The use of absorbents from Maximarin for growing spinach contributed to its faster germination, increased plant growth and development, and resulted in an increase in yields of commodity products by 2.0–6.1 t ha-1 and an increase in chemical composition. The use of absorbents in open ground for spinach made it possible to obtain the highest amount of contingent net profit for making the drug Maximarin in the form of a gel and the company Eco – with small granules, and in the Krasen Polissia variety – 2,160 and 2,102 USD ha-1 , in the Malakhit variety for introduction the drug Maximarin in the form of a gel 1,949 USD ha-1 and the company Eco absorbent with potassium – 1,575 USD ha-1 . Profitability for the Matador variety has reached 75%, Malakhit grade – 69–75%, Keb – 3.0–3.2. It was established that in the closed ground application of the drug Maximarin in the form of gel and granules for spinach made it possible to obtain the highest amount of contingent net profit, which was Matador 3,079 and 3,025 USD ha-1 , in the Malakhit variety for the introduction of gel 4,304 USD ha-1 and granules – 4,245 USD ha-1 . Profitability for the use of drugs for the Krasenʹ Polissia variety reached 84–77%, Malakhit – 118–116 %, the bioenergy efficiency ratio – 3.0–3.3.

Received: February 8th, 2021 ; Accepted: April 24th, 2021 ; Published: April 30th, 2021 ; Correspondence: grigory.slesarev@urfu.ru

Received: January 31st, 2021 ; Accepted: March 28th, 2021 ; Published: May 19th, 2021 ; Correspondence: jelena.pubule@rtu.lv

Received: January 10th, 2021 ; Accepted: February 13th, 2021 ; Published: February 17th, 2021 ; Correspondence: maris.klavins@lu.lv

Received: February 1st, 2021 ; Accepted: May 2nd, 2021 ; Published: May 18th, 2021 ; Correspondence: Zane.Kusnere@rtu.lv

Indoor air disinfection has become particularly relevant recently because of the Covid-19 pandemics. A shielded device for air and surface disinfection with UV radiation and ozone has been developed. It contains 28 low intensity (11 W) UV lamps (254 nm) in a specially designed three-dimensional grid to provide a large flow cross-sectional area and long path for the air particles to be irradiated. The device can be used in medical institutions, veterinary clinics, manufacturing plants, public premises, poultry, and livestock farms. It does not generate air-ions and ozone concentrations do not exceed the allowed 8-hour average values. The large number of UV lamps and powerful fans ensure air disinfection in large rooms in a relatively short time (400 m3 h-1). Simultaneously, the floor surface under the appliance is disinfected. Disinfection efficiency tests demonstrated 99.9999% reduction for Escherichia coli, Staphylococcus aureus and Pseudomonas phage 6 aerosols within a single transfer through the system (10 seconds of treatment). The housing of the device protects from direct UV radiation;therefore, people can be in the room during the operation of the device. © 2021, Eesti Pollumajandusulikool. All rights reserved.