Axillary Shoot Control With BASF 131

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Transplant Production
General Info
• Most common size is 35 ft. X 100-300 ft.
• Walkway down middle
• Sectioned into 16 ft. wide beds on each side
of walkway up to 100 ft long
• Beds lined with black plastic
• Filled with 3.5 – 5 inches of water
• Side-curtains, exhaust fans, heaters
Transplanted Acres and Costs from a
30’X 245’ Greenhouse - 288 cell Trays
Usability
(%)
85
Acres
Planted
102.7
80
96.6
75
90.6
70
84.5
Water Quality
• Have water tested every year (NCDA)
• Avoid pond and river water
• Most common problems
– High bicarbonates (eastern NC)
• Add sulfuric acid
– Low boron (Piedmont)
• Add boron
Trays and Media
• Trays are made of polystyrene, float
– 200-332 cells per tray, Most common is 288
• Filled with media
– Peat, vermiculite, perlite, wetting agent, lime,
fertilizer
• 3 cubic ft. bag of media will fill 18-20 trays
Fertility
• Water soluble fertilizer added to water
– 3-1-3, 2-1-2, 4-1-4 analysis
• 150 ppm N added 10 days to 2 weeks after
seeding
• 100 ppm N 4 weeks later
• Or maintain 100-125 ppm N with Injector
Fertilizer Effects on Water pH
• Well water ranges from 4.5-8.5 pH
• 16-4-16, 15-5-15, and 21-5-20 are acidic
and should only be used on high pH water
• pH of 4 and below can burn off roots in the
float water
Fertilizer Salts Injury
• Fertilizer salts accumulate in the top of the
tray as float water evaporates
• Salts can kill very small seedlings
• Waiting to add fertilizer to bed reduces loss
• Check fertilizer salts with conductivity
meter
• Water overhead to lower salt level
Sulfur Deficiency
• If media not supplemented with MgSO4 or
gypsum
• Most media contain sulfur and some
fertilizers do
• General yellowing of plants
• Add epsom salts
Boron Deficiency
•
•
•
•
Causes bud distortion
If no boron in water or fertilizer
Add Borax
Very small amount needed, toxicity is
problem
Seed Germination
• Seed no more 60 days before anticipated
transplanting
• Optimum Temperatures: 70 night/85 day
• Lower Temperature only slows germination
• Higher Temperatures slow germination and
can reduce total stand
Effect of Temperature on
Germination of NC 71
60
40
20/30 (68/86)
20/35 (68/95)
30/40 (86/105)
30
20
10
Hours After Seeding
30
9
26
6
21
3
18
2
16
2
13
8
0
11
6
No/50
50
50
45
40
35
30
25
20
15
10
5
0
Hours After Seeding
30
9
26
6
21
3
18
2
16
2
20/30 (68/86)
20/35 (68/95)
30/40 (86/105)
13
8
11
6
No./50
Effect of Temperature on
Germination of K 326
Summary
• Response to 68/86 is always better than
68/95.
• Some tolerate it hot, others don’t.
– Spt 168, NC 606, and NC 72 performed well at
86/105.
– NC 71, NC 297, and NC 291 performed poorly
at 86/105.
Effect of Temperature on Days to
Reach Maximum Germination
Variety
68/86
68/95
-Days to Max. Germ.K 326
7
8
K 346
7
9
NC 71
9
11
NC 297
7
9
Uniform Emergence
• Maintaining optimum temps.
• Seed by 5- day forecast for sunny days
• Uniform tray filling, growing media and
seed placement
• Ants and Mice
Total and Usable Plants at Day 50
100
Total
Usable
80
70
60
Treatment
25X4 1-4
25/75 - 3
50/50 - 3
75/25-5
40
75/25-3
50
Check
Percent
90
2000
Primed Seeds
• Seed treatment process that promotes
germination
• Response is variable
• Should be a seed company decision
Spiral Roots
• First root at germination fails to go into media
• Can be a few or up to 60%
• Causes:
– Seed pelleting
– Environment
• 50-75% will never make a usable transplant
Spiral Roots
Effect of Pellet and Variety on
the Incidence of Spiral Roots,
NCSU-2001
25
20
15
Pellet A
Pellet B
Percent
10
5
0
Spt 179
Spt 168
Spt 172
Spt NF 3
Effect of Pellet and Variety on
the Incidence of Spiral Roots,
VPI-2001
10
9
8
7
6
Percent 5
4
3
2
1
0
Pellet A
Pellet B
Spt 179
Spt 168
Spt 172
Spt NF 3
Uniform Growth
•
•
•
•
•
•
High quality media
Monitor fertilizer salts
Monitor temperatures
Clip plants properly
Quality water
Manage insects and disease
Clipping
• Increases usable transplants
• Increases uniformity of transplants
– Stem length and stem diameter
•
•
•
•
Improves hardiness
Holds plants for transplanting
Optimum is around 5 times
Many are clipped 20 or more times
Clipping
• Start when total plant height is 2-2.5 inches
above bud
• Clip every 3-5 days
• No closer than 1-1.5 inches above the bud
• High vacuum mower
• Dump clippings 100 yards from greenhouse
Disease Management in
Greenhouses
• SANITATION (before seeding)
– Rinse old trays and fumigate with Methyl
Bromide
– Rinse walkways and side curtains
– Remove weeds in and around greenhouse
Disease Management in
Greenhouses
• SANITATION
– Dump clippings 100 yards away from
greenhouse
– Clean mowers after clipping with 50% bleach
solution
– No tobacco products in greenhouse
– Clean hands shoes before entering
Common Greenhouse Diseases
•
•
•
•
•
Rhizoctonia Stem Rot
Pythium Root Rot
Blue Mold
Collar Rot (Sclerotinia)
Tobacco Mosaic Virus
Carryover of Rhizoctonia on Trays
Rhizoctonia Management
• SANITATION
Pythium Damping-Off
• Roots turn light brown and groups of plants turn
yellow
• Worse during cool wet conditions inside GH and
when pH is high (usually above 6.0-6.2)
• Tray sanitation and high quality media are
important to help prevent the disease.
• More severe with warmer float water temperature.
Pythium Root Rot in Tobacco
Greenhouses
Pythium Management in
Greenhouses
• Use new or sanitized trays
• Keep media pH below 6.2
• Float trays:
– Wash, then methyl bromide @ 3 lb/1000 cu ft
for 24 hr, then aerate 24 to 48 hr.
• Thoroughly mix Terramaster 35 at 2 oz
wt/100 gal of float water 2-3 weeks after
seedling.
Blue Mold on Seedlings
Blue Mold Prevention in
Greenhouses
• Grow your own plants from seed.
• Apply Dithane DF at ½ lb per 100 gal spray
– Every 7 to 10 days from quarter size to
transplanting
– 6 to 12 gal water per 1000 sq ft depending on
plant size
• Destroy all plants in a greenhouse if blue
mold is found and plants had not been
treated.
Sclerotinia Ascocarps Outside Greenhouse
Collar Rot Management
• Seed ONLY 55-60 days ahead
• Use good ventilation and circulation
• Dump clippings, dead plants, and media at
least 100 yards from greenhouse
• Plant vegetable gardens at least 100 yards
from greenhouse
TMV
Mosaic
(NC 297)
Local
Lesions
Mosaic Prevention in Greenhouses
• Thoroughly clean mower and sanitize with 50%
clorox. Sanitize between clipping beds.
• Use 10% clorox to wash side curtains.
• Avoid excessive clipping.
– Clip no more than 10 times
– Keep temperatures cooler and don’t over fertilize
• Do not allow the plants to be touched until
transplanting.
Mosaic Prevention (cont.)
• Do not allow users of tobacco products in
the greenhouse.
• Carefully check plants for tmv before
transplanting.
• Do not allow weeds to grow in the
greenhouse, especially horsenettle or
nightshades.
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