture, coupled with an increase in surface area, volume and dry matter of embryonic roots and root dry matter in the subsoil, appears to be a more feasible approach for reducing lodging incidents and enhancing nitrogen absorption at a dense population.

为进一步挖掘秋季糯玉米种植潜力,筛选出适合我国南方种植的糯玉米品种,本研究进行了19个糯玉米品种的比较试验,对产量、 品质、 植株性状等6方面进行考察,最终筛选出适宜当地种植的秋季优质糯玉米品种,为新品种推广应用提供依据.试验结果表明,在19个糯玉米品种中,中鲜糯818、 万农甜糯158在产量、 品质、 抗病性、 穗部性状等方面综合表现较好,可作为秋季种植的糯玉米品种.

为明确50％氯虫苯甲酰胺、40％溴酰·噻虫嗪和50％吡虫·硫双威3种悬浮种衣剂对糯玉米苗期草地贪夜蛾的防治效果与持效期,将糯玉米种子采用种衣剂包衣法处理,从出苗后10 d开始,每隔7 d调查不同种衣剂对田间草地贪夜蛾的防效和叶片被害级别.结果表明,3种种衣剂对糯玉米出苗率和苗后10 d株高均无显著影响,对玉米安全;出苗后第10天,3种种衣剂处理对草地贪夜蛾为害的株防效在64.1％～74.2％,对玉米叶片均具有一定的保护效果;出苗后24 d,3个处理均失去对草地贪夜蛾幼虫的有效防治.50％氯虫苯甲酰胺、40％溴酰·噻虫嗪和50％吡虫·硫双威3种种衣剂可以控制苗期草地贪夜蛾为害,在较高虫口压力地区的有效控制时间为出苗后10 d左右.