Impact of Improved Aeration on Decomposition Rate of Enriched Compost
Seminar on Greenhouse Vegetable Production in Ontario
1. Greenhouse Vegetable
Production:
Sweet Bell Pepper (Capsicum annum L.) culture in Leamington
Ontario
Lecture Presented by:
Dr. Ozair Chaudhry, Ph.D.,C P Ag. (USA)., OCT ( Canada)
Albert Campbell Collegiate Institute (NS) Con.Ed. Toronto, Ontario
and
Dr. Muhammed Saeed, Ph.D.,(UK) CPH (USA)
Kapital Produce Ltd. Leamington, Ontario
September, 2008
Copyrighted. Users advised to quote author’s reference.
2. Greenhouse Vegetable
Production: Sweet Bell Peppers (Capsicum annum L.)
culture in Leamington, Ontario
Bell Peppers Production in Gutter Type Greenhouse
Phases of Study
Introduction Structure Operation Production Economics
Planting Harvesting & Packing
4. Introduction
Focus on controlled, intensive production of high
quality, fresh market produce under very
diverse conditions
Optimum use of controlled variables;
Air & root zone temperature,
Vap.pressure deficit,
Fertilizer, CO2 enrichment, Suitable growing
media, and plant maintenance.
5. Management Goals
Intelligently control greenhouse operational
variables to,
Maximum yield and profit,
To simplify the decision-making on dynamics of
the crop-environment interaction.
7. Topic - 1 (Greenhouse Structure)
Gutter-connect-design offers
expansion (“bays”) compartment,
Roof has many arches, each cover
one bay,
Arches connected with Gutters where
1 bay meets the next.
10. GH Structure Conted.
Lower part of roof are gutters (the point
where adjacent arches begin or end).
Single bay greenhouse 240 m2 (2500 Ft 2)
can be expanded by addition of bays to
cover 1Ha (2.5 Ac)or more
11. GH Structure Conted
Advantages of Gutter Types:
Accommodate taller indeterminate
cultivars (e.g. pepper attains 3.5m
12 Ft.
provide larger air mass easily
optimize Env than smaller air mass
per unit area of greenhouse
12. GH Structure Conted.
Material
Glass Panels (24 %)*
PLASTIC (76 %)*
Polycarbonate Panels
Polyethylene Skins
*As in 2006-07
13. GH Structure conted.
Material
Double Polyethylene Skin has 2 layers,
pressurized air filled in between
provides rigidity(4 yr.)
Allow light, conserves energy, reduce
heat loss in winter
Newer material selectively exclude
wavelength, reduce insect / disease
16. Greenhouse (GH) Operation conted.
Heating Options as in 2006-07:
Boiler 42 %
Steam 27 %
Hot water 19 %
Natural Gas 5 %
Forced Air 4 %
Air applied heat influence canopy
Floor applied influence root zone
20. GH Operation conted.
(Primary Heating)
Boiler delivers heat by (5 cm or 2//
pipe) run on the floor between
rows
Return pipe run parallel to one
another forming “rail” used by the
cart run up and down, help pruning
and harvesting.
23. GH Operation conted.
Importance of Plant Canopy Air Heating
Target temp. 18-21 0C,
Temp. below 15 0C is sub optimal for root zone,
Irrig. Temp. above 23 0C injurious to roots,
Summer temp. can be 25 0C if grown in saw dust
or rock wool slab.
24. GH operation conted.
(Secondary Heating)
2 // pipe run under the top gutter to
heat the roof for snow melt down in
winter
provide precise temp to optimize
pollination, promotes early fruits &
leaf
25. GH Operation conted.
(Ventilation & Air Cooling
Ventilation helps:
air circulation, uniform climate by heat
distribution from system, dehumidifying,
In winter warm humid is exhausted and cool
dry air brought in.
Summer ventilation aid cooling the crop
26. GH Operation conted.
(Relative Humidity)
Measure of water vapour contents in air,
Maintained below threshold point to avoid
diseases
Humidity RH α transpiration rate+temp + light intensity
High humidity increase VP in GH air mass
*VPD measured by sensors used to control
transpiration rate for sustained yield.
__________________________________
* Measurement units vary: milibar or Kpa, g/m3
28. GH operation conted.
(Cooling System)
During high light intensity, ventilation is
insufficient
Increased GH temp. also lowered with pad
& fan evaporative cooling system
30. GH Operation Conted. Floors & Potting
Concrete floors expensive but ideal for nursery,
Seedlings rooted in rock wool slabs or bags with
growing media,
Small water *channels run between rows,
These channels allow drainage from irrigation
from one end to holding tanks for re-circulation.
_______________________________________
*( channel sized 6x6 inch width x depth)
31. Growing Media ( as in 2006-07)
Rock Wool Slabs 57 %
Coconut 39 %
Peat moss 1%
Soil 0.6 %
NFT 0.5 %
Others (Foam) 2.2 %
33. GH Operation conted.
CO2 Supplementation
Co2 diffused pipes are placed below the gutters
Co2 Source: Natural gas combustion contains
impurities
In summer temp hike so, hard to maintain ambient
level of Co2, it requires extra cooling
Liquid Co2 clean but costly
34. GH Operation conted. (CO2 Supplementation)
Optimum GH CO2 conc. Ranges 700-900
ppm.
Rubp Enz. Fix either ------> CO2 : O2
Higher conc. CO2 will favour CO2 fixation
CO2 limit photosynthesis rate
35. GH Operation conted. (CO2 Supplementation)
On high ventilation, cost efficient conc. of
CO2 is 350 ppm, just above the ambient.
There won’t be net exchange of CO2 via
vents,
At higher temp.25 OC, Photosyn. declines,
CO2 suppl. beyond this point is cost
inefficient,
Younger nursery plants have expon. Gth.
than older. CO2 enrichment benefits.
36. Liquid CO2 Tank & Vaporizers
Liquid CO2 at 20 0C, passes through Vaporizers & converted to gas
before fed on plants)
37. GH Operation conted: (Irrigation / Fertigation)
Water & Fertilizer has control on delivery to
plants,
Both are precisely programmed, delivered as
frequently required,
Both pumped from supply tanks in header
house via hoses to aisles,
Small spaghetti tubes supply equal rationing
from hose to each plant.
39. GH Operation Conted.
Nutrient Control System
Electrical Conductivity (EC) gives indirect
measure of nutrients / ions conc. to be
delivered to plants
Greater the ions dissolved in H2O, greater
the current flow and hence, high EC value
EC unit mili mohs/cm or mili Siemens/cm, or
micro Siemens/cm
43. .
GH Operation Conted (Environmental Control)
Computer Integrated manipulation provides
optimal plant growth,
Internal Env. contact with Sensors installed in
aisles records Temp, RH, Light & CO2 level,
Sensor quality, maintenance and proper
placement in vegetation records accurate and
reliable reading.
47. Topic 3-a Production Conted.
Bell Peppers Planting
Greenhouse peppers are Indeterminate
cultivars therefore, plants continually develop
and grow from new meristems that produce
new stems, leaves, flowers and fruit.
These cultivars require constant pruning to
manage their growth, optimize yield, a balance
between vegetative & generative growth.
52. Bell peppers Production conted.
Biological Growth
GROWTH
Increase in Biomass
Vegetative Growth Generative Growth
Associated with gth of leaves and branches Generate Carbohydrates
Associated with flowers & fruits Assimilates Carbohydrates
53. Bell Peppers Production Conted.
Effect of light intensity on Growth & Development
Corrective environmental actions: ( light, Temp,
RH, nutrients) trigger balance between Veg. &
generative growth.
Light promote and limit photosynthesis
Light intercept = latitude,canopy geometry, row
orientation
At 340 L, N-S orientation gets high intercept
At 500 L, E-W maximize light interception.
54. Bell Peppers Production Conted.
Effect of light intensity on Growth & Development
Leaf Area Index (LAI) ratio of leaf area over
the land that leaf covers,
Crop productivity increases with the increase
of LAI. (LAI 8 is the max value for GH crops).
Highest LAI for Bell Peppers= 6.3,
Cucumbers= 3.4 and Tomatoes= 2.3
White plastic floors reflects light to canopy (
add 9 % intensity).
55. Bell Peppers Production conted.
Effect of light intensity on Growth & Development
In North American winter (Nov-Feb) light is
limiting, 16-20 Hrs photoperiod is
supplemented.
120-180 W/m2 intensity applied from 400 W
sodium light
56. Bell Peppers Production Conted.
Effect of Temperature Regime on Growth & Development
*24 hrs mean temp. manipulation for consecutive
days direct either veg. or generative gth.
Day temp 21-23 0C is optimum for photo-synthesis
of GH pepper, (1-1.5 variation Lower-->Veg &
higher --->generative gth)
For pepper fruit set, night temp 16-18 0C is
optimum.
_______________________________________
* Vary within crops and cultivars
57. Bell Peppers Production Conted.
Seedling/ Transplantation
Seed to seedling ready 7-10 DAP*
Receives 1st transfer to bigger rock wool
blocks 10x10 cm when difoliate, 2 WAE**
Receives 2nd transfer to production GH at
6 WAE, 10 inch tall
__________________________________
*[DAP=Day After Planting, **WEP=Week After Emergence]
58. Bell Production Conted.
Seedling/ Transplantation
*Pre-filled rock-wool slab ( 100x20x7.5 cm)
has EC 2.5-2.8 m S/cm 21 0C has 6 planting
slots on the top,
After rooting in to slabs, cut 2 slit on the
bottom for drainage.
_____________________________________
*D/N 20/21 0C, RH 70-80, VPD 3-5 gm/cm3, CO2 800-1000ppm.
Post-establ. E C= 4-4.5
59. Bell Peppers Production Conted.
Green House Plant Production
1 *WATp maintain **D/N 21/16-17 0C. As
such plant is directed to set flowers, maintain
opt. Veg. Growth and opt. fruit & yield.
Each plant pruned and thinned to 2 strong
stems, twine hung from overhead support wire
Ensure least damage on main stem.
_____________________________________
[* WATp= Weeks After Transplant, ** D/N= Day/Night]
60. Bell Peppers Production Conted.
Green House (Flower & Fruit Set Control)
Opt. Temp. flower/fruit = 17 0C
-----------------------yield = 21 0C
[poor pollination cause fruit flattened / button if <14 0C N
temp.pointed fruit due to hormonal imbalance.
In early winter, precise head heating
pipes are lowered on canopy for
optimized temp.
61. Bell Peppers Production Conted.
Green House (Flower & Fruit Set Control)
Fruit set reduced > 270C and low RH,
Increased light intensity reduce fruit size
[Can be overcome by 10 % shading of GH ].
Lowering Rt. Zone Temp (15 0C) directs plants
remain Vegetative,conversely, floral/ fruit
abortion.[low light intensity also abort flowers]
63. Bell Peppers Production Conted.
Insect Pest & Biological Control
Aphid sps. Myzus persicae is the most common
and is controlled by wasp parasites: Aphidus
colemani & A. ervi. Aphids become silvery brown with
small whole in back when parasite emerges.
[Lady beetle is alternate predator used in some cases]
OR
The larvae of midge Aphidoletes aphidimyza feeds on
most aphids.
Thrips sps.controlled by predatory mites
Amblyseius cucumeris.
75. Cost Benefit Summary ( as on 2007)
Category Total Dollars $/Sq M
A. Gross Revenue = 372324.00 92.00
B. Operating Cost = 299964.00 74.12
C. Invest. Cost = 25698.00 6.35
D. Building/Equip = 38649.00 9.55
depreciation
E. Production cost = 364311.00 90.02
[B + C+ D]
Revenue over Op. cost [A-B] = 72360.00 17.88
Return to Management = 8013.00 1.98
76. Thank You
Authors contact: ozair.chaudhry@tel.tdsb.on.ca
msaeed@kapitalproduce.com
Courtesy of Kapital Produce Ltd. Leamington, Ontario is appreciated