Posts Tagged ‘19:7’

Label Additions for Presidio

Friday, May 6th, 2011

Bob Mulrooney, Extension Plant Pathologist; bobmul@udel.edu

Valent USA just reported that brassica leafy vegetables, root and tuber vegetables, potatoes and carrots have been added to the Presidio label. The other good news is that the rotation interval for wheat has been reduced from 18 months to 30 days. Hopefully this will be the beginning of the reduction of the other rotational intervals for other crops that follow cucurbits that have limited its use for downy mildew control in pickling cucumbers particularly. The supplemental label is available online here: http://agdev.anr.udel.edu/weeklycropupdate/wp-content/uploads/2011/05/PresidioSupplementalLabel.pdf. Presidio is an excellent fungicide for cucurbit downy mildew control and will be another excellent fungicide for control of late blight and pink rot on white potatoes.

 

Storing Vegetable Seed

Friday, May 6th, 2011

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

Vegetable growers and processors throughout the region have purchased seeds for this crop year. Many of those spring planted seeds are already in the ground or are growing in greenhouses. However, seed for successive plantings through the summer must be stored. Much harm can be done to seed viability through the storage period and germination can be greatly reduced.

Many smaller growers buy larger quantities than they can use in a season to get volume discounts and then save the seed for upcoming years. Again, how that seed is stored can greatly affect germination in coming years. The most detrimental storage condition for seeds is high temperature coupled with very high humidity (think Delmarva in the summer). Seeds that have picked up moisture from the air will lose viability quickly. For each 1% increase in seed moisture, seeds lose half of their storage life. For each 9º F increase in temperature, seeds lose half of their storage life.

Uninsulated metal buildings make poor summer storage whereas older wooden sheds and barns or concrete block buildings are better. Seeds also should be kept in the dark. Most seed packaging excludes light but opened seed bags or containers can be at greater risk.

The ideal would be a well insulated structure that is shaded and kept dark. Air conditioning and refrigeration may be a good answer in the short term, especially for smaller lots.

As a general rule of thumb the combination of temperature with relative humidity in storage should be less than 100 ( 50°F + 50% RH, 40°F + 60 % RH, etc.) for seed storage. The colder the storage, the higher the allowable humidity, the hotter the temperature, the lower the allowable humidity. However, for longer term storage, the temperature and relative humidity should be kept somewhat lower (40°F; 30 % RH for most seeds).

How about freezing seeds (for example, long-term germplasm collections are stored at 0ºF)? Freezing will work very well if seeds are dry. If they have picked up significant moisture, they can be damaged in the freezing process. Also, freezing and thawing cycles can be damaging to seeds so remove seeds to be used and place the remainder back in the freezer quickly.

Vegetable seed that come in sealed containers or packaging should not be opened until just ready for use. Seeds in bags should also not be opened until being used. Open bags should be completely planted unless sealed and placed back in proper storage.

Vegetable seeds also vary by type in their ability to store for extended periods. For example, onion seed has less than 1 year storage potential and should be bought new each year. Sweet corn also stores poorly over 1 year, as does spinach. Beans and peas are intermediate with 2 year storage potential and peppers are also in the 2 year range. Melon, cucumber, squash, and pumpkin seed, as well as cole crop seeds (cabbage, broccoli, cauliflower, kale, collards), tomatoes, and eggplants can be stored for 3 years.

 

Bacterial Fruit Blotch Continued…

Friday, May 6th, 2011

Kate Everts, Vegetable Pathologist, University of Delaware and University of Maryland; keverts@umd.edu

As of Thursday, May 5, no Bacterial Fruit Blotch (BFB) had been confirmed in Delaware or Maryland. Please continue to monitor both locally grown transplants and transplants purchased from other areas, because BFB has been reported in Georgia.

Management of BFB in greenhouse plant production includes the following steps: 1) use seed that has been tested for Acidivorax avenae subsp. citrulli, 2) monitor plants for BFB symptoms, 3) if potential symptoms are observed, submit plants for diagnosis. If BFB is confirmed in a greenhouse, the symptomatic transplants and those in a 15-foot radius should be destroyed. Additional trays that are 15 to 20 feet from the infected plants should be removed and isolated in a warm humid location and observed closely for five days for symptom development. If symptoms develop, then the epidemic has not been contained and additional plants should be destroyed.

If, despite best practices, BFB is observed in a field following setting out transplants, BFB will continue to spread. The rate of spread depends on the environment and irrigation practices. Spread will be fastest in fields irrigated with a travelling gun, intermediate where center pivot irrigation is used, and slowest with drip irrigation. Likewise, spread will occur within a field during rainfall, especially during “driving” rains. Spread of BFB from field to field in air is not common (though the bacterium could move in an aerosol). However, spread from field to field will occur on tractors or truck tires, cultivation equipment, peoples’ hands and shoes, and other direct contact.

The best spray practices to minimize BFB spread in the field are to use copper and Actigard. Copper fungicide should be applied weekly beginning before flowering until after fruit set (approximately the first five sprays). Another option is to include a copper fungicide in the first, third and fifth fungicide application and include Actigard or Actigard plus copper in the second and fourth fungicide application. These programs have provided suppression (but not elimination) of BFB. Additional labor at harvest may be necessary to separate symptomatic fruit from symptomless fruit.

 

Vegetable Crop Insects – May 6, 2011

Friday, May 6th, 2011

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Asparagus
Asparagus beetles adults can still be found laying eggs and feeding on spears. As a general guideline, a treatment is recommended if 2% of the spears are infested with eggs. Since adults also feed on the spears, a treatment is recommended if 5% of the plants are infested with adults.

Cabbage
Continue to scout fields for imported cabbage worm and diamondback larvae. Larvae can be found and sprays will be needed before they move deep into the heads. As a general guideline, a treatment is recommended if you find 5% of the plants infested with larvae.

Melons
Watch for aphids in the earliest transplanted fields. When sampling for aphids, be sure to watch for beneficial insects as well, since they can help to crash aphid populations. In past years, we have been asked about ants being found near melon transplants. In many cases, if ants are present you should look carefully on the undersides of leaves for melon aphids. Ants are commonly found associated with melon aphids in fields. They are often present in fields to collect honeydew from the aphids and can even hinder predation by other insects. As a general guideline, a treatment should be applied for aphids when 20% of the plants are infested, with 5 aphids per leaf. Foliar treatments labeled for melon aphid control on melons include Actara, Assail, Belay, Beleaf, Fulfill, Lannate and Thionex. These materials should be applied before aphid populations explode. The Fulfill label states that the addition of a penetrating type spray adjuvant is recommended to provide optimum coverage and penetration. Admire, Belay and Platinum are also labeled at planting for aphid control.

Peas
Continue to sample fields for aphids. On small plants, you should sample for aphids by counting the number of aphids on 10 plants in 10 locations throughout a field. On larger plants, take 10 sweeps in 10 locations. As a general guideline, a treatment is recommended if you find 5-10 aphids per plant or 50 or more aphids per sweep. When sampling dry land peas, you may want to reduce the threshold, especially if they are drought stressed. Be sure to check labels for application restrictions during bloom.

Potatoes
As soon as plants emerge, be sure to sample fields for Colorado potato beetle adults, especially if an at-planting material was not used. Low levels of the first emerged adults can now be found. A treatment should not be needed for adults until you find 25 beetles per 50 plants and defoliation has reached the 10% level

Sweet Corn
Be sure to scout emerged fields for cutworms and flea beetles. As a general guideline, treatments should be applied for cutworms if you find 3% cut plants or 10% leaf feeding. In order to get an accurate estimate of flea beetle populations, fields should be scouted mid-day when beetles are active. A treatment will be needed if 5% of the plants are infested with beetles. In fields that were planted under plastic, begin to scout for corn borers as soon as the plastic is removed.

 

Annie’s Project Reunion: Lunch & Learn

Friday, April 29th, 2011

Friday, May 20, 2011     11:00 a.m. – 3:00 p.m.
Todd Performing Arts Center
Chesapeake College, Route 50 & Route 213
Wye Mills, Maryland

It has been four years since Annie’s Project began in Maryland.  Since then, over 250 women in Maryland and Delaware have completed the course.  Annie’s Project focuses on the many aspects of farm management and is designed to empower women in overall farm decision making and to build local networks throughout the state. The target audience is farmwomen with a passion for business, agriculture and involvement in the farm operation.

The program will include a luncheon and numerous breakout sessions covering farm management topics as well as a chance to meet farmwomen from Maryland and Delaware and to catch up with Annie’s Project classmates. The Keynote speaker will be Annie’s Project Founder, Ruth Hambleton.

Cost: $25 (includes the meal and materials)

Register online at www.anniesproject.umd.edu or by mailing the registration form http://agdev.anr.udel.edu/weeklycropupdate/wp-content/uploads/2011/04/AnniesProject.pdf

Please feel free to contact Shannon Dill sdill@umd.edu, (410) 822-1244, Jenny Rhodes jrhodes@umd.edu, (410) 758-0166 or Tracy Wootten, wootten@udel.edu, (302) 856-7303 if you have any questions.

We hope you will join us for a great day!