Posts Tagged ‘potato’

Continuing Vegetable Sales in Fall and Winter

Friday, September 21st, 2012

Gordon Johnson, Extension Vegetable & Fruit Specialist; gcjohn@udel.edu

While most vegetable growers finish up with fall crops around Thanksgiving, there is potential to produce throughout the fall and winter. There are fall and winter sales potentials with schools, institutions, and restaurants; for CSA’s; and for specialty wholesale markets.

One strategy is using storage to have products available out of season. This has been a common practice on a large wholesale scale with potatoes and apples where large controlled environment storage facilities are used. On a smaller scale, there are many vegetables that can be stored in sheds, cold boxes, or greenhouses as long as products are kept above freezing and have adequate humidity. It should be noted that critical minimum temperatures will vary according to the type of produce.

Probably the easiest vegetables to store are hard shelled winter squash such as butternuts. If kept around 50°F, most of the hard shelled squashes can be kept for at least 3 months, some for over 6 months. Potatoes store best at 45°F in high humidity and sprouting can be a problem for longer storage. Sweet potatoes, once cured, can be stored for months as long as the storage temperature is kept around 60°F. Colder temperatures damage the roots. Onion storage depends on the type but longest storage is just above freezing in dry conditions. Cabbage can also be stored for long periods. The key is to grow storage varieties that are dense. Longest storage is at 32 F° in high humidity. Napa type chinese cabbage also stores well in refrigeration (several months). Other crops successfully stored include carrots, parsnips, rutabegas, and turnips. In fruits, long keeping apple varieties can be stored for months in cool temperatures.

Field storage is another way to extend sales of some vegetables. Root crops such as carrots, parsnips, and beets can be kept for extended periods in the field if kept from freezing with row covers or straw mulch. Certain cabbage varieties can field store into winter if protected from hard freezes with row covers. Green onions and leeks also field store well.

An alternative strategy is to make used of high tunnels, low tunnels, row covers, or a combination to grow cool season crops for fall and winter harvest. Greens crops in the mustard family (mustard, turnip, kale, collard, cress, many asian greens); spinach, chard, and beet greens; and lettuces and endive can be planted in the late summer or fall and harvested repeatedly through the fall and winter in these protected systems without additional heat. Some day neutral strawberries can be harvested into the late fall in high tunnels or low tunnel/row cover systems. The use of row covers can also extend harvest periods for crops such as broccoli where side shoot production can be maintained after main heads are harvested, often through Christmas, and Brussels sprouts where sprout production can be extended into winter.

Of course, there is potential for production of many crops in heated greenhouses. The choice of varieties becomes important for greenhouse production because of the lower light and reduced daylength conditions in fall and winter. Specific greenhouse varieties of crops such as tomatoes, lettuce, and cucumbers have been developed for fall and winter production.

Potato Disease Advisory #21 – July 26, 2012

Friday, July 27th, 2012

Phillip Sylvester, Kent Co., Ag Agent; phillip@udel.edu

Late blight Advisory
Location: Art and Keith Wicks Farm, Rt 9, Leipsic, Kent County, Delaware
Greenrow: April 20

Date

DSV

Total DSV

Accumulated
P-Days

Spray Interval Recommendation

6/19-6/21

1

80

478

10-days

6/22-6/25

2

82

507

10-days

6/25-6/27

0

82

524

10-days

6/28-7/2

0

82

549

10-days

7/3-7/5

0

82

561

10-days

7/6-7/11

0

82

593

10-days

7/12-7/18

2

84

632

10-days

7/19-7/25

11

95

685

7-days

 

The spray interval recommendation is 7 days. Continue to scout for late blight and maintain spray programs if the plants are still growing. There have been no reports in Delaware and no recent reports of late blight on potato in the region. Visit http://www.usablight.org/ to see where late blight has been found on potato and tomato.

This is the last Potato Disease Advisory for the season.

Commercial fungicide recommendations can be found in the 2012 Delaware Commercial Vegetable Recommendations Guide at http://ag.udel.edu/extension/vegprogram/pdf/potatoes.pdf

Potato Disease Advisory #20 – July 19, 2012

Friday, July 20th, 2012

Phillip Sylvester, Kent Co., Ag Agent; phillip@udel.edu

Late blight Advisory
Location: Art and Keith Wicks Farm, Rt 9, Leipsic, Kent County, Delaware
Greenrow: April 20

Date

DSV

Total DSV

Accumulated
P-Days

Spray Interval Recommendation

6/15-6/18

0

79

460

10-days

6/19-6/21

1

80

478

10-days

6/22-6/25

2

82

507

10-days

6/25-6/27

0

82

524

10-days

6/28-7/2

0

82

549

10-days

7/3-7/5

0

82

561

10-days

7/6-7/11

0

82

593

10-days

7/12-7/18

2

84

632

10-days

The spray interval recommendation is 10 days. The hot and dry weather we experienced earlier in the week should reduce the threat of late blight. The weather is forecast to change with lower temperatures and possible thundershowers. Maintain spray programs if the plants are still growing. There have been no reports in Delaware and no recent reports of late blight on potato in the region. Visit http://www.usablight.org/ to see where late blight has been found on potato and tomato.

Commercial fungicide recommendations can be found in the 2012 Delaware Commercial Vegetable Recommendations Guide at http://ag.udel.edu/extension/vegprogram/pdf/potatoes.pdf.

Potato Disease Advisory #19 – July 12, 2012

Thursday, July 12th, 2012

Phillip Sylvester, Kent Co., Ag Agent; phillip@udel.edu

Late blight Advisory
Location: Art and Keith Wicks Farm, Rt 9, Leipsic, Kent County, Delaware
Greenrow: April 20

Date

DSV

Total DSV

Accumulated
P-Days

Spray Interval Recommendation

6/4-6/6

0

71

355

10-days

6/7-6/11

0

71

395

10-days

6/11-6/14

8

79

424

7-days

6/15-6/18

0

79

460

10-days

6/19-6/21

1

80

478

10-days

6/22-6/25

2

82

507

10-days

6/25-6/27

0

82

524

10-days

6/28-7/2

0

82

549

10-days

7/3-7/5

0

82

561

10-days

7/6-7/11

0

82

593

10-days

 

The spray interval recommendation is 10 days. The hot and dry weather we continue to experience should reduce the threat of late blight. There have been no reports in Delaware. Visit http://www.usablight.org/ to see where late blight has been found on potato and tomato in the region.

Commercial fungicide recommendations can be found in the 2012 Delaware Commercial Vegetable Recommendations Guide at http://ag.udel.edu/extension/vegprogram/pdf/potatoes.pdf.

Potato Disease Advisory #18 – July 6, 2012

Friday, July 6th, 2012

Phillip Sylvester, Kent Co., Ag Agent; phillip@udel.edu

Late blight Advisory
Location: Art and Keith Wicks Farm, Rt 9, Leipsic, Kent County, Delaware
Greenrow: April 20

Date

DSV

Total DSV

Accumulated
P-Days

Spray Interval Recommendation

6/4-6/6

0

71

355

10-days

6/7-6/11

0

71

395

10-days

6/11-6/14

8

79

424

7-days

6/15-6/18

0

79

460

10-days

6/19-6/21

1

80

478

10-days

6/22-6/25

2

82

507

10-days

6/25-6/27

0

82

524

10-days

6/28-7/2

0

82

549

10-days

7/3-7/5

0

82

561

10-days

 

The spray interval recommendation is 10 days. The hot and dry weather we continue to experience should reduce the threat of late blight. There have been no reports in Delaware. Visit http://www.usablight.org/ to see where late blight has been found on potato and tomato in the region.

Commercial fungicide recommendations can be found in the 2012 Delaware Commercial Vegetable Recommendations Guide at http://ag.udel.edu/extension/vegprogram/pdf/potatoes.pdf.

Potato Disease Advisory #16 – June 28, 2012

Friday, June 29th, 2012

Phillip Sylvester, Kent Co., Ag Agent; phillip@udel.edu

Late blight Advisory
Location: Art and Keith Wicks Farm, Rt 9, Leipsic, Kent County, Delaware
Greenrow: April 20

Date

DSV

Total DSV

Accumulated
P-Days

Spray Interval Recommendation

5/24-5/28

8

65

279

5-days

5/28-5/30

3

68

294

5-days

5/31-6/3

3

71

331

7-days

6/4-6/6

0

71

355

10-days

6/7-6/11

0

71

395

10-days

6/11-6/14

8

79

424

7-days

6/15-6/18

0

79

460

10-days

6/19-6/21

1

80

478

10-days

6/22-6/25

2

82

507

10-days

6/25-6/27

0

82

524

10-days

 

The spray interval recommendation has been set at 10 days. The hot and dry weather we are experiencing should reduce the threat of late blight. There have been no reports in Delaware. Visit http://www.usablight.org/ to see where late blight has been found on potato and tomato in the region.

Commercial fungicide recommendations can be found in the 2012 Delaware Commercial Vegetable Recommendations Guide at http://ag.udel.edu/extension/vegprogram/pdf/potatoes.pdf.

Potato Disease Advisory #14 – June 21, 2012

Friday, June 22nd, 2012

Phillip Sylvester, Kent Co., Ag Agent; phillip@udel.edu

Late blight Advisory
Location: Art and Keith Wicks Farm, Rt 9, Leipsic, Kent County, Delaware
Greenrow: April 20

Date

DSV

Total DSV

Accumulated
P-Days

Spray Interval Recommendation

5/20-5/22

11

55

229

5-days

5/22-5/23

2

57

238

5-days

5/24-5/28

8

65

279

5-days

5/28-5/30

3

68

294

5-days

5/31-6/3

3

71

331

7-days

6/4-6/6

0

71

355

10-days

6/7-6/11

0

71

395

10-days

6/11-6/14

8

79

424

7-days

6/15-6/18

0

79

460

10-days

6/19-6/20

1

80

474

10-days

 

The spray interval recommendation has been set at 10 days. The hot and dry weather we are experiencing should reduce the threat of late blight. There are no reports in Delaware. Visit http://www.usablight.org/ to see where late blight has been found on potato and tomato in the region.

Commercial fungicide recommendations can be found in the 2012 Delaware Commercial Vegetable Recommendations Guide at: http://ag.udel.edu/extension/vegprogram/pdf/potatoes.pdf.

Potato Disease Advisory #12 – June 15, 2012

Friday, June 15th, 2012

Phillip Sylvester, Kent Co., Ag Agent; phillip@udel.edu

Late blight Advisory
Location: Art and Keith Wicks Farm, Rt 9, Leipsic, Kent County, Delaware
Greenrow: April 20

Date

DSV

Total DSV

Accumulated
P-Days

Spray Interval Recommendation

5/20-5/22

11

55

229

5-days

5/22-5/23

2

57

238

5-days

5/24-5/28

8

65

279

5-days

5/28-5/30

3

68

294

5-days

5/31-6/3

3

71

331

7-days

6/4-6/6

0

71

355

10-days

6/7-6/11

0

71

395

10-days

6/11-6/14

8

79

424

7-days

 

The spray interval recommendation has been lowered to 7 days. Rainfall and high humidity earlier in the week made conditions for late blight more favorable. The forecast is predicting sunny and dry weather, which should make conditions less favorable.  There are no reports of late blight in Delaware.

Continue to scout for late blight symptoms in local potato fields. Please notify and submit samples with symptoms to your local county extension office (Kent: 302-730-4000, Sussex: 302-856-7303) or contact the UD Plant Diagnostic clinic (302-831-1390) to have the sample confirmed. You may also email Nancy Gregory at ngregory@udel.edu or Phillip Sylvester at phillip@udel.edu if you have a sample to submit.

Late blight has been found in the region. You can monitor where late blight is showing up by visiting the USA blight website at: http://www.usablight.org/?q=map. Confirmations of late blight on potato and tomato are tracked and added to the map as they are reported.

Early Blight
A total of 424 P-days have accumulated at this site as of Thursday, June 14. Protectant fungicide applications targeted at early blight are recommended at this time. Commercial fungicide recommendations can be found in the 2012 Delaware Commercial Vegetable Recommendations Guide at http://ag.udel.edu/extension/vegprogram/pdf/potatoes.pdf

Potato Disease Advisory #10 – June 7, 2012

Friday, June 8th, 2012

Phillip Sylvester, Kent Co., Ag Agent; phillip@udel.edu

Late blight Advisory
Location: Art and Keith Wicks Farm, Rt 9, Leipsic, Kent County, Delaware
Greenrow: April 20

Date

DSV

Total DSV

Accumulated
P-Days

Spray Interval Recommendation

5/20-5/22

11

55

229

5-days

5/22-5/23

2

57

238

5-days

5/24-5/28

8

65

279

5-days

5/28-5/30

3

68

294

5-days

5/31-6/3

3

71

331

7-days

6/4-6/6

0

71

355

10-days

 

The spray interval recommendation is now 10 days. The forecast is predicting warm and dry weather which should reduce the threat. Late blight has been reported in Virginia and Pennsylvania over the past seven days. The map below shows confirmed reports of late blight. The red shaded areas indicate the report was made in the past seven days while the blue shaded areas indicate an older report (more than seven days ago). You can visit this map at http://www.usablight.org/. There have been no reports of late blight in Delaware this year.

Continue to scout for late blight symptoms in local potato fields. Please notify and submit samples with symptoms to your local county extension office (Kent: 302-730-4000 Sussex: 302-856-7303) or contact the UD Plant Diagnostic clinic (302-831-1390) to have the sample confirmed. You may also email Nancy Gregory at ngregory@udel.edu or Phillip Sylvester at phillip@udel.edu if you have a sample to submit.

Early Blight
A total of 355 P-days have accumulated at this site as of Wednesday, June 6. Protectant fungicide applications targeted at early blight are recommended at this time. Commercial fungicide recommendations can be found in the 2012 Delaware Commercial Vegetable Recommendations Guide at http://ag.udel.edu/extension/vegprogram/pdf/potatoes.pdf.

Potato Disease Advisory #8 – May 31, 2012

Friday, June 1st, 2012

Phillip Sylvester, Kent Co., Ag Agent; phillip@udel.edu and Nancy Gregory, Plant Diagnostician; ngregory@udel.edu

Late Blight Advisory
Location: Art and Keith Wicks Farm, Rt 9, Leipsic, Kent County, Delaware
Greenrow: April 20

Date

DSV

Total DSV

Accumulated
P-Days

Spray Interval Recommendation

4/20-4/30

12

12

None

4/30-5/1

8

20

7-days

5/1-5/8

15

35

5-days

5/8-5/10

4

39

5-days

5/10-5/13

0

39

149

10-days

5/13-5/16

5

44

177

7-days

5/17-5/20

0

44

209

7-days

5/20-5/22

11

55

229

5-days

5/22-5/23

2

57

238

5-days

5/24-5/28

8

65

279

5-days

5/28-5/30

3

68

294

5-days

 

The threshold of 18 DSV’s has been exceeded. Sixty-eight (68) DSVs have accumulated as of Wednesday, May 30. This includes any potatoes that established green row (approximately 50% emergence) prior to and on April 20. An additional three (3) DSVs accumulated from Monday, May 28 to Wednesday, May 30. The spray interval recommendation is 5 days.

Continue to scout for Late blight symptoms in local potato fields. Please notify and submit samples with symptoms to your local county extension office (Kent: 302-730-4000, Sussex: 302-856-7303) or contact the UD Plant Diagnostic clinic (302-831-1390) to have the sample confirmed. You may also email Nancy Gregory at ngreogry@udel.edu or Phillip Sylvester at phillip@udel.edu if you have a sample to submit.

Good coverage with preventative fungicides application is very important for Late blight control. Commercial fungicide recommendations can be found in the 2012 Delaware Commercial Vegetable Recommendations Guide at http://ag.udel.edu/extension/vegprogram/pdf/potatoes.pdf

Early Blight
We are using the predictive model WISDOM to determine the first fungicide application for prevention of early blight. The model predicts the first seasonal rise in the number of spores of the early blight fungus based on the accumulation of 300 physiological days (a type of degree-day unit, referred to as P-days) from green row. A total of 294 P-days have accumulated at this site as of Wednesday, May 30. Airborne Early blight inoculum should rise 5-10 days after accumulating 300 P-days. Judging by the forecast, the 300-P day threshold will probably be exceeded in a day or two. A protectant fungicide application should be made once we exceed that threshold. Commercial fungicide recommendations can be found in the 2012 Delaware Commercial Vegetable Recommendations Guide at http://ag.udel.edu/extension/vegprogram/pdf/potatoes.pdf