Article kindly published on hortidaily.com
Publication date: 6/9/2016
Spanish baby leaf grower optimizes summer production with combined screens
Greenhouse leafy greens grow perfectly in Spain, especially during the spring when average yields of 1kg/sqm can be achieved. However, during the hot summer months the growers are often challenged by high temperatures, and yields can be halved. That is why Italian screen manufacturer Aduno invested in the development of a screen solution that would improve these conditions.
by Elisabetta Pircher of Aduno
Spanish grower La Linea Verde Navarra approached Aduno for a solution for the 10 hectare greenhouse operation. Elisabetta Pircher of Aduno explained that the company installed a combination of their BASIC5 Reflex BW shading and thermal screen together with their BASIC5 Umbra shading net (BASIC5 Comboscreens).
Grower Luis de la Soldevilla said that this combination and its automation, allowed him to increase the summer yield by 100% with a quality similar to that of spring’s. The extra revenue; 0.3 kg/m X 3.00 €/kg = 0,9 €/sqm.
The growers consultant and agronomist Dr. Carlo Bignami, collected concrete technical data. Bignami: “The use of shading during sowing means reducing the presence and growth of weeds. Since herbicides are prohibited and due to limited use of fumigants, it also reduces manual operations with a significant saving (€ 0.3/sqm). Furthermore, the automatic movable screen installation eliminates the risk of burns, when in spring the sun comes out suddenly and, at the same time, it allows for maximum light transmission when clouds come and go. All of these result in quality and safety of delivering a product without sunburns.
Diana Belloso, agronomist of Vegetales, noted that the combined use of the thermal screen and shading net results in a lower incidence of fungal diseases and increased plant growth: “The automatic movable screen installation enables to pack the thermal screen and the shading net. This allows for direct light and increased evapotranspiration, and therefore greater photosynthesis. In addition, it also involves a flow of water from soil to air, which leads to soil drying and plants growth. The stagnation of water in the ground and in the air instead results into the development of diseases such as Rhizoctonia, Bremia, Powdery Mildew and Black Root. The solution BASIC5 REFLEX BW + BASIC5 UMBRA (BASIC5 Comboscreens) then creates the best environmental conditions for the plants, which result in higher yield.”
“In winter, BASIC5 REFLEX BW thermal screen and BASIC5 UMBRA shading net also allow you to have another advantage,” says Carlo Bignami “which is the increase in nightime greenhouse temperature of about 2-3 degrees, reducing the dew effect on leafs: the open structure of the thermal screen + shading net brings hot-humid air to rise slowly upwards, limiting the hours of wetting and reducing fungal diseases.”
The costs/benefits ratio definitely leans towards the benefits: an automatic movable screen installation with BASIC5 REFLEX BW thermal screen and BASIC5 UMBRA shading net (BASIC5 Comboscreens) leads to a direct increase of the income of about 1 €/sqm during three cycles in the summer and a better quality in other periods of the year.
It will hence always ensure the supply agro-industry, which will not reduce the average annual purchase planning: in ten years, the farm will set aside some 30 € per square meter.
Aduno will be exhibiting at GreenTech – Amsterdam – 14/15/16 June 2016