Page 15 - Griffin Gazette Q3 2017
P. 15

The primary support for high-wire tomatoes is the trellising twine.     Truss supports are a staple for tomato
This major structure does little to support the cluster stem, which     growers to prevent damage to the
can break with the weight of the fruit. J-hooks are one solution.       cluster stems.
The top of the hook attaches to the twine, while the smooth hook
supports the weight by hooking within the cluster to reduce the        With very few exceptions, directing fans onto the crop is avoided.
stress on the cluster stem.                                            While a little airflow is a good thing, turbulent air flow over a crop
                                                                       resulting in visible movement of the crop can have a detrimental
Truss supports can also protect against cluster stem breaks.           impact on crop growth. When air flow over a leaf surface is high,
These plastic pieces are placed over the cluster stem at the           the stomates close to balance transpiration and reduce excessive
union with the vine before the fruit forms. As the fruit matures, the  moisture loss. Stomatal closure reduces photosynthesis, the
plastic piece supports the cluster stem, with no additional cluster    process that drives growth.
support needed. We like the newer flexible truss supports, which
can be placed without bending the stem. If you have experienced        See the Digital Bonus material for discussion of the one time when
damaged cluster stems in the past, give the flexible truss supports    you should direct gentle airflow onto a crop.
or traditional J-hooks a try and increase your yield.
                                                                       While each hydroponic crop has special needs, some needs are
The primary support for medicinal crop is trellis netting, generally   universal. If your production plan includes gaps in monitoring your
used in several layers. While the trellis netting often provides       water quality, protecting your crop from physical damage or if you
enough structure to support the stems, some extra support may          lack good air flow in your production space, ask your Griffin sales
be needed. Enter the stem holder and J-hook from the veggie            representative for help. We have solutions to these and many more
world. Either can be used to attach crop stems to the trellis netting  problems, solutions that will help you grow your profits along with
to minimize movement and provide additional support.                   your crop.

Move the Air
All hydroponic production areas benefit from good air flow around
the crop. For both greenhouses and warehouse production
spaces, horizontal air flow fans (HAF fans) are the standard tool to
improve environmental uniformity in a production space, which is
the first step to producing a uniform crop. Through gentle, laminar
flow around the crop, HAFs can greatly reduce temperature
gradients that naturally exist in production spaces that have
directional heating and cooling. This same linear movement can
also help to prevent microclimates of humid, stagnant air. The key
to success with HAF fans is a professional plan for fan placement.
In small production spaces, this plan may call for a small number
of fans to drive a circular flow. In larger spaces, the fans are used
to create more complex flow patterns.

Good air flow is also important to reduce incidence of disease.
Growers recognize that foliar diseases are often encouraged by
humidity. With improper airflow, a production space can develop
microclimates of stagnant, high-humidity air. HAF fans generally do
a great job of eliminating these microclimates, but sometimes the
crops benefit from a different airflow pattern. This is when vertical
fans can be helpful. Fans like the VFloFan from Vostermans will
draw air from the crop, pulling it up, then pushing it out to return
down to crop level in a wide circular pattern.

Vertical flow fans provide gentle air movement over crops

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