Turnips. The turnip is a cool-season, biennial, fresh-market vegetable that reaches the edible stage in 50 to 70 days. The tops are eaten as greens and the root as a fresh or boiled vegetable. Both white- and yellow-fleshed types are available, but white-fleshed varieties are more common. Best quality results when the crop reaches usable size under moderately cool temperatures.

Radishes. The common radish is a quick growing, annual, cool-season root vegetable. The seed germinates in three to four days at soil temperatures between 65° and 85°F and good moisture. Best quality and root shape are obtained when the crop grows and matures at moderate temperatures (50° to 65°F) in intermediate to short day lengths. Most varieties reach usable size in 23 to 28 days under favorable growing conditions, but in cold weather 40 to 50 days may be required.

Good quality radishes can be produced on either mineral or muck soil. Preferred planting dates are early spring and August, but suitable crops can be obtained from plantings made from April through August in certain sections of New

York, particularly if soil moisture is adequate. Radishes remain in prime condition only a short time, especially in warm weather.

Table 27.2.1 Recommended spacing.

Crop Row In-row Seed Depth

(inches) (inches) (lb/A) (inches)

Turnip 14-18 2-3 1-2 0.5

Radish 8-15 1 10-15 0.5

27.3 Fertility

Maintain a pH of 6.0 to 6.5. Add one to two pounds of boron per acre with broadcast fertilizer. See Table 27.3.1 for the recommended rates of nitrogen, phosphorus, and potassium.

27.4 Harvesting

Turnips. At maturity, turnips are usually two to three inches in diameter. Turnips are sold bunched or topped. They can be stored for several weeks at low temperatures (32° to 35°F) and high relative humidity (95 percent or above). With good air circulation, topped turnips can be stored four to five months.

Radishes. Radishes remain in prime condition for only a short time, especially in warm weather. Roots will become pithy if overmature. Most radishes are marketed with tops removed in plastic bags. Those sold with tops will lose moisture and quality more rapidly than those without tops. Radishes, like turnips, should be stored at 32° to 35°F and 95 to 100 percent relative humidity.

27.5 Disease Management

Under normal conditions, diseases are not a problem.

Table 27.3.1 Recommended nutrients based on soil tests.
N pounds/acre	P2O5 pounds/acre			K2O pounds/acre			Comments
	Soil Phosphorus Level			Soil Potassium Level
	low	med.	high	low	med.	high
50	100	75	50	150	100	50	*Total recommended*

50	100	75	50	150	100	50	Broadcast and disk-in.

27.6 Insect Management

27.6.1 Cabbage root maggot, Delia radicum

Time for concern: April through July

Key characteristics: Small, white, legless worm with a blunt end, about 1/4 inch long. Look for brown tunnels in stems and roots.

*Management Option*			*Recommendation*
Scouting/thresholds			A degree-day model to predict the flight periods of cabbage root maggot adults can help growers manage this pest. A detailed description of the flight periods for your area can be obtained through the NYS IPM program’s Northeast Weather Association. As a general guide for conditions around Ontario County, adults from the overwintering population first begin to emerge about May 1. After this spring emergence, another generation of adults will have its peak flight in mid to late June, another generation in the middle of August and a final generation in early September. Another general guideline for Ontario County for time of occurence is to note the flowering period for some wild plants. Research has shown that Yellow Rocket roughly correlates with the first brood adult emergence, Day Lily with the second brood, Canada Thistle and Goldenrod with the third brood, and New England Aster with the fourth brood. Growers may want to apply an insecticide if planting occurs close to an adult peak.
Note(s)			Cabbage maggot eggs can be killed if soil temperature are above 95°F for several days. During May and June these temperatures will often be reached unless soil moisture is high due to rains.
Spunbonded row covers			Spunbonded row covers can control cabbage maggots. At time of seeding, place in the field and seal the edges to keep cabbage maggots out. It is important to make use of crop rotation when using row covers. Otherwise, flies may emerge under the row covers and damage the crop.
Site selection			Soils with high organic matter content will be more problematic.
Postharvest			Crop debris should be destroyed as soon as possible after harvest to minimize the spread of root maggots.
Resistant varieties			No resistant varieties are available.
Crop rotation, Site selection, Postharvest, and Sanitation			These are not currently viable management options.
Compound(s)
Common name		Rate/A		PHI	REI	Field
	Trade name	Product		(days)	(hours)	Use EIQ	Comments
chlorpyrifos
	*Lorsban 4E 4 lb/gal	1.6-2.75 fl oz			24	2-4	For use on turnips. Apply in bands behind the planter shoe but in front of the presswheel to achieve shallow incorporation. There has been at least one documented case of resistance to chlorpyrifos in Suffolk County.
	Lorsban 15G 0.15 lb/lb	4.6-9.2 oz/1000'			24	2-4/1000'
	*Lorsban 4E 4 lb/gal	1 fl oz			24	1	For use on radishes. Apply as a water-based drench in the seed furrow at planting in a minimum of 40 gals of water/A.
	Lorsban 15G 0.15 lb/lb	3.3 oz			24	1	For use on radishes. Apply in the seed furrow at planting.
*Restricted use only.

27.6.2 Flea beetle, Phyllotreta striolata and P. cruciferae

Time for concern: Cotyledon, seedling, and mature plant 

Key characteristics: Shiny, black beetle, about 1/16 inch long that jumps when disturbed and chews tiny holes in foliage.

*Management Option*			*Recommendation*
Scouting/thresholds			Scout fields two to three times per week, especially during warm, sunny weather when beetles are most active. Record the occurrence and severity of the flea beetle infestation. No thresholds have been established.
Natural enemies			Natural enemies help to control flea beetle populations. These can be preserved by using pesticides that are less harmful to them. Use Reference 2 for identification of natural enemies.
Resistant varieties			No resistant varieties are available.
Spunbonded row covers			Spunbonded row covers may control flea beetles. At time of sighting, place in the field and seal the edges to keep flea beetles out. The yields of late plantings may be reduced by row covers.
Crop rotation, Site selection, Postharvest, and Sanitation			These are not currently viable management options.
Compound(s)
Common name		Rate/A		PHI	REI	Field
	Trade name	Product		(days)	(hours)	Use EIQ	Comments
beta-cyfluthrin
	*Baythroid XL 1 lb/gal	1.6-2.8 fl oz		0	12	<1
carbaryl
	Sevin XLR Plus 4 lb/gal	0.5 qt		3	12	9
imidachloprid
	*Admire Pro 4.6 lbs/gal	4.4-10.5 fl oz		21	12	5-10	Do not use as a foliar spray
	*Provado 1.6F 1.6 lb/gal	3.5 fl oz		7	12	1
* Restricted use only.

27.7 Weed Management

Key characteristics: Weed fact sheets provide a good color reference for common weed identification. See Chapter 4 for information on scouting/thresholds, site selection, cultivation, and banding of herbicides.

Compound(s)
Common name		Rate/A	PHI	REI	Field
	Trade name	Product	(days)	(hours)	Use EIQ	Comments
postemergence
clethodim (annual and perennial grasses)
	*Select 2EC 2 lb/gal	6 - 8 fl. oz.	15 radish 30 turnip	24	2	For control of numerous annual and perennial grasses. DO NOT apply more than 16 fl. oz. of Select 2EC (0.25 lb ai) per acre per season. DO NOT apply more than 8 fl. oz. per application. Always use a crop oil concentrate at 1% V/V in the finished spray volume.
clopyralid (ragweed, hairy galinsoga, smartweed, wild buckwheat, dandelion, hairy nightshade, Canada thistle)
	†*Stinger 3EC 3 lb/gal	0.5 pt	15 tops 30 roots	12	4	NOT FOR USE IN NASSAU AND SUFFOLK COUNTIES. Turnips only. Make 1 application per season.
*Restricted use only.		† Not for use in Nassau/Suffolk Counties

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Pest Management Guidelines A Cornell Cooperative Extension Publication	Cornell Guide for Pest Management of Vegetables
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