Effects Of Nutrition Regulation And Temperature Increase And Root Promotion Measures On Yield And Quality Of Flue-cured Tobacco At High Altitude In Chongqing

Flue-cured tobacco is one of the important cash crops in China.Good control technology is beneficial to the absorption and utilization of nutrients in tobacco plants and the formation of good quality of flue-cured tobacco.Affected by subjective and objective factors such as climate and fertilizer amount,tobacco in C hongqing tobacco-growing areas grew in low temperature and rainy environment in the early stage,and chemical fertilizer was applied again for a long time,and improper use of nitrogen and potassium fertilizer led to imbalance of soil nutrients,and the root development of flue-cured tobacco was blocked in the early stage,and the yellowing was delayed in the later stage,which led to the decrease of tobacco yield and quality.After a large number of previous literature review and field investigation,this paper focuses on cultivating high-quality flue-cured tobacco,and studies the influence of nutrition control（nitrogen and potassium control measures,organic and inorganic application）and early early-growing and fast-growing technology control（temperature increase measures,root promotion measures）on the growth,development and quality of flue-cured tobacco in Chongqing high-altitude areas,providing theoretical basis for improving the yield and quality of flue-cured tobacco in C hongqing high-altitude areas.The main results of this paper are as follows:（1）The experiment of controlling nitrogen and potassium showed that N _FP+0.5K₄₀treatment could obviously improve plant height,stem circumference,maximum leaf length and maximum leaf width at different growth stages.Compared with N _FPK_FP,N_FP+0.5K₄₀ and N_FP-0.5K₄₀ treatments can improve the yield,output value,the proportion of superior tobacco and the average price of tobacco leaves,among which N _FP+0.5K₄₀has the best effect,with the output value increased by 1.79%and 0.82%respectively,and the proportion of superior tobacco increased significantly by 10.51%（P<0.05）.The chemical composition of N_FP-0.5K₄₀ tobacco leaves is more suitable.（2）Compared with CK,FR,FC and FE treatments can promote the increase of agronomic characters,physiological indexes of leaves and tobacco plants,increase dry weight of tobacco leaves,increase the ratio of yield to superior tobacco,and increase quality and economic benefits in mature period.Compared with CK,the dry weight of roots,stems and leaves increased significantly by 28.22%,43.88%and 10.0%（P<0.05）,and the output value increased significantly by 40.06%and 32.64%（P<0.05）.The results showed that FC treatment had the best increase in dry matter,nitrogen,phosphorus and potassium,and had the greatest influence on the quality and economic benefit of flue-cured tobacco at high altitude,while FR treatment had the best coordination effect on agronomic characters and chemical components of tobacco leaves.（3）Different warming experiments show that all warming measures can effectively increase the soil temperature by 1-3℃,especially the effect of SPR on increasing the ground temperature within one week after transplanting tobacco seedlings,which promotes the early growth and rapid growth of flue-cured tobacco.In addition,the root index,agronomic status,chlorophyll content,dry matter content and economic characters of each warming treatment are obviously superior to CK,among which DP treatment is the best in agronomic characters,with high plant uniformity and higher chlorophyll content and dry matter content in dome stage,but SPR treatment is better in economic characters.Compared with CK,SPR treatment significantly increased the output value by 20.25%and 15.15%respectively（P<0.05）.（4）Different root-promoting experiments showed that different root-promoting agents had different effects on shoot and root development of flue-cured tobacco compared with CK.Among them,ABT,CTS,SCP+SA treatments can promote shoot growth or root development.ABT treatment promoted root tip number and root activity best,which increased by 25.55%and 21.54%respectively compared with CK（P<0.05）.ABT and C TS treatments not only promoted the root development and agronomic characters of flue-cured tobacco,but also promoted the economic benefits of dry matter in dome stage and cured tobacco leaves.ABT treatment had the best economic benefits,increasing the yield and output value by 12.41%and 14.01%respectively（P<0.05）.