Disease Control In Plantbeds


 For the best control of all soil-borne diseases, use the plant-growing mix described in table A-2 orA-3. If this is not possible, use one of the following procedures:

Preplant
 The only practice that ensures complete sterilization of soil is the use of steam. When steam is used, a temperature of 180°F (82.2°C) must be maintained throughout the entire mass of soil for a period of 30 minutes.
Soil fumigation is a method used to provide disease control in plant beds. The following materials are suitable for small lots of soil:

chloropicrin--5cc/cu ft
metam-sodium (Vapam HL)--1 qt in 5 gal of water per 1/2 cu yd of soil.

 For larger areas, such as plantbeds or seedbeds, the following materials are suitable:
chloropicrin--50 gal/A (3 cc/injection)
metham-sodium (Busan, Nemasol, Vapam HL)--
drench--1 qt/100 sq ft
injection--1 pt/100 sq ft

 See the Soil Fumigation section for proper application techniques

Seed Treatment
 Seed treatment is essential to control seed-borne diseases in many transplanted crops. Failure to treat seed properly could lead to diseases in the plant bed that will reduce plant stands or that are carried into the field at transplanting. Crop failures could result. Seed treatment is especially important for asparagus, broccoli, brussels sprouts, cabbage, cauliflower, collards, eggplant, kale, kohlrabi, pepper, radish and tomato. In the case of peppers and tomatoes, a chlorine seed treatment is essential for prevention of bacterial diseases (bacterial canker, bacterial leaf spot and bacterial speck). See crop sections for specific seed treatment recommendations.

Postplant
 For damping-off on broccoli, cabbage, cauliflower, cucumbers, melons, squash, lettuce, spinach, onions, and tomatoes in open field beds caused by Pythium and/or Phytophthora, use mefenoxam (Ridomil Gold 4E or Ultra Flourish 2E).
Foliar diseases can be a problem in plant beds. To prevent foliar diseases, it may be necessary to apply fungicide sprays as plants become crowded in plant beds.
Refer to label clearance before use.

Materials Cubic Yard 22 Bushels 2 Bushels
Shredded sphagnum peat moss 11 bu 1 bu (10 gal)
No. 2, 3, or 4 domestic vermiculite(1) or horticulture grade (dust screened), or 11 bu 1 bu (10 gal)
African vermiculite (1) 11 bu 1 bu (10 gal)
Pulverized limestone use dolomitic lime for mixes made with domestic vermiculite, or 10 lb 1 lb (1 1/4 cups)
use calcitic lime mixes made with African vermiculite 6 lb 9 oz (3/4 cup)
Superphosphate (20% P2O5) or 2.5 lb 4 oz (1/2 cup)
triple superphosphate (46% P2O5 1 1/4 lb 2 oz (1/4 cup)
Sulfate or muriate of potash (50%-60% K2O 1/2 lb 1 oz (2 tbs)
Osmocote(2) (18-6-12)
Tomatoes 4 lb 6 oz (3/4 cup)
Eggplants 8 lb 12 oz (1 1/2 cups)
Peppers 8 lb 12 oz (1 1/2 cups)
Micronutrient mix use according to mfgr.°s recommendations
Wetting agent (such as Aqua-Gro granular) 1 1/2 pt 1 oz (4 tbs)
(1) Vermiculite should be approximately pea-sized and relatively free of fines and dust. Final mix should have a pH of 6.0-6.5.
(2) Osmocote is a slow-release fertilizer. Use a formula that will release nutrients over a period of 8 to 9 months. Therefore, mixes should be made just prior to seeding. Plants grown in mixes containing Osmocote must be carefully watered and the temperature carefully controlled prior to planting. Reduced rates are suggested to control plant height when using small cells.

Information provided is intended for consideration by the user, but is not intended to be a recommendation. Production decisions should be based on consideration of many types of information (scientific, experiential, economic, legal, etc.) available to the user.

Where trade names are used no discrimination is intended, and no endorsement by the Cooperative Extension Service is implied.

 Dr. Alan A. MacNab, Professor, Plant Pathology
Penn State College of Agricultural Sciences
211 Buckhout Lab, University Park, PA 16802

Updated: March, 2003; EMH
Loaded: June, 2003; AAM

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