Yield Of Flue-cured Tobacco Research Articles

Determining nitrogen status using a universal critical nitrogen dilution curve for predicting flue-cured tobacco yield and quality

The critical nitrogen (Nc) dilution curve is considered an effective method for crop nitrogen (N) diagnosis, fertilization decision-making, and crop modeling. The Nc dilution curve is typically described using a power function curve (Nc = A1W−A2). This study established a universal Nc dilution curve and evaluated its potential application in flue-cured tobacco (Nicotiana tabacum L.) N diagnosis, yield, and quality regulation. Field experiments were conducted involving three tobacco varieties (Honghuadajinyuan, Yunyan87, and K326) and four N application rates (0 to > 90 kg N ha−1). The study was conducted in Southwest China from 2021 to 2022. The universal Nc curve obtained across all experimental data was 3.45 W−0.39. The parameter A2 was more susceptible to genotype and environment interactions than parameter A1. The uncertainty first rapidly decreased and then remained at a lower value as biomass increased. The relationship between leaf biomass and days after transplantation and accumulated growth degree was robust. The N nutrition index (NNI) and accumulated N deficiency effectively determined leaf N status and N demand, respectively. There was an inverse correlation between the NNI, leaf yield, and between the superior and medium leaf ratios. The quantitative relationship can be used to adjust the synergistic production of tobacco yield and leaf quality.

Response of agronomic and physiological traits of flue-cured tobacco (Nicotiana tabacum L.) to plant stem cell soil amendments

Black shank disease is an important factor limiting the yield of flue-cured tobacco. Soil amendments have the potential to improve soil health and increase crop yield and quality. However, the application effects of soil amendments have not been elucidated in flue-cured tobacco. Here, we conducted field experiments in the major tobacco planting area, Exploring the effects of plant stem cell soil amendments at different levels on the occurrence and physiological growth of tobacco black shank disease, The purpose is to evaluate the effectiveness of plant stem cell soil amendments and recommend feasible applied rates. Plant stem cell soil amendments are applied at four levels: T0 (0 kg ha−1), T1 (1500 kg ha−1), T2 (2250 kg ha−1), and T3 (3000 kg ha−1). Nutrient absorption, agronomic traits, dry matter quality, chemical composition, and economic benefits of flue-cured tobacco black shank disease were explored. The results showed that the application of plant stem cell soil amendments effectively reduced the incidence rate of tobacco black shank disease, and significantly improved the agronomic traits (leaf number, plant height, leaf length, and width) and dry matter quality of flue-cured tobacco. At the same time, the nutrient content (N, P, and K), the proportion of high-quality tobacco leaves, and the content of coordinated chemical components (total nitrogen, total plant alkali, total sugar, reducing sugar, potassium and chlorine) of flue-cured tobacco plants were increased. In addition, the application rate of stem cell soil amendment at 3000 kg ha−1 showed the best effect on reducing the occurrence of black shank disease, which resulted in improved tobacco yields and economic benefits to the greatest extent of flue-cured tobacco. The study indicates that plant stem cell soil amendments can significantly enhance the yield and quality of flue-cured tobacco and offers an effective method for sustainable crop production in the tobacco industry.

Exploring the effect of different application rates of biochar on the accumulation of nutrients and growth of flue-cured tobacco (Nicotiana tabacum).

Biochar application has become one of the most potential tools to improve soil fertility and plant growth for sustainable and eco-friendly agriculture. However, both positive and negative effects of biochar application have been recorded on plant growth and soil fertility. This study investigated the impact of different application rates (0, 600, 900, 1200, and 1800 kg/ha) of biochar on the soil nutrient contents, accumulation of nutrients and dry matter in different plant parts, and growth of flue-cured tobacco plants under field conditions. Results demonstrated that soil organic carbon pool and carbon/nitrogen ratio were increased proportionally with the increasing dosage of biochar, 25.54 g/kg and 14.07 g/kg compared with control 17 g/kg and 10.13 g/kg, respectively. The contents of soil total nitrogen were also significantly increased after biochar application in the middle (1.77 g/kg) and late-growth (1.54 g/kg) stages of flue-cured tobacco than in control (1.60 g/kg and 1.41 g/kg, respectively). The contents of soil nitrate nitrogen were also higher under low (600 and 900 kg/ha) application rates of biochar and reduced when higher (1200 and 1800 kg/ha) dosages of biochar were applied. However, it was observed that varying application rates of biochar had no impact on soil ammonium nitrogen content during the growth period of flue-cured tobacco plants. The nutrient accumulation (N, P, K) in different parts of flue-cured tobacco plants was significantly increased under a low application rate of biochar, which enhanced the soil and plant analyzer development values, effective leaves number, growth, dry matter accumulation, and leaf yield of flue-cured tobacco. In contrast, the high biochar application rate (1200 and 1800 kg/ha) negatively impacted nutrient accumulation and growth of flue-cured tobacco. Conclusively, the optimum application of biochar (600 and 900 kg/ha) is beneficial for plant growth, soil fertility, accumulation of nutrients, and dry matter in different plant parts. However, excessive biochar application (> 900 kg/ha) could inhibit flue-cured tobacco plant growth. This study provides a theoretical foundation for biochar application in tobacco and other crop production to obtain agricultural sustainability and economic stability.

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.

Influence of Different Herbicide Based Weed Management Practices on Growth and Yield of Flue Cured Tobacco in Northern Light Soils of Andhra Pradesh, India

Flue cured tobacco requires clean and weed free environment and thereby reduce the competition for nutrients and moisture for achieving quick early season growth. Deploying effective weed management practices play a key role in achieving better yields and quality. Field experiments were conducted at Peddpauram village of West Godavari district (Andhra Pradesh) during (Rabi) seasons of 2018-19 and 2019-20, to study the effect of different herbicide based weed management practices on growth and yield of flue cured Tobacco crop. The experiment was performed as Randomized Block Design with 11 weed management practices replicated thrice. The results recorded on growth parameters, in both the years revealed that six inter cultivations with two manual removal of weeds significantly impacted plant height (113.5 cm and 114.4 cm) and leaf area index (2.63 and 2.83) at 90 DAT over Imazethapyr applied at 0.05 kg a.i ha-1. Number of leaves plant-1 were higher with six inter cultivation and two manual removal of weeds (21.5 and 20.6) over Imazethapyr 0.05 kg a.i ha-1. Inter cultivations and manual weeding resulted in significantly enhancing yield attributes such as leaf thickness (0.143 mm and 0.143 mm for cutters and 0.183 mm and 0.173 for leaf) and lower leaf count (Number of leaves kg-1) (137 and 129) over weedy check. Application of Sulfentrazone 0.03 kg a.i ha-1 was comparable with inter cultivation and manual weeding. Sulfentrazone 0.3 kg a.i ha-1 contributed for significantly higher yield (2302 kg ha-1 and 2424 kg ha-1) over weedy check and comparable with six inter cultivations and two manual weeding operations. The application of pre emergence herbicides like Pendimethalin, Alachlor and Oxyflurfen resulted achieving higher yield levels over the application of post emergence herbicides such as Quiazalofop-p-ethyl, Fenoxaprop ethyl, Carfentrazone ethyl and Imazethapyr during both years of experimentation.

Responses of soil aggregates, organic carbon, and crop yield to short-term intermittent deep tillage in Southern China

Long-term shallow rotary tillage has reduced the soil quality and restricted the crop yield growth of farmland in Southern China. Deep tillage can effectively loosen the soil and reduce the compaction of deep soil, while no-tillage can ensure the sustainable use of soil. In this study, we selected three paddy-upland multiple cropping rotation areas in Southern China. Two tillage regimes were carried out, one (DT) where rice straw mulching was followed by deep tillage (subsoiling 30 cm) and then, for the next three years, no-tillage in the flue-cured tobacco planting season and rotary tillage in the rice planting season vs a control (RT) where no tillage after rice straw mulching was carried out, and rotary tillage was conducted in both the flue-cured tobacco planting season and rice planting season for the next three years. We compared the yield and output value of flue-cured tobacco and grain yield under DT and RT tillage regimes in the three areas, and analyzed the economic benefits brought by DT. Furthermore, we identified the effects of DT on soil aggregates, soil organic carbon (SOC), crop growth, and nutrient uptake at the experimental site in Yunyuan. Compared with RT, DT can increase the weight proportion of macroaggregates and SOC content in the 10–30 cm soil layer and improve the stability of soil aggregates in the 0–30 cm soil layer. In 2019, the mean weight diameter (MWD) and geometric mean diameter (GMD) of the 0–30 cm soil layer increased by 0.47 mm and 0.20 mm, respectively, on average. In 2020, the MWD and GMD increased by 0.33 mm and 0.11 mm, respectively, on average. DT promoted the roots of flue-cured tobacco to extend down to the 30–40 cm soil layer, and DT flue-cured tobacco plants had more leaves, higher dry matter weight, and greater N and P absorption than RT flue-cured tobacco. These results were conducive to the increase of yield and output value of flue-cured tobacco. During the three-year test period, the yield of flue-cured tobacco increased by 4%–9%, the output value increased by 7%–13%, and the net economic benefits also increased. In the paddy-upland multiple cropping rotation areas of Southern China, DT is more conducive to the improvement of dryland crop yield than paddy field crop yield. Intermittent deep tillage (one-time deep tillage and then no tillage) is expected to provide a potential way to effectively increase production, high economic efficiency, and soil improvement in promoting sustainable agricultural development and cleaner production.

Breeding for Yield, Quality and Associated Traits in the Zimbabwean Flue-Cured Tobacco (Nicotiana tabacum L.): A Review

Tobacco (Nicotiana tabacum L.) has grown to become a major cash crop and foreign currency earner in Zimbabwe. The crop’s popularity in the country is dependent on the climatic and soil conditions that promote the production of flavour style cures which are well sought after by the majority of tobacco merchants and cigarette manufacturers across the world. The success story of tobacco farming in Zimbabwe is mainly attributed to the presence of an organised research system in the form of the Tobacco Research Board (TRB) that includes a dedicated division in the research unit specialising in variety development and promotion. Improvement in yield and quality of the cured leaf has are the main objectives of flue –cured tobacco breeders. Since the beginning of research in flue cured tobacco production in Zimbabwe, a lot of effort has been dedicated to improving these and other associated traits. This review paper traces the process of breeding for improvement in yield and quality in flue-cured tobacco in Zimbabwe. It shows the methods employed and identifies some of the potential sources of genes for use in improvement in flue-cured tobacco yield and quality in present and future breeding work.

增施锌肥对烤烟农艺性状、光合特性及产量的影响

增施锌肥对烤烟农艺性状、光合特性及产量的影响

Effects of Irrigation Amount and Irrigation Frequency on Flue-Cured Tobacco Evapotranspiration and Water Use Efficiency Based on Three-Year Field Drip-Irrigated Experiments

This study aimed to determine the effect of irrigation amount and irrigation frequency on drip-irrigated flue-cured tobacco evapotranspiration (ETa), yield, and water use efficiency. Four irrigation treatment levels were imposed: 100% IRT (fully irrigated treatment, no stress), 85% IRT, 70% IRT, RFT (rainfed treatment), and high, medium, and low irrigation frequencies were set. The relationship between irrigation volume and yield is a quadratic curve. The evapotranspiration had a positive relationship with the irrigation amount. The yield of flue-cured tobacco was the highest in 2016 (wet year), and the corresponding ETa was the smallest. The irrigation water use efficiency (IWUE) in the driest year, 2017, was lower than IWUE in the wet years 2015 and 2016, and the crop water use efficiency (CWUE) had similar results for the three years. IWUE increased with irrigation amount. The effect of irrigation frequency on CWUE was not significant. The CWUE had a positive relationship with yield. No significant differences due to irrigation frequency were found for yield.

Tobacco growth, yield and quality affected by soil constraints on steeplands

Soil tillage/management systems with minimum tillage and mulch are predominant in agriculture of southern of Brazil, but little is known for tobacco crop under conservation agriculture. Objective of this study was to evaluate soil tillage systems for tobacco crop and possibilities of changing the traditional system of tobacco cropping to improve the soil physical conditions and maintain high yield. In a randomized compete block design with three replicates, six tillage/management systems were studied: inverting tillage (IT); minimum tillage after fallow (MTf); minimum tillage after oat as cover crop (MTo); no-tillage without ridge (NT); no-tillage with ridge (NTr); and no-tillage with consolidated ridge (NTrc). The experiment was installed in a small, hilly watershed, located in southern Brazil, on a soil classified as Leptosol. The main physical properties evaluated were soil moisture measured with a time domain reflectometer in 0.00–0.06, 0.06–0.12 and 0.12–0.18 m soil layers, and soil temperature at 0.05 m depth measured with termopars, both during 87 days in the growth cycle; total porosity, macroporosity, microporosity, bulk density and soil water retention curve (WRC), in 0.00–0.06, 0.06–0.12, 0.12–0.18 and 0.18–0.24 m soil layers, 30 days after transplanting (DAT) and on 135 DAT, except for WRC, in 0.00–0.06 and 0.06–0.12 m soil layers; soil mechanical resistance to penetration; root distribution; nutrient availability in root zone; crop parameters leaf area, plant height, number of leaves and yield. Soil water retention was similar among tillage/management systems and soil layers, and decreased, approximately 50%, from soil saturation up to 33 kPa water tension. Soil moisture was longest within the range of available water of no-tillage (NTrc) and minimum (MTf and MTo) systems. Soil air-space was above the critical value (0.15 m3 m−3) during most days throughout the tobacco cycle in the surface soil layer for all systems. NTrc, MTo, NT and NTr provided longest consecutive period (30, 20, 13 and 11 days, respectively) with airspace below the critical in deepest soil layer. Soil temperature amplitude during tobacco crop cycle was highest for MTo and lowest for NT. Soil temperature had greater variations in the first 55 DAT, while from 55 to 75 DAT, there was a reduction in thermal amplitude and daily temperature average for most systems, with the increase in soil moisture and crop shading. The tillage/management systems did not show differences in bulk density in the surface, but differed in subsurface soil layers, being higher in no-tillage systems, but not reach critical values. Macroporosity behaved similar to total porosity and inverse to bulk density. Soil penetration resistance increased with depth in no-tillage systems, down to approximately 0.20 m and reaching 3 MPa. In NT, soil PR of 3 MPa was reached before 0.15 m depth; in IT and MTf, soil RP was less than 2 MPa down to 0.15 m depth and close to 3 MPa in deeper depths. No-tillage systems had the shallowest root development, not exceeding the 0.18-m soil depth. Contents of K and P in the tobacco rhizosphere were high, but there was no clear relationship between plant size (small vs. large) with the nutrient content in the root zone. The MTo and no-tillage systems, except NTrc, had higher leaf area index compared with IT and MTf. At 63 DAT, NTrc had significantly lowest leaf area index. The systems with higher dry-mass (NTr) and stem length (MTo) also showed higher productivity. The greatest productivity per area was observed in tilled soil (IT, MTf and MTo), while lower productivity was observed for NT. Less tillage and more surface mulch contributed to soil physical quality improvement, while no-tillage system reached some critical physical values, particularly in the deepest soil layer. Furthermore, tillage and ridging for tobacco cropping in shallow soil reduced the effect of some soil physical stressors to tobacco growth and development. Consequently, soil management systems with winter cover crop, ridging and reduced soil tillage increased flue-cured tobacco yield, even low effect of tillage and ridging occurred for leaves qualitative classification, cropped on shallow soils on steeplands.

Research on Drought Resisting Effect of Water- Retaining Agent in Flue-Cured Tobacco Production

Pot experiment was used to simulate the effect of water-retaining agent on agronomic trait, root growth and yield of flue-cured tobacco under different drought conditions (including drought in root extension period, drought in flourishing growth period, drought in maturation stage, as well as severe, medium and mild drought in the growth duration) in the growth duration of flue-cured tobacco. The results showed that the effect of water-retaining agent on increasing area of flue-cure tobacco leaf was apparent when simulated irrigation amount was 250mm and 100mm, and water-retaining agent could effectively promote growth of flue-cured tobacco root system. While the yield of flue-cured tobacco was the highest when the simulated irrigation amount was 400mm and applied water-retaining agent was 45g/pot.

Safety evaluation of the migration in oily cosmetic products in contact with plastic packagings

In this paper, the quantitative evaluation of CO yields of flue-cured tobacco under the low-temperature heating conditions was investigated using a steady state tube furnace (SSTF) on the basis of controlled equivalence ratio method. Then the effect of temperature, ventilation condition and elemental compositions on the CO yields was studied, respectively. There was a strikingly low CO yield of heated tobacco under a fixed ventilation condition in comparison with flaming or even smouldering tobacco, and the temperature just slightly influenced the CO yield of flue-cured tobacco under the low-temperature heating states. At a fixed temperature of 450 °C, the CO yield, with reducing air velocity, first increased fast and then tended to remain unchanged. The correlation study indicates that there were no significant relationships between CO yields and the individual element except for the content of carbon and hydrogen, while the significant negative correlations of CO yields with the ratio of potassium to sulphur (K/S) at the 0.01 level appeared. Further random-Forest analysis revealed that K/S is another important factor influencing CO yields of fuel-cured tobacco under the externally heated pyrolysis conditions after hydrogen content.

Quantitative evaluation of CO yields for the typical flue-cured tobacco under the heat-not-burn conditions using SSTF

In this paper, the quantitative evaluation of CO yields of flue-cured tobacco under the low-temperature heating conditions was investigated using a steady state tube furnace (SSTF) on the basis of controlled equivalence ratio method. Then the effect of temperature, ventilation condition and elemental compositions on the CO yields was studied, respectively. There was a strikingly low CO yield of heated tobacco under a fixed ventilation condition in comparison with flaming or even smouldering tobacco, and the temperature just slightly influenced the CO yield of flue-cured tobacco under the low-temperature heating states. At a fixed temperature of 450°C, the CO yield, with reducing air velocity, first increased fast and then tended to remain unchanged. The correlation study indicates that there were no significant relationships between CO yields and the individual element except for the content of carbon and hydrogen, while the significant negative correlations of CO yields with the ratio of potassium to sulphur (K/S) at the 0.01 level appeared. Further random-Forest analysis revealed that K/S is another important factor influencing CO yields of fuel-cured tobacco under the externally heated pyrolysis conditions after hydrogen content.

Water Consumption Characteristics and Water Use Efficiency of Flue-Cured Tobacco under Different Conditions of Irrigation

The experiments were carried out in lysimeters to study water consumption characteristics and water use efficiency of flue-cured tobacco under different conditions of irrigation. By comparing the T and the invalid E of the tobacco K326, it is concluded that in the period of root extending most of the irrigation water is used for the E, in the early vigorous period, plants with all of the treatments show a T higher than the E, in the late vigorous period and the maturity, this ratio remains at 50%. Based on measured data, it was shown that the amount of irrigation water in the vigorous period had the most important influence on the yield of the tobacco.The nonlinear equation of the yield and WUE is Y=-2531.3X2+6113.8X-624.49,R2=0.7324; the equation of the yield and ET is Y=4E-0.7X3-0.0032X2+8.8458X-4806.7, suggesting that the WUE is not maximized at the highest yield of flue-cured tobacco. In the high-yield range, reducing irrigation appropriately could reach the harmonization of high production and water saving.

Effects of Different Nitrogen Levels on the Yield and Water Use Efficiency of Tobacco

Based on field experiment, the yield and water use efficiency (WUE) of tobacco under different nitrogen levels were studied in Hunan province, China. The results show that the evaportranspiration (ET) of flue-cured tobacco dealt with N2 (90kg N fertilizers per ha) gets to the maximum. In addition, the vigorous period has the maximum ET due to the critical period of water requirement. The linear relationship is established among fertilization, yield and water use efficiency. Reasonable fertilizer application can increase water use efficiency and flue-cured tobacco yield.

Spatial Variability of Soil Total Nutrients in a Tobacco Plantation Field in Central China

The spatial variability of soil total nutrient levels, which may be greatly affected by parent material, plays an important role in both agriculture and environment, especially with regard to soil fertility and soil quality. Little research has been done that addresses the spatial characteristics of total nutrients. Soil samples (0–20 cm) were taken from 111 points on an approximately 20-m grid in March 2009 using a global positioning system (GPS) to define sample locations. Sixteen soil total chemical properties were analyzed by classical statistical and geostatistical methods. Soil aluminum (Al), calcium (Ca), chromium (Cr), copper (Cu), nitrogen (N), sodium (Na), silicon (Si), strontium (Sr), titanium (Ti), and vanadium (V) exhibited strong spatial dependence, with the nugget–sill ratios ranging from 3.39% (Na) to 23.53% (Si). Soil barium (Ba), iron (Fe), potassium (K), manganese (Mn), phosphorus (P), and zinc (Zn) had moderate spatial dependence, with nugget–sill ratios of 3.39% to 23.53%. The spatial correlation distances varied from 15.7 m (Zn) to 286.5 m (Cr). The clearly patchy distributions indicated that significant positive correlations among Al, Ba, Fe, K, Mn, Na, Si, Ti, and V led to strong positional similarity. The interpolated maps of the nutrients showed the spatial distributions of the soil variables, which is helpful for better understanding their spatial variability and delineating the potential agricultural management zone. The soil total nutrient distribution maps could be used as the basis for site-specific fertilizer application to improve quality and increase yield of flue-cured tobacco in the study area.

EFFECTS OF STAND LOSS, PLANTING DATE, AND REPLANTING METHOD ON YIELD AND QUALITY OF FLUE-CURED TOBACCO

Abstract Research was conducted at one location in 2003 and two locations in 2004 and 2005 to evaluate the effects of stand loss, planting date, and replanting method on flue-cured tobacco yield and quality. Stand loss treatments included a 10%, 20%, 30%, and 40% stand loss at two and four weeks after transplanting (WAT). In recent years, early season infections by Tomato spotted wilt virus (TSWV) have caused significant stand losses in North Carolina, so an additional treatment was included to simulate the effects of plant loss to tomato spotted wilt. Simulated losses consisted of a 10%, 10%, and 20% stand loss at 3, 4, and 5 weeks after transplanting, respectively. Planting date treatments included planting at the normal transplanting date and at 2, 3, 4, and 5 weeks after the normal transplanting date. To evaluate the effects of replanting method, tobacco was replanted at 2 or 4 weeks after normal replanting on an existing row ridge, a rebedded row ridge, and a tilled and rebedded row ridge. Due to exc...

Effects of soil tillage on the yield and quality of tobacco in Croatia

The effect of soil tillage on the yield and quality of flue-cured tobacco was studied from 1998 to 2001 at the Experimental Station of the Tobacco Institute Zagreb in Croatia. The trial soil was a Luvisol with an acid reaction and a low content of colloids and organic matter. There were three treatments in the experiment: 1. autumn ploughing, 2. spring ploughing, and 3. autumn ploughing + chisel ploughing in spring. The treatments were arranged in random blocks with four replications. Soil ploughed in both autumn and spring gave higher yields of flue-cured tobacco in comparison with autumn ploughing alone. Soil ploughed only in autumn became compacted due to settling during the winter and spring because of the unstable structure and unfavourable texture.

ROTATION WITH TAGETES SP. FOR CONTROL OF ROOT-LESION NEMATODES AFFECTS FLUE-CURED TOBACCO GROWTH, YIELD, QUALITY, AND COST OF PRODUCTION

Abstract The root-lesion nematode (Pratylenchus penetrans) can cause significant reduction in tobacco yield and quality. This nematode also is a parasite of cereal rye (Secale cereale), which is a common rotation crop in tobacco areas. Row fumigation prior to transplanting tobacco in the spring is practiced by >95% of Ontario growers to control nematode populations. Planting of Tagetes sp. (marigold) also reduces nematode populations, and when used instead of rye as a rotation crop with tobacco, can provide an alternative to chemical fumigation. Field trials were conducted from 1996 to 1998 to compare the impacts of marigold rotation vs. a traditional fall rye rotation crop, with and without chemical fumigation, on flue-cured tobacco yield, quality, and cost of production. Both the marigold rotation and the non-fumigated rye rotation resulted in slightly less early season N available in the following tobacco crop year compared to the rye + fumigation check. Plant height in July and days to flowering, both...

Tobacco Budworm and Tobacco Aphid Control on Flue-Cured Tobacco, 1996

Abstract This study was conducted at the Southern Piedmont Agric. Res. and Ext. Cntr., Blackstone, VA, to evaluate various foliar insecticides for the control of TA and TBW and for their impact on the yield of flue-cured tobacco. Tobacco ‘NC 37NF’ was transplanted into experimental plots, 8 X 40 ft (2 rows X 24 plants), on 20 May. Eight treatments and an untreated check were established in a RBC design with 4 replications. A Gandy granular applicator mounted on a tractor was used to apply Temik as a side-dress treatment to the Temik + Tracer plots on 18 Jun. Foliar treatments for TBW control were applied on 25 Jun and 19 Jul using a CO2-pressurized backpack sprayer that delivered 28 gpa at 60 psi through TX-10 nozzles (3/row). Foliar applications of Provado and Orthene in combination with Silwet 77L (4 fl oz/acre) were applied for TA control on 5 Jul and 8 Aug. Before the first application for TBW control, TBW larvae were collected from untreated fields and released at one larvae per plant on 10 plants per plot on 25 Jun and natural infestations were assessed on 10 additional plants in each plot. Before the second application for TBW, newly hatched larvae were released at 1 larva/plant on 20 plants/plot on 18 Jul. TBW were counted on 20 plants/plot at 3, 7, and 14 DAT. On 20 Aug, TBW damage was rated on a scale of 0 to 5: 0 = no damage and 5 = severe damage. TA were counted on the upper 4 leaves of 10 plants/plot. TA damage was rated on a scale of 0 to 10: 0 = no sign of TA infestations; 10 = very severe damage. The tobacco was harvested and cured and yield was determined. Data were analyzed by ANOVA and significantly different means were separated by Waller-Duncan K-ratio t-test (K - 100). TA data were transformed to log10 (x + 1) before analysis. TBW data were transformed to SQRT (X + 0.25). Actual means are presented in the table.