NC Weekly Strawberry Advisory


Strawberry crop report - March 16, 2000.

Plasticulture strawberry growers who protected over the weekend saved a significant amount of crop - in locations we visited on Tuesday (March 14) and Wednesday (March 15), it is clear that growers who did not protect had losses of as many as 2 viable blossoms per Chandler plant. If the grower has approximately 15000 plants per acre, then last weekend's frost took away approximately 30000 flowers. In the early season, Chandler fruit will easily weigh ¾ oz/fruit (21 g). So, with average berry weight of 21 g x 30000 blossoms = approximately 1390 lbs/acre. At a U-pick price of $0.85, that translates into a loss of about $1180. There are other problems as well: 1) market season is delayed by one week, and 2) increased botrytis pressure (dead blossoms). So, when a grower asked, "Is it really worth it to run?", I must respond with the questions:
1) can you afford to lose $1000 or more per acre?
2) can you afford to open a week later than your competition?
3) do you like the idea of creating more of a botrytis problem?

Immediate tasks and concerns:

1) Bees can be very beneficial for improved pollination and fruit set - get the hives moved into berry fields now (recommend 1-2 hives/acre).
2) Make sure that you have made your first fungicide application by this time (usually made at 10 % bloom), and most growers are now on their second or third application. Elevate was recently registered and is very good for the second and third cover sprays (cost is about $33/ lb x 1.5 lbs/acre = $49.50/acre). We are possibly looking at some wetter conditions next week. It concerns us that where frost protection was omitted last weekend that there is now a better opportunity for the botrytis fungus to colonize and produce spores in the dead flower tissues. Avoid making more than two applications of Elevate in a row. The Rovral label has changed, and is essentially not an option after the first fruiting flower is seen.
3) Prepare for this weekend's possible frost/freeze - get your irrigation system set up now (additional information below).
4) Send any suspicious looking plants into the Disease and Insect Clinic right away. The reason this is particularly important is that if there is an anthracnose infection, you will want to take advantage of the emergency exemption that is still in force for Quadris until April 12, 2000. Quadris is a protectant fungicide and should be applied beprior to or in the early stages of disease development (but, not after April 12th).
5) Apply a mulch to the aisle area now if you wish to keep the berries free of sand and grit.
6) If your strawberry plants are smaller in size this year (the plants in-the-row should be "touching" at this stage), my guess is that you should anticipate a shortfall in fruit production for your market. Be advised that we are looking at a number of plants that will not produce in excess of ½ lb fruit per plant, or as little as 7500 to 10000 lbs per acre. We will try to get some pictures posted to www.smallfruits.org next week to give you a better idea about this problem. One of the best things you can do is to be sure to PLANT ON TIME for your area. A number of growers set plants 2 and 3 weeks late last year, and these plants have not sized up, and will not exceed the usual 1 lb of fruit/plant that we normally get with Chandler.
7) Weather advisory services: You can contact Skybit at 1-800-454-2266 to subscribe to their Agmaster daily report. Also, another forecasting service is AWIS (subscribe by going right to their web site: www.awis.com)

Frost/freeze potential this weekend (Saturday March 18): We are seeing forecasts of temperature minimums of 29-30 F for early Saturday morning, and again we are looking for potentially damaging temperatures on Sunday morning.
What is interesting at this stage is that the winds are being forecasted to be quite high (> 10 mph). If winds stay up (as predicted), it could turn out that with the good mixing taking place, irrigation may not be needed. The still conditions that we had last Sunday produced a classic radiation frost. The strawberry blossom is tolerant to temperatures down to 30 F, but below this temperature you can see serious losses occur.

Please check out our teletip service for day-to-day changes in frost/freeze advisories: in the event of possible frost freeze: ask for advisory 5147 - these advisories on 5147 will be updated on a daily basis in frost/freeze period. Call 1-800-662-7301; press 1 on touchtone phone; enter 5147 for the strawberry frost report.

Barclay Poling
Extension Small Fruit Specialist (Strawberries and Muscadines).