Plant growth system

A system for controlling plant growth conditions in hydroponic growing systems, the system for controlling plant growth conditions comprising:

• at least one wireless detector;
• central detector data processing means;
• and
• an irrigation device;
• the or each detector being arranged to measure a property or properties indicative of a temperature, a water content, and a nutrient content, of a hydroponic plant growth substrate;
• the or each detector being further arranged to transmit a detector identifier and the measured property or properties over a communications link to the central detector data processing means;
• the central detector data processing means being arranged to:
• hold in a memory predefined irrigation data defining a
• relationship between:
• plural values for one or more of temperature, pH level, water content and/or nutrient content of the substrate;
• and
• plural desired irrigation output values;
• process the measured properties received from each detector to determine calculated properties of the substrate;
• and
• provide an output indicative of a desired irrigation input for the growth substrate in the form of an irrigation cycle defining lengths of on and off periods of irrigation for an irrigation cycle and a length of time over which the irrigation cycle should be applied, based upon calculated properties received from the detector or detectors and the predefined irrigation data and based on maintaining an electrical conductivity of the substrate within a predetermined range to control nutrient content, the output indicative of a desired irrigation input for the growth substrate being provided to control the level quantity of water provided to the growth substrate in dependence on nutrient content of the substrate;
• and
• the irrigation device is arranged to provide water and nutrients directly to a top of the growth substrate based on the output indicative of the desired irrigation input for the growth substrate, and the at least one wireless detector is disposed on a side of the growth substrate.

A system for controlling plant growth conditions in hydroponic growing systems, the system for controlling plant growth conditions comprising:

• at least one wireless detector;
• central detector data processing means;
• and
• an irrigation device;
• the or each detector being arranged to measure a property or properties indicative of a temperature, a water content, and a nutrient content, of a hydroponic plant growth substrate;
• the or each detector being, further arranged to transmit a detector identifier and the measured property or properties over a communications link to the central detector data processing means;
• the central detector data processing means being arranged to:
• hold in a memory predefined irrigation data defining a
• relationship between:
• plural values for one or more of temperature, pH water content and/or nutrient content of the substrate;
• and
• plural desired irrigation output values;
• process the measured properties received from each detector to determine calculated properties of the substrate;
• and
• provide an output indicative of a desired irrigation input for the growth substrate in the form of an irrigation cycle defining lengths of on and off periods of irrigation for an irrigation cycle and a length of time over which the irrigation cycle should be applied, based upon calculated properties received from the detector or detectors and the predefined irrigation data to control start and stop of supply of water and nutrients to the growth substrate and adapt supply and frequency of supply of water and nutrient, the output indicative of a desired irrigation input for the growth substrate being provided to control the level quantity of water provided to the growth substrate in dependence on nutrient content of the substrate;
• and
• the irrigation device is arranged to provide water and nutrients directly to a top of the growth substrate based on the output indicative of the desired irrigation input for the growth substrate, and the at least one wireless detector is disposed on a side of the growth substrate.