Subject: FAQ: Turnips

From: Brian Lo <[email-masked]>
Date: Wed, 8 Mar 1995 13:43:23 -0800

TURNIPS 
                         Brassica rapa (Rapifera Group)

VARIETIES (approximately 60 days for roots, 30 days for greens)

      Purple Top White Globe;  hybrids for trial:  Royal Globe II Hybrid,
Royal Crown;  all white hybrids for trial:  Tokyo Cross, White Lady.  Club
root resistant, for trial:  York.

      Greens:  Shogoin, Seven Top, Topper, All Top  (see seperate file on
turnip greens). 

SEED COMPANIES

Abbott & Cobb Inc. POB F307, Feasterville, PA 19047
Asgrow Seed Company, POB 5038, Salinas CA 93915
Elsoms Seeds Ltd. Spalding, Lincolnshire, England PE11 1QG
Ferry-Morse Seed Co. POB 4938, 555 Codoni Ave. Modesto, CA 95352
Harris Moran Seed Co. 3670 Buffalo Rd. Rochester, NY 14624
Johnny's Selected Seeds, Foss Hill Rd. Albion, ME 04910
La Marche Seeds International, POB 190, Dixon, CA 95620
Nickerson-Zwaan Seed Co. POB 1787, Gilroy, CA 95021
Northrup King Co. Vegetable Seed Group, POB 1827, Gilroy, CA 95021
Royal Sluis Inc. 1293 Harkins Rd. Salinas, CA 93901
Sakata Seed America Inc. Morgan Hill, CA
Sluis & Groot of America Inc. 124 Griffin Street, Salinas, CA 93901
Stokes Seeds Inc. POB 548, Buffalo, NY 14240
W. Osborne Seed Co. Int'l. 1679 Highway 99 South, Mount Vernon, WA 98273 
Zenner Bros. Seed Co., Inc.  1311 S.E. Gideon St. Portland, OR 97202

SOIL
     
      Use deep loam or sandy loam soil types that have good drainage.  It is
desirable to have a good amount of organic matter in the soil as well.

SEED AND SEED TREATMENT

      Turnip seed numbers approximately 192,000 per pound.  Use hot-water and
fungicide treated seed to protect against several serious seed borne diseases. 
Hot water seed treatments are very specific (122 F exactly, for 25 to 30
minutes; the wet seed then quickly cooled and dried).  The seed treatments are
best done by the seed company, and can usually be provided upon request.

PLANTING AND SPACINGS

      For summer harvest plant as early in the spring as possible.  For later
harvests plant up to the 7th of June.  Seed 1 to 2 lbs seed/acre at a depth of
1/2 to l in.   Space rows 1-3 ft. apart and plants within the row 2-6 inches
apart.  Turnip seed is easy to precision plant and germinates readily.  No
pelleting is necessary with precision planters.  When these planters are used,
adjust the seeding rate considering plant stand desired, seed count per pound
and germination percentage.  

FERTILIZER

      A soil test is the most accurate guide to fertilizer requirements.  The
following recommendations are general guidelines.  

      Manure - If manure is available, apply the year before and not in the
year of seeding.

      At time of seeding, band 2 in. to the side of the seed, at a depth of 2
inches below the seed, the following:

      Nitrogen: 50-75 (N) lb./acre 
      Phosphate: 100-150 (P2 O5) lb./acre 
      Potash: 80-150 (K2 O) lb./acre
      Boron:  Broadcast and disc in 2-4 lb./acre of boron prior to planting. 
If additional boron is required, use Solubor or Borospray at l/2 to l lb./acre
when turnips are l in. in diameter.

IRRIGATION

      Water uniformly for best shape and quality.  Turnips may require from 8-
12 inches of water depending on planting date, seasonal variation and variety.

      Soil type does not affect the amount of total water needed, but does
dictate frequency of water application.  Lighter soils need more frequent
water applications, but less water applied per application.         

HARVESTING, HANDLING, AND STORAGE

      Turnip yields are approximately 300 cwt./acre.  Handle roots with care
during harvest to reduce injury and rots during storage.  Store only healthy
roots as indicated below.

      STORAGE (quoted form USDA Ag. Handbook # 66):

      Store turnips at 32 F and 95% relative humidity.  Topped turnips require
storage conditions similar to those for topped carrots.  Turnips in good
condition can be expected to keep 4 to 5 months at 32 F and high relative
humidity.  At higher temperatures (40 F and above) decay will develop much
more rapidly than at 32 f.  Injured or bruised turnips should not be stored. 
Turnips should be stored in slatted crates or bins, and good air circulation
around containers should be provided.

      Packaging turnips in perforated plastic bags helps keep the humidity
high around the roots during marketing and reduces shriveling.

      Dipping turnips in hot melted paraffin was gives a glossy appearance and
is of some value in reducing moisture loss during handling.  However, waxing
is primarily to aid in marketing and is not recommended before long-term
storage.

PACKAGING

      Topped turnips are commonly packaged in 25 lb. film bags; 50 lb. film
and mesh bags; or 24 pound cartons holding 24 film bags, 1 pound each.

                            PEST CONTROL FOR TURNIPS

     THE PESTICIDES LISTED BELOW, TAKEN FROM THE PACIFIC NORTHWEST PEST
CONTROL HANDBOOKS, ARE FOR INFORMATION ONLY, AND ARE REVISED ONLY ANNUALLY. 
BECAUSE OF CONSTANTLY CHANGING LABELS, LAWS, AND REGULATIONS, OREGON STATE
UNIVERSITY CAN ASSUME NO LIABILITY FOR THE CONSEQUENCES OF USE OF CHEMICALS
SUGGESTED HERE.  IN ALL CASES, READ AND FOLLOW THE DIRECTIONS AND PRECAUTION-
ARY STATEMENTS ON THE SPECIFIC PESTICIDE PRODUCT LABEL.

                          USE PESTICIDES SAFELY!

Wear protective clothing and safety devices as recommended on the label.  
Bathe or shower after each use.

Read the pesticide label--even if you've used the pesticide before.  Follow
closely the instructions on the label (and any other directions you have).

Be cautious when you apply pesticides.  Know your legal responsibility as a
pesticide applicator.  You may be liable for injury or damage resulting from
pesticide use.

WEED CONTROL

     Cultivate as often as necessary when weeds are small.  Proper cultiva-
tion, field selection and rotations can reduce or eliminate the need for
chemical weed control.  

     THE WEED TREATMENTS LISTED BELOW ARE TAKEN FROM THE PACIFIC NORTHWEST
WEED CONTROL HANDBOOK, AND ARE FOR INFORMATION ONLY.  CONSULT PRODUCT LABELS
FOR CURRENTLY LEGAL REGISTRATIONS, RATES, AND COMPLETE INSTRUCTIONS.

WEED MANAGEMENT GENERAL STRATEGY

Weed suppression in crucifers begins by rotating crops that involve different
weed control practices or herbicides to disrupt weed life cycles.  Row
spacings and plant densities vary to achieve head size depending on the market
and to suppress weeds.  Early season weed control comprises application of an  
herbicide and/or cultivation(s).
______________________________________________________________________________

STALE SEEDBEDS FOR VEGETABLE PRODUCTION

Stale seedbeds are sometimes used for vegetable production when other selec-
tive weed control practices are limited or unavailable.  The concept depends
on controlling the first flush of emerged weeds before planting or emergence
of the crop followed by minimal soil disturbance which reduces subsequent weed
flushes during establishment of the crop.  Following establishment, other weed
control practices including cultivation or use of other herbicides can be
used.

1.  Prepare a seedbed, preferably 2 to 3 weeks before planting to achieve 
    maximum weed seed germination near the soil surface.  Soil temperatures 
    and moisture must be reasonable or results will be erratic.

2.  Plant the crop with minimum soil disturbance.  Otherwise, new weed seed 
    will be exposed to favorable germinating conditions.

3.  Just before or after planting but before crop emergence, treat the 
    field by flaming or with herbicide to kill all germinated or exposed 
    weeds.

Weed Treatment           Active Ingredient Per Acre and Application Comments
------------------------------------------------------------------------------
Flaming                                      

      Use liquid propane or similar fuel-burning equipment to quickly sear the
      weeds, but not consume them with flame. 
______________________________________________________________________________

PREEMERGENCE

DCPA                                            4.5 to 9 lb ai/A
  Dacthal

      Performs erratically west of Cascades.  Elsewhere, apply immediately
      after seeding or transplanting.  Results can be improved if rainfall or
      overhead irrigation occurs immediately after application.  Consult label
      for planting sensitive crops within 8 months. (Inhibits mitosis).
______________________________________________________________________________
______________________________________________________________________________

INSECT CONTROL

     Proper rotations and field selection can minimize problems with insects. 

     THE PESTICIDES LISTED BELOW ARE TAKEN FROM THE PACIFIC NORTHWEST INSECT
CONTROL HANDBOOK, AND ARE FOR INFORMATION ONLY.  CONSULT PRODUCT LABELS ARE
CURRENTLY LEGAL REGISTRATIONS, RATES AND COMPLETE INSTRUCTIONS.

Insect and Description                  Control, Active Ingredient Per Acre
---------------------------------------------------------------------------
Aphids including                            malathion - 2 lb      
Cabbage aphid                                  
 Brevicoryne brassicae                      diazinon - 0.5 lb     
Turnip aphid                                                      
 Hyadaphis pseudobrassicae                  Phosdrin - 0.25 lb    
                                                                  
Both species closely resemble               Metasystox-R - 0.5 lb
each other. Gray, mealy plant                                     
lice form colonies.                         dimethoate - 0.25 lb 
                                                                  
                                            Dibrom - 1 to 1.5 lb       

                                            Pyrellin - 1 to 2 pt
---------------------------------------------------------------------------
Flea beetles, including                     diazinon - 0.5 lb     
Phyllotreta cruciferae                                            
                                            methoxychlor - 2.25 lb  
Small, shiny, steel-blue jump-                                    
ing beetle. Frequently attacks              carbaryl - 1 lb
and destroys seedlings.                                           
                                            Pyrellin - 1 to 2 pt       
---------------------------------------------------------------------------
Cabbage maggot                              Lorsban 4E - 0.05 to 0.86 lb 
Delia brassicae                             ai/1000 row ft.
                                           
White legless larvae feed on                Lorsban 15G - 0.69 to 1.38 lb 
roots.                                      ai/1000 row ft.
---------------------------------------------------------------------------
Diamondback moth                            diazinon - 0.5 lb   
Plutella maculipennis                                                      
                                            methoxychlor - 1 lb            
Gray or brown moth with white               
margins on forewing. When                   Bacillus thuringiensis - 1 to 2 qt
folded, white margins form dia-             Apply with appropriate spreader-
mond. Larvae are pale yellow-               sticker.
ish-green in color with finely              
scattered erect black hairs.                permethrin - 0.05 to 0.1 lb
---------------------------------------------------------------------------
Wireworms                                   Telone II or C-17 - preplant
               
Brown, jointed larvae of click              diazinon 14G - 3 to 4 lb
beetles.  Chew holes in edible roots.
______________________________________________________________________________
______________________________________________________________________________

DISEASE CONTROL

     Proper rotations, field selection, sanitation, spacings, fertilizer and
irrigation practices can reduce the risk of many diseases.  Fields can be
tested for presence of harmful nematodes.  Using seed from reputable seed
sources reduces risk from seed born diseases.

     THE PESTICIDES LISTED BELOW ARE TAKEN FROM THE PACIFIC NORTHWEST DISEASE
CONTROL HANDBOOK, AND ARE FOR INFORMATION ONLY.  CONSULT PRODUCT LABELS FOR
CURRENTLY LEGAL REGISTRATIONS, RATES AND COMPLETE INSTRUCTIONS.

TURNIP - BORON DEFICIENCY

Cause: Deficiency of boron in the soil and subsequent deficiency in the turnip
plant. All vegetables require boron for growth but vary considerably in the
amount required.

Symptoms:

Leaves - May or may not show abnormalities. Leaves may turn reddish in color.
If deficiency is severe, both roots and leaves may be stunted. The leaves may
be twisted and curled and finally die.

Roots - Glassiness or water core of the root flesh followed by internal gray,
punky flecks or spots that later change to brown or black areas.

Control: Since the amount needed to correct boron deficiency varies so widely
in different areas, and since boron if used in excessive amounts can act as a
soil sterilant, check with your county extension agent or processor field pe-
rson for local recommendations.  However, where boron deficiency has been a
problem, particularly in alkaline soils, one or two foliar applications of
soluble boron are recommended. 
---------------------------------------------------------------------------
TURNIP - BLACK ROOT ROT

Cause: Aphanomyces raphani and Rhizoctonia solani, fungi.  The organisms over-
winter in the soil and on diseased plant residue in the soil.

Symptoms:  Aphanomyces raphani invades the fine rootlets of the young seed-
lings and develops resting spores in large numbers within the roots. On the
main taproot dark surface lesions develop which turn grayish with age. These
enlarge into grayish-black discolored areas of irregular size and shape just
beneath the root surface. The main root may be girdled and growth of the plant
interrupted until new roots are formed above the girdle. Systemic infection
occurs occasionally, resulting in darkened vascular tissue within a normal
appearing root.

Control:

1. Where possible, avoid planting any of the crucifers on the same land for 3
or more years.

2. Growers have obtained good control using fumigants containing a combination
of chloropicrin and methyl bromide sealed with plastic tarp.

Residues: Use 82.5 to 115.5 lb actual chloropicrin plus 167.5 to 234.5 lb
actual methyl bromide/A with a plastic seal.
---------------------------------------------------------------------------
TURNIP - CLUB ROOT

Cause: Plasmodiophora brassicae; this organism survives indefinitely in
infested soil.

Symptoms: Injured diseased plants are chlorotic, later turning a yellowish
color, and are slow in growth and development. They often partially wilt
during warm days. Beneath the fleshy turnip root, enlarged clublike growths
develop. These ultimately become infected with secondary bacteria, rot, and
break down.

Control:

1. The European rutabaga variety, `Marian' is tolerant to club root as is the
turnip variety `York'.

2. High applications of lime have been used on infested soil. This material
apparently retards the development of the causal fungus.  See Cabbage--Club
Root for lime rates.
---------------------------------------------------------------------------
TURNIP - POWDERY MILDEW

Cause: Erysiphe polygoni, a fungus. This organism is perpetuated from year to
year on turnip and rutabaga refuse and other hosts including weeds.

Symptoms: A powdery, whitish-gray coloring consisting of the fungus and fungus
spores of the mildew develops on infected leaves. In the advanced stages, the
leaves are distorted, twisted, and retarded in growth. They ultimately turn
yellow and die.

Control: Sulfur dust or wettable sulfur sprays (6 lb in 100 gal water) are the
best fungicidal controls.

Residues: Sulfur-no time limitations.
---------------------------------------------------------------------------
TURNIP - SEED TREATMENT

Aids in control of black rot, Alternaria leaf spot, and black leg.

Thiram - Follow product directions.

Captan - Follow product directions. 

When Pythium is a problem, use Anchor flowable at 1.5 fl oz/cwt seed or
Ridomil at 4 to 8 pt/A either incorporated preplant or as a
postplant/preemergence application.  See label for further information.
Note: Where black leg is a problem, soak seed in hot water, 122 F for 25
minutes. Dry. Just before planting, use treatments listed above.
______________________________________________________________________________
______________________________________________________________________________

         ---------------------------------------------------
         --------------------------------------------------- 
         This  information was prepared by the Oregon  State 
         University   Extension  Service  from  Oregon   and 
         Pacific NW publications as well as other  vegetable 
         production   guidelines  from  public  institutions 
         in  the  U.S.  and  Canada.  These  guidelines  are 
         intended  as a general guide for Oregon  commercial 
         vegetable producers.  Address comments or questions 
         to  your  County  Extension  Agent  or  Dr.  N.  S. 
         Mansour,  Department of Horticulture,  Oregon State 
         University, Corvallis, OR 9733l. 
         ---------------------------------------------------