Posts Tagged ‘18:2’

2010 Fungicide Update for Vegetables

Thursday, March 25th, 2010

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

There are some new additions and a few deletions:

Beans
Folicur 3.6F has been added for the control of common bean rust on snap beans. The section on soybean rust on snap and limas beans was removed. This disease has not developed on any other host other than soybeans and kudzu. At this time it is not a threat to snap and lima bean production. Omega 500F is labeled on snap and lima beans for white mold control. It also has good activity on downy mildew on limas. Hopefully by application time there will be a 2(ee) registration for downy mildew as well.

Cucumber, Cantaloupe, Pumpkin, Winter Squash and Watermelon
Switch and Folicur (tebuconazole) have been added for gummy stem blight control. The fungus that causes gummy stem blight has developed resistance to Pristine in South Carolina and may be occurring here. The addition of these two products is very important to control this important disease. Folicur has also been added to these crops and summer squash for powdery mildew control in addition to the other two triazole fungicides Rally and Procure.

Peppers
Chlorothalonil (Bravo) has been labeled to replace maneb which is no longer being manufactured for anthracnose fruit rot control.

Sweet Corn
Maneb is no longer being manufactured for use on sweet corn.

Tomato
Revus Top was added this year for control of leaf spots and late blight. Scala is labeled for early blight and gray mold control in the field as well as in the greenhouse and high tunnels.

Potatoes
Tanos was added for early blight control. Revus and Revus Top were added for late blight control.

Maneb is no longer being made but existing stocks can be used until maneb is gone.

Producing Quality Seedless Watermelon Transplants

Thursday, March 25th, 2010

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

Watermelon transplants for early production are being started this week. Those destined for later field plantings will be started throughout the month of April. Growing quality seedless watermelon transplants requires attention to detail and conditions required are different than for seeded types. Common problems include incomplete germination, uneven growth, weak plants, and stretching (leggy plants).

Seedless watermelon production can be broken into 6 phases: seeding, initial germination, emergence, seed leaf stage to first true leaf, first true leaf to second true leaf, and hardening off.

Seeding
Trays with square cells at least 2 inches deep and 1 inch square should be evenly filled with a general greenhouse growing medium like Pro-Mix BX , Fafard #2, or Sunshine #1 (these all have a starter fertilizer charge). Do not use fine seed starter or plug mix types. Do not compress the media. Trays should be watered to capacity and then allowed to drain off excess for 24 hours. During this 24 hour period, trays should be placed in a heated area so that the media reaches a temperature of 85°F. Make planting holes 1” deep with a dibber and plant seeds with the pointed side up. Cover with a small amount of warm moist media just enough to fill over seeds in the holes. Do not water after seeding. Seeding should be done in a way that trays stay at 85° F (do not allow trays to get cold).

Initial Germination
Germination should be done in a room or chamber where temperatures can be maintained at 85-90°F and where there is high humidity. Uniform tray temperature is critical. This phase will last 2 day – trays should be kept in this high temperature growth area for 48 hours and no more. To insure even germination, it may be necessary to move trays around after 24 hours (trays on bottom shelves moved to top shelves and vice versa). In this phase the seed root will emerge but the crook that will carry the seed leaves above the surface should not be visible. If you see crooks, you have left trays in the germination area too long and you may experience plant stretch during emergence (if plants have emerged you are too late – stretch has already occurred).

Emergence
After initial germination, it is critical to move plants immediately from germination areas to the greenhouse for emergence. If you are having another grower germinate your seeds, it is important to schedule pickup or delivery so that there are no delays. Greenhouses should be set for 72-75°F day temperatures and 65°F night temperatures. Do not water until after you see emergence and even then water sparingly as needed to keep trays and emerging seedlings from drying out. Excess water and high greenhouse temperatures during the emergence phase will lead to stretch.

Seed Leaf Stage to First True Leaf
Maintain greenhouse temperatures in the 72-75°F day and 65°F night range during this period. Water moderately to keep plants from drying out but do not fertilize during this period (this assumes that the media you are growing in has a starter fertilizer charge). You want the plants to grow slowly for highest quality.

First True Leaf to Second True Leaf
Continue maintaining greenhouse temperatures in the 72-75°F day and 65°F night range during this period. You can fertilize once the first true leaf emerges. Generally 2 fertilizations of 100 ppm nitrogen concentration one at first true leaf and one at second true leaf will be all that is needed. If a constant feed system is used, set for 50 ppm nitrogen each watering once the first true leaf has emerged. These fertilization rates are for the media listed in the seeding section that contain a starter fertilizer charge. Avoid using fertilizers with high amounts of ammonium N as the nitrogen source as this can lead to stretch (use fertilizers with calcium nitrate and potassium nitrate as the main nitrogen sources). Avoid over-watering. Again, you want plants to grow slowly for highest quality.

(Some growers will use a media with no starter fertilizer charge. If that is the case, a different fertilizer program will be needed. Use fertilizers with calcium nitrate and potassium nitrate as nitrogen sources. Use 50 ppm N from emergence to first true leaf every 3 days, 200 ppm N every other day from first true leaf to second true leaf)

Hardening Off
It will take 4-6 weeks to finish transplants. Prior to transplanting, harden off plants starting one week before setting in the field. This is accomplished by lowering day time temperatures in the greenhouse (if greenhouses have side curtains roll them up during days if temperatures are not too cool). Reduce watering and stop fertilization. Some growers have the ability to place plants on wagons or move benches outside during the day, bringing them in at night. This is advised where possible but make sure the area is sheltered from high winds and avoid days where the temperature is below 60°F.

Pollenizers
The above information is for growing the seedless watermelons. Seeded pollenizers do not need special germinating conditions and can be grown directly in the greenhouse. The key is to time the production so that plants are produced and hardened off at the same time as the seedless types. They also should be grown slowly and attention should be paid to avoid stretch. Follow the same recommendations from seed leaf stage through hardening off.

New Castle County Agronomic Grower Meeting and 3rd Annual Dinner

Thursday, March 4th, 2010

Tuesday, April 6, 2010     5:30 – 9:00 p.m.
Blackbird Community Center
120 Blackbird Forest Rd.
Townsend, DE 19734

This session will gear you up for the season ahead with the latest in pest pressures and control, variety trial updates and agronomic planning for the year. We’ll be sure to cover nutrient management topics, as well. A detailed agenda is available online.

This meeting is free and everyone interested in attending is welcome.

There is no fee, but registration by April 2 is required. To register, request more information or if you require special needs assistance for this meeting, please call our office in advance at (302) 831-2506. 

Invitation to Join the Fruit and Vegetable Growers Association of Delaware

Thursday, March 4th, 2010

As the new Extension Vegetable and Fruit Specialist for the University of Delaware, I encourage you to consider joining the Fruit and Vegetable Growers Association of Delaware. I have just developed a new website for the group.

Take a look at:
http://delawarefruitvegetable.wordpress.com
or
http://delawarefruitvegetable.org

You may join by following the instructions on the membership page at the website http://delawarefruitvegetable.wordpress.com/membership

We welcome growers, farm owners, farm employees, farm family members and spouses, market masters, market owners and operators, restaurant owners, produce buyers, suppliers, consultants, industry representatives, agency representatives, university representatives, and all other supporters of our fruit and vegetable growers to become members.

Member benefits include:

• A member farm page or links to farm websites on the new web page

• Newsletter and weblog, Twitter page, and Facebook page (new in 2010)

• Winter educational meetings and educational programs throughout the year.

• Promotional materials for use by member farms (such as recipes)

• Promotion of the industry and farms at events throughout the state.

• Voice in legislative activities and input into regulations affecting the industry.

• Programs that can help produce businesses such as “Farm to School”

• Training programs such as Produce Food Safety

and much more…

Members of the Fruit and Vegetable Growers Association of Delaware are very diverse – from market gardeners selling at nearby farmers markets to grower-shippers who supply supermarkets throughout the east; from farms offering Community Supported Agriculture subscriptions to nearby families to processing vegetable growers providing regional freezing and canning plants with tons of raw product that will be sold throughout the country.

Local Farmers Wanted for Western Sussex Farmer’s Market

Thursday, March 4th, 2010

Saturdays 8:30 a.m. to Noon
July 3 through August 28
The Boys and Girls Club of Western Sussex
310 Virginia Ave.
Seaford, DE 19973

Needed: Produce, cheese, eggs, meats, fruit, nuts, bread & baked goods, jellies, herbal products, flowers, etc.

Easy access for vendor set-up!

Call (302) 629-2686 for more information.