Chapter 14 Beets
Contents
14.5.1 Leaf spots, caused primarily
by Cercospora beticola but also by Phoma batae
14.5.4 Sugar beet cyst nematode, Heterodera schachtii
14.6.1 Spinach leafminer, Pegomya hyoscyami
14.1
Recommended Varieties
Detroit Dark Red
Red Ace
Ruby Queen
Crosby (greens or roots)
14.2
Planting Methods
The beet is a cool-season, root vegetable that tolerates frosts and mild freezes. Seed germinates at soil temperatures between 40° and 90°F, optimally 50° to 85°F. Because beet plants withstand cool growing conditions and the seed germinates at soil temperatures below 50°F, planting can begin in late April. The best root quality and color are obtained when the crop matures during cool temperatures and bright sunlight. When grown under warm conditions, root color is lighter, sugar content is lower, and color zoning in roots is more pronounced than under cool conditions.
Beets are biennial, normally producing an enlarged root the first growing season and, after a cold induction period, a seedstalk. Premature seedstalk initiation can occur if the plants are subjected to two to three weeks of temperatures below 45°F after they have several true leaves. Plants of some varieties initiate premature seedstalks more readily than others; many of the newer varieties are less sensitive to this problem.
Well-drained, sandy loam to silt loam soil is preferred for best growth and quality. Beets can also be grown on muck soil, but weed control is difficult. A soil with good structure is highly recommended because beets respond favorably to aeration.
A beet seedball normally contains from two to four viable seeds, and more plants than seedballs may result, especially if conditions are favorable for germination. Larger seedballs contain more seeds than do smaller seedballs. Desired plant spacing is obtained by adjusting seeding rate. Plants are sometimes thinned for the fresh market. See Table 14.2.1 Recommended spacing
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Table 14.2.1 Recommended spacing. |
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Type |
Row (in inches) |
In-row seeding rate1 (in pounds per acre) |
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Fresh-market |
16-24 |
8-10 |
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Processing |
16-24 |
15-25 |
1: The lower rate of seed is sown
early so the roots will size quickly for early harvest
14.3 Fertility
Use lime to maintain a pH of 6.5 to 6.8 in all parts of the field. Beets are especially sensitive to low pH and should not be planted in soil with a pH below 6.0. Because beets use boron inefficiently, this element must be applied to most soils in New York. A boron deficiency causes plant foliage to be stunted and distorted, and roots exhibit symptoms of internal breakdown. Boron is less available in high pH soils. Apply 2 1/2 to 5 pounds of boron per acre mixed with fertilizer. Use the lower rate if nutrients have been applied two to three times in the previous five years. Boron is toxic to many plants and care must be taken when developing a rotation plan. Beans, peas, and cucurbits are especially sensitive to boron residues. See Table 14.3.1 for the recommended rates of nitrogen, phophorus, and potassium.
14.4 Harvesting
For fresh market, the crop is usually ready for harvest in 60 to 85 days. The processing crop is harvested in 90 to 110 days, but a thick plant stand can be held in the field for a relatively long time. Processing beets are usually harvested until mid-November. Yields for the fresh market range from eight to 12 tons per acre and approximately 15 to 20 tons per acre for processing.
Machine harvesters are used for the processing crop and for the market crop that is sold topped. Beets for bunching are handpicked and tied. Topped beets can be stored for several months at temperatures near 32°F and 95 to 98 percent relative humidity.
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Table 14.3.1 Recommended application rate of nutrients based on soil tests.1,2 |
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N (pounds/acre) |
P2O5 (pounds/acre) |
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K2O
(pounds/acre) |
Comments |
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Soil Phosphorus Level |
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Soil Potassium Level |
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low |
med. |
high |
|
low |
med. |
high |
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150-175 |
150 |
100 |
50 |
|
300 |
200 |
100 |
Total recommended |
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25-50 |
75 |
25 |
0 |
|
225 |
150 |
50 |
Broadcast and disk-in. |
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25 |
75 |
75 |
50 |
|
75 |
75 |
50 |
Band place with planter. |
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50 |
0 |
0 |
0 |
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0 |
0 |
0 |
Apply three weeks after planting |
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50 |
0 |
0 |
0 |
|
0 |
0 |
0 |
Apply eight weeks after planting |
14.5
Disease Management
14.5.1
Leaf spots, caused primarily by Cercospora
beticola but also by Phoma batae
Time for concern: Most prevalent in mid to late season with daytime
temperatures of 75° to 80°F and with frequent rainfall or long periods of 90 to
100 percent relative humidity.
Key characteristics: Cercospora leaf spot appears as small, circular lesions that are light tan to brown with a distinct dark brown to purple halo. Phoma leaf spot appears as lesions of various size with concentric ring pattern and fruiting bodies of the pathogen. When lesions of both pathogens mature, the centers become gray and brittle and fall out.
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Management
Option |
Recommendation |
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Scouting/thresholds |
Record the occurrence and severity of leaf spot. No
thresholds have been established. |
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Resistant varieties |
No resistant varieties are currently available. |
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Crop rotation |
Minimum two year rotation out of beets with nonhost crops
preferably grains. |
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Site selection |
Avoid fields with tree lines and stagnant air circulation,
as long duration of leaf-wetness is
conducive for disease development.
Also, weeds belonging to the family Chenopodiaceae may serve as a
source of inoculum. |
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Fertility |
Use nitrogen to promote growth and development of new
leaves which are less susceptible to both pathogens and will aid in
harvesting. |
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Seed selection/treatment |
Plant commercially treated seed to prevent seed decay and
reduce seedborne inoculum. |
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Postharvest |
If possible, crop debris should be destroyed as soon as
possible to remove this source of disease for other plantings and to initiate
decomposition. |
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Sanitation |
This is not a currently viable management option. |
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Compound(s) |
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Common name |
Rate/A |
PHI |
REI |
Field |
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Trade
name |
Product |
(days) |
(hours) |
Use EIQ |
Comments |
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azoxystrobin |
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Quadris
F |
6.2-15.4 fl oz |
0 |
4 |
1.3-3.4 |
Do not apply more than 2 sequential foliar applications of
these products or other strobilurin (Group 11) before alternating with a
fungicide that has a different mode of action. Do not spray these products where spray
drift may reach apple trees or use same sprayer to apply sprays to apple
trees. |
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Amistar
80 WDG |
2-5 oz |
0 |
4 |
1.5-4.6 |
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copper compounds |
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Champ
F |
1 1/3 – | ||||||