Transcript Asoxystobrin - NC Cooperative Extension

2015 Tobacco Production Update:
Agronomy
Loren Fisher
Matthew Vann
Crop Science Department
Estimated FC Variety Plantings
North Carolina, 2014
Variety
% Of Acres
NC 196
K 326
CC 143
CC 27
GF 318
NC 299
K 346
CC 67
CC 700
GL 395
53
13
8
3
3
3
2
2
2
2
Varieties With Above AVG Yield/A
3yr avg. in OVT
Variety
CC 35
PVH 2254
K 326
NC 299
GF 318
PVH 2110
CC 27
NC 72
PVH 1118
NC 196
CC 33
NC 92
CC 13
GL 338
CC 37
CC 700
CC 1063
* Limited Data
Acreage
Yield
Value
BS
GW
%
lbs/acre
3185
3055
2938
2909
2906
2906
2868
2839
2834
2820
2817
2801
2792
2761
2760
2752
2745
$/acre
5240
5237
5248
5174
5167
5017
4986
4791
5025
5034
5056
4490
5004
4762
4800
4741
4817
23
No Data
24
27
17
19
34
30
11
13
10
36
20
39
18
18
12*
49
No data
40
27
31
38
20
19
35
28
22
25
29
33
23
39
19*
13
3
3
3
53
2
1
EPS Tray Sanitation
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Clean tray with plain water
Allow to dry
Fumigate with MB or Steam
Surface sterilization is not as effective as
fumigant or steam on polystyrene trays
• If bleach or other tray cleaning solutions are
used make sure trays are rinsed WELL with
CLEAN water and allowed to dry before
seeding
Hard Plastic Trays
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New Hard Plastic tray for float system
Easier to sanitize
Extended life span (15-20+ years)
Trilogy Tray by BeltWide Inc.
Limited number of 288 cell trays available in
2015. Other cell sizes available in 2016.
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
Greenhouse Management
• Optimum Germination
– 65 to 70 F at night
– No more than 85 F during the day
• Warmer temperature (above 90 F) reduces total stand
• Cooler temperatures only delay germ.
• Constant temperatures can reduce stand
– Need difference in day/night temp for some varieties
• A short time above 105 F can kill newly germinated seed
– Don’t trust automatic curtains
– 110 + F for extended period can kill larger plants
• Only takes 55 days to produce a transplant
• Can drop temp at night to 55 F after you have a good stand
to save fuel
Cold Injury
• Looks similar to B
deficiency.
• Occurs when
temperature falls
quickly.
• Warmer temperatures
will correct the issue.
Cold Injury
• Looks similar to B
deficiency.
• Occurs when
temperature falls
quickly.
• Warmer temperatures
will correct the issue.
Dry Cells
• Occurs when water
does not wick.
• Old media
• Buy new media
• Water overhead
Fertility
• Water soluble fertilizer added to water
– 3-1-3, 2-1-2, 4-1-4 analysis
• 150 ppm N added within 7 days after seeding
• 100 ppm N 4 weeks later
• Or maintain 100-125 ppm N with Injector
High Bicarbonates
• As detected by water sample
• Battery Acid (sulfuric acid)
• Recommendation on water sample report
• “Checker board” pattern in greenhouse
• Slow growth, pale to gray color
Boron Deficiency (GH)
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Causes bud distortion
If no boron in water or fertilizer
Add Borax
Very small amount needed, toxicity is worse than
deficiency
• Recommendation is for 1-2 ppm B
• Most fertilizers will supply 0.5 ppm or less
– Enough unless environmental conditions are favorable
for deficiency, Rapid growth/or slow growth
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, but no lasting effects
Fertilizer Salts Injury
• Fertilizer salts accumulate in the top of the
tray as float water evaporates
• Salts can kill very small seedlings
• Increases spiral root plants
• Waiting to add fertilizer to bed reduces loss
– But don’t wait more than 7 days
• Check fertilizer salts with conductivity meter
• Water overhead to lower salt level
Spiral Roots
Spiral Roots
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First root at germination fails to go into media
Can be a few or up to 60%
Causes:
Damage to root tip at emergence
– Seed pellet, but uncommon
– Environment
• 50-75% will never make a usable transplant
Clipping
• Increases usable transplants
• Increases uniformity of transplants
– Stem length and stem diameter
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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
Spray Equipment
• Take extreme care if you ever use a “field”
sprayer to power the spray boom in your
greenhouse
• “Clean” sprays kill transplants every year
• Spartan Charge: Aim
Nitrogen Application
• 50% at transplanting + 50% at layby
– Often does not supply enough N in a wet year
– Often supplies too much N in a dry year
• Consider making more than two applications
– 50% at transplanting + 25% at layby + 25% two
weeks after layby with liquid N if needed
– Can be applied directly to the soil surface with a
high clearance sprayer
2014 Calcium Deficiency
• Bud/tip leaves are most
likely show deficiency
– Downward cupping/hooded look
• Typically occurs at flowering
– Result of rapid plant growth
• Often disappears once
topping occurs
– Removal of affected tissue
– Root growth stimulation
Lower Photo Courtesy of Mitch Smith-Pitt County Extension Agent
Addressing Calcium Issues in the Field
• Collect routine soil samples in each field that tobacco
will be produced in.
– This will determine the amount of soil available Ca
• Most tobacco fields will have sufficient Ca reserves due
to previous applications of lime.
• To prevent or reduce the risk of Ca deficiency top
plants as early as possible.
– Topping will stimulate root growth, which increases Ca
uptake
• Ca deficiency is transient and will correct itself
– Foliar Ca applications are not recommended
– Little to no foliar Ca uptake, must be absorbed in the roots
2014 Boron Deficiency
• Symptoms:
– Deformed Bud
– Misshapen Leaves
– Twisted Bud/Leaves
• Likely Causes:
– Low Soil B
– Excessive Rainfall
– Rapid Plant Growth
Photos Courtesy of David Dycus (retired NCDA Agronomist)
Boron Deficiency Symptoms
Photos courtesy of
Dr. David Hardy, NCDA
Boron Deficiency Symptoms
Addressing Boron Issues in the Field
• Consider using a base fertilizer material that will supply 0.25-0.50
pounds of B per acre.
– Works well with blended materials
– Consider tank mixing liquid B with liquid N where dry materials are not utilized
• Only apply foliar B if tissue samples are deficient.
– 0.5 lbs B/acre in a single foliar application should correct deficiency
– DO NOT apply unless nutrient deficiency is confirmed
– DO NOT over apply, B can be toxic at 1.0 lb/acre
• 0.25 lbs B/acre + 0.25 lbs B/acre, both applied foliar
Weed Control
• Increasing focus on weed
control in recent years.
– Weed seed contamination
in exported leaf
• Limited herbicide options
for tobacco production.
– Available herbicides will
help
Weed Control
• Spartan offers the best broadleaf control.
– Excellent control of pigweed, nutsedge, and
morningglory
– Lower rate (4.0-4.5 fl.oz./acre) on sandy soil
– Higher rate (5.0-6.0 fl.oz./acre) on heavier soil
• Command offers best grass and ragweed
control.
– 1.5-2.0 pts/acre for best results.
Weed Control
• Both materials can be applied PPI or PreTransplanting.
– PPI ensures herbicide activation but increases
injury potential with Spartan
– PRE-T reduces injury potential but may require
irrigation or cultivation for activation when soil
moisture is low
– Tank mixing the two products reduces crop injury
without reducing efficacy
Questions??