1Beijing Research Center of Intelligent Equipment for Agriculture，National Engineering Research Center of Intelligent Equipment for Agriculture，Key Laboratory of Agricultural Intelligent Equipment Technology，Beijing 100097，China；2College of Horticulture，Shanxi Agricultural University，Taigu 030801，Shanxi，China
为探明番茄不同生育期的声发射信号特征规律，通过负水头灌溉下番茄盆栽试验，测定6 000 Pa 吸力值下番茄植株耗水量、土壤含水率及声发射特征参数等指标，研究负水头灌溉下番茄不同生育期植株耗水量、土壤含水率、声发射波形信息及频谱特征参数变化。结果表明，番茄初果期和盛果期植株耗水量显著高于幼苗期和开花期，土壤含水率的变化为逐步下降后趋于稳定；对声发射信号的连续监测结果表明，番茄开花期至盛果期声发射信号波形参数呈逐渐下降的趋势，共振峰频率呈逐渐上升的趋势。Pearson 相关性分析结果表明，温室环境温度和开花期土壤含水率均与声发射波形参数幅值呈显著正相关。综上，通过对番茄不同生育期的声发射信号特点、波形参数和频谱特征的比较分析，可将番茄超声发射信号数量、频率和能量与番茄生长阶段建立联系。
In order to acquire the characteristics of acoustic emissions signal of tomato at different growth stages，this paper measured under 6 000 Pa value the water consumption，soil moisture content and acoustic emissions signal of tomato plant，etc. indexes with negative pressure irrigation in tomato potted cultivature
experiment；and studied the changes in water consumption，soil moisture content，acoustic emissions signal and spectral characteristics parameter of tomato plant at different growth stages under negative pressure irrigation. The results showed that the water consumption of tomato plant in initial fruit and full fruit stages was significantly higher than that in seedling stage and flowering stage，and the changes of soil water content tended to be stable after gradually decreasing. The results of continuous monitoring of AE signal indicated that the acoustic emission signal of tomato flowering to fruiting stages，AE signal waveform parameters were decreased gradually，the resonance peak frequency showed a gradual upward trend. The results of Pearson correlation analysis showed that the environmental temperature of greenhouse and soil content was positively correlated with the amplitude of AE waveform parameters，respectively. In summary，through comparative analysis of the characteristics of AE signals，waveform parameters and spectral characteristics of tomato in different growth stages，the ultrasonic signal number，frequency and energy could be associated with tomato growth stages.
