Control of the environment of berries crops and the industry in California

The importance of the berry industry in the United States is unquestionable, especially in counties of Santa Cruz and Monterey.  Accelerated growth from the 1960s to the present day has resulted in an increase of the production value by 593% in Santa Cruz and 424% in Monterey during 2014, according to the official agriculture reports of both counties reviewed in the study “The evolving fresh market berry industry in Santa Cruz and Monterey counties.” The question becomes, how to maintain that production value and even improve it? Can we directly influence that increase? What resources do we have available?

Prices, government regulations, workforce, plant diseases, weather conditions and climate change are some of the variables, that growers have had to overcome to improve the volume and value of their production. As we can see, some of these variables do not depend on the grower, but they can be affected by the control of the crops’ environments to favor the ripening, setting, flowering and fruit production processes.

How can we control the environment in berry crops? In the decade of the 1990s, the introduction of farming with Spanish Tunnels that protected the plants and helped to control the environment represented a breakthrough but it was not the only important factor.  The type of covers mattered as well. The cover’s quality, its maintenance, and its care during the installation process are all important. All of these factors increase the advantages of the use of covers to improve agricultural production, offering the grower a greater margin of management and control of the crop.

The use of Spanish Tunnels or High Tunnels

Controlling the environment in crops with the use of Spanish Tunnels, also known as High tunnels or Hoop Houses,  with plastic covers has helped stabilize the market of cane-berries in the counties of Santa Cruz and Monterey.  Using covers extends the production season which, in turn, allows growers to sell their merchandise at a higher price when the supply of berries from other regions is lower or outside of the usual season. In addition, it also improves the quality of the fruit that is grown in controlled environments (increasing uniformity of size, reduction of damages due to rain, avoiding the cracking of berries, and greater volume of marketable fruit).

The advantages of controlling the environment in crops apply to both cane-berries and other berries, such as strawberry and blueberry/cranberry, as confirmed by the case of Dave Akahoshi reviewed in the article “The Strawberry grower goes hydroponic with Masterplan label,” who decided to transfer part of the production to hydroponic cultivation using “Spanish-Tunnels.” According to the owner of the company Plan Berries Inc., this change has allowed him to produce a premium quality strawberry throughout the year reducing labor costs by half, as well as the use of water and fertilizers. This case is particularly interesting to demonstrate how the use of Spanish-Tunnels, in these crops became an excellent solution to deal with water scarcity and torrential rains in the Santa Maria area, Luis Obispo County, California.

Advantages of cultivating berries with Spanish-tunnels or High Tunnels versus open-air berries crops:

• Protection of the fruit against damage by hail or heavy rains that may cause damage to the fruit, cracking, stains, or decay.
• Protection of the crop and the fruit against sunburn, heat stroke, and/or stains that would depreciate their commercial value or even make them non-tradable.
• Significant reduction in losses due to spring frosts.
• Delaying or advancing the harvest, looking for market windows with greater profitability. The conditions inside the Spanish tunnel facilitate precocity (at least 10-14 days), therefore, we can obtain the first cut when there is a deficiency of fruit in the market and sell at better prices.
• It allows to harvest a greater % of fruit with exportable quality, thus, with a higher market value.
• Appropriate transmission and light diffusion at the time of change of colouring ensures that it occurs with guarantees, and that there are no cases of albinism or almost disappearance, achieving first class fruit.
• Higher water efficiency, less evaporation due to wind and sun.
• Higher crop yields and quality, since the crop will be subject to fewer situations of abiotic stress.
• It leads to lower spending on phytosanitary products, since it prevents the fruits from getting wet when it rains, which would cause an increase in the incidence of diseases of fungal origin, especially powdery mildew, and botrytis.

A temperature above 15 degrees Celsius (59 degrees Fahrenheit) is ideal for strawberry crops, for this reason and depending on the geographical area where it is grown, the use of special plastics will be necessary. During nights or cold mornings, a thermal film (IR poly) slows down the loss of temperature in the Spanish tunnel or High Tunnels, which means that the crop will be in an optimal temperature range and out of stress for a longer period. There are films that even raise the temperature in crops up to 5 degrees Celsius (9 degrees Fahrenheit) and, in areas with high temperatures, the use of plastics that reduce heat by controlling the entry of light and preventing the plants from burning.

The technology used in these plastic covers will be the key to overcoming the challenges involved, which include, the restrictions on the use of pesticides in crops and the possibilities of even manufacturing custom plastics depending on UV radiation, climatic conditions, and the new demands in the planting processes. Plastics capable of modifying the light, temperature, and humidity conditions of crops.

Advanced technology and quality controls as differential factors

Regarding cover films, the technology with plastic manufacturing machines capable of producing plastics of up to 7 layers allows the production of films with greater and better properties. This will reduce costs and increase the quality of the cultivated fruit in the long-term. The capacity of manufacturing with 7 layers allows the combination of several properties in the same film.  The addition of additives to the plastic that control the appearance of fog and drip on the roof of the greenhouses, photoselective additives to filter light waves, control viruses or dust adhering to the film are all material improvements.

If we also add to this technology the research and development component to achieve improved formulas for each crop, an improvement in the retention of heat during the nights and cold mornings in California, we will have a controlled variable in the never-ending competition to improve and increase the value of crop production.

The companies that belong to Grupo Armando Álvarez distribute and manufacture products in the US, with advanced quality controls and state-of-the-art technology in the market so the companies that have contributed significantly in the production increase of strawberry varieties in Huelva in the Fortuna, Candonga, and Sabrina areas, just to name a few, which is a very important province since it feeds Europe in terms of berries.

Some of the plastics the offer for greenhouses or macro-tunnels:

•    Duratermic Strawberry
•    Duratermic Raspberry
•    Durasol plus