Search Results (125)

Ratoon rice is a sustainable planting model, and its yield is closely linked to the light and temperature use efficiency. The photothermal quotient (PQ), a key parameter for evaluating the light and temperature use efficiency, significantly influences ratoon rice yield. However, research on how different stubble heights affect PQ and the utilization efficiency of light and temperature resources remains limited. Here, we conducted a two-year field experiment to investigate the radiation use efficiency (RUE), effective accumulated temperature use efficiency (TUE), PQ, interception percentage (IP), intercepted photosynthetically active radiation (IPAR), and total dry weight (TDW) of six ratoon rice varieties under two stubble height treatments (HS: high stubble, LS: low stubble) during the ratoon season. This study aimed to analyze how different stubble heights impact ratoon rice yield by evaluating light and temperature resource utilization efficiency and investigates the relationship between PQ and ratoon rice yield. The results showed that the HS treatment significantly increased ratoon season yield compared to LS treatment, with average yield increases of 21.2% and 28.1% in 2022 and 2023, respectively. This yield enhancement was attributed to improved TDW under HS treatment, driven by increased IP, IPAR, RUE, and TUE. Notably, PQ was significantly lower under HS than under LS treatment. This reduction was primarily attributed to the decreased duration available for light and heat accumulation, consequently lowering PQ. Correlation analysis revealed a significant positive association between main season yield and PQ, while ratoon season yield exhibited a negative correlation with PQ. In conclusion, the HS treatment increased IP and IPAR, enhanced TUE and RUE, and reduced PQ, collectively contributing to higher ratoon season yields. Importantly, our findings indicate that PQ can more effectively predict yield changes in the ratoon season under HS treatment, providing a theoretical basis for optimizing light and temperature resource utilization in ratoon rice. Full article

Integrating bioenergy crops into existing agricultural systems may influence soil biodiversity, yet evidence remains limited for second-generation bioenergy crops such as energycane. This study examined the impact of energycane integration on soil arthropod communities in the Everglades Agricultural Area, Florida, compared to traditional sugarcane and sweetcorn cropping systems. Over two crop cycles (plant cane and first ratoon), soil arthropod abundance and diversity were assessed using pitfall traps. Energycane and sugarcane, both perennial crops, showed no significant differences in order richness or Shannon diversity. Similarly, when energycane was compared with sugarcane and sweetcorn (during the first sampling), it had similar arthropod abundance. However, sweetcorn remained fallow in the second and third samplings, attracting arthropods like fire ants and earwigs, particularly due to pigweed. Diversity metrics based on Hill numbers revealed a decline in the effective abundance of ground-dwelling arthropods with increasing diversity order, influenced by differences in sampling duration. Importantly, no previous studies have been found that have reported on the effects of energycane integration into the existing cropping system on soil arthropod biodiversity. These findings highlight that energycane supports biodiversity levels comparable to sugarcane cropping systems with no negative impacts on soil arthropod abundance. This study underscores the need to consider soil biodiversity impacts when evaluating sustainable bioenergy crop transitions and the potential ecological trade-offs of perennial cropping systems. Full article

The ratooning capacity of sugarcane cultivars represents a crucial agronomic trait that significantly influences the sustainability of crop yields. This study elucidates the physiological and molecular mechanisms underlying the sugarcane ratooning ability observed in ratoon-competent GuiTang 29 (GT29) and ratoon-deficient Badila cultivars following stem excision. Through integrated hormonal profiling and transcriptome analysis, we identified significant differences in hormone levels and gene expression patterns. The quantification of 15 endogenous hormones via HPLC revealed marked reductions in zeatin (ZA) and zeatin riboside (ZR) in both cultivars. Additionally, GT29 exhibited notable reductions in gibberellins (GA3 and GA5) and strigolactone (5-DS) post-stem-excision, while Badila displayed stable or distinct hormonal changes. Additionally, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses indicated that hormone signal transduction, MAPK signaling pathways, phenylpropanoid biosynthesis, flavonoid biosynthesis, and other metabolic pathways were significantly enriched in both GT29 and Badila, with a particularly higher enrichment of plant hormone signal transduction in GT29. Furthermore, several differentially expressed genes (DEGs) had different expression patterns between GT29 and Badila, including the cytokinin receptor B-ARR and transcription factor A-ARR, gibberellin pathway components GID1 and DELLA, and AUX/IAA and SAUR in the auxin pathway. The real-time quantitative PCR (qRT-PCR) validation of 12 DEGs corroborated the RNA-seq data, further supporting the reliability of the transcriptomic analysis. This study delineates a clear molecular framework distinguishing ratoon competence, offers novel insights into the molecular basis of perennial regeneration and provides reliable candidate genes for functional marker development in sugarcane breeding. Full article

Water scarcity in semiarid regions represents a critical challenge for sustainable agriculture, reducing the availability of forage and affecting livestock systems. The reuse of treated wastewater offers an environmentally friendly alternative to meet water and nutrient needs, supporting the principles of the circular economy. Sweet sorghum, with its remarkable tolerance to abiotic stress, represents a resilient crop option. Evaluating its agronomic and industrial responses to different depths of irrigation using reclaimed water is essential for improving resource-efficient agricultural practices in water-limited environments. This study evaluated the effects of different irrigation regimes with treated wastewater on the growth, productivity, and water use efficiency of sweet sorghum grown in a semiarid region of Brazil. The experiment was conducted in a randomized complete block design, with five irrigation regimes ranging from 50% to 150% of crop evapotranspiration (ETc) and four replications. Irrigation was carried out with treated wastewater using a drip irrigation system. Growth parameters, fresh biomass, water use efficiency, and soluble solids content (°Brix) were analyzed in two consecutive harvests (main and ratoon crop). Deficit irrigation regimes (50% and 75% of ETc) resulted in higher water use efficiency and higher °Brix, whereas regimes above 100% of ETc reduced water use efficiency and biomass productivity. The ratoon crop showed greater sensitivity to water management, with significant productivity responses under irrigation around 100% of ETc. The first harvest was more productive in terms of fresh biomass and plant growth. Reclaimed water is a sustainable and efficient strategy for cultivating sweet sorghum in semiarid regions. Deficit irrigation regimes can be technically viable for maximizing water use efficiency and production quality, while proper irrigation management is crucial to avoiding losses associated with excessive water application. Full article

Sugarcane (Saccharum spp.) is a crop of significant industrial and nutritional value, essential for producing various products. Due to its importance, genetic improvement programs involve a rigorous selection process. In this study, growth curve models were used to analyze the maturity curves of 33 hybrids (currently in the adaptability testing phase) and 6 control varieties (MEX 69-290, ITV 92-1424, CP 72-2086, COLMEX 94-8, COLMEX 95-27, RB 85-5113) during both plant and ratoon periods at the Melchor Ocampo Sugar Mill fields in Jalisco, México. With the use of clustering techniques, the materials were classified into four maturity groups: early, early–intermediate, intermediate–late, and late. Hybrids with a larger intercept and smaller slope were classified as having early and early–intermediate maturity. Conversely, hybrids with a smaller intercept and larger slope were classified as having intermediate–late and late maturity. According to the Connectivity and Dunn indexes, the DBSCAN algorithm provides the best clustering structure for materials in the plant cycle, while for the ratoon cycle, the k-means algorithm offers the best clustering structure. This highlights the versatility of each algorithm in the context of hybrid and varietal maturity analysis. These results are crucial for optimizing the productivity and sustainability of the crop, with significant implications for the sugar industry. Full article

Efficient sugarcane ratooning management requires maintaining soil organic carbon (SOC) balance and improving soil physical properties. Retaining agricultural residues and applying organic fertilizers are essential for sustaining SOC levels. However, excessive soil compaction caused by heavy machinery remains a challenge, and no existing implements are specifically designed to alleviate soil compaction and apply organic fertilizers in sugarcane ratoon fields. This study aimed to design, develop, and evaluate an organic fertilizer applicator capable of performing a single-step operation that integrates subsoiling, fertilizer application, and soil mixing. The developed implement consists of four main components: (1) a pyramid-shaped hopper, (2) a two-way horizontal screw conveyor, (3) a subsoiler, and (4) a disk harrow set. The results indicated that the specific mass flow rate is directly proportional to screw size and inversely proportional to PTO shaft speed. The optimal configuration for the organic fertilizer applicator included an 18-inch harrow set, a 10-degree harrow angle, an inclined-leg subsoiler, and the Low3 gear at 1900 rpm, which required a draft force of 12.75 kN. Field performance tests demonstrated an actual field capacity of 0.89 ha·h⁻¹ and a field efficiency of 66.17%, confirming the implement’s effectiveness in improving soil conditions and integrating tillage with fertilizer application. Full article

Drought significantly impacts sugarcane yield, making drought resistance an important trait in drought-prone regions. The effects of the timing and duration of drought on yield and yield components, including relationships among these traits, were examined using a diverse set of sugarcane genotypes in a 2-year (planted cane and first ratoon) field study. Three drought treatments (no water stress (SD0), short-term (SD1), and long-term (SD2) drought) were assigned as the main plot and replicated four times. Within each plot, six genotypes were nested in a split-plot design. Drought reduced yield and its components, with the decline greater in SD2 than in SD1. Strong relationships between yield and its components like stalk height and density and height growth rate, especially under drought, make these traits potential surrogates for yield in drought screening experiments. The genotypes F03–362 and KK3 displayed high, stable yield potential across drought treatments, but KK3 lost potential in ratoon crop under drought. Although KK09–0358 displayed high yield potential, it was very sensitive to drought stress while UT12 and KK09–0939 displayed low yield potential and sensitivity to drought. TPJ04–768 displayed low but stable yield potential across drought treatments and crops. F03–362 and TPJ04–768 have utility in studies seeking to couple physiological with agronomic parameters promoting drought resistance and as parents for developing cultivars combining high and stable yield performance under drought. Full article

The expansion of sugarcane production has led to increased nitrogen (N) fertilizer use, contributing to greenhouse gas emissions and environmental concerns. Optimizing N management is crucial for sustainable agriculture. Soil apparent electrical conductivity (EC_a) has emerged as a valuable tool for mapping soil spatial variability and yield potential, potentially guiding more efficient fertilization strategies. This study evaluated sugarcane yield and N responsiveness across two areas with distinct soil types over two crop cycles. Experimental plots were classified into high (HC) and low (LC) EC_a zones, with randomized blocks receiving four N rates and a control. Higher yields were generally observed in HC plots, except for the second ratoon in area 2 (Ultisol). HC plots required lower N rates to achieve maximum yield compared to LC plots. In area 1 (higher clay content), optimal N rates were lower than in area 2 (lower clay content), indicating that yield potential is linked to soil attributes and spatial variability. Although EC_a alone may not define precise N doses, it effectively identifies zones with different yield potentials, supporting site-specific N management. These findings highlight the potential of EC_a to improve nitrogen use efficiency and contribute to more sustainable sugarcane production. Full article

Rice cultivated in cadmium (Cd)-polluted acidic paddy soil poses important health risks in China. Mitigating Cd accumulation in rice is of crucial importance for food safety and human health. In this study, using Chuangliangyou 669 as the ratoon rice variety, a field experiment was conducted in paddy fields with severe Cd pollution (Cd concentration > 1.0 mg kg⁻¹). The aim was to explore the impacts of different nitrogen (N) fertilizer levels (N1-180 kg hm⁻², N2-153 kg hm⁻², N3-126 kg hm⁻²) and planting densities (D1-20 cm × 20 cm, D2-16.7 cm × 16.7 cm) in the main crop on the yield and Cd accumulation characteristics of ratoon rice. The results showed that reducing the amount of N fertilizer would lead to a decrease in the yield of ratoon rice, while increasing the planting density could increase the yield, mainly by increasing the effective panicle. Among the various combined treatments, the yields of N1M2 and N2M2 were relatively high. The planting density had no significant impact on the Cd concentration, translocation factor and bioaccumulation factor of ratoon rice. The Cd concentration in various tissues of ratoon rice decreased significantly with the reduction in N fertilizer application. Reducing N fertilizer application could increase the pH, reduce the concentration of available Cd in the soil and consequently reduce the Cd bioaccumulation factor of various tissues of ratoon rice and the Cd translocation factor from roots and stems to brown rice. Considering both the yield and the Cd concentration in brown rice, N2M2 was the optimal treatment of reducing N and increasing density, which could maintain a relatively high yield while significantly reducing the Cd concentration. Full article

Ratoon rice can improve rice yield by increasing the multiple cropping index in China. However, the greenhouse gas (CH₄ and N₂O) emission characteristics from ratoon rice fields and the cultivation methods to reduce CH₄ and N₂O emissions are rarely reported. This study first conducted the analysis of genotype differences in greenhouse gas emission fluxes using five strong ratoon ability rice varieties in 2020. Second, water management methods, including alternating the wet–dry irrigation (AWD) pattern and conventional flooding irrigation (CF) during the main season, were carried out in 2021. CH₄ and N₂O emission flux, agronomic traits, and rice yield during both main and ratoon seasons were investigated. The results showed that the CH₄ emission flux during the main and ratoon seasons was 157.05–470.73 kg·ha^–1 and 31.03–84.38 kg·ha^–1, respectively, and the total N₂O emission flux was 0.13–0.94 kg·ha^–1 in the ratoon rice system over the two seasons (RRSTS). Compared with the main season, the CH₄ emission flux during the ratoon season was significantly reduced, thus decreasing the greenhouse gas global warming potential (GWP) and greenhouse gas emission intensity (GHGI) in the ratoon rice system. Cliangyouhuazhan (CLYHZ) showed a high yield, and the lowest GWP and GHGI values among the five rice varieties in RRSTS. Compared with CF, the AWD pattern reduced the CH₄ emission flux during the main and ratoon seasons by 67.4–95.3 kg·ha^–1 and 1.7–5.1 kg·ha^–1, respectively, but increased the N₂O emission flux by 0.1–0.6 kg·ha^–1 during the RRSTS. Further, compared with CF, the AWD pattern had a declined GWP by 14.3–19.4% and GHGI by 30.3–34.3% during the RRSTS, which was attributed to the significant reduction in GWP and GHGI during the main season. The AWD pattern significantly increased rice yield by 21.9–22.9% during the RRSTS, especially for YX203. Correlation analysis showed that CH₄, GWP, and GHGI exhibited significant negative correlations with spikelet number per m² and the harvest index during the main and ratoon seasons. Collectively, selecting the high-yield, low-emission variety CLYHZ could significantly reduce greenhouse gas emissions from ratoon rice while maintaining a high yield. The AWD pattern could reduce total CH₄ emission during the main season, reducing the GWP and GHGI while increasing the ratoon rice system yield. It could be concluded that a variety of CLYHZ and AWD patterns are worthy of promotion and application to decrease greenhouse gas emissions in the ratoon rice area in the upper reaches of Yangtze River, China. Full article

Ratooning rice plants have a high moisture content and strong adhesion during harvesting. Traditional cleaning devices are prone to clogging when processing ratooning rice, resulting in a series of problems such as high grain loss rate and high grain impurity rate. In response to the above issues, this article adopts the CFD-DEM coupling method to design a spiral step cleaning device. A detailed analysis was conducted on the influence of the cone angle and thickness of the spiral-stepped skeletons on the flow state, and flow velocity and pressure distribution cloud maps were obtained under different structural parameters. The vortex morphology under different thicknesses of the spiral-stepped skeletons was compared, and the structural parameters of the device were determined. The motion trajectory and distribution of impurity particles under different inlet flow velocities were analyzed using data superposition, and the appropriate inlet flow velocity range was determined. A test bench was built, and a three-factor quadratic regression orthogonal rotation combination experiment was conducted with fan speed, feeding rate, and device inclination angle as experimental factors. The results of the bench test show that the performance index reaches its optimum when the device inclination angle, fan speed, and feeding rate are 2.47°, 2906 r/min, and 4.0 kg/s, respectively. At this time, the grain impurity rate, grain loss rate, and sieve clogging rate are 2.21%, 2.15%, and 3.5%, respectively. Compared to those of traditional cleaning equipment, these value are reduced by 44.5%, 39.6%, and 83.9%, respectively. This study can provide ideas for the design of ratooning rice cleaning devices. Full article

This study aimed to develop and genetically characterize thermosensitive genic male-sterility (TGMS) lines for use in hybrid rice (Oryza sativa L.) breeding. Male-sterile F₂ to F₄ generation lines were screened during the high-temperature summer season, and ratoon crops of selected male-sterile rows were harvested for pure seed. Sixty-six F₅ TGMS lines were genotyped using DNA markers controlling 16 traits from the LSU80 QA/QC Rice PlexSeq SNP Panel. Ten TGMS lines with desirable traits that included semidwarf, glabrous, non-aromatic, long-grain, narrow brown leaf spot resistance, and blast resistance genes were selected for further genotypic characterization using markers for low chalkiness (chalk5), wide compatibility (S5-n), cold tolerance (qSCT-11 and qCST-12), and anaerobic germination (AG1 and AG2). TGMS lines TIL21051S and TIL21052S possess favorable alleles for each of the genes evaluated in this study and are desirable parents for two-line hybrid breeding in the southeast United States. TIL21044S, TIL21095S, TIL21060S, and TIL21066S each contain three blast resistance genes and have potential as parental lines. TIL21014S-2, TIL21015S, and TIL21016S-1 include the fgr allele for aroma and can also be used as parental lines for aromatic two-line hybrids. Full article

The influence of potassium fertilizer on sugarcane (interspecific hybrids of Saccharum Spp.) yields and leaf and soil potassium levels was evaluated at six locations in Louisiana. The objective of this study was to determine if the sugarcane yields in Louisiana could be improved with potassium application. Different rates of potassium fertilizer (0–179 kg K₂O ha⁻¹) were applied to plant cane and ratoon sugarcane fields in Louisiana. Soil samples and sugarcane leaf samples were also collected from all experiments. Yield data were collected by harvesting plots with a single row, chopper harvester and a field transport wagon equipped with electronic load sensors. At all locations and soil types, potassium fertilizer did not increase cane or sugar yields. Soil properties data showed that significant increases in soil potassium levels did not occur until the second ratoon crop, where soil potassium increased by 30% for the high rate. Increases in plant potassium were also not observed until the second ratoon crop, where plant potassium increased by 10.5% for the high rate. The potential cause of the observed lack of response may be explained by interference from calcium and magnesium, combined with fixation by smectite and vermiculite clay minerals. Our soil and plant uptake data would suggest that repeated K applications at recommended rates, which currently vary from 90 to 157 kg ha⁻¹, may be required to achieve the potential benefits of K fertilizer in Louisiana sugarcane soils. However, this must be verified by additional on-farm trials. Full article

To solve the problem of the high loss rate of threshing devices during the mechanical harvesting of ratoon rice, we propose a method using the principle of rigid–flexible coupling in this paper to reduce losses. Through analysis of the forces and collisions on ratoon rice grains during the threshing process, it has been confirmed that changing the structure and materials of the threshing contact components can effectively reduce grain loss. A rigid–flexible coupling rod tooth was designed, and the overall structural parameters of the device were determined based on force analysis results and dimensional boundary conditions. The MBD-DEM coupling method was used to simulate the threshing process, and the force conditions of the threshing rod teeth and threshing drum were obtained. The influence of the feeding amount and of the flexible body thickness on the crushing of ratoon rice grains was analyzed. In order to obtain the device’s optimal parameter combination, a three-factor quadratic regression orthogonal rotation combination experiment was conducted with drum speed, flexible body thickness, and rod tooth length as experimental factors. The optimization results showed that when the drum speed, flexible body thickness, and rod tooth length were 684 r/min, 3.86 mm, and 72.7 mm, respectively, the crushing rate, entrainment loss rate, and uncleaned rate were 1.260%, 2.132%, and 1.241%, respectively. The bench test showed that it is feasible to use the MBD–DEM coupling method to measure the motion and force of ratoon rice. The rigid–flexible coupling threshing device can reduce the grain crushing rate while ensuring grain cleanliness. Compared with traditional threshing devices, the crushing rate and entrainment loss rate of the rigid–flexible coupling threshing device were reduced by 55.7% and 27.5%, respectively. The research results can provide a reference for the design of threshing devices for ratoon rice harvesters. Full article

Selenium (Se) is an essential trace element that has various beneficial effects for human healthy. However, the effects of different Se forms and concentrations on growth and development, photosynthetic characteristics and antioxidant capacity are still unclear with regard to the dual grain-and-feed dual-use of ratoon rice (RR). In this study, three concentrations of three different Se forms were applied to RR using the foliar spraying method, and the results showed that Se treatment can increase the Se content of rice grain and straw. All the Se treatments improved the photosynthetic indexes and activities of antioxidant enzymes. The Se and trace elements contents, and the percentages of organic Se and protein Se of brown rice were found to be similar in all three Se forms. A higher organic Se content was found in the grain by spraying sodium selenite and Se-Met, in which the resistant starch (RS) content was increased with the increase in amylose content in grains. The main Se species in the grain was SeMet and the SeMeCys was found only with SeMet treatments. The grain quality showed that all three Se forms increased the consistency of gelatinization. Our study indicated that exogenous Se could improve the nutritional quality of both grain and straw by improving photosynthetic traits and antioxidant enzyme activities, especially sodium selenite and Se-Met. These results underscore the potential of foliar biofortification to enhance the functional component contents of RR grains and provide an insight into the Se enrichment of ratoon rice. Full article