High volume hydraulic sprayer is the most common application in commercial greenhouses. This technique is a great assistance for spot treatment and general application. Hydraulic spraying equipment allows operator to have controlled chemical application by forming finer droplets over crops and do not let plants to become over wet. Standard characteristics of machinery can be operated at pressures ranging from 75 and 700 psi with having average molecule sizes between 200µ (microns) and 400µ. Backpack sprayers, spraying robot with tank, spraying trolleys, and boom sprayers are used widely as high volume pesticide sprayers. HV technique requires more liquid in comparison with low volume method and largely operated in the growing process of flowers and vegetables.
Automated spraying robot with a liquid tank provides a substantial assistance in spraying large surface with minimum labor. Spraying robot can move among crops easily on pipe rail system, which enables to spray thoroughly plants and helps to grow upwards (see Harvesso spraying robot). When it comes to horizontal spraying equipment, it is used for ornamental and pot plants, since vertical sprayers cannot reach to cover the whole plant properly.
Generally, stationary and thermal foggers are used in ULV chemical application. Foggers create millions of droplets (smaller than 25µ) by using only small amount of water. 2 liters of water in mixed liquid solution is enough to spray 1,000 square meter area. It must be done in closed greenhouses by circulating air thoroughly. To achieve better results, chemical drops should move sideward to diffuse the underneath of leaves. There is an increased tendency to use foggers by growers as they are convenient to spray and timesaving.
Automatic foggers use air that has been generated by compressor or blower motor and erupt at particular pressure through nozzles. Chemicals are conveyed upward into the air stream by the help of low pressure generated in the tip of nozzle and atomization process occurs. Through this process, it produces equal particles and propel them evenly over crops.
Air source of thermal foggers is propulsion originated by burning of fuel inside of resonator. Heat derived from firing generates the fog by thermally exciting the chemical drops. Thermo-kinetic technique creates a dense fog in a short period. Main specifications of thermal fogger are its speed and capacity to spray on large spaces rapidly. Some units could funnel the fog tens of meters from the equipment in seconds, covering areas as wide as 5,000 square meters in less than 15 minutes.
A disadvantage of thermal fogging is that the atomization process could be sloppy and produces wide range of drops. Temperature raised from burning could lead to vaporization of droplets more rapidly than intended. To handle these side effects, growers add specific chemicals into liquid tank before spraying process.
Having a primary knowledge about spraying equipment and characteristics of crop would help you to find out what is the right tool for spraying. If you are having a trouble on deciding, our expert team is ready to advise you on selecting greenhouse sprayer for your greenhouse.