Compiled by Mark Hoffmann, Small Fruits Extension Specialist, NC State University, Raleigh NC; and Barclay Poling, Prof. and Extension Specialist (retired), NC State University, Raleigh NC
Summer: After season to pre-plant 2019
The most important strawberry chores for the summer are: removing plastic and old planting material, order your plants, and of course: pre-plant preparations.
Destroy plants now! The season is over. Use Gramoxone to kill the plants, and cut vigorous plants off before applying it. If you have high crown or fruit rot incidences this year, try to remove as much planting material as possible before plowing and disking under old plants. This is the best strategy for preventing further spread of diseases. Also remove and recycle your plastic – some growers use tobacco balers to compress the plastic before it goes to the landfill; consider planting a summer cover crop if you want to reuse the same site. A two-three year crop rotation cycle is recommended, but many can’t do that. A summer cover crop can help to restore soil health and replenish some of the nutrients.
Reevaluating your 2018/19 season
Before making the same plant order as last year, critically evaluate the relative profitability of your different markets (U-pick, Ready Pick, Whole Sale, other Off-Farm). Did you do customer evaluations? Were they happy with a specific variety? Often customers ask for specific varieties. Do varieties such as Chandler or Ruby June sell better in U-Pick or Ready Pick, do others (Camarosa, Sweet Charlie, Albion) work better as whole-sale? If your crop was really late this year, have you considered growing an early ripening variety Sweet Charlie or Rocco? But, you will have to hurry to place this plant order, as plant supplies may be limited.
Golden Rule: Always try new varieties, always use more than one plant supplier
We recommend to always try a few new varieties (a few 100 plants maybe) on your site to see if you and your customers like them. The microclimates and soil types in Southeastern strawberry production differ from field to field, and varieties which might work for one growers, don’t necessarily work for every grower.
NC State University has released two new varieties, ‘Liz’ and ‘Rocco’. View a list of supplying nurseries. Besides ‘Camarosa’ and ‘Chandler’, other varieties to be considered are: ‘Rocco’, ‘Liz’, ‘Ruby June’, ‘Camino Real’, ‘Merced’. The variety ‘Ruby June’ has worked for several growers in the past., but not for everyone. For extended season production ‘San Andreas’ and ‘Albion’ are favorable. It is advisable to try a certain variety for a minimum of two seasons!! Please use a min of two plant suppliers for each season if possible.
Don’t wait until the last minute to order plants. Nurseries need time to fulfill the orders. If you want to grow plug plants from tips, make sure you have your propagation equipment set up (get a mist system set up, order soil, trays, fertilizer, Rodomil) – to develop a high quality plug plant, tips need to arrive six weeks prior to planting.
Pre-plant preparations also should being end of July, early August latest. Soil tests should be done in early July! Lime early in the summer if necessary to raise pH to 6.0 to 6.2. Incorporate lime when existing beds are broken down. Use overhead irrigate to soften soil as needed and subsoil completely. Being to think about a fumigation plan, set a schedule, talk to custom fumigator and/or acquire necessary materials. If you fumigate your own: Check all your PPE (respirator, Tyvac, chemical resistant gloves, rubber boots) for functionality. Check your fumigation rig and do any adjustments and repairs well in advance of fumigation. Be sure to allow appropriate plant-back intervals and an additional cushion in case of bad weather. Renew respirator fit testing (must be current within one year of fumigation). Make sure you have new respirator cartridges. Make sure you have all the licensing required. For organic growers, crop-rotation is a must. Organic growers should be on a three-year crop rotation, including one year of cover-crops. Organic growers should make sure not to re-use plastic, and clean row covers with bleach. Replacing row covers after every or every other season in organic systems is highly recommended. If low-tunnels are used in an organic systems, clean all re-usable parts with Bleach. It is not recommended to re-use the plastic in organic low-tunnel systems.
Preparing the next season
If you haven’t already, make key decisions about varieties, plant source and plant types for next season early August latest! Order your plants!! Stay in close contact with your plant supplier this summer and do not be afraid to ask for periodic reports updates on plant health, especially after sever weather events. Chose plant suppliers which use certified clean planting stock for propagation if possible. For some areas , planting can be as early as mid-Sept. Fumigants and pre-plant fertilizer need to be applied a minimum of 21 days before planting date! Get you fumigation material ordered. Order plastic, drip-tape, waterline. Check pump, sand-filter for functionality and replace broken or worn out parts of the irrigation system. Attend the pre-plant meetings in Virginia and North Carolina in August!
Prepare your Fumigant Management Plan as required by the regulations. Don’t wait until the last minute. We recommend to hire specialized fumigation services to custom fumigate.
If you fumigate yourself, please read the following suggestions carefully. All fumigants and fumigant alternatives which are currently in use have a high potential to impact your health if you don’t protect yourself! Install a “blow-out tube” on your fumigation rig – this is an important safety measure in case pressure builds up excessively in the nitrogen tank. Before fumigation, pressure-test your fumigation system using only nitrogen (a special connector can be obtained to do this). Make sure that the knives on the fumigation rig are open and filters are clean. Consult your fumigant supplier to determine fumigation equipment specifications (orifice size, pressure, flow meter percentage, etc.) to achieve proper application rates of the selected fumigant. Calibrate the fumigation rig every year again and every time you change the bottle or gas tank!
NEVER fumigate or use any other pesticide without using the required protective measures! READ the label of the fumigant carefully and follow all the instructions. The safety of you and others around you should always come first!
Have the required signs ready. Put them at all corners of the field. Not putting up signs violates the law and also has the potential to harm potential future customers.
Pre-plant fertilizer and Bed-Shaping
Apply pre-plant fertilizer, according to your soil test. As a rule of thumb, apply ca. 50% of all estimated required Nitrogen for the season, and all the Phosphorous which is required. If applying compost before bed-making in late summer, do your homework first: Nutrient content? Heavy metals? N release pattern? Get advice from your extension agent on issues related to usage of any animal manures in strawberries. Set up overhead irrigation system. Check pump, pipes, and nozzles. If soil conditions are dry, overhead irrigate 1/4 inch per cycle until soil conditions are optimum for both bed making (firm but not clumpy) and fumigation (optimal retention time of product for maximum efficacy). Supplemental irrigation amounts will vary by soil type. Be careful not to over-wet soil.
Plant ryegrass soon after fumigating and before punching holes for planting. The recommended seeding rate for annual ryegrass is 25 lbs/acre. (You are only covering half of the area with seed, so this rate is equivalent to 50 lbs per acre.) Heavier seeding rates will result in a thick, luxuriant stand that often has to be sprayed twice to get it to lay down. Allow for a minimum three-week plant-back period. Be sure to consult the fumigant label and to clarify with your supplier any questions you have about required plant-back period. It is very risky to attempt transplanting before the minimum plant-back requirement for the fumigant you are using has been met.
Maintain adequate mist to facilitate quick rooting of tips. If tips flag or wilt excessively, increase misting frequency until plants remain turgid during irrigation intervals. Typical schedules irrigate for 20 to 30 seconds every 2 minutes for the first 3 to 5 days, then increase the interval by a few minutes each day as plants tolerate (20 to 30 seconds every 10 to15 minutes by week 2). Misting schedules will vary depending on propagation environment (indoor vs. outdoor, temperature, relative humidity, wind etc…). Tips should have fully functional root systems after 21 days. To finish the plugs, transition to a watering schedule using either the misting system at lower frequency and longer duration. High quality plug plants need 5-6 weeks to develop from tip to finished product.
Do not fertilize just-planted tips. The fertilizer charge in most potting media will be sufficient until the plants are well rooted. Fertilizer applications can be made to plugs in the third or fourth week of the program. Fertilizer formulations with low phosphorus are desirable to keep plants from stretching (15-5-15, 13-2-13). Apply at a rate of 50 ppm of nitrogen once a day for the last week prior to field planting/delivery. A tray drench with 150-200 ppm of nitrogen the day prior to planting is a common practice.