Photoselective Films For Greenhouses.

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Still digging for more info on this and wondering if anyone here is using them with success. Basically it is a film that allows you to filter targeted wavelengths....This has me thinking filter out red during the early months to promote short and stockier plants much like a metal halide does.Then heres the big one come flowering time switch to a filter that allows red and yellow but limits the blue wavelength like high pressure sodium bulbs....In my head I am thinking this would eliminate my biggest problem I have growing outdoors LEAFY BUDS not fluffy just leafy it seems that no matter what strain I put outside they all tend to have a higher leaf to bud ratio.
So farmer tell me what you know/think I'm gonna keep digging.
 
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Instead of film photoselective shade screens! Much easier on and off! Also has effects on pest infestation.
I copied this for some reason I cant post a link
Abstract
Photoselective shade-netting is an emerging approach in protected
cultivation. The photoselective net products are based on the introduction of various
chromatic additives, light dispersive and reflective elements into the netting
materials. They are designed to selectively screen various spectral components of
solar radiation (UV, PAR, and beyond), and/or transform direct light into scattered
light. The spectral manipulation is aimed to specifically promote desired
physiological responses, while the scattering improves the penetration of the
modified light into the inner plant canopy. Additional potential benefits relate to
photoselective effects on plant pests, beneficial insects, or diseases. Studies of
ornamental crops, traditionally grown in shade-net houses, revealed distinct
responses to the Red, Yellow, Blue Grey and Pearl nets, compared with common
black nets of the same shading factor. These include stimulated vegetative vigor,
dwarfing, branching, leaf variegation, and timing of flowering. The photoselective
netting concept was further tested in vegetable cultivation in either net-houses, or in
combination with insect-proof nets or greenhouse plastic film covers. The Red and
Pearl nets repeatedly increased the productivity of leafy crops, bell peppers and
ornamentals, compared with each crop’s standard cover. Although the shade-net
holes allow free passage of small pests, the rates of pest infestations and vector-borne
viral diseases were affected by the color and reflectivity of the nets. For example, the
incidence of an aphid borne cucumber mosaic virus disease was significantly lower
under the Pearl (10 folds) and Yellow (3 folds) nets, compared to black nets.
Whiteflies penetration and establishment was 2 fold lower under the Yellow net
compared to the black net. The photoselective, light-dispersive shade nets provide a
unique tool that can be further implemented within protected cultivation practices.
INTRODUCTION
The photoselective netting is an emerging approach, which introduces additional
benefits, on top of the various protective functions of nettings. These nets are unique in
that they both spectrally-modify, as well as scatter the transmitted light. The
photoselective net products are based on the incorporation of various chromatic additives,
light dispersive and reflective elements into the netting materials during manufacturing.
The photoselective nets include “colored-ColorNets” (e.g. Red, Yellow, Green, Blue net
products) as well as “neutral-ColorNets” (e.g. Pearl, White and Grey) absorbing spectral
bands shorter, or longer than the visible range. The spectral manipulation is aimed at
specifically promoting photomorphogenetic-physiological responses, while light ISHS International Workshop on Greenhouse Environmental Control and Crop Production in Semi-Arid Regions, Tucson AZ (C. Kubota
and M. Kacira, eds.) Acta Hort. 2008 797: 75-80.
2
scattering improves light penetration into the inner canopy (reviewed by Rajapakse and
Shahak, 2007). Radiation use efficiency increases when the diffuse component of the
incident radiation is enhanced under shade (Healey et al., 1998).
In addition to its direct effect on the plants, the photoselective filtration of sunlight
may also affect plant pests, beneficials and diseases. Some of the photoselective shade
nets contain pigments known to attract whiteflies and thrips (i.e. yellow and blue).
Therefore, crops grown under those nets could potentially be at a higher or lower risk for
pest infestation. Covering greenhouses with films or screens containing UV absorbing
additives is known to provide better protection against most pests, relative to standard
cladding materials (reviewed by Antignus and Ben-Yakir, 2004).
In this report we review the responses of numerous horticultural crops to
photoselective netting, including crop performance, pest infestation, and some uses in
combination with other covering materials.
MATERIALS AND METHODS
The photoselective shade nets and insect-proof screens were developed in
collaboration with, and produced by Polysack Plastics Industries, Nir-Yitzhak, Israel
under the trade mark ChromatiNets and OptiNets, respectively. Spectral properties of the
various photoselective net products (light transmittance, scattering and reflectance) were
previously described (Shahak et al. 2004a&b; Rajapakse and Shahak, 2007; Ben-Yakir et
al., 2008).
RESULTS AND DISCUSSION
The photoselective, light-dispersive netting concept is being studied in a
continuously growing number of crops. These include crops that were traditionally grown
in shade-houses, open field, or greenhouses.
Shade-Net Houses
1. Foliage crops. Photoselective netting was tested in foliage crops, traditionally cultured
under black shade nets of 50-80% shading (e.g. Pittosporum variegatum, Fatsia japonica,
Monstera deliciosa). Compared with black nets of the same shading factor (in PAR), the
Red and Yellow nets were found to specifically stimulate vegetative growth rate and
vigour, the Blue net caused dwarfing, and the Grey net specifically enhanced branching
and bushiness, and also reduced leaf size and variegation in Pittosporum (Oren-Shamir et
al. 2001; Shahak, 2008). The effects of the Blue, Yellow and Red nets result from their
enriching/reducing the relative content of blue, yellow and red spectral bands of the
transmitted light, and might be related to similar effects reported for photoselective films
and artificial illumination (reviewed by Rajapakse and Shahak, 2007). The effects of the
Grey net might relate to its distinct absorption in the IR range.
2. Cut flowers. Several cultivars of Lisianthus (Eustoma grandiflorum), sunflower
(Helianthus annuus) and Trachelium were found to develop longer and thicker flowering
stems under the Red and Yellow nets, while shorter under the Blue, compared with their
equivalent black shade net. Additionally, the Red net induced shorter time to flowering in
some species. The extent of responsiveness varied amongst the different species and
cultivars (Oren-Shamir et al., 2003; Rajapakse and Shahak 2007). The highly dispersive
Pearl net was recently reported to enhance branching of Myrtus communis pot plants,
while in Crowea ‘Poorinda Extasy’ it increased the number of flowers per branch,
compared with a black net of the same shading capacity (Nissim-Levi et al., 2008). ISHS International Workshop on Greenhouse Environmental Control and Crop Production in Semi-Arid Regions, Tucson AZ (C. Kubota
and M. Kacira, eds.) Acta Hort. 2008 797: 75-80.
3
3. Fruit trees. Low-shading photoselective netting of fruit tree crops (e.g. peach, apple,
pear, table grapes) traditionally cultivated un-netted, revealed differential effects of the
colored nets on orchards performances. The net-covering by itself was found to mitigate
extreme climatic fluctuations, reduce heat/chill/wind stresses, enhancing photosynthesis
and canopy development, compared with the un-netted orchards. On top of that, the
photoselective, light-dispersive filtration of sunlight further affected the following traits in
a differential manner, depending on the chromatic properties of each net. The
photoselective responses include fruit-set, harvest time (early or late maturation), and fruit
yield, size, color, internal and external quality (Shahak et al., 2004a&b; Rajapakse and
Shahak, 2007; Shahak et al., 2008).
4. Vegetables. Bell pepper (Capsicum annuum) is commercially grown at the arid Besor
area in Israel under shade nets of 30-40% shading for producing high-quality fruit,
avoiding sunburns, and saving on irrigation. We have compared the traditional black
shade nets with the Red, Yellow and Pearl nets for their effect on pepper productivity and
quality. The spectra of transmittance of total light, and spectra of scattered (diffused) light
under these nets is illustrated in Fig. 1A and 1B, respectively. Pepper cultivation under
the colored shade nets increased productivity of 5 different cultivars tested during 3
successive years. Depending on the year and cultivar, the total fruit yields (in t/ha per
season) under the colored nets were higher by 115%-135%, relative to the equivalent
black shade net. The higher fruit yield resulted mostly from enhanced rates of fruit
production, namely the number of fruits produced per plant (see Fig. 2A&B), while
average fruit size was not significantly affected in most cases (not shown).
Why is productivity increased? Air temperatures and relative humidity under the
different nets did not differ from one another. Measurements of average leaf chlorophyll
content, photosynthesis rate of exposed leaves, and canopy fresh and dry weight did not
reveal significant differences either (data not shown). We speculate that the modification
of light quality by the tested photoselective shade nets promotes fruit-set, and/or fruitlet
survival rate. This might result from either the higher content of scattered/diffuse light
under these nets compared with the equivalent black nets, or from the modified spectral
composition, or both. The Pearl, Yellow and Red nets all transmit highly scattered light
which is enriched in the green+red+far-red spectral range relative to the UV+blue (Fig.
1). Further studies are required to establish the hypothesis and mechanisms involved.
Colored Shade Nets Integrated with Other Covering Materials
Greenhouses and tunnels covered by plastics films often require additional
shading for reducing the heat load. Below, we provide a few examples for substituting the
traditional shading practice by photoselective shading.
1. Colored shade nets in film-covered tunnels. Lettuce (Lactuca sativa) grown in the
west-Negev area of Israel in walk-in tunnels covered by clear plastic films plus 30%
shading nets produced lettuce heads, which were 20-30% larger (‘Noga’), or 40-50%
larger (‘Iceberg’), if the Red or Pearl nets were used instead of the equivalent Blue, black
or Aluminet (reviewed in Shahak, 2008). In Almeria, Spain, the 30% Red shade net was
found by the group of Fernández-Rodriguez to promote higher pepper and tomato yields,
compared with the traditional white-wash (Shahak et al, 2004c).
2. Pepper in insect-proof-net houses. Winter pepper cultivation in 25-50 mesh insectproof
houses in the Arava valley, Israel, requires supplemental 30% shading during the
first month after planting (August), and again towards the end of the season. The Red net ISHS International Workshop on Greenhouse Environmental Control and Crop Production in Semi-Arid Regions, Tucson AZ (C. Kubota
and M. Kacira, eds.) Acta Hort. 2008 797: 75-80.
4
promoted early season fruit yield by 8-21% (depending on the year and cultivar), relative
to the black, Grey or Blue nets, and induced an additional fruit cycle at the end of winter.
3. Rose cultivation in a greenhouse. Red nets of 30% shading which were applied inside
greenhouses of roses (Rosa cultivars) covered by clear plastic films in Naivasha, Kenya,
promoted the average stem length by ca 5 cm, and improved coloration in bicolor
cultivars, as well as crop uniformity, compared with the common practice cover of the
same shading capacity (not shown).
Photoselective Shade Nets Differentially Affect Vegetable Pest Infestation
As expected, whiteflies and thrips preferred landing on Yellow and Blue nets,
respectively. Nevertheless, the number of pests trapped inside chambers or tunnels
covered by these nets were similar to, or lower than the equivalent black net (Table 1).
The number of whiteflies found on traps and plants under the Yellow net was 2-3 folds
lower than under the black net (Table 1). The lack of correlation between the number of
pests landing on their preferred colored nets, vs. the number penetrating through these
nets, may suggest that the pests remain on these nets for an extended period of time (an
arrestment response; Bukovinszky et al., 2005). Yellow shade nets were previously
reported to affect aphids in a similar manner (Harpaz, 1982). The Red net did not differ
from the black shade net, while the white and Pearl shade nets significantly lowered both
aphid infestation and the incidence of PVY and CMV (Harpaz, 1982 and Table 1),
probably due to their reflectivity of sunlight, deterring pest landing.
Photoselective Insect-Proof Screens Reduce Thrips Infestation
OptiNet® transmits only 40-50% of the UV range (280-380 nm) of solar radiation,
compared with 80-90% by the standard transparent screen . At the range of 380-800 nm
the OptiNet® transmits 60-70% of sunlight, compared with 85-95% by the standard
screen. However, the reflection of sunlight in the range of 400-750 nm by OptiNet® was
about 2.5 times greater than the reflection by the standard screen (not shown). The
numbers of thrips (mainly Thrips tabaci) found on cucumber leaves in tunnels covered by
the OptiNet® screen were significantly lower (3-9 folds), compared with the standard
screen (Table 1). Similarly, fewer thrips were caught (about 5 folds) in tunnels of chive
covered by OptiNet®, vs. the standard screen.
The mechanism by which the OptiNet® provides better protection against
arthropod pests may be explained by two alternative hypotheses: (i) the light inside the
screen-house contains less UV and therefore becomes “invisible” to the pest (see
Antignus and Ben-Yakir, 2004); (ii) higher levels of reflected/scattered sunlight deter pest
landing (e.g. Matteson et al., 1992).
CONCLUSIONS
Photoselective, light-dispersive shade nets and screens provide a new tool that can
be implemented within protected cultivation practices for improving crop performance,
pest control and overall profitability of agricultural crops. The technology can be used by
its own, in net- and screen-houses, or alternatively combined with other covering
materials used in protected cultivation.
 
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Interesting. Same strains and everything?

I know some strains like og kush perform different outdoor than in. For example, og indoors grows tall and lanky, sativa like. Outdoors it will grow more bush like.

However I still stand by outdoor plants should not produce more leaf than indoor plants due to light color spectrum's. Plus, any shading will also have a negative effect on the photosynthesis process. Just my two cents.

Would love to hear what others think about this.....
 
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Yeah man same cuts actually. Who knows maybe I am fucking something up. But I believe its worth a try before we dismiss it.
 

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