Crop Plants Research Articles

Influence of Different Methods of Application of Lignogumate on the Product Quality of Green Crops and Medicinal Plants

The effectiveness of the use of lignohumate on lettuce (annual, green crop) and peppermint (perennial, medicinal plant) grown under the conditions of vegetation experiments was studied. The combination of lignohumate with the introduction of chelated fertilizers containing trace elements (zinc, copper) into peat showed a significant positive effect in obtaining high-quality plant products. The most effective was the fertilizer system, which included a combination of lignohumate with chelated forms of zinc and copper: the increase in lettuce biomass was 29–32, mint – 71–79%, the content of macroand microelements in plants became optimal.

Exploring Genetic Variability for Yield and Its Attributing Traits in Rice (Oryza sativa L.) under Low Soil Phosphorous Condition

Phosphorus (P) is a vital macro-nutrient essential for the growth and development of all crop plants including rice. Inadequate availability of P in the soils hinders crop growth, resulting in reduced rice yields. Genetic variability for low P tolerance is of utmost importance to understand the genetics and improvement of rice genotypes for the trait. The present study was conducted under low soil P condition to assess the genetic variability for yield and its attributing traits in rice genotypes. The experimental material consists of 245 rice genotypes along with six checks which were planted in low P plot at ICAR-IIRR, Hyderabad using augmented block design and phenotyped for the traits viz., days to 50% flowering, plant height, total number of tillers, number of productive tillers per plant, panicle length, single plant yield, thousand grain weight and spikelet fertility. ANOVA analysis revealed that MSS due to test genotypes were significant (p<0.01) for all the traits under study. PCV and GCV were found to be high for single plant yield, total number of tillers and number of productive tillers while, plant height, thousand grain weight and spikelet fertility showed moderate PCV and GCV. Genetic advance as percentage of mean coupled with heritability was observed to be higher for all the traits except panicle length, which was moderate in nature. These results signify that there was sufficient amount of genetic variability for all the studied traits under low P in the studied genotypes. Therefore, genetic improvement through selection for these traits would be more rewarding and could be useful for developing genotypes tolerant to low P stress.

Moving forward from escaping the poverty trap in China's greenest regions: Examining four decades of socioecological evolution to re-orient sustainable development policies

Afforestation is an important aspect of ecosystem restoration (ER) and poverty alleviation (PA) through direct and indirect social, economic, and environmental effects. However, the existing afforestation projects worldwide have mainly viewed economic benefits through the narrow lens of subsistence and livelihood, thereby underestimating both indirect PA and the associated negative effects on agricultural production when formulating long-term solutions to global poverty. This study aimed to systematically examine the ecological, agricultural, and economic effects of ecosystem restoration in southeastern China over four decades based on biophysical models and statistical records, and further proposed an upgraded strategy for sustainable PA through ER that addresses conservation objectives and resource needs. We found that ER promoted vegetation growth and enhanced carbon sequestration and soil retention. Meanwhile, industrial transformation improved the economic scale and livelihood diversity (i.e., disposable income), which alleviated poverty and improved social services and infrastructure conditions. Nevertheless, the secondary and tertiary industries gradually replaced the primary industry in terms of output, and increased animal husbandry and forestry development weakened crop planting. Planting structure adjustments further threatened the stability of the grain supply, particularly after 1999, which could potentially lead to a grain crisis. Therefore, we propose upgraded forest management and coordinated development policies to avoid a grain crisis, improve livelihood diversity, balance multidimensional benefits, and facilitate sustainable development. Study results serve as a valuable reference for policy formulation and ER measures for more inclusive, resilient, and sustainable PA.

Editorial: Genomics assisted improvement of crop plants for adaptation to marginal environments

Editorial: Genomics assisted improvement of crop plants for adaptation to marginal environments

Transcriptome analysis of the molecular basis of 11‐eicosenoic acid‐mediated salt stress tolerance in rice

AbstractSalt stress is one of the major abiotic factors severely hampering rice production. Fatty acids play a crucial role in plants response to such stress. Previous studies have demonstrated the potential of unsaturated fatty acid (11‐eicosenoic acid [EA]) to enhance salt tolerance in rice, but the molecular mechanism remains unclear. Our study indicates that the exogenous application of EA could alleviate salt stress‐induced damage as well as improve the survival rate of rice seedlings. Transcriptome analysis was performed following treatment of rice seedlings with EA, NaCl, and NaCl + EA. The results showed that there were 4970, 11, 304, and 4735 differentially expressed genes (DEGs) in NaCl versus CK, EA versus CK, NaCl + EA versus NaCl, and NaCl + EA versus CK, respectively. Notably, pathways such as unsaturated fatty acid metabolism, diterpenoid phytoalexin biosynthesis, and phytohormone signal transduction were significantly enriched in NaCl + EA versus NaCl. Specifically, genes related to ethylene, abscisic acid, jasmonic acid, salicylic acid, gibberellin signaling, and fatty acid metabolism were implicated in the mitigation effect of EA on salt stress in rice. Furthermore, DEGs involved in rice diterpenoid biosynthesis were analyzed in detail, revealing that EA induced the biosynthesis of multiple diterpenoids. Metabolomic analysis showed that the levels of various fatty acids, phytohormones, and terpenes increased. The presented data may serve as a useful guide for further exploration of the various biological functions of EA in enhancing plant resilience to salt stress. Additionally, it offers a valuable list of genes for the development of crop plants with improved salt resistance.

Growth and Yield of Okra (<i>Abelmoschus esculentus</i> (L.) Moench) as Affected by Weeding Regimes in Mubi, Adamawa State

The two-year experiments were conducted to evaluate the effect of weeding regimes on the growth and yield of okra (Abelmoschus esculentus L. Moench) in Mubi Adamawa State, Northern Guinea Savannah, grown at the Tree Crop Plantation (TCP) Farm, School of Agriculture, Federal polytechnic, Mubi, during 2022 and 2023 rain cropping season. Mubi is located in the North-eastern part of Adamawa State laid between Latitude 90 26ʹ and100 10ʹN and Longitude 130 10ʹ and 130 44ʹE. at an Altitude of 696m above sea level. The experiments were laid out in Split Plot Design with four (4) treatments: No weeding (W1), 1 Weeding at 3 weeks after sowing (WAS) (W2), 2 weeding at 3, and 6 WAS (W3) and 3 weeding at 3, 6 and 9 WAS (W4), replicated 3 times. Data were collected on plant height, Number of leaves, stem diameter, days to 50 % flowering, fruit length, fruit diameter, fresh fruit yield per plot, fresh fruit yield per hectare and dried fruit yield per hectare. The data on growth and yield parameters were subjected to analysis of variance (ANOVA) using Statistical Analysis System (SAS), (SAS, 2000) and means that showed significant differences were separated by F-test using Duncan Multiple Range Test (DMRT). The results revealed that weeding regimes significantly influenced plant height, number of leaves, and stem diameter, at 3, 6 and 9 WAS. On the response of phonological traits and yield components of okra, to weeding regimes and significant influences were observed in days to 50 % flowering, fruit length, fruit diameter, fresh fruit yield per plot, fresh fruit yield per hectare and dried fruit yield per hectare, accordingly. Treatment W4 performed significantly higher than the other treatments. The study therefore recommends 3 times weeding at an interval of 3 WAS to okra farmers in Mubi and its environs for optimum fruit yield.

Xylem Sap Proteome Analysis Provides Insight into Root–Shoot Communication in Response to flg22

Xylem sap proteomics provides crucial insights into plant defense and root-to-shoot communication. This study highlights the sensitivity and reproducibility of xylem sap proteome analyses, using a single plant per sample to track over 3000 proteins in two model crop plants, Solanum tuberosum and Hordeum vulgare. By analyzing the flg22 response, we identified immune response components not detectable through root or shoot analyses. Notably, we discovered previously unknown elements of the plant immune system, including calcium/calmodulin-dependent kinases and G-type lectin receptor kinases. Despite similarities in the metabolic pathways identified in the xylem sap of both plants, the flg22 response differed significantly: S. tuberosum exhibited 78 differentially abundant proteins, whereas H. vulgare had over 450. However, an evolutionarily conserved overlap in the flg22 response proteins was evident, particularly in the CAZymes and lipid metabolism pathways, where lipid transfer proteins and lipases showed a similar response to flg22. Additionally, many proteins without conserved signal sequences for extracellular targeting were found, such as members of the HSP70 family. Interestingly, the HSP70 response to flg22 was specific to the xylem sap proteome, suggesting a unique regulatory role in the extracellular space similar to that reported in mammalians.

PhieDBEs: a DBD-containing, PAM-flexible, high-efficiency dual base editor toolbox with wide targeting scope for use in plants.

Dual base editors (DBEs) enable simultaneous A-to-G and C-to-T conversions, expanding mutation types. However, low editing efficiency and narrow targeting range limit the widespread use of DBEs in plants. The single-strand DNA binding domain of RAD51 DBD can be fused to base editors to improve their editing efficiency. However, it remains unclear how the DBD affects dual base editing performance in plants. In this study, we generated a series of novel plant DBE-SpGn tools consisting of nine constructs using the high-activity cytidine deaminase evoFERNY, adenosine deaminase TadA8e and DBD in various fusion modes with the PAM-flexible Streptococcus pyogenes Cas9 (SpCas9) nickase variant SpGn (with NG-PAM). By analysing their editing performance on 48 targets in rice, we found that DBE-SpGn constructs containing a single DBD and deaminases located at the N-terminus of SpGn exhibited the highest editing efficiencies. Meanwhile, constructs with deaminases located at the C-terminus and/or multiple DBDs failed to function normally and exhibited inhibited editing activity. We identified three particularly high-efficiency dual base editors (C-A-SpGn, C-A-D-SpGn and A-C-D-SpGn), named PhieDBEs (Plant high-efficiency dual base editors), capable of producing efficient dual base conversions within a narrow editing window (M5 ~ M9, M = A/C). The editing efficiency of C-A-D-SpGn was as high as 95.2% at certain target sites, with frequencies of simultaneous C-to-T and A-to-G conversions as high as 81.0%. In summary, PhieDBEs (especially C-A-D-SpGn) can produce diverse mutants and may prove useful in a wide variety of applications, including plant functional genomics, precise mutagenesis, directed evolution and crop genetic improvement, among others.

Cold tolerance of woodland strawberry (Fragaria vesca) is linked to Cold Box Factor 4 and the dehydrin Xero2.

Domesticated strawberry is susceptible to sudden frost episodes, limiting the productivity of this cash crop in regions, where they are grown during early spring. In contrast, the ancestral woodland strawberry (Fragaria vesca) has successfully colonised many habitats of the Northern Hemisphere. Thus, this species seems to harbour genetic factors promoting cold tolerance. Screening a germplasm established in frame of the German Gene Bank for Crop Wild Relatives we identified, among 70 wild accessions, a pair contrasting with respect to cold tolerance. By following the physiological, biochemical, molecular, and metabolic responses of this contrasting pair, we identified the transcription factor Cold Box Factor 4 and the dehydrin Xero-2 as molecular markers associated with superior tolerance to cold stress. Overexpression of GFP fusions with Xero-2 in tobacco BY-2 cells conferred cold tolerance to these recipient cells. A detailed analysis of the metabolome for the two contrasting genotypes allows to define metabolic signatures correlated with cold tolerance versus cold stress. This work provides a proof-of-concept for the value of crop wild relatives as genetic resources to identify genetic factors suitable to increase the stress resilience of crop plants.

Climate Change impact on Weeds and Herbicide Efficacy

Climate change is the change in statistical distribution of weather pattern that lasts for an extended period of time. There are several components of these climate changes occurring globally that includes uneven rainfall, droughts, floods, warming of atmosphere etc. These are the most important challenges influencing natural ecosystems, agricultural productivity and food security. Climate change is not only influencing crop plants and forests directly but can also impact the pests of these crops. Weeds respond to climate change by changing the duration of their life cycles, population dynamics and shift to new habitats and become a potential competitor to crop plants thereby reducing the production and productivity of crops. Elevated temperature and elevated CO2 level in the environment interfere with herbicide activity, which affects the herbicide absorption, translocation and thereby reduces the efficacy of the applied herbicide. Weeds’ resistance to herbicides may probably increase due to further aggressive growth of weeds in future climate conditions, which can cause a decline in the efficacy of routinely used herbicides.

Scenario Analysis of Food Phosphorus Footprint in Kisumu, a Lakeside East African City in Lake Victoria (Kenya)

Increased food production and consumption patterns have resulted in higher urban food phosphorus footprints, leading to a series of resource and environmental problems worldwide. We quantified the food phosphorus footprint of the African city of Kisumu using substance flow analysis. Our aim was to develop Kisumu’s sustainable phosphorus management framework so that the city would reduce phosphorus losses into the food system. Our results show that in the year 2023, the import and export of food phosphorus in the Kisumu food system was 2730.26 ± 2.7% t P yr−1 and 3297.05 ± 2.4% t P yr−1, respectively. There was −566.79 ± −18% t P yr−1 food phosphorus deficit in the Kisumu food system. Crop planting subsystem runoff/leaching/erosion loss, household consumption subsystem waste loss, and pit latrine subsystem blackwater loss are the major pathways of phosphorus losses into the environment and the main contributors to the food phosphorus footprint in the city. The 2030 scenario analysis shows that implementing a comprehensive scenario scheme throughout the entire lifecycle process from phosphorus input to waste disposal is the best choice for reducing phosphorus losses and suppressing the growth of food phosphorus footprint in the future. Our study shows that the food phosphorus footprint in the Kisumu food system was 0.67 kg P cap−1yr−1 in 2023, which is still at a low level but may enter a continuous upward trend with the improvement of socio-economic development of the city. In our framework, we have proposed a few essential measures that include urine separation, installation of septic tank, adjustment of dietary structure, flexible layout of sanitary disposal facilities, and separation of organic waste streams to reduce food phosphorus footprints in Kisumu. Given the similarity of cities along the shores of Lake Victoria, our calculation methods and management strategies can be applied to other cities in the region.

Strategies for combating plant salinity stress: the potential of plant growth-promoting microorganisms

Global climate change and the decreasing availability of high-quality water lead to an increase in the salinization of agricultural lands. This rising salinity represents a significant abiotic stressor that detrimentally influences plant physiology and gene expression. Consequently, critical processes such as seed germination, growth, development, and yield are adversely affected. Salinity severely impacts crop yields, given that many crop plants are sensitive to salt stress. Plant growth-promoting microorganisms (PGPMs) in the rhizosphere or the rhizoplane of plants are considered the “second genome” of plants as they contribute significantly to improving the plant growth and fitness of plants under normal conditions and when plants are under stress such as salinity. PGPMs are crucial in assisting plants to navigate the harsh conditions imposed by salt stress. By enhancing water and nutrient absorption, which is often hampered by high salinity, these microorganisms significantly improve plant resilience. They bolster the plant’s defenses by increasing the production of osmoprotectants and antioxidants, mitigating salt-induced damage. Furthermore, PGPMs supply growth-promoting hormones like auxins and gibberellins and reduce levels of the stress hormone ethylene, fostering healthier plant growth. Importantly, they activate genes responsible for maintaining ion balance, a vital aspect of plant survival in saline environments. This review underscores the multifaceted roles of PGPMs in supporting plant life under salt stress, highlighting their value for agriculture in salt-affected areas and their potential impact on global food security.

Impact of Vineyard Fallow Practices on Reducing Meloidogyne hapla Population Densities

The northern root-knot nematode (Meloidogyne hapla) is a common plant-parasitic nematode in northern grape production regions. This nematode induces small galls on roots, which restricts water and nutrient uptake, resulting in poor vine establishment or exacerbated decline in stressed vines. A study was conducted to explore the impacts of site management practices on M. hapla population densities following removal of wine grape (Vitis vinifera) vineyards in Washington State. Soil was collected from 38 fields, M. hapla second-stage juvenile densities in soil were determined, and to assist in identifying M. hapla in potentially low-population density samples, an eight week-long tomato (Solanum lycopersicum) bioassay was conducted. Vineyard managers also provided information on site management techniques. Of the 20 total management techniques and combinations explored (e.g., fallow duration, cover crops, mowing, irrigation, herbicide applications), only one component resulted in lower M. hapla population densities: duration of vine-free period. A duration of at least one-year post vineyard removal showed a decline in M. hapla population densities in the sampled former vineyard sites. These results suggest that a fallow period could be useful as a non-chemical management tool for M. hapla in vineyard replant soils. However, consideration of additional site management factors such as weed management, soil series and amendments, interim crop planting, and irrigation or accumulated rainfall that may support M. hapla development is necessary.

Effects and remediation of heavy metals contamination in soil and vegetables from different areas: A review

Heavy metals are non-biodegradable and thus persist in the environment, potentially infiltrating the food chain via crop plants and accumulating in the human body through biomagnification. Due to their toxic nature, heavy metal poisoning poses a severe threat to human health and the environment. Consuming vegetables contaminated with heavy metals can lead to increased accumulation of these metals in the human body. This review discusses the risks of heavy metal contamination in various areas, as reported in some research studies, and the implications for human health. Data obtained from several journals indicated that levels of lead (Pb) and cadmium (Cd) in vegetables were generally within permissible limits, though cadmium concentrations were found to be low in some studies. High concentrations of lead (Pb) can affect metabolic functions, growth, and photosynthetic activities. Cadmium (Cd) levels, which are lower than the permissible limit of 0.2 mg kg−1 set by WHO, can lead to chromosomal aberrations and sister chromatid exchanges in cells. Zinc (Zn) levels were within permissible limits except in lettuce and spinach in some findings. Low zinc content in vegetables impacts human health, plant health, and agricultural productivity. Addressing zinc deficiency requires integrated approaches such as soil management, crop biofortification, and dietary diversification. Ensuring adequate zinc levels is essential for improving public health and achieving sustainable agricultural practices. Addressing heavy metal contamination in vegetables requires a combination of remediation and preventive strategies. Implementing soil and water management practices can mitigate these risks and ensure the safe production of vegetables.

Effect of nano-urea and irrigation regimes on growth parameters of wheat (Triticum aestivum L.)

Wheat (Triticum aestivum L.) is a crucial cereal crop globally, serving as a staple food for a vast population. Its productivity faces challenges such as nutrient imbalance and terminal heat stress exacerbated by climate change, particularly in regions like the North-Eastern Plain Zone of India. To address these issues, a study was conducted during the rabi season of 2021–2022 in Jharkhand, India, aiming to examine the impacts of irrigation regimes and nano-urea-based nitrogen management practices on wheat. Employing a split-plot design with three replications, the experiment assessed three irrigation regimes and five nitrogen management practices. Results revealed that irrigation regimes registered non-significant effects on crop growth parameters like plant height, LAI (leaf area index), root dry weight, flag leaf area and tillers/m2 , which might be due to frequent rain up to the flowering stage during the crop growth period. Higher levels of nitrogen in commercial urea significantly increased plant height, LAI, flag leaf area, recovered root dry weight and dry matter accumulation. However, nano-urea spray at 45 DAS helped crop plants positively to increase all growth parameters more compared to nano-urea spray at 60 DAS. All growth attributes with 50% RDN+2-nano-urea spray were statistically at par with 50% RDN+1 nano-urea spray up to 40 DAS, but after the flowering stage, it was statistically similar with 100% RDN. The maximum tillers/m2 was found under 100% RDN, followed by 75% RDN+ one nano-urea spray and 50% RDN+2 nano-urea spray. Thus, 3- irrigations at CRI, flowering and milk stage and 100% RDN (120 kg N/ha) were found sufficient for enhancing the growth parameters of wheat.

Enhancing sustainable solutions for food security in Jordan: using bacterial biofertilizer to promote plant growth and crop yield

Enhancing sustainable solutions for food security in Jordan: using bacterial biofertilizer to promote plant growth and crop yield

LsFUL–LsSMU2 module positively controls bolting time in leaf lettuce (Lactuca sativa L.) under high temperature

High temperature (HT) is an environmental factor that considerably affects plant physiology, development, crop yield, and economic value. HT can cause diseases and early bolting of leaf lettuce, thereby reducing the yield and quality of leaf lettuce. Herein, we used two leaf lettuce (Lactuca sativa L.) cultivars (bolting-resistant ‘S24’ and bolting-sensitive ‘S39’) to investigate the key factors and molecular mechanism impacting bolting. We found that 14 MADS-box genes implicated in bolting and flowering, LsMADS54 (also referred to as L. sativa FRUITFULL, LsFUL), was significantly up-regulated 1,000 times after 5-d HT treatment and that HT-induced up-regulation of LsFUL was higher in bolting-sensitive than in resistant cultivars. The overexpression lines of LsFUL exhibited an earlier bolting time than that in the non-transformed ‘S39’(CK). However, the RNA interference, and CRISPR-Cas9-mediated knockout lines of LsFUL exhibited a later bolting time than that in CK. In addition, we found that L. sativa SUPPRESSORS OF MEC-8 AND UNC-52 PROTEIN 2 (LsSMU2) and L. sativa CONSTANS-LIKE PROTEIN 5 (LsCOL5) interact with LsFUL, and these interactions could stimulate or prevent bolting. We observed that elevated temperature stimulated the abundance of LsSMU2 in the stem, which collaborated with LsFUL to accelerate bolting. Conversely, room temperature (RT) condition led to relatively more stable LsCOL5, which worked with LsFUL to postpone bolting. In summary, our findings demonstrate a molecular regulatory module of LsSMU2–LsFUL associated with HT-induced premature bolting, which serves as a reference for understanding HT-induced premature bolting phenomenon in leaf lettuce.

CRISPR/Cas9-mediated genome editing technique to control fall armyworm (Spodoptera frugiperda) in crop plants with special reference to maize

CRISPR/Cas9-mediated genome editing technique to control fall armyworm (Spodoptera frugiperda) in crop plants with special reference to maize

Transcriptome profiling reveals the impact of various levels of biochar application on the growth of flue-cured tobacco plants

BackgroundBiochar, a carbon-rich source and natural growth stimulant, is usually produced by the pyrolysis of agricultural biomass. It is widely used to enhance plant growth, enzyme activity, and crop productivity. However, there are no conclusive studies on how different levels of biochar application influence these systems.Methods and resultsThe present study elucidated the dose-dependent effects of biochar application on the physiological performance, enzyme activity, and dry matter accumulation of tobacco plants via field experiments. In addition, transcriptome analysis was performed on 60-day-old (early growth stage) and 100-day-old (late growth stage) tobacco leaves to determine the changes in transcript levels at the molecular level under various biochar application levels (0, 600, and 1800 kg/ha). The results demonstrated that optimum biochar application enhances plant growth, regulates enzymatic activity, and promotes biomass accumulation in tobacco plants, while higher biochar doses had adverse effects. Furthermore, transcriptome analysis revealed a total of 6561 differentially expressed genes (DEGs) that were up- or down-regulated in the groupwise comparison under different treatments. KEGG pathways analysis demonstrated that carbon fixation in photosynthetic organisms (ko00710), photosynthesis (ko00195), and starch and sucrose metabolism (ko00500) pathways were significantly up-regulated under the optimal biochar dosage (600 kg/ha) and down-regulated under the higher biochar dosage (1800 kg/ha).ConclusionCollectively, these results indicate that biochar application at an optimal rate (600 kg/ha) could positively affect photosynthesis and carbon fixation, which in turn increased the synthesis and accumulation of sucrose and starch, thus promoting the growth and dry matter accumulation of tobacco plants. However, a higher biochar dosage (1800 kg/ha) disturbs the crucial source-sink balance of organic compounds and inhibits the growth of tobacco plants.

Transcriptome profiling reveals the impact of various levels of biochar application on the growth of flue-cured tobacco plants

BackgroundBiochar, a carbon-rich source and natural growth stimulant, is usually produced by the pyrolysis of agricultural biomass. It is widely used to enhance plant growth, enzyme activity, and crop productivity. However, there are no conclusive studies on how different levels of biochar application influence these systems.Methods and resultsThe present study elucidated the dose-dependent effects of biochar application on the physiological performance, enzyme activity, and dry matter accumulation of tobacco plants via field experiments. In addition, transcriptome analysis was performed on 60-day-old (early growth stage) and 100-day-old (late growth stage) tobacco leaves to determine the changes in transcript levels at the molecular level under various biochar application levels (0, 600, and 1800 kg/ha). The results demonstrated that optimum biochar application enhances plant growth, regulates enzymatic activity, and promotes biomass accumulation in tobacco plants, while higher biochar doses had adverse effects. Furthermore, transcriptome analysis revealed a total of 6561 differentially expressed genes (DEGs) that were up- or down-regulated in the groupwise comparison under different treatments. KEGG pathways analysis demonstrated that carbon fixation in photosynthetic organisms (ko00710), photosynthesis (ko00195), and starch and sucrose metabolism (ko00500) pathways were significantly up-regulated under the optimal biochar dosage (600 kg/ha) and down-regulated under the higher biochar dosage (1800 kg/ha).ConclusionCollectively, these results indicate that biochar application at an optimal rate (600 kg/ha) could positively affect photosynthesis and carbon fixation, which in turn increased the synthesis and accumulation of sucrose and starch, thus promoting the growth and dry matter accumulation of tobacco plants. However, a higher biochar dosage (1800 kg/ha) disturbs the crucial source-sink balance of organic compounds and inhibits the growth of tobacco plants.