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Lettuce
Frank J. Dainello,
Extension Horticulturist
Department of
Horticultural Sciences,
Texas A&M University |
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VARIETIES
| Crisp head= |
Great Lakes 659 MT, Mission |
| Loose leaf= |
Prizehead, Red Sails, Grand Rapids, Salad Bowl, Two Star, Waltman's
Green, Flame |
| Butter head= |
Buttercrunch |
| Romaine= |
Valmaine, Paris Island |
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SOIL PREFERENCE
Deep, well drained, black sandy loams with a pH 6 - 7.6; can tolerate
a wide range of soils from fairly sandy (spring planting) to heavy clays
(fall planting). Will not tolerate acid soils. |
OPTIMUM GROWING CONDITIONS
Cool-season, mean temperatures between 55 - 60oF, cool nights
especially critical for head quality. Temperature above 80oF
retards heading and induces seed stalk initiation, tends to cause loose
heads and bitterness. |
ESTABLISHMENT METHODS
Mostly direct seeded, can transplant
| Optimum time= |
| Spring- |
soil seed zone temperature >40oF; |
| Fall- |
soil seed zone temperature <90oF. |
| Seeding rate lbs/A= |
Cool soils, 1.5 - 2; Warm soils, 2.5 - 3.5; precision planted
(raw seed), .25 - .5; coated seed= 3 - 4 seed/row ft/seedling row. |
| Approx seed/oz= |
25,000 |
| Seeding depth= |
1/8 - 1/4" |
| Seedling spacing= |
9 - 12" in 40" raised beds; 2 lines, 12 - 14" apart. |
| Transplanting= |
9 - 12" in-row with 2 lines/bed. |
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FERTILITY/FERTILIZATION
Rates presented as actual lbs/Acre N, P2O5 and K2O (base actual rates
on soil test results).
| Generalized rate lbs/A: |
70 - 80 - 120 |
| N- |
60 - 100 lbs preplant incorporated. |
| P- |
80 - 120 lbs banded approx 2" below seed at planting. |
| K- |
60 - 170 (mainly in East Texas). |
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WATER/IRRIGATION
8 - 12" uniformly applied; key stage during stand establishment; avoid
excessive moisture just prior to head maturity, can cause puffiness or
soft heads. |
PEST MANAGEMENT
| Major Diseases |
Control |
| Downy mildew |
Acrobat, Aliette, maneb, Quadris |
| Sclerotina drop |
Ronilan, Rovral |
| Damping off |
Ridomil Gold |
| Cercospora leaf spot |
maneb, Quadris |
| Gray mold |
Botran, Endura, Ronilan, Rovral |
| Virus |
Mosaic indexed seed |
| Tip burn |
Factors related to bright days following cool damp weather |
| Nematode |
K-Pam, Telone II, Telone C-17 |
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| Major Insects |
Control |
| Cabbage looper and corn earworm |
Ammo, Asana (head lettuce only), Avaunt, B.t.'s, Fury/Mustang,
permethrin, Spintor, Warrior |
| Armyworm |
Avaunt, Lannate, Larvin, Intreprid, Proclaim (head lettuce only),
Spintor |
| Aphid |
acephate, Admire, Assail, dimethoate, Di-Syston, endosulfan, Fulfill,
Meta Systox R, Provado |
| Grasshopper and Cricket |
diazinon, malathion, Sevin |
| Leafhopper |
dimethoate, Di-Syston, Fury/Mustang, permethrin, Thimet, Warrior |
| Leafminer |
Agri-mek, Spintor, Trigard |
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| Weeds |
Control |
| Preplant incorporated |
Kerb, Prefar |
| Preemergence |
Prefar |
| Postemergence |
Poast, Select |
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| * NOTE--The above is
a partial listing of controls intended as examples. Some labels may have
been revoked since the publication of this guide. Refer to product labels
for specifics and use accordingly. Failure to do so may result in crop
injury, death and/or citation for law violation. Humans, animals and the
environment may also be adversely affected by misuse. |
HARVEST
Hand
| Days after planting= |
45 - 85 |
| Containers= |
Field cartons 18 - 30 heads each. |
| Grades= |
Field graded based on defects and head firmness. |
| Packaging/Handling= |
40 - 45 lb fiberboard boxes; immediate cooling (preferably vacuum
type) required to preserve quality and extend shelf life. |
| Anticipated yield= |
22,500 lbs/A (500 cartons). |
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TRANSIT/CONDITIONS
32oF at 98% RH |
COMMENTS/PRODUCTION KEYS
- Extremely perishable vegetable. Rapid pre-cooling a must.
- Crisp head types, discontinue or reduce irrigation at the onset
of maturity.
- High temperatures tend to cause loose heads and bitterness
- Raised beds culture is ideal for lettuce, reduces incidence of soil
compaction during stand establishment, reduces disease, and enables
better soil moisture management.
- Cannot tolerate low pH soils(below 6 may need liming).
- Shallow planting of the small seed causes problems with stand establishment,
especially with early fall planted crop.
- Will tolerate considerable frost during its early stages of development;
severe frost when nearly mature increases the incidence of slime development.
- Shallow rooted crop, very poor competitor for nutrients.
- Shallow root system dictates uniform moisture levels throughout
growth for optimum yield and quality.
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Texas Cooperative
Extension, Horticulture Crop Guides Series
Revised November, 2003
http://aggie-horticulture.tamu.edu/extension/vegetable/cropguides/lettuce.html
Prepared for Web delivery by Brooke Bludau, Amanda Zan, and Dan Lineberger |