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Defoliation: 6 Key Benefits for Hydroponic Crops · Hydroponics Daily

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  Hi, welcome back to Hydroponics Daily. Today we're going to be talking about
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  defoliation, why in some cases you use it, in some cases you try to avoid it.
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  It's a common practice for many crops and the first thing you think about,
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  it's done when the canopy is developed over a number of months and you want
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  to reduce the leaf numbers down.
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  You can do mechanical defoliation or manual defoliation.
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  For high value crops, obviously it's going to be more to the manual so
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  that you don't wound the flowers or the fruits or things
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  you're trying to harvest there's a number of reasons why you
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  would defoliate a crop and the first is to
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  allow more light into the canopy and that
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  includes for things like ripening so if you've got
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  a plant like a tomato or an apple and you want
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  to turn those green fruit red getting more light in there
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  will help ripen the fruits just increase
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  photosynthesis get them warmer increase airflow it all helps ripen up crops
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  the other one is light quality when a light a beam of light travels through
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  a leaf it takes out the red and the blues and the yellows and leaves the green
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  light behind so light that's gone through a canopy is very.
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  High in green light which is known is it
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  worse photosynthesis it tells the
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  plant to do certain things so like increase stem elongation and other such deleterious
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  effects in many crops and so you want to make sure the plant is receiving as
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  much white light with a high red to far red ratio so the phytochrome pigments
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  in the plants don't detect the high far red and,
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  shoot up and and keep fruit unripe and things like this so light quality is
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  just as important as light,
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  levels intensity the other reason you might want to reduce the
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  number of leaves in the canopy is to
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  reduce the humidity in and around that crop you might
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  have a very low humidity in your grow room or in
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  your greenhouse but if you have a very dense
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  canopy the humidity around that crop can
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  be very very high localized and that helps
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  reduce the humidity and airflow increase the
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  co2 that actually gets into the plant the other reason you might do it is to
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  stimulate wounding and this depends on the crop so some plants if you wound
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  them they have deleterious effects like bolting of cabbages for example you
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  know flower you don't want your cabbages to flower other crops like walnuts benefit from wounding.
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  There's a famous old saying that was like, the tree, the dog and the woman all
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  benefit from a good beating.
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  And that's obviously not true for dogs, not true for women. But for walnuts,
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  they thought that it improved the quality of the crops. And.
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  When you remove a leaf, you're producing a wounding signal that then might stimulate
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  secondary metabolites, the production of pigments, the production of terpenes,
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  for example, the production of resins and things like this through the crop.
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  So wounding effects, positive wounding effects, might be stimulated by defoliation.
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  And then the final one is, if you have to remove those leaves anyway for harvest,
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  rather than removing all the leaves at once at time of harvest when you've cut the stems off,
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  There's obviously a time benefit from removing the leaves first while the flowers
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  and the fruits are still in situ and not having negative effects of being harvested.
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  You can get that crop processed a lot faster if the leaves have been removed
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  before, which actually the stems are removed from the plants.
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  So five major benefits of defoliation. Go for a sixth one.
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  Reduced pest and disease pressure. If you're starting to get pests on your crop
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  and you don't want to use a pesticide or any other methods, you don't want to
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  buy in biological controls, simply getting rid of,
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  80% of the leaves in that area could take you from what would have been a dead
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  spider mite infestation or aphid infestation to something that's much more manageable
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  and much more controllable because there's not as much food for them.
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  Especially things like aphids. Aphids they
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  use things called what we call green bridges where
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  they are leaf touching another leaf to
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  move around plants it's only when they become much older
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  and adults that they fly between plants a lot of the time they're using green
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  bridges to infect so if you can reduce the foliage levels then you can potentially
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  reduce pest and disease six benefits of defoliation there if you can think of
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  another one drop us a comment or an email we do a follow-up thank you very much
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  that's been Hydroponics Daily for today.