Abstract:
To establish an accurate and efficient method for applying napropamide in tobacco field, field drip irrigation experiments were conducted in tobacco fields of Xiangcheng County in Henan Province. Residue levels of napropamide in soil and tobacco leaves were determined. The results showed that comparing with mechanical spray, drip irrigation of the herbicide was superior in terms of weed controlling, total tobacco leaf yield and yield of high grade leaves. The napropamide residue levels in soil and leaves were also reduced. The effect of weed control was improved by more than 1% (
P=0.136 0); the total yield and the yield of high grade leaves was increased by 109.13 kg·ha
-1 (
P=0.088 9) and 56.16 kg·ha
-1 (
P=0.000 1), respectively. The differences of napropamide residues in soil and tobacco leaves between the two application methods reached significant levels (
Psoil=0.003 0,
Ptobacco leaf=0.008 0). Therefore, napropamide application via drip irrigation is desirable in tobacco fields where drip irrigation is suitable. Taking weed control effect, the yield and quality of tobacco leaves and the napropamide residues in soil and leaves into account, the appropriate application rate of napropamide was 2.25-3.00 kg·ha
-1.