Automatic Monitoring of Chilling Requirement for Sweet Cherry and Its Application in Protected Cultivation

For sweet cherry,the economic benefit of protected cultivation is much higher than that of open field cultivation. However,problems such as nonuniform germination,aberrant flower,abortion,bad fruit setting and delayed maturation appear frequently due to the inaccurate regulation of chilling requirement. In order to solve the problems,an automatic system for monitoring,selecting and recording of chilling requirement in protected cultivation of sweet cherry was designed and developed. The system,which consisted of temperature detection,effective chilling temperature selection,signal conversion and output and chilling accumulation display,had been continuously used in protected cultivation of sweet cherry for 3 years and good effects had been achieved. The system monitored chilling accumulation accurately and made it more reasonable for the time selection of greenhouse covering,thus avoiding risks of nonuniform germination,bad fruit setting and delayed maturation,etc. Under the coordinate application of this system with other modern measuring and controlling techniques such as automatic detection and alarming of temperature and humidity,the environment in greenhouses was regulated precisely that the uniform fruits were obtained and the expected yield,quality and harvest time were achieved.