September Task List (9/4/14)

— Written By Barclay Poling

September Growers Checklist (Sept 4, 2014)

By E. Barclay Poling, Professor Emeritus & Interim Executive Director, NCSA


1. Prepare your Fumigant Management Plan as required by the new regulations. Don’t wait until the last minute. Make sure you have required respirators, fit testing, and signs. Note that new buffer zone and notification rules are in effect this year.

2. 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.

3. IInstall a “blow-out tube” on your fumigation rig – this is an important safety measure in case pressure builds up excessively in the nitrogen tank.

4. Before fumigation, pressure-test your fumigation system using only nitrogen (a special connector can be obtained to do this).

5. Make sure that the knives on fumigation rig are open and filters are clean.

5. Consult your supplier to determine fumigation equipment specifications (orifice size, pressure, flow meter percentage, etc.) to achieve proper application rates of the selected fumigant.

6. Set up overhead irrigation system. Check pump, pipes, and nozzles.

7. 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.

8. Plant ryegrass soon after fumigating and before punching holes for planting. The recommended seeding rate for annual ryegrass is 25 lbs. (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.

9. Set up deer fence shortly after bedding, even before the ryegrass germinates.

10. Allow for a minimum three-week plant-back period for most fumigants. 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.

Tip/Plug Management

1. 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 to 15 minutes by week 2). Misting schedules will vary depending on propagation environment (indoor vs. outdoor, temperature, relative humidity, wind etc…).

2. 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 (10 to 20 minutes 2x a day) or hand watering.

3. Do not fertilize just-planted tips. The fertilizer charge in most potting media will be sufficient until the plants are well-rooted.

4. 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.

Planting dates for NC

1. Chandler:

a) Mountains, high elevation: first week of September (NOW)

b) Mountains, lower elevation: second week of September

c) Foothills: third week of September

d) Upper Piedmont and tidewater: fourth week of September

e) Piedmont transition to coastal plain: first week of October

f) Sandhills: first week of October, but possibly as late as October 10 in more southerly parts of the Sandhills like Ellerbe. In colder areas of the Sandhills, the first week of October is recommended for Chandler plugs.

g) Lower coastal plain: second of week of October or third week for warmer sites.

Additional Chandler notes: for southeastern counties like Brunswick, the fourth week of October is okay. In more inland areas of the coastal plain, like Kinston, Chandler plugs can be set in the 3rd week of October – we had good results setting Chandler plugs in the 3rd week of October last year (2013) at the Cunningham Research Station (Kinston, NC). Chandler fresh dugs should be set about 5 days earlier than plug plants.

Staggering Chandler plug planting dates:

Because of the difficulty of knowing what type of fall/winter season it will be in 2014-2015, it may be a good strategy to stagger Chandler plug planting dates over a week’s time, and not set them all at once:

  • Example (Lower Mountains of NC)
  • Chandler – if planting date is around Sept 15

–      here is where you have opportunity to stagger your planting of Chandler plugs over 1 week

  • Sept 12th à 1/3rd plugs planted
  • Sept 15th à another 1/3rd
  • Sept 18th à final 1/3rd

2. Camarosa:

Plant Camarosa plugs about 5-7 days ahead of Chandler in Piedmont regions – Camarosa needs earlier planting than Chandler, especially in colder fall/winter seasons.

Note: These are recommended planting dates are for conventional strawberry systems that utilize soil fumigation and preplant nitrogen forms that are readily available for plant growth and development at planting. Consider setting 5 to 7 days earlier than the listed dates for each location in alternative systems that do not fumigate and/or use organic sources of nitrogen that have unpredictable nitrogen release rates.

3.  Other varieties:

Sweet Charlie plugs are usually set one week to 10 days ahead of Chandler.

Example (Lower Mountains of NC)

  • Sweet Charlie – a week to 10 days earlier than Chandler (e.g. if Chandler is Sept 15, Sweet Charlie may be Sept 5-8…tips cut early Aug.)

As a general rule, Albion day-neutral plugs should be set about one week ahead of Chandler. Do not attempt to fruit in the fall – this will weaken plant growth and development. It is recommended that blossoms should be removed in the fall.

4. Cutoff plants:

Cutoff plants should be transplanted as soon as they become available from high elevation California nurseries. Typically, Camarosa cutoffs are not available until about October 7-9; and, Chandler cutoffs are not normally available until mid-October.

Wishing you a successful strawberry planting season!

Dr. E. Barclay Poling
Professor Emeritus (Strawberry Plasticulture Researcher)
& Interim Exec. Dir., NC Strawberry Assn., Inc.
Department of Horticultural Science
Campus Box 7609, 162A Kilgore Hall
NC State University
Raleigh, NC 27695-7609
“When everyone is thinking the  same…  someone isn’t   thinking ….”  —  George S  Patton