Agricultural netting may appear to be a simple mesh of different colored threads. However, their manufacturing, properties, and characteristics have a significant impact on agricultural operations as they can influence certain physiological aspects of crop growth, in addition to providing protection against weather conditions and pests.
They have a set of parameters that define and differentiate them, including:
- Structural characteristics: material type, thread type and dimensions, texture, pore diameter, porosity, strength, and weight.
Based on the type of fabric, agricultural nets can be classified as:
- Flat or Italian fabric: anti-insect nets, mosquito nets, windbreakers.
- English weave, back leno, or leno weave: hail nets.
- Raschel fabric: shading nets.
The most used raw material in their manufacturing is high-density polyethylene (HDPE), which is a completely recyclable, non-toxic material (safe for direct contact with plants), and durable (if stabilized against ultraviolet (UV) radiation). During the thread extrusion process, a series of additives are added, primarily to improve or alter the mechanical and physical characteristics of the net and its durability. The most common additives are colorants and UV stabilizers (UV radiation being the main cause of agrotextile degradation). The resistance to degradation is expressed in kilolangley (kly) and usually ranges from 400 to 800 Kly.
- Radiometric properties: such as color, transmissivity, reflectivity, and shading factor. Color influences the spectral distribution of radiation passing through the net, absorbing its complementary colors. Therefore, the choice of color combined with the plant’s radiation requirements could be strategic for optimizing production and overall yield:
- Red and yellow nets can stimulate growth.
- Blue nets can cause dwarfism in ornamental plants.
- Gray nets stimulate branching and produce “bushy” plants with short branches and small leaves.
The transmissivity of photosynthetically active radiation (PAR, 400-700 nm) could be considered one of the main parameters, from an agronomic point of view, influencing the choice of nets. Transparent or semi-transparent threads can be used to reduce excessive solar radiation, generate more diffuse and soft internal light, and provide more uniform conditions.
The shading factor: is related to the color, thread density, and texture of the net.
- Physical properties: such as air permeability.
- Mechanical properties: such as tensile strength, elongation at break, and plastic deformation.
In an increasingly challenging climate and natural resource context, where protected agriculture is positioned as one of the most sustainable techniques, with more efficient use of resources and comparatively higher crop security, it is important to understand all aspects related to agricultural nets.
For more information, please contact us at info@greennetsagro.com
Source: Sociedad Americana de Ingenieros Agrícolas y Biológicos). Castellano, G. Scarascia Mugnozza, G. Russo, D. Briassoulis, A. Mistriotis, S. Hemming, D. Waaijenberg