Date post: | 01-Jun-2018 |
Category: |
Documents |
Upload: | muhammadrazif |
View: | 215 times |
Download: | 0 times |
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 1/29
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 2/29
Pract ic ing agr icu l ture is becom ing more
chal leng ing due to -
Global cl imate changes; Extreme
c ilmat ic events .
Urbanizat ion pushing Ag towards
margin al areas.
Market standards go ing up: betterquali ty, less chemicals,
env ironmental-f r iend ly p ract ices.
2Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 3/29
What can we do about i t?
We cannot do much about the cl imate,
bu t we can p rotect the crops , making themless dependent on their env i ronment.
Protect ion can be prov ided by
Net- (screen-) houses
Greenhouses
Develop ing resistant (to lerant) cu lt ivars.
3Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 4/29
Nett ing is used to p rotect crops againstexcess ive radiat ion , environm ental hazards
and f ly ing pests
We have taken it one step fu rther, to alsophoto -select ively screen sunl igh t
This is a sophistication of a “low - tech”
pro tected agr icu l ture
4Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 5/29
Plant -l igh t Interact ion
Sunl ight is the source of energy fo r plant l i fe .It also prov ides signals fo r plants to sense theirenvi ronment,
and to respo nd best for their survival .
Plants can sense even sm al l changes in theirsur round ing l ight reg ime :
Spectra l compos i t ion (quali ty)
Direct ion Ligh t intensi ty (quant i ty)
Durat ion (per iod )
5Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 6/29
Addi t ional players in agr icu l ture
Who else is respo nding to l ight qu al i ty? Fung al diseases
Insect p ests
Insect-borne Viral dis eases
Benefic ial ins ects
The final crop perform ance integrates al l of theabove
6Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 7/29
*Polysack Plast ics Industr ies, kibbutz Nir Yi tzhak 7
Photoselect ive nett ing is a new agro- techn olog icalapproach
Developed by a col labo rat ion between the Volcani
Center and an Israel i Plast ics indus try*
We have designed several ser ies o f shade/pro tect ive
net products , each screening di f ferent parts o f the
spect rum
“colored ColorNets ”: Blue , Green , Yellow , Red , purp le
“neutral ColorNets ”: White, Grey , Pearl
and tested them under f ield con di t ions
Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 8/29
8
Major goals:
Achieving speci f ic physiological benef its , in
add i t ion to the basic protect ive funct ion ofthe nets,
To make the investment in the net-cover ing
cost-ef fect ive the growers.
Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 9/29
what is un ique about them?
Net type Main purpose
Light q ual ity m odi f icat ion
Sp ectrum? Scatter in g?
B lack Shad ing No No
Clear(“crystal”) Insect screens;hai l protect ion
No Yes
Photoselect ive
( =Colo rNets)
Imp rov ing crop
per formance Yes Yes
Light under the ColorNets is both spectral ly modi f ied andscattered.
The spectra l modi f ication promotes phy s io logical responses.
The scatter ing improv es the penetrat ion o f the spectral ly- modif ied l ight into the inner plant canopy.
9Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 10/29
Examples for resul ts in
Ornamentals
10Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 11/29
Ornamental fo l iage crops (shade p lants)
Aral ia grown for decorat ive branches under 60% shade nets .
Photographed 10 month s after net app l ication
Yellow net Black net Blue net
Both Red and Yellow nets enhance the overal l vegetative
vigor (stem leng th, width, and leaf size)
The Blue net reduce vigo r relat ive to the B lack net
These nets do not m odify R and/or FR !!
Bo th results are desirable, to f i t varying market demands.
Y. Shahak 18.1.11 11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 12/29
Perennial o rnamentals
The branching su rpr ise
Two of the “neutral ColorNets ” were found to enhance
branching: the Grey and Pearl nets
This is a desired response in th e product ion of cu t t ings and
po tted plant .
10
20
30
40
50
60
70
Green Red Blue Grey Black Aluminet
N o
. o f b r a n c h e s / p l a n t
Pit tosporum var iegatum under
50/75% shad ing
Y. Shahak 18.1.1112
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 13/29
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 14/29
14
Combined covers in ornamentals:
3 retractable screens in one greenhou se: a Blue net used dur ing the vegetat ive stage; Red net towards
f lower ing ; and a thermal sc reen for ch i l l /heat contro l dur ing dayand/or night through out the whole season.
Orchids in B razi l
(Phalaenopsis)
Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 15/29
Vegetables
15Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 16/29
Vegetables: Leafy c rops
Higher yield under the Red and Pearl nets, com pared
with the black or B lue nets of the same shading capacity
Let tuce cov ered b y a 30% shade
net on to p o f a clear f i lm
282
393 418
258
0
100
200
300
400
שת ר
%03לל
נה י נ פ %03
ה מ ו ד %03
לה ו ח כ
ש
ל
ש
מ
,
ם
282
393 418
258
0
100
200
300
400
שת ר
%03לל
נה י נ פ %03
ה מ ו ד %03
לה ו ח כ
ש
ל
ש
מ
,
ם
Blue Red Pearl No net H e a
d w e
i g h t ,
g r
Red Pearl Black
2
3
4
5
Y i e l d
, K
g / m
2
Red Pearl Black
2
3
4
5
Y i e l d
, K
g / m
2 Summer Basi l in net- tunnels
(50% shading )
16Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 17/29
Vegetables: Bel l pepper
Summer-autumn pepper were tradi t ionally grow n und er blackshade-nets (~35% sh ading ) at the Besor area (arid).
We have stud ied the performance of p epper und er 3 selectedColorNets: Red , Pearl and Yellow
(A) Plant response stud y (un der prophylact ic pest contro l )
(B) Pest response stu dy (no pest ic ides!)
Besor Experimental Station, Israel 2005-2008
A B
17Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 18/29
Plant respon ses to photose lect ive shading
Export-qual i ty Net
%Ton/Ha
100 45 Black
154 69 Red
171 77 Yellow
* High -quali ty yield 2007
More frui ts produced per plant per season , and higher yield
(Ton /Ha): 15-40% more th an b lack nets,The order of produ ct iv i ty : Red > Pearl > Yellow >> Black
Export-qual i ty frui t yield: Pearl and Yellow were the best
Als o less po st-harvest decay in frui t grown und er the Pearl
and Yellow nets .
'Vergasa' cumulative yield
0
10000
20000
30000
40000
50000
60000
29.8.06 29.9.06 29.10.06 29.11.06 29.12.06
Harvesting date
F r u i t / d u n a m
Red
Pearl
Yellow
Black
Total yield: # fru it / dunam
18Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 19/29
Pest Response summary
Even though th e net holes were large enough to al low free
passage of the pepper pests,Infestation w as selectiv ely affected by the Pearl and Yellow shade nets .
Both Pearl and Yellow nets reduced aphid-borne viral diseases!
They al low a more environmental-fr iend ly pest con trol .
19
0
20
40
Red Black Yellow Pearl
% of CMV-infected Pepp er plants
Jun-0
20
40
60
Red Black Yellow Pearl
% of PVY-infected Tomato p lants
Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 20/29
Orchard Nett ing Research in Israel
• Table grapes
• Peach
• App le
• Pear
• Pomegranate • Pers immon
• Loquat
• Banana
• Avocado
• Citrus
• Frui t tree nu rser ies
20Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 21/29
Fru it t rees - Summary
Pho toselect ive t ree responses
(which depend on the color of the cover ing net)
Flowering
Fruit-set
Product iv i ty
Time of maturat ion (early & late)
Fruit s ize
Vegetat ive grow th
Water-use-eff ic iency
21Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 22/29
Protect ion from hai l, w ind, birds,
etc.
No sunburn s, less w ind s cars,
smoo ther fru i t sk in
Water saving
Frui t trees
Addi t ional benefi ts from the nett ing(independent of the co lor of the net)
22Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 23/29
23
Photoselective respon ses:
Effects on the rate of frui t maturat ion and berry s ize Exp: early table grapes (Jordan Valley and Arava 2000-2006 )
Advanced maturat ion(sug ar accum ulat ion)
under Whit e and Pearlnets (wh ite nets family ),
Delayed m aturat ion under Red and Grey nets,
Larger berr ies and better frui t qual i ty un der the l ight -dispersivenets (wh ite, Pearl, Red, Yellow nets); reduced s ize under Grey
and black
Fol lowing th is research, al l vineyards at the Jo rdan Val ley andArava region s are now covered by nets,
10
12
14
16
18
20
10.5.04 17.5.04 24.5.04 31.5.04Date
S u g a r c o n t e n t , % T S S
Red Grey Pearl No net
Prime 2004
Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 24/29
App l icat ions by grow ers
Late table-grape cu lt ivarsLakhish “ Tali Grapes” , Israel 2009
24
Red net for delaying fru i t maturat ion , Wh ite net for
advancing maturat ion; bo th also improv ing berry size
and quali ty,
+ prevent ing sunburns , w ind-scars, and bird d amage.
Y. Shahak 18.1.11
Ph t l ti f f t
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 25/29
25
Photoselective ef fects :
Fruit size & y ield in GD Apples Average of 5 su ccess ive years (2002-2006)
0
20
40
60
80
100
Pearl Red Wh ite B lu e No -n etB lac k Gr ey
K g / T r e e / Y e
a r b b bc
c c c
a
Ton / Ha /year
94 84 83 79 70 67 66 2005 Size distribution
0
10
20
30
40
50 55 60 65 70 75 80 85
Fruit Diameter, mm
K g / T r e e
ת ר ו ק י ה נ י נ פ ה ר ו ח ש
Black
Pearl
No net
Larger frui t size and fru i t yield under the l ight-dispersiveColorNets, but no t under black and Grey nets.
Order of eff ic iency :
Pearl > Red , White > Blue > No-net > Black , Grey
Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 26/29
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 27/29
Final words
Photoselect ive nett ing enables better ut i l ization of
solar energy by ho rt icu l tura l crop s,
whi le reducing chem ical appl icat ions (PGRs,
pest ic id es, fungic ides).
And prov id ing pro tect ion from envi ronmentalhazards
The new techn ology can be adjusted to f i t di f ferent
crop s/cul t ivars, cl imates, market demands
We are current ly test ing the techn ology in m ore
crop s, and fur th er develop the next generat ion o f
photos elect ive nett ing m ater ials .
27Y. Shahak 18.1.11
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 28/29
28
Take-home message
The qual ity o f the ligh t w ith in the
shade can make a lot o f dif ference!
Y. Shahak 18.1.11
B’sor Experimental Station, Negev
P bli ti
8/9/2019 Photoselective Netting
http://slidepdf.com/reader/full/photoselective-netting 29/29
Publications (partial list)
Y. Shahak
• Oren-Shamir et al. (2001) Coloured shade nets can improve the yield and quality of green decorative
branches of Pittosporum variegatum. J. Hort. Sci. Biotech 76: 353-361
• Shahak et al. (2004) ColorNets: A new approach for light manipulation in fruit trees. Acta Hort. 636: 609-
616.
• Shahak et al. (2004) ColorNets: crop protection and light-quality manipulation in one technology. Acta
Hort. 659 (1): 143-151.
• Rajapakse and Shahak (2007) Light quality manipulation by horticulture industry. In: Light and Plant
Development (G. Whitelam and K. Halliday, eds.), pp 290-312, Blackwell, UK. (A book chapter).
• Elad et al. (2007) Effect of colored shade nets on pepper powdery mildew (Levillula taurica).
Phytoparasitica 35 (3): 285-299.
• Shahak (2008) Photoselective netting for improved performance of horticultural crops. A review ofornamental and vegetable studies carried in Israel. Acta Hort. 770: 161-168.
• Ganelevin (2008) World-Wide Commercial Applications of Colored Shade Nets Technology
(ChromatiNet). Acta Hort. 770: 199-203.
• Shahak et al. (200 8 ). Improving solar energy utilization, productivity and fruit quality in orchards and
vineyards by photoselective netting. Acta Hort. 772: 65-72.
•Retamales et al. (2008) Colored shading nets increase yields and profitability of highbush blueberries. Acta Hort. 770:193-197.
• Shahak et al. (2008) Photoselective shade netting integrated with greenhouse technologies for
improved performance of vegetable and ornamental crops. Acta Hort. 797: 75-80.
• Ovadia et al . (2009) Coloured shade nets influence the stem length, time to flower and flower size of
ornamental crops. J. Hort. Sci. Biotech., 84(2): 161-166.
• Fal l ik et al . (2009) Can colored shade nets maintain sweet pepper quality during storage and
marketing? Acta Hort. 830: 37-43.29