IDEAL POTATO STORAGE CONDITIONS
(from Long Island Fruit and Veg Update)
The holding environment for good quality potatoes should be maintained at a high relative humidity (90 to 95%) and 38 to 40 degrees F. During this period, tuber quality should be preserved by keeping weight loss to a minimum and by controlling sprouting and rot. Temperature should not vary by more than 2 to 3 degrees F from the bottom to the top of the pile or from the desired holding temperature. Fluctuating temperatures may cause condensation within the pile (promoting disease) and can accelerate sprouting.
CORRECT WEB ADDRESS FOR SOIL SURVEYS
The last newsletter explained that soil survey maps for most of Vermont are now on-line. The correct place to get these is: http://websoilsurvey.nrcs.usda.gov. If you need assistance using the site, please contact Martha H. Stuart, at NRCS in White River Junction at (802) 295-7942 x28
FARMER EDUCATOR WANTED ON LABOR ISSUES
The Northeast Sustainable Agriculture Research and Education (SARE) program is seeking applications for its Sustainable Farmer Educator program, specifically for a farmer with a background in farm labor issues. The program supports skilled and articulate farmers as they travel to meetings, conferences and workshops around the Northeast to address topics in sustainable agriculture. Other farmer educators have covered topics such as agritourism, grazing and farm management. The appointment provides up to $6,000 that can be used for travel, meals, lodging, and compensation for hours worked. Appointments normally run one year and the application process is competitive. To learn more go to www.uvm.edu/~nesare and follow the "sustainable farmer educator" link, or to have an application mailed to you call (802) 656-0471. The deadline is January 9, 2006 and the award will be announced in March.
MASS. GROUP SEEKS AN EXPERIENCED FARMER FOR NEXT SPRING
North Amherst Community Farm, Inc. is a non-profit organization created to purchase and protect 39 acres of prime farmland in Amherst, MA. Its goals includes the creation of a CSA Farm, a retail farmstand open to the public, and community and educational programming. Experienced farmer(s) are invited to submit proposals to develop a thriving farm business using organic practices, with farming to begin in spring 2006. A lease of 3 to 5 years, renewable for a longer period, is anticipated. The farm has 36 tillable acres, a farmhouse, 6 barns, and a perennial stream. It is surrounded by 10,000 residents, and has frontage on a major road near the UMass. For more information go to www.nacfonline.org. To visit the location (by November 20) contact Steve Dunn at (413) 549-3799. Proposal review begins Nov. 30th and concludes when a suitable applicant is found. Send proposals to: firstname.lastname@example.org or to NACF c/o Steve Dunn, 161A Pine St., Amherst, MA 01002.
WEB SITES FOR GRAPE GROWERS
A new website for the vineyard industry in New England, called the New England Wine Grape Growers' Resource Center, is www.newenglandwinegrapes.org/. It features: scouting reports, weekly weather summaries, cultural practices, pest and disease management, New England vineyard web sites, equipment sources, nurseries, upcoming events, and a photo gallery. The UVM website, http://pss.uvm.edu/grape/, contains useful information, has a great collection of links, and details on upcoming meetings.
GRAFTING TECHNIQUES FOR GREENHOUSE TOMATOES
(adapted from an article in Crop Talk by Richard McAvoy, Univ. of Connecticut)
Greenhouse tomato growers are using grafting to manage root diseases and increase fruit production through increased plant vigor. Grafting involves splicing the fruit-producing shoot (called the ‘scion’) of a desirable cultivar (Trust, Buffalo, etc.) onto the disease resistant rootstock of another cultivar. Two cultivars widely used for rootstock in the greenhouse are ‘Maxifort’ and ‘Beaufort’. Both cultivars have tolerance to a variety of soil-borne diseases. ‘Maxifort’ confers very vigorous growth while ‘Beaufort’ confers moderate increase in plant vigor.
Three primary techniques used for grafting are: cleft grafting, tube grafting and tongue approach grafting. Cleft grafting and tube grafting are similar in that the shoot of the fruit-producing variety is completely cut off from its own roots and attached to the severed stem of the rootstock plant. Tube grafting originally relied on a tube to attach the shoot to the root but clips are now used. Tube grafting is quicker and less complicated to do than cleft grafting because it only requires a single straight cut on both the root and shoot portions of the graft. Also, because fewer intricate cuts are involved, this technique can be used on very small seedlings.
When grafting it is vital that the diameter of the cut ends of the shoot and the rootstock match up perfectly, otherwise the graft is slow to heal and the rootstock may starve to death. Because rootstock cultivars tend to have long thin stems, we generally sow seeds for the rootstock earlier than seed for the scion. For cleft grafting sow rootstock seed 5 to7 days prior to seed for the shoot. When the plants reach the 4 to 5 leaf stage, cut the stem for both the shoot and the rootstock at right angles, each with 2 to3 leaves remaining on the stem. Next the stem of the shoot is cut in a wedge, and the tapered end fitted into a cleft cut in the end of the rootstock. The graft is then held firm with a plastic clip.
For tube grafting sow rootstock seed just1 to 2 days prior to seed for the shoot because smaller plants are used than with cleft grafting. You should be able to graft plants two or three times faster than with the cleft method. The optimum size for tube grafting varies according to the kind of plug tray used and your ability to handle small plants. I find it hard to handle plants smaller than about 4 inches tall and 1/8 inch stem diameter, but you can graft smaller plants.
The first step in tube grafting is to cut the rootstock at a slant, as that allows more surface contact on the graft. The shoot is cut in the same way. Place the two cut ends in direct contact and use a small clip to hold the cut surfaces together. If you plan to have the rootstock support a double leader in the production house the graft must be made below the cotyledons (seed leaves) on both the rootstock and the scion. With a double leader, the top of the plant is pinched soon after the graft heals and two equal-sized leaders are produced from the buds at the base of the seed leaves. With ‘Maxifort’ a double leader is recommended. ‘Beaufort’ is a good rootstock for a single leader plant.
Tongue approach grafting allows the scion-donor plant to remain on its own rootstock until the graft heals. This is commonly used with melons and cucumbers because it produces a higher success rate. Some growers also prefer the technique for tomato, especially when greenhouse conditions for healing and acclimation are less than ideal. With this method, larger plants are used (seedlings 14 to 21 days old for tomato, 10 to 13 days for cucumber, and 7 to 10 days for pumpkin) to ensure sufficient stem diameter to perform the graft.
First, the top of the rootstock is removed so that the shoot cannot grow. Next, the stems of both the scion and rootstock are cut in such a way that they tongue into each other, and the graft is secured with the larger clips. The roots of the scion are left intact for 3 to 4 days while the graft union heals and then the stem of the scion-donor is crushed between the fingers or partially cut.
Tips for success: Expose plants to full sun and some water stress before grafting to keep the plants short and increase tolerance to water stress. Immediately before starting to graft, make sure plants have been watered and are not wilted. Make grafts early or late in the day to avoid undue water stress and drying of the cut plants. Ideally, grafting should be done in a place that is sheltered from the wind and bright sun. Always cut the scion plants and the rootstock plants at the same angle with a razor. Do not cut more plants than you can graft together in a few minutes, so the cut surfaces do not dry out. Always match the scion with a rootstock of equal stem diameter and place the cut surfaces together in tight contact before clipping in place in order to maximize the chances for the vascular bundles (‘plumbing’) to connect to each other.
After grafting keep plants at about 86 degrees F and at least 95% relative humidity for 3 to 5 days while the cut ends heal together, under a heavily shaded area with fog or mist. In small scale operations newly grafted plants can be placed under opaque plastic or even newspaper to reduce light levels and misted once or twice a day. Over 3 to 4 days increase light exposure by removing the plastic covering or by cracking open the tent or domes a few hours in the early or late part of the day and increase the exposure time each day. After a few days, move the plants completely into the house but continue to mist as needed to avoid wilt. Finally, when you set plants in the production house keep the graft union above the soil line. Tomatoes tend to root easily and if the scion roots into the soil, the plant will be susceptible to soil-borne diseases.
More information will be presented on grafting at the Greenhouse Tomato School, Nov. 10 in Vernon CT (near Hartford). See www.uvm.edu/vtvegandberry, click on meetings, or call me at 802-257-7967 ext.13 for a copy of the program. To view the full article, above, with figures: www.hort.uconn.edu/ipm/veg/croptalk/croptalkpdfs/croptalk1.3.pdf
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