Yield Of Tobacco Research Articles

Integrative analysis of transcriptome and metabolome provides insights into the underlying mechanism of cold stress response and recovery in two tobacco cultivars

Low temperature is one of major environmental factors limiting the growth, quality and yield of tobacco. However, the molecular mechanism of tobacco cold response remains largely unknown. Here, integrated biochemical, transcriptomic and metabolomic analyses were carried out on tobacco leaves of cold-tolerant cultivar Xiangyan7 and cold-sensitive cultivar Taiyan8 under short- /long-term cold stress and recovery. Physiological and biochemical results showed that Taiyan8 was sensitive while Xiangyan7 was insensitive to cold stress. Integrated transcriptomics and metabolomics analysis revealed several key pathways in tobacco response to cold, including flavonoid biosynthesis, glutathione metabolism, zeatin biosynthesis, phenylpropanoid biosynthesis, starch and sucrose metabolism; two important pathways in the recovery, namely glyoxylate and dicarboxylate metabolism, flavonoid biosynthesis. The two cultivars had similar mechanisms in response to long-term cold stress. Whereas, more enriched pathways were identified in Taiyan8 under short-term stress, and the specifically enriched pathways were mainly involved in amino acid metabolism. By analyzing the metabolites involved in these pathways, a total of 26 key metabolites were screened out. These metabolites contents and biochemical indicator values were used as trait data for correlation analysis with gene expression modules, and 5 highly correlated modules were found. Within these modules, we identified 12 key candidate genes weighted as module hub genes, which involved ATPases, chlorophyll A-B binding protein, S-adenosine methionine decarboxylase, chalcone and stilbene synthases, UDP-glucosyltransferases, alcohol dehydrogenase, abhydrolase, proteins with ankyrin-repeat domains. The expression profiles of these genes further verified their involvement in tobacco cold response and recovery. These findings provide new insights into the regulatory networks of tobacco response to cold stress. • Compared with Taiyan8, Xiangyan7 is relatively insensitive to low temperature stress. • There are some similar mechanisms in the two cultivars response to long-term cold stress. • Amino acid metabolism is specifically enriched in Taiyan8 under short-term cold stress. • Five correlated modules are identified through module-trait relationship analysis. • Twelve key candidate genes are expression validated and discussed.

Evaluation of the use of polyethylene mulches in the production of organic flue‐cured tobacco

AbstractWeed and insect pest management in organic flue‐cured tobacco (Nicotiana tabacum L.) is challenging due to lack of effective and affordable approved control options. Polyethylene plastic mulches are used in vegetable and berry production to manage in‐row weed populations, buffer soil temperatures, limit rain‐induced soil loss, and maintain soil moisture. Mulch color can affect plant growth, soil temperature, and insect pest populations in vegetable crops. Field trials were conducted in Kinston, NC, in 2019 and 2020 and Whiteville, NC, in 2020. Red, white, black, and silver polyethylene mulch (with drip irrigation) and bare ground with and without drip irrigation were compared to evaluate effects on tobacco yield, quality, and pests. Tobacco yields were elevated by at least 290% in mulch treatments compared with bare ground with irrigation in 2020 (p < .05), but did not differ in 2019 due to precipitation and temperature differences that conveyed an increased benefit in 2020. Opaque mulches successfully suppressed weed emergence. Fewer aphids were present in highly reflective silver mulch than all other treatments with irrigation in both years. Black and red mulch warmed soils while silver cooled them, affecting nitrogen mineralization rates. Higher levels of plant available nitrogen were maintained in mulch treatments, but tobacco nitrate levels and overall quality were not affected. These results are consistent with plasticulture research in other crops. The factors that make plasticulture well suited to intensively managed, high value crop production may benefit organic flue‐cured tobacco production especially when grown in rotation with other intensively managed crops.

Nematicidal Activity of Burkholderia arboris J211 Against Meloidogyne incognita on Tobacco.

Root-knot nematode (Meloidogyne incognita) is the most widespread nematode affecting Solanaceae crops. Due to the lack of effective measures to control this nematode, its management can be achieved, using biocontrol agents. This study investigated in vitro efficacy of the antagonistic bacterial strain J211 isolated from tobacco rhizosphere soil against M. incognita, and further assessed its role in controlling nematodes, both in pot and field trials. Phylogenetic analysis of the 16S rRNA gene sequence of strain J211 assigned to Burkholderia arboris. Culture filtrates B. arboris J211 exhibited anematicidal activity against the second-stage juveniles (J2s) of M. incognita, with a 96.6% mortality after 24 h exposure. Inoculation of J211 in tobacco roots significantly reduced the root galling caused by M. incognita, both in pot and field trials. Meanwhile, plant growth-promoting (PGP) traits results showed that J211 had outstanding IAA-producing activity, and the IAA production reached 66.60 mg L−1. In the field study, B. arboris J211 also promoted tobacco growth and increase flue-cured tobacco yield by 8.7–24.3%. Overall, B. arboris J211 as a high-yielding IAA nematicidal strain effectively controlled M. incognita and improved tobacco yield making it a promising alternative bionematocide.

Effects of Supplementary Irrigation and Nitrogen Fertilization on Characteristics of Sun Cured Tobacco in Semi-Arid Conditions

ABSTRACT Nitrogen and water should be applied at the right time and amount to obtain optimum crop yield in arid and semi-arid regions. The study was carried out in 2017–2018 to investigate the effects of different supplementary irrigation levels applied after harvests, and different nitrogen sources on water use efficiency (WUE), yield and quality characteristics of sun-cured tobacco. The study included five different nitrogen sources (N1: zero-nitrogen, N2: ammonium nitrate, N3: ammonium sulfate, N4: calcium ammonium nitrate, and N5: urea) and four different irrigation treatments (I0:No irrigation; I33:66% deficit, I66:33% deficit and I100:100% full irrigation). The effects of nitrogen sources and supplementary irrigation treatments on plant height, leaf number, leaf width, leaf height, yield, quality grade, sugars, nicotine, phenolics, WUE and irrigation water use efficiency (IWUE) were statistically significant. Seasonal crop evapotranspiration values ranged between 117.7 and 235.3 mm. The highest WUE 1.65 kg m−3 and IWUE: 10.48 kg m−3 were recorded in I33 treatment. Plant characteristics were different between nitrogen sources; however, the results did not indicate a prominent nitrogen form. The results for supplementary irrigation revealed that the I100 treatment in semi-arid conditions increased the sun-cured tobacco yield by 22% with acceptable quality improvements. The gross income increased 1705 $ ha−1 with the increase in tobacco yield and sale price per hectare.

Comparative Proteomic Analysis by Isobaric Tags for the Relative and Absolute Quantification Reveals the Responses of Tobacco (Nicotiana tabacum L.) Roots to Different Soil Types.

Tobacco (Nicotiana tabacum) root affects the yield and quality of tobacco leaves. To gain insight into the responses of the tobacco root system to different soil types, we integrated morphological characteristics, the physiological index, the metabolic pathways of the root system, and the aboveground biomass of tobacco cultivated in limestone soil (LS), paddy soil (PS), and red soil (RS). Compared with plants growing in LS and PS, the chemical composition of tobacco leaves in RS tended to be coordinated. Red soil facilitated the accumulation of aboveground and belowground biomass of flue-cured tobacco and had the most significant effect on the dry matter quality of the roots. In addition, it promoted an increased root length, root surface area (RSA), root volume, and a higher number of root forks and improved root vigor and nitrate reductase (NR) activity; however, the activities of superoxide dismutase (SOD) and peroxidase (POD) were decreased. We studied differentially the abundant proteins (DAPs) of the flue-cured tobacco roots cultivated in different soil types by isobaric tags for the relative and absolute quantification (iTRAQ) of the proteomic profiles of cultivar. In total, 699, 650, and 569 differentially abundant proteins (DAPs) were identified from limestone soil (LS) vs. PS, LS vs. RS, and PS vs. RS, respectively, including 412/287, 291/359, and 323/246 up-/downregulated proteins, respectively. These DAPs were mainly involved in starch and sucrose metabolism, phenylalanine metabolism, the biosynthesis of secondary metabolites, microbial metabolism in different environments, and ribosomes. The parallel reaction monitoring (PRM) and quantitative reverse transcription PCR (qRT-PCR) analysis showed that the results of the iTRAQ proteomics were reliable. Overall, our study facilitates a new understanding of the responses of tobacco roots to different soil types at the protein level.

Application of Manure Rather Than Plant-Origin Organic Fertilizers Alters the Fungal Community in Continuous Cropping Tobacco Soil.

Continuous cropping leads to the development of serious fungal diseases in tobacco plants and depleted yield of tobacco (Nicotiana tabacum), which can be mitigated by organic fertilization. Yet, we know little about how organic fertilizers affect the fungal community of continuous cropping tobacco soil. In this study, we investigated the soil fungal community after 11 years of tobacco planting with chemical fertilization (CF) or chemical fertilization combined with organic fertilizers obtained from plant or animal origin, including oil cake (CFO), straw (CFS), and farmyard fertilizer (CFM). The predominant phyla of Ascomycota (70%) and Mortierellomycota (15%) were identified in all the treatments. A significantly higher proportion of Pyrenochaetopsis and lower relative abundance of Sordariomycetes were observed in the CFM group compared to the controls. Compared to CF and non-fertilized control (CK), CFO and CFS led to higher species richness (P < 0.05), while CFM led to a less uniform fungal community, indicated by lower Shannon and higher Simpson diversity indices (P < 0.05). Pearson’s correlation and redundancy analysis suggested that fertilizations primarily influenced the fungal community by altering the soil nutrient conditions, among which soil organic carbon and total phosphorus significantly correlated with the fungal diversity and community composition (P < 0.05). Notably, FUNGuild annotation suggested that while other treatments showed no significant effect on the fungal trophic modes, CFM strongly increased the abundance of saprotrophic fungi by more than 30% (P < 0.05), thus preventing the prevalence of potential pathotypes and symbionts. The results suggest that the type of organic fertilizers is essential to the long-term effects of organic application on the fungal community, and the animal-origin manure seems to be a better choice than plant-origin materials in continuous cropping tobacco fields.

Building Process of Potato Virus Y (PVY) Management on Tobacco Plants in the Northern Vietnam

In recent years, some viral diseases have been increasing in the tobacco-growing regions of Vietnam and causing serious damage to the tobacco yield and quality. If it has no effective control, the viral diseases will injure serious harm in the tobacco field next time. Based on the research results in the prevention of viral diseases from 2016 to 2021, the Vietnam Tobacco Institute has built a process to control Potato Virus Y that harms the tobacco plants in Vietnam. During the experiment and application in tobacco cultivation practice, the process was effective against PVY disease. The application of the process, the disease rate and disease index of PVY were significantly reduced in the tobacco field, contributing to increasing yield, quality, and income for tobacco farmers. The insecticides and antivirus drugs made according to the process have increased their effectiveness, do not harm the growth and development of tobacco plants, little have residues in tobacco production. This process can control many other viral diseases on tobacco plants.

Heterosis and inheritance studies on morphological and chemical characters of tobacco

AbstractHybrid breeding provides excellent convenience in obtaining products that meet the demands of producers and the market. This study aimed to develop new hybrid tobacco (Nicotiana spp.) varieties that meet the demands of tobacco producers and buyers to provide continuity in homogenous products and genetically to determine the effects of parameters investigated. In this study, five parents (OZE S2 [P1], OZE S1 [P2], Katerini [P3], Prilep [P4], and Bozcakaldere [P5]) with different characters and 10 hybrid genotypes obtained from the five parents were tested in five different locations in Aktekke in 2018, and Aktekke, Kelikler, Seyhulas, and Huseyinbeyli in 2019. The morphological and chemical parameters of genotypes were significantly (p &lt; .05 and p &lt; .01) different from each other. The average leaf width, leaf length, nicotine content, yield, and phenolic contents of the hybrids were higher than those of the parents (respectively hybrids and parents; 17.2–15.3 cm, 29.6–27.1 cm, 0.81–0.72%, 1,982–1,720 kg ha–1, 9.30–8.26 g kg–1). The results can be attributed to the slight influence of environmental factors and the high performance of hybrids. The results showed that especially the effect of leaf width on yield is higher than the leaf length and number of leaves, and the leaf is more important in terms of heredity. In addition, the results revealed that the nicotine ratio could be used as the primary selection criteria and the reducing sugar ratio as the main selection criteria for the next generations. Tobacco yield and quality grade index of P1×P3, P1×P4, and P1×P5 hybrids (respectively 2,030, 2,050, 2,060 kg ha–1 and 56, 52, 55%) were higher compared with the other hybrids.

Rapid quantification of alkaloids, sugar and yield of tobacco (Nicotiana tabacum L.) varieties by using Vis–NIR–SWIR spectroradiometry

Tobacco genetic improvement programs, as well as the tobacco industry, require techniques that allow the estimation of its attributes in a fast and cheap way. The use of remote sensing through visible, near infrared and short-wave spectroscopy (Vis-NIR-SWIR) has been studied aiming to meet such demand. Thus, the aim of this work was to evaluate the use of Vis-NIR-SWIR spectroradiometer as a rapid tool to estimate alkaloids, sugars and yield of tobacco varieties. For that purpose, a study was carried out in a greenhouse with plants grown in pots (18 dm−3) containing nutrient solutions. The experimental design was completely randomized, with 30 treatments (tobacco varieties) and 10 repetitions. Tobacco leaf reflectance was collected at 13, 34 and 68 days after transplantation (DAT) with a plant-probe device connected to the spectroradiometer by an optical fiber. Subsequently, leaf analysis of alkaloids, sugars and yield were performed, and such attributes were estimated by using the Partial Least Squares Regression (PLSR), combined with the following pre-processing (PP) techniques: multiplicative scatter correction (MSC), Savitzky-Golay (SG) and standard normal variate (SNV). The results showed presence of typical inflections of chemical and structural components of the plants, which allowed obtaining PLSR models with R2p and RPDp superior to 0.71 and 2.27, respectively, for all PP techniques and attributes evaluated. The most important wavelengths were well distributed within the three operating ranges of the spectroradiometer (Vis-NIR-SWIR). Thus, the methodology proposed by this research was able to simultaneously determine all the three attributes (alkaloids, sugars and yield) with excellent predictive capacity. This is a promising result for genetic improvement and processing of tobacco (as well as other crops), since it is necessary to evaluate a large number of samples within a short period and at a low cost.

On-Line Monitoring of the Tobacco Leaf Composition during Flue-Curing by Near-Infrared Spectroscopy and Deep Transfer Learning

The yield, quality, and output value of tobacco leaves are strongly affected by the flue-curing conditions. To effectively control the flue-curing and guarantee quality, it is necessary to quantify the chemical composition of tobacco leaves and provide timely feedback during this process. Therefore, the practicability of on-line monitoring of moisture, starch, protein, and soluble sugars for tobacco leaves by near-infrared (NIR) spectroscopy and deep transfer learning was explored. The results showed that the use of an NIR spectrometer equipped with a fiber-optic probe with a deep learning algorithm accurately predicted the content of these components during the curing process. The convolutional neural networks model showed greater potential for on-line monitoring than partial least squares and support vector machines. Furthermore, a network-based deep transfer learning strategy was crafted to include seasonal and temperature variability to accurately predict samples from a new harvest season in a curing barn. The overall studies indicated the efficacy of NIR diffuse reflectance spectroscopy as a rapid and nondestructive method for on-line and simultaneous determination of moisture, starch, protein, and soluble sugars in the flue-curing process to assist in making decisions.

Water use efficiency, yield and quality of tobacco (Nicotiana tabacum L.) using negative pressure irrigation

Plant available water can affect tobacco yield and quality, but in a greenhouse environments fluctuating water availability can be controlled. Compared with conventional irrigation (CK), typically used in greenhouse, negative pressure irrigation (NPI) can enhance water use efficiency (WUE) and nutrient uptake efficiency (NUE), while also decreasing water consumption. Pot experiments were conducted to investigate differences in CK and NPI water pressure (−5kpa, −10kpa and −15kpa) on growth, WUE, NUE, yield and quality of tobacco (Nicotiana tabacum L.). Results suggest that water consumption and nutrient uptake efficiency improved with water pressure; The biomass of plant organs reflected a pattern of: leaf > stem > root. Compared with CK, NPI can improve WUE by 110.90% and decrease water consumption by 42.28%, and increase yield by 23.09%. Supply water pressure can significantly improve the flavor of Nicotiana tabacum L.. Our results suggest that NPI is a better method of irrigation for Nicotiana tabacum L. given the steadier supply of water during the growth period of tobacco.

Thymol improves salinity tolerance of tobacco by increasing the sodium ion efflux and enhancing the content of nitric oxide and glutathione

Background and objectiveSalt stress is one of the most important abiotic stresses affecting the yield and quality of tobacco (Nicotiana tabacum). Thymol (a natural medicine) has been widely used in medical research because of its antibacterial and anti-inflammatory activities. However, the influence of thymol on the root growth of tobacco is not fully elucidated. In this study, the regulatory effects of different concentrations of thymol were investigated.MethodologyHere, histochemical staining and biochemical methods, non-invasive micro-test technology (NMT), and qPCR assay were performed to investigate the effect of thymol and mechanism of it improving salinity tolerance in tobacco seedlings.ResultsIn this study, our results showed that thymol rescued root growth from salt stress by ameliorating ROS accumulation, lipid peroxidation, and cell death. Furthermore, thymol enhanced contents of NO and GSH to repress ROS accumulation, further protecting the stability of the cell membrane. And, thymol improved Na+ efflux and the expression of SOS1, HKT1, and NHX1, thus protecting the stability of Na+ and K+.ConclusionOur study confirmed the protecting effect of thymol in tobacco under salt stress, and we also identified the mechanism of it, involving dynamic regulation of antioxidant system and the maintenance of Na+ homeostasis. It can be a new method to improve salinity tolerance in plants.

Deep tillage reduces the dependence of tobacco (Nicotiana tabacum L.) on arbuscular mycorrhizal fungi and promotes the growth of tobacco in dryland farming.

The traditional shallow tillage method reduces soil quality and affects the efficiency of agricultural production. Using conventional rotary tillage (12 cm) as the control, Yunyan 87 as the test variety, and paddy soil as the test site, we studied the effects of deep tillage (subsoiling 30 cm) on soil nutrients, arbuscular mycorrhizal fungi (AMF), and tobacco (Nicotiana tabacum L.) growth. The results showed that deep tillage increased the content of organic carbon, available phosphorus (AP), and available potassium (AK) in the 20-40 cm soil layer. The AMF community was also affected by deep tillage. Glomus, the dominant genus in both groups, increased significantly in soil after deep tillage. The AMF colonization rate was lower than that of conventional rotary tillage. Deep tillage was beneficial for tobacco growth in the middle and late stages. The root growth and nutrient content of the tobacco plants increased. Deep tillage significantly improved the output value of tobacco plants. Deep tillage is conducive to improving soil fertility, promoting the vigorous growth of roots, reducing the dependence of tobacco on AMF, and promoting the high quality and yield of tobacco in the drylands of Hunan.

Effect of vermicompost on yield and quality of Kemloko tobacco

The role of organic fertilizer is essential as an ameliorant of soil for tobacco cultivation. This study aimed to determine the effect of organic fertilizer types and N fertilizer on soil chemical characteristics, yield, and quality of tobacco. The study was carried out in the field experimental station, located in Glapansari village of Temanggung in 2017. The research was arranged in a split-plot design with two factors and three replications. The first factor as the main plot is two organic fertilizer types (vermicompost and manure). The second factor as the subplot is N fertilizer consisting of three levels (90, 120, and 150 kg N ha−1). The result showed that the effect of vermicompost and manure was not significantly different on soil chemicals, except on soil C content. At the same level of N rate, vermicompost gave a higher tobacco yield than manure fertilizer. Vermicompost with the lowest N level (90 kg kg N ha−1) produced a high tobacco crop index (crop value index). Vermicompost can reduce inorganic N fertilizer input and could be used as an ameliorant of tobacco dryland.

Overexpression of a Nitrate Transporter Ntnpf2.11 Increases Nitrogen Accumulation and Yield in Tobacco

Overexpression of a Nitrate Transporter Ntnpf2.11 Increases Nitrogen Accumulation and Yield in Tobacco

Improving the production and quality of virginia tobacco through topping and suckering : A Review

Tobacco production in Indonesia continues to increase along with the number of requests tobacco industry due to the shift in consumer tastes from smoking kretek cigarettes to white. Virginia’s domestic tobacco has not been able to cover the needs of the tobacco industry, so part of this is fulfilled from imported tobacco. In terms of cultivation, the emergence of flowers resulted in stunted growth and decreased quality of tobacco. Increasing tobacco production and quality can be done by applying Good Agriculture Practices (GAP) by cutting the top (topping) and removing side shoots (suckering). The timely application of topping and suckering can increase the production of tobacco leaf accompanied by an increase in the quality of the tobacco leaves produced. Based on the research results, it is known that topping and suckering treatment can increase production by 60-80% and nicotine levels by 40-60%. The application of suckericide can reduce labour costs without reducing the yield, quality, and chemical content of tobacco. The impact of increasing production and quality of Virginia tobacco will increase farmers’ bargaining power and economy.

Available Contents and Spatial Distribution of Soil Microelements of Tobacco Fields in Liupanshui City

The contents of soil microelements can affect the growth, yield and quality of tobacco, but it is not clear of the status quo of soil microelements in tobacco fields in Liupanshui city. In this study, soil samples of the plough layers (0 - 20 cm) were collected from January to March in 2021 from 500 typical tobacco fields in Liupanshui City (100, 180 and 220 fields in Zhongshan, Shuicheng and Panzhou, respectively), the particle size composition, pH, the contents of organic matter (OM), available boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo) and zinc (Zn) were measured and discussed. the results show that the mean contents of B, Cu, Fe, Mn, Mo and Zn are 0.92, 2.55, 66.47, 47.26, 0.39 and 3.96 mg/kg, respectively, and among which, B, Cu and Zn are at the high grades while Fe, Mn and Mo are at the very-high grades. There are significant differences in B, Fe and Zn among the three regions, while Cu is significantly different between Zhongshan and Shuicheng, Mn is significantly different between Panzhou with Zhongshan and Shuicheng, and Mo is significantly different between Zhongshan and Panzhou. The proportions of fields deficient in microelements are relatively low, no field is Fe-deficient, and the fields deficient in Mo, B, Cu, Zn and Mn are only account for 10.40%, 9.40%, 7.40%, 2.80% and 2.00% of the total fields respectively. B-deficient fields (green and light green colors, the same below) are mainly scattered in the northwest of Zhongshan and in the north and south of Panzhou, Cu-deficient fields mainly in the middle of Shuicheng and Panzhou, Mn-deficient fields mainly in northern Zhongshan, central Shuicheng and north of Panzhou. Mo-deficient fields are mainly in the middle of Shuicheng and the middle and east of Panzhou, while Zn-deficient fields are mainly in the middle of Shuicheng and the middle and east of Panzhou. Altitude is negatively correlated with Mn (P < 0.05), pH is negatively correlated with B (P < 0.05), Fe and Mn (P < 0.01), and OM is positively correlated with Fe and Zn (P < 0.01). Sand is negatively correlated with B (P < 0.05), Mn and Mo (P < 0.01), but positively correlated with Zn (P < 0.01). Silt is positively correlated with Mo (P < 0.05); clay is positively correlated with B (P < 0.05) and Mn (P < 0.01), but negatively correlated with Zn (P < 0.01). In conclusion, most of the fields do not need to apply micro-fertilizers in Liupanshui, but the fields deficient in microelements should be considered to use the corresponding fertilizers.

Exploitation of heterosis in tobacco breeding in Brazil

This study estimated the general and specific combining abilities and mean heterosis of tobacco lines of the varietal groups Flue-Cured Virginia (FCV) and Air-Cured Burley (BY). In addition, possible advantages and an improved strategy of using hybrids in tobacco breeding in the tropics were discussed. Ten BY and 13 FCV lines were crossed in a diallel mating design. The hybrids and parental lines were evaluated at two locations in Southern Brazil. The mean heterosis was 5.37% for FCV and zero for BY lines, although higher than 15% in some combinations. The occurrence of heterosis indicates dominance in the control of tobacco yield. Tobacco breeding programs must focus primarily on improving the performance of lines per se and then on the identification of the best hybrid by testing combinations.

𝘚𝘰𝘳𝘨𝘩𝘶𝘮 𝘴𝘶𝘥𝘢𝘯𝘦𝘯𝘴𝘦 AS COVER CROP AND BIOLOGICAL PRODUCTS ON INCIDENCE OF 𝘚𝘤𝘭𝘦𝘳𝘰𝘵𝘪𝘯𝘪𝘢 𝘴𝘤𝘭𝘦𝘳𝘰𝘵𝘪𝘰𝘳𝘶𝘮 AND YIELD OF TOBACCO

Brazil is the world's second largest producer of tobacco (Nicotiana tabacum) with part of its production concentrated in Santa Catarina. The incidence of Sclerotinia sclerotiorum in tobacco areas has promoted a decrease in productivity, and control alternatives are needed due to the limited use of agrochemicals for the crop. With the hypothesis that the sudan grass (Sorghum sudanense) and Trichoderma harzianum reduce the attack of S. sclerotiorum in tobacco crops on the coast of Santa Catarina; the objective here was to test the incidence of S. sclerotiorum and the use of sudan grass associated with biological products on tobacco yield. A study with application of straw from sudan grass (SG); SG + Trichoderma harzianum (TH); SG + TH + Melaleuca alternifolia essential oil; SG + TH + Bacillus subtilis Bacillus licheniforimis; and SG + TH + Bacillus subtilis in a conventional system of tobacco were carried out in São João do Sul and Santa Rosa do Sul, Santa Catarina. Results showed that in São João do Sul, there was no difference between the treatments in yield and incidence of S. sclerotiorum. However, in Santa Rosa do Sul, the association of SG + TH, SG + TH + B. subtilis B. licheniforimis, and SG + TH + B. subtilis presented greater yields than others. In both sites, sudan grass and associations promoted a higher financial return compared to control. More studies are requested to elucidate the physiological effect of biological products and sudan grass as a cover crop on tobacco.

Вплив густоти насаджень на біометричні показники і продуктивність рослин тютюну в умовах Центрального Лісостепу України

Goal. To study the influence of different densities of planting tobacco varieties on the growth, development, plant yield, and quality of tobacco raw materials in the Central Forest-Steppe of Ukraine. Methods. Field (laying the experiments, phenological observations and biometric measurements, morphological description of plants), laboratory (assessment of yield and quality of tobacco raw materials), statistical (mathematical processing of research results). Results. Experiments were performed based on the Tobacco Research Station of the NSC “Institute of Agriculture of NAAS”. They showed that the biometric parameters of tobacco plants depended on the weather conditions, cultivation, and crop density. With the increasing density of plantations in tall varieties (Krupnolystyi and Virginia cultivars) plant height decreased by 1.5–15 cm and amounted to 166–192 cm (57 thousand plants/ha). For low-growing tobacco varieties (Berlei cultivar) the optimal planting density was 48 thousand plants/ha, at which the height of plants was 127–161 cm. The number of leaves on plants depended on their height and was 19.7–25.7 pieces. Their largest size was found at plantation densities of 40 thousand plants/ha. The maximum yield of tobacco was obtained at plantation densities of 57 thousand plants/ha in tall varieties and 48 thousand plants/ha — in low-growing varieties. However, increasing the density of plantations reduced the yield of marketable raw materials by 2.3–4.8%. The highest marketability of raw tobacco was characterized by varieties Berley 9 and Temp 321, whose indicators were 73.9 and 74.8%, respectively, with plantation densities of 40 thousand plants/ha. For large-leaved tobacco varieties with plantation densities of 40,000 plants/ha, it was easier to break leaves by hand, and leaves that remained on the plant were less mechanically damaged, i.e. productivity at harvesting works increased. Conclusions. For soil and climatic conditions of the Central Forest-Steppe of Ukraine the best density of plantings for tall tobacco varieties (Krupnolystyi and Virginia cultivars) should be considered 57 thousand plants/ha, and for low-growing varieties (Berley cultivar) — 48 thousand plants/ha.