Newsletter Articles

We get many inquiries from organic growers about the sourcing of plant material athat will meet the requirements of organic certification. We have researched this question with NOFA, our New England Organic Farmers Association.

To comply with an organic certification, an organic grower can purchase bare root plants from Nourse Farms and fruit the plants one year later under an organic label. The certification requirement is the plants have to be planted one full year in an organic certified site. If you have further questions, you may contact your regional organic growers group.

Fall mulching of plants is an important management consideration for minimizing winter damage to crowns, which can result in lower crop yields. Plants should be well into dormancy before beginning the mulching process, but it should not be delayed too long as early “artic” blasts can damage plants.

A good mulch material should be free of weed seeds, coarse enough that it does not pack down and cause smothering, but heavy enough so that it doesn’t blow away.

Straw – This is the best option because it satisfies the above requirements.

The following materials, although not as good an option as straw, are still good options when properly managed:

Corn Stalks – Generally weed free and quite clean; corn stalks are a good option but they are a more difficult product to handle; appropriate handling equipment is necessary.

Hay Sources – A coarse hay such as alfalfa offers good winter protection but can carry many weed seeds, causing weed problems the following season. This can be controlled with a fall application of Devrinol prior to mulching. A spot treatment of Poast in the spring for germinating grasses may also be necessary.

Sawdust or Wood Chips – A good alternative mulching material when available.

Clear Plastic – A good option, but warm winter temperature can be a problem with the plants heating under the plastic necessitating early removal.

Row Covers – Does not offer the protection of other mulches. Use of row covers is better than using no mulch at all.

The use of plasticulture has become a standard practice for many vegetable crops. In addition, we have seen the practice increase with the strawberry planting as well. Plasticulture will enhance the performance of T.C. raspberry plugs too.

Cornell University research has shown with data, that a plasticulture environment will assist in maximizing the growth and performance of T.C. plugs the first growing season. Growers are now evaluating this for continuous use.

We recommend planting T.C. raspberry plugs on raised beds with drip irrigation lines placed 1” deep in the soil, and the bed then covered with plastic. Plug planters will accurately plant the T.C. raspberry plugs through plastic. Not only does the environment provide maximum growth of the plug plants, but the plastic also provides excellent weed control and conservation of moisture. In a cool spring, the plastic will also get the plugs off to a head start.

Changes in temperature of only a few degrees can have a big impact on the quality of plants you receive.

We do everything possible to keep our planting stock in a constant condition. From the time the plants are dug until we ship to our customers we maintain a temperature of 28°F. Plants shipped via UPS do thaw in transit. In these situations, plants not set immediately require proper refrigeration to protect them and to ensure good performance.

Upon inspection of thawed plants, those found to be without growth can be restored at 28°F until planted. We recommend the cartons be opened and the plastic liners loosened upon arrival, so refrigeration can pull the temperature down as quickly as possible. Otherwise, it could take a considerable length of time for good cooling to result. After inspection, if plants have started to grow, cool only to 30°F and plant as quickly as possible.

When you receive your plants via pooled, refrigerated truck, they are maintained at 28°F throughout the trip. Upon receipt they should be returned to cold storage (28°F) until planting is possible.

It’s vital to select a ship date that will allow you to set the plants in the ground as quickly as possible. We highly recommend that you let us hold the plants until you are ready to receive and plant them.

Control of slugs can be a major problem in the moist, wet conditions that can occur during strawberry harvest.

A Preventive Program

Because slugs cause fruit damage and elicit a negative response when customers see slugs on their berries, we recommend a preventive control program. A commercial product called Deadline Mini-Pellets is manufactured by Pace International and is distributed by Helena Chemical, UAP, Terra and possibly other chemical distributors.

This product was previously available as an inconspicuous brown granule. The granule is now blue and very noticeable. The active ingredient is encased in plastic that breaks down over a longer period of time, thus providing longer slug control. We recommend this product be applied 10-14 days prior to harvest. If any blue granules are still present at picking time, you can irrigate them away.

Apply Deadline Mini-Pellets at 10-40lbs. of material per acre. We broadcast 40lbs. Per acre. Apply the material at a time when the foliage is dry, conditions are breezy, and at least 2 or 3 dry days are forecast. This lets the slugs feed before the material is washed or rained away. We have found this preharvest application usually controls slugs for the season.

Applications During Harvest

Conditions may develop when slugs appear during mid-harvest. The difficulty in controlling slugs at this time is that they have developed a taste for strawberries and may not feed on the bait. As the label says, do not apply on edible plant parts. Apply after you have harvested all ripe fruit. After 2 or 3 days, irrigate the bait off the plants prior to picking again. Field re-entry is 12 hours.

Reminder. If you had a slug problem last season, there is a strong chance that slugs will be present this season. Therefore, it will be important to use a preventative program to control this pest. Please contact us if you have any questions. As always, read the label before applying any product.

The Strawberry Sap Beetle can sometimes be a problem for growers. Here’s some information about this annoying pest.

The adult Strawberry Sap Beetle (Stelidota geminate) like other “picnic beetles”, have knobbed antennae and are about 1/8 inch long with a uniform light to dark brown color. They tend to look flat when viewed from above and have no distinctive markings.

Sap beetles over winter as adults in protected areas. They emerge in spring, mate and begin egg layering in April continuing through June. Beetle larvae and pupae are white, pupae then turn a tan-cream color before emerging as adults. The life cycle from egg to adult takes about 30 days. The newly emerged adults do not breed again but instead they begin congregating and feeding in areas with decaying plants and sweet or fermenting fruit.

PYO marketing many times provides conditions that promote Strawberry Sap Beetle infections. Uncompleted harvesting, caused by bad weather or inexperienced pickers, leaves larger amounts of fruit in the field; this wasted fruit is the primary target for the beetle. The beetle bores into ripe, nearly ripe or decaying fruit leaving holes in the fruit that make it unusable.

Because the Strawberry Sap Beetle is a bit more difficult to control it is essential to keep your fields as clean as possible. Baiting with baskets of over ripe fruit around the edge of the field can stop some migration of pests into the fields. Because the pest is active on ripe fruit, using any type of control must be done with care. Diazinon 50WP at 1 lb./acre has a 5 day preharvest interval. Sevin 50W at the 2-4lb./acre rate is not as effective, but it only has 1 day to harvest interval. Growers have reported that the use of Dibrom in their pest control programs has given some good results. Please read all labels carefully before using any chemical on your fruiting beds.

If the sap beetle has been a problem in your location it is important to plan to aggressively control this pest prior to the picking season. This will allow you to use the most effective plant protectorates, which often have the longer harvest intervals.

Sunscald on raspberries causes druplets facing the sun to turn white. The white druplet condition can also be caused by Tarnished Plant Bug. However, the usual cause of the symptoms is sunscald.

Sunscald appears to be decreased with water management. When hot temperatures are predicted, use drip irrigation early in the morning to allow ample uptake of water in the plants before the temperatures rise. With ample access to water, as the respiration rate in the plant increases at sun-up, the increased water uptake to the plant tissues appears to decrease sunscald. The amount of water needed will vary according to soil type and amount of rainfall received.

Our general experience at fruiting time indicates more water is required to maintain fruit size and the growth of next year’s wood.

Thrip damage to strawberry fruit is a relatively new development. While older literature ascribes Thrips as a cause for fruit deformity, a serious outbreak in 1996 caused complete crop failure in many areas of Maryland, Pennsylvania and parts of New York and the Mid-West. Since then, there has been extensive damage in various regions.

General Information

• Thrips come north on weather fronts. There is no indication they over-winter.
• They are extremely small, cigar shaped, and therefore very difficult to see.
• Thrips are approximately 1.5mm in length or 1/16 of an inch.
• They are weak fliers, but move around quickly through a strawberry field.
• Thrips hide down underneath flower parts, the hull or calyx and around the newly formed seeds of the berry.
• Thrips damage results in bronzing of the fruit, scarring and cracking the berries. They feed by rasping and/or sucking on newly developing fruit parts causing dwarfed and unmarketable fruit.

Monitoring or Scouting Methods

Method # 1: Collect 10 flower trusses in a plastic zip-lock bag. Put the bag in a warm place (like the hood of your car). The warming will cause the thrips to leave the plant parts and move to the surface of the plastic bag, where they can be counted. Repeat this process in several (5 or 6) locations of the production.

Method #2: Hold a flower cluster in your fingers down inside a white Styrofoam cup and blow on to the flower. The warm air will cause the thrips to move from the plants to the side of the cup where they can be counted.

Threshold Numbers

Several Extension Specialists and many articles reviewed report the threshold range as 2-10 thrips per blossom. The higher threshold resulted in damage levels of 20%. The lower threshold of 2 per blossom was suggested for fruit that was to be picked and marketed. Presently there is no closer guide.

Scouting Recommendations

• Start scouting in early bloom (same time as with Tarnished Plant Bug), and continue throughout the blossom period.
• During each scouting event, check 5-6 locations throughout the field.
• During periods of warmer temperatures (68?-74?F) scout at closer intervals.
• Treat with insecticides once you have reached the threshold level you have selected for your operation.

Chemical Controls

• First consult your local state recommendations.
• Materials recommended for Tarnished Bug will also control thrips.
• Most common materials suggested:
  • For Organic Growers – Neem Extracts, Rotenone
  • For Non-Organic Growers – Thiodan, Lorsban, Guthion, Brigade, Malathion and Lannate are suggested.

Important Spraying Recommendations

• Use high gallonage per acre. As Thrips are extremely small and well hidden, good and thorough coverage is essential. Good control uses a minimum of 100 GPM, and up to 200 GPM to insure coverage.
• When spraying during bloom, strategize your timing to minimize bee damage!
• When controlling Thrips and Plant Bug during blooms, most insecticides are compatible and can be combined with fungicides – CHECK LABELS.
• Silicone spreaders have demonstrated to be highly efficient for spray coverage and should help in controlling the difficult Thrips.