Page 12 - Griffin Gazette Issue 2 - 2018
P. 12



        Helping new lettuce and herb growers find success

                         By Tami Van Gaal,   Production systems                supply of product. While basil likes warmer
                         CEA Division      Lettuce, leafy greens and herbs can   temperatures, lettuce requires cooler
                         Leader            be produced in a number of ways, with   temperatures. All flower growers know what
                                           the most common approach  using     it means to heat a greenhouse. Maintaining
                         Consumer interest   hydroponics. Deep water culture (DWC)   cool conditions in the warmer months
                         in sustainable, locally   involves supporting the crop with a raft that   is something that fewer growers have
                         produced food is   floats on the top of a shallow pond in the   needed to address. For most locations,
                         driving small markets,   greenhouse. The pond contains a nutrient   lettuce crops will require active cooling
                         local  restaurants,  solution that feeds the crop. Only the roots   during the warmer months. This is one
                         and  both  regional   come into contact with the solution. DWC   reason that greenhouse lettuce production
                         and national grocery   is most commonly used for head lettuce,   is  more  common in  northern states than
        chains  to  source  greenhouse-produced   though it can be adapted to leafy greens   southern states. In lettuce production, it’s
        crops. A review of the restaurant menus   production, too.             not uncommon to cool the nutrient solution
        and a walk through grocery store aisles                                in addition to cooling the production space.
        proves this out: Locally sourced produce   For new growers converting existing   In some cases, cooling the space may be
        is heavily marketed and carries a stronger,   greenhouse space, the easiest approach   achieved with traditional fan/pad systems.
        perceived value. Griffin works with a   will be to retrofit the production space   Larger growers will often turn to advanced
        large number of controlled environment   with a nutrient film technique (NFT)   chiller technology to support predictable,
        agriculture  (CEA)  growers  producing   system. NFT systems are highly efficient,   year round production.
        lettuce and herbs in greenhouses    recirculating systems in which a thin
        around the country. This is definitely a    stream of water runs through food-grade   Lettuce, especially head lettuce, can
        growing market.                    gutters or channels. The gutters support   develop tip burn under certain conditions
                                           the crop so that the roots are bathed in the   when transpiration is limited (low light,
        Odds are good that most flower growers   nutrient solution. Head lettuce, leaf lettuce,   high humidity, poor air flow). As in flower
        can name a couple of growers that have   leafy greens and herbs are all commonly   production, HAF fans are important in
        expanded into food in the last two or three   grown in NFT systems.    maintaining a constant environment
        years. Are you thinking of growing your                                across the production space. However,
        business into this rapidly expanding arena,   Climate control          lettuce  needs  a  little  extra  help  on  this
        too? If so, let’s look at how production of   Year-round production of food crops   front, as HAF fans will not break down the
        lettuce and herbs will differ from what you   requires good environmental control   microclimate that develops at the growing
        know in flower production.         through the summer and winter to maintain   tips. The best way to prevent tip burn in
                                           crop quality and to ensure a consistent

        12   |   Griffin Gazette 2018         More to see online  |  See our digital Gazette for more on Moving from Flowers to Food!
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