基肥施用量对临武稻茬烤烟生长及品质的影响OA

To investigate the effects of tobacco-specific base fertilizer application rate on the growth,economic traits,and leaf quality of rice-stubble flue-cured tobacco,and to provide support for rational base fertilizer application in southern Hunan rice-stubble tobacco areas,Yunyan 87 was used as the test material.Three application rates of tobacco-specific base fertilizer which were T1(1 500 kg/hm2),T2(1 200 kg/hm2),and T3(900 kg/hm2)were set.The agronomic traits,fresh leaf SPAD value,dry matter accumulation,nutrient accumulation,economic traits,and tobacco leaf quality of different treatments were compared and analyzed.The results showed that increasing the application of tobacco-specific base fertilizer improved the agronomic traits of flue-cured tobacco,increased the chlorophyll content of upper leaves,and enhanced dry matter accumulation in the whole plant and its organs.The appearance quality index of middle and upper leaves was highest in the T2 treatment.With increasing fertilizer application rate,leaf expansion degree,single leaf weight,leaf thickness,and leaf area mass increased,while the equilibrium moisture content of cured leaves decreased.Higher fertilizer application led to excessive nicotine content in upper leaves and reduced sugar-nicotine ratio and two-sugar ratio(ratio of reducing sugar to total sugar).The T2 treatment achieved the highest proportion of first-grade tobacco leaves,average price,yield,and output value.Compared with T1 and T3,T2 increased the proportion of first-grade tobacco leaves by 3.59 and 8.10 percentage points,respectively;the average price by 5.62%and 10.82%,respectively;the yield by 11.08%and 40.86%,respectively;and the output value by 17.33%and 56.14%,respectively.Considering both economic traits and leaf quality indicators,the recommended application rate of tobacco-specific base fertilizer in the Linwu rice-stubble tobacco area is 1 200 kg/hm2.