Effects of Applying Trace Clements on Yield and Quality of Flue-cured Tobacco Cu

Xingchuan HU, Yifeng WANG, Yufeng DU, Yukuo HU, Shanhe XU*

1. China Tobacco Fujian Industrial Co., Ltd., Xiamen 361012, China; 2. Longyan Branch of Fujian Cigarette and Tobacco Co., Ltd., Longyan 364000, China; 3. Sanming Branch of Fujian Cigarette and Tobacco Co., Ltd., Sanming 365000, China

Abstract [Objectives] To optimize the fertilization technology of flue-cured tobacco Cuibi-1. [Methods] From 2015 to 2016, the experiment of spraying Saikun multi-trace element water-soluble fertilizer was carried out. [Results] 7 d and 14 d after transplanting tobacco seedlings, 3 750 mL/ha, 300 times diluted Sakun multi-trace element aqueous solution was sprayed, the growth period of Cuibi-1 in the field was extended by 3-5 d. The incidence of mosaic disease at the rosette stage and granuville wilt at the foot leaf harvesting and curing stage decreased by 4.50-20.85 kg/ha, the yield increased by 67.8-68.7 kg/ha, the proportion of high-quality tobacco increased by 1.29-3.01 percentage points, and the output value increased by 2 692.5-3 441 yuan/ha, the sensory smoking quality has improved. [Conclusions] Increasing the application of multiple trace elements can increase the economic benefit and industrial use value of tobacco leaf production of Cuibi-1.

Key words Flue-cured Tobacco, Cuibi-1, Fertilizer, Trace element, Yield, Smoking quality

1 Introduction

Mineral elements are the material basis for tobacco growth and development. Although the content of trace elements in tobacco is low, they play an important role in tobacco plant growth and physiological metabolism[1]. At present, the research on the physiological and biochemical effects of trace elements on tobacco has received widespread attention from scholars[2-5]. Extensive studies have proved that the application of trace element fertilizers can effectively increase the yield and value of tobacco, and increase the industrial use value of tobacco[6-7]. Most researches focus on one or a few trace elements[8-10], however, in actual production, it is often necessary to apply multiple trace elements at once to promote the growth and development of tobacco plants[11]. As a typical characteristic high-quality variety of flue-cured tobacco with fresh sweet scent, Cuibi-1 has been in great demand in recent years. At present, the research on the supporting fertilization technology of Cuibi-1 mainly focuses on macro elements[12-14], while there is no report on the application of multiple trace elements. In this situation, research the effects of applying multiple trace elements on the growth and development, pests and diseases, yield, economic characteristics and smoking quality of Cuibi-1 has practical significance for further improving the supporting fertilization technology of Cuibi-1 and raising the tobacco production level and industrial availability of of Cuibi-1.

2 Materials and methods

2.1 General situation of experimental siteThe experiment was carried out in Xiachuan Village of Banmian Town, Youxi County, Sanming City, Fujian Province from 2015 to 2016. The soil type was paddy soil, the previous crop was rice, the fertility was medium and uniform, 0-20 cm plow layer organic matter 19.29 g/kg, alkali hydrolyzable nitrogen 132.45 mg/kg, available phosphorus 25.76 mg/kg, exchangeable potassium 63.74 mg/kg, exchangeable calcium 155.35 mg/kg, exchangeable magnesium 23.23 mg/kg, available copper 2.07 mg/kg, available zinc 2.73 mg/kg, and available boron 0.15 mg/kg.

2.2 Trace element fertilizerThe trace element used in the experiment was a Saikun water-soluble fertilizer special for tobacco[Nongfei (2015) Zhunzi No.4667], mainly containing zinc, boron, manganese, and iron, with a total content of Fe+Cu+Zn+Mn+B ≥ 30 g/L, and also containing Al, Ti, Si, Sr, V and Rb. These materials were purchased by China Tobacco Fujian Industrial Co., Ltd. through bidding.

2.3 Experiment designThe experiment set 2 treatments, and each treatment was repeated 3 times. Treatment 1: sprayed Saikun trace element fertilizer 7 d and 14 d after transplanting tobacco seedlings, at a dosage of 3 750 mL/ha each time, diluted with 1 125 kg of water 300 times; Treatment 2: control group, sprayed the same volume of water at the same stage. For each treatment of 90 m2, applied ternary compound fertilizer at a ratio of 97.5 kg/ha of pure nitrogen, N∶P2O5∶K2O=1∶0.8∶3.0, and a ratio of base fertilizer to topdressing of 6∶4, and the plant spacing of tobacco seedling transplanting rows was 1.2 m×0.5 m. The field management was carried out with reference to theTechnicalStandardsforTobaccoProductioninYouxiBaseinSanmingCityofChinaTobaccoFujianIndustrialCo.,Ltd.

2.4 Observation indicators

2.4.1Field growth period. For each treatment, 10 consecutive fixed-point tobacco plants were selected to observe the time when the tobacco plants entered the rosette stage, budding stage, mature harvest of lower leaves, and the end of harvest.

2.4.2Plant diseases and insect pests. Surveyed the occurrence of major diseases such as mosaic disease in tobacco plant rosette stage and granuville wilt at the foot leaf harvesting and curing stage in accordance with the GB/T 23222-2008 standard.

2.4.3Economic traits of tobacco. In accordance withTechnicalStandardsforTobaccoProductioninYouxiBaseinSanmingCityofChinaTobaccoFujianIndustrialCo.,Ltd., mature tobacco leaves were harvested and cured in a timely manner; after curing, the tobacco leaves were classified according to the GB 2635-1992 standard, and the yield and the output value were calculated.

2.5 Smoking qualitySensory evaluation was performed in accordance with NY/YCT 008-2002 standard, and a professional tobacco evaluation committee containing 5-7 personnel made blind evaluation for each treatment of C3F and B2F single-material cigarette, and then calculated the average value. The smoking indicators included quality of aroma, volume of aroma, aftertaste, offensive taste, irritancy, combustibility, and ash color[15].

2.6 Data processingWith the help of Microsoft Excel 2013 and SPSS 11.5 statistical software, we processed and analyzed the data, and used theLSDmethod to make multiple comparisons.

3 Results and analysis

3.1 Field growth period of different treatments of Cuibi-1 tobacco plantsFrom Table 1, it can be seen that the budding period, lower leaf harvesting and harvesting end dates were delayed by 2, 2 and 3 d in 2015 treatment 1 compared with treatment 2, and the budding period, lower leaf harvesting and harvesting dates of 2016 treatment 1 were delayed 1, 3 and 5 d compared with treatment 2, indicating that applying trace elements can effectively extend the field growth period of tobacco plants, and promote the full development and maturity of tobacco plants.

3.2 Field incidence rate of different treatments of Cuibi-1 tobacco plantsFrom Table 2, it can be seen that in 2015-2016, the incidence of major tobacco diseases such as mosaic disease in tobacco plant rosette stage and granuville wilt at the foot leaf harvesting and curing stage of treatment 1 showed a downward trend compared with treatment 2, the difference between treatments in 2015 was 0.3%, which was not significant; the difference between treatments in 2016 was 1.39%, which was significant. These indicate that applying trace elements can reduce, to a certain extent, the incidence rate of mosaic disease in tobacco plant rosette stage and granuville wilt at the foot leaf harvesting and curing stage.

Table 1 Field growth period of different treatments of Cuibi-1 tobacco plants (month/day)

3.3 Economic traits after curing of different treatments of Cuibi-1 tobacco plantsFrom Table 2, it can be seen that the yield, output value, average price and percentage of high-class leaf after curing in 2015-2016 were increased by 67.8-68.7 kg/ha, 2 692.5-3 441 yuan/ha, 0.26-0.69 yuan/kg, and 1.29-3.01 percentage points for treatment 1 compared with treatment 2, and the difference in output value, average price and percentage of high-class leaf reached significant levels. In addition, through comparison between each year, the tobacco yield, output value, and the percentage of high-class leaf in 2015 were significantly higher than in 2016, indicating that the transplanting period has a great impact on the economic traits of tobacco production.

3.4 Sensory smoking quality of different treatments of Cuibi-1 tobacco plantsThe results of sensory smoking quality of tobacco leaf samples in different years, parts, and treatments show (Table 3) that the scores of each item of treatment 1 were slightly higher or equivalent to those of treatment 2, which is mainly manifested in that the tobacco leaves have sufficient aroma and better aroma quality, aftertaste is more comfortable, the offensive taste is lighter, and the irritancy is less. Viewed from different parts, the sensory smoking quality of upper tobacco leaves of the treatment 1 was improved more obviously than that of the treatment 2. Through comparing different years, it is found that the overall tobacco smoking quality in 2015 was better than that in 2016.

Table 2 Incidence rate and economic traits after curing of different treatments of Cuibi-1 tobacco plants

Table 3 Sensory smoking quality of different treatments of Cuibi-1 tobacco plants

4 Conclusions and discussions

The experiment indicates that applying Saikun multi-trace element solution to flue-cured tobacco Cuibi-1 can extend the field growth period of tobacco plants, reduce the incidence rate of major tobacco diseases such as mosaic disease in tobacco plant rosette stage and granuville wilt at the foot leaf harvesting and curing stage, which are consistent with findings of Zhang Xuejie[16]; besides, it can increase the yield, output value, average price and percentage of high-class leaf, which are consistent with research results of Ke Meifuetal.[17]; also, it can improve the aroma quality and aroma volume of tobacco leaves, make the aftertaste comfortable, the offensive taste lighter, and irritancy lighter, which are consistent with research results of Li Yinkeetal.[18]. The possible reason is that applying trace elements can promote the internal chemical components of tobacco leaves to become more coordinated[17], and improve the overall sensory smoking quality of tobacco leaves after curing. Applying trace elements can influence the growth, output value, and industrial availability of field tobacco plants. According to the experiment, the growth and development of tobacco plants, the yield and quality of tobacco leaves, and smoking quality of flue-cured tobacco in different years were quite different, which may be caused by different transplanting periods. The delay of tobacco plant transplantation will result in the shortening of tobacco plant growth period, reduced dry matter accumulation, and insufficient conversion of the internal chemical components of tobacco leaves[20-21], accordingly leading to discoordinated aroma substances and affecting the smoking quality of cured tobacco leaves.