Facts for Fancy Fruit 99-12 September 8, 1999 Crop Conditions: Apples remain about 7-10 days ahead of normal. The warm weather has not been particularly conducive to good coloring, although with some cooler nights now hopefully coloring will be acceptable on our main season varieties. Overall fruit size and quality look to be good. Having said that, some orchards have small fruit size due to under-thinning - the temptation with light flowering is not to thin, and some of these blocks set up surprisingly heavy, with small fruit size resulting from this. Dry conditions continue in many parts of the state, but we havenÕt fared as badly as our counterparts in more eastern states. Grape harvest is ongoing and yield and quality are excellent. Early ripening varieties have been low in sugar and generally high in pH, but mid and late season varieties are developing excellent fruit chemistry. Dry Conditions: This has been a year where our crops would definitely benefit from some supplemental irrigation. If you have the capacity to irrigate, hopefully you have been applying frequent irrigation throughout the season and avoiding the worst of the drought. For those with irrigation, do not apple large amounts of water after the trees have been dry. This can lead to fruit cracking and splitting, and can also make the fruit more susceptible to bruising. However, many of us do not have the capacity to irrigate our trees, so how badly affected are we going to be? Well this is going to be the biggest problem in trees that have just been established - make sure your weed control is excellent to avoid the weeds competing for water with the trees. In established trees, the dry conditions will probably cost us a little in terms of fruit size, but flowering next year shouldnÕt be adversely affected unless it has been exceptionally dry. -Hirst Cider Update: No news from the FDA regarding HACCP, so this would seem to be a case where no news is good news. Also, no news from the FDA regarding approval for UV treatment of cider, which is not so good news. Remember, pasteurize or put warning labels on the jug - these are your choices this year. -Hirst Fall Small Fruit Care: Grapes- Grapes should be encouraged to harden off for winter by avoiding nitrogen fertilizers and supplemental watering at this time. Apply non-nitrogen fertilizers and lime as needed based on soil and tissue test results. It is especially important to maintain healthy leaves through fall to promote proper hardening. Downy and powdery mildews often build to epidemic levels on susceptible cultivars in fall. Both can cause defoliation and reduced winter hardiness, so itÕs important to maintain protection against these diseases throughout the fall until leaves drop naturally. Blueberries- As with grapes, blueberry plants should be encouraged to harden off for the winter. However, growers should continue to irrigate if dry weather persists. Fruit buds are developing now for next yearÕs crop so it is important to avoid water stress on the plants during this time. Apply non-nitrogen fertilizers and materials for soil pH adjustment based on foliar analysis and soil tests. Apply these before fall rains begin and also before adding any supplemental mulch to the plants. Strawberries- Flower bud initiation occurs during late summer and fall, so maintaining good plant health into the fall is important for high yield potential next year. The recent dry weather can significantly reduce fruitfulness next year. Irrigate to provide at least 1 inch of water per week. Nitrogen fertilizer should be applied in early September to bring your seasonal total up to about 75-100 lb./acre. Most growers apply about 50-70 lb. of nitrogen at renovation so the fall application should provide another 25-30 lb. This stimulates good root growth in the fall and supplies nitrogen needed for flower bud initiation. Ammonium nitrate (33% N) is a good choice for fall fertilization. If tissue analysis shows deficiencies in magnesium or boron, early fall is a good time for foliar applications of Epsom salts (15 lb./100 gal./acre) for magnesium and Solubor (3 lb./100 gal./acre) for boron. Phytotoxicity can be a problem with these materials so read the labels. In addition to fertility, controlling leaf diseases improves the ability of the plant to carry on photosynthesis and store starch in the crowns. Check fields for infestations of leafhopper or aphids. Generally, plants can take a fair amount of feeding by these insects, but heavy infestations can be a problem. Brambles- Encourage hardening off of canes in summer bearing varieties of brambles by avoiding nitrogen fertilizers and supplemental watering at this time. Spent floricanes can be removed now, but itÕs better to wait until later in the winter unless they are significantly affected by disease or winter injury. Fall bearing raspberries can still benefit from irrigation in this dry weather to help maintain fruit size. Apply non-nitrogen fertilizers and lime as needed based on soil and tissue test results. If Phytophthora root rot has been identified in a field, treat the affected area with Ridomil Gold or Alliette in September or early October. This timing is important to get the material in place in the root zone before the onset of cool wet weather in the fall. -Bordelon Third Generation Codling Moths?: In most years, growers in the southern part of the state have the potential for at least a partial third generation of codling moths. This can be particularly important on your late varieties, since you may have put your sprayer away several weeks earlier. In an unusually hot year like 1999, the potential exists for a third generation of codling moths throughout the state. Some growers in central Indiana are catching third generation moths in their pheromone traps. I advise all growers to have traps active so that they know if third generation moths are flying in your area of the state. If you catch the moths, accumulate degree-days just as you would for the first or second generations. Proper timing for a spray would be at approximately 250 degree-days. However, with these sprays you also have to consider the preharvest interval (PHI). The PHI for Imidan and Guthion on apples is 7 days. If the PHI is going to be a problem with a particular variety, I would suggest applying the insecticide early (before reaching 250 degree days). Applying early may mean that you donÕt have the maximum residue of insecticide present at egg hatch, but it will insure that you have met the legal requirements of the PHI and not have excessive residues on the fruit at harvest. -Foster Pinpoint Scab: Even though it has been dry, you never know when the rains may comeÉso, wet weather during the apple harvest period can lead to the development of pinpoint scab and other fruit infecting diseases such as sooty blotch and fly speck. Pinpoint scab can infect fruit up to and during the harvest period if wet weather persists at this time, however, the symptoms of pinpoint scab may not show up until the fruit have been stored for several months. Late season apple scab can also build up on leaves after harvest, resulting in large quantities of primary scab spores the following season, even though a good spray program was followed early this year. Help prevent such problems by maintaining scab fungicides in late cover sprays; also do not stop cover sprays too early. Check the label for days-to-harvest restrictions before making the final application. -Pecknold Collar Rot: Late summer is a good time to inspect trees for above-ground symptoms of collar rot. Look for weak trees with premature leaf reddening (especially on goldens); sparse, yellow foliage; and many small, highly colored fruit. Keep in mind that such symptoms are general stress symptoms that may be caused by a number of factors, e.g. wet feet, mouse injury, trunk decay, root rot, etc. However, trees that show the above-described symptoms and also have a canker at or just below ground level are likely infected with collar rot. If collar rot is suspected we advise the use of Ridomil 2E in the fall after harvest. Apply Ridomil as soon as possible after harvest so it will be in place before the fall rainy periods begin and possible new infections occur. Also be sure to concentrate your Ridomil treatment on surrounding healthy appearing trees, not just trees already showing severe symptoms of collar rot. Ridomil is best used to prevent collar rotÉ. not cure it. -Pecknold Soil Management and Cover Crops: Fall is a good time for cultivating fields, adding lime and fertilizer, and planting cover crops in fruit plantings. Cover crops can be an integral part of the orchard floor management plan. If you plan on establishing new orchards or vineyards next year, you should consider a pre-plant soil management program which includes deep subsoiling, soil pH adjustment and addition of fertilizer, especially P and K, according to soil test recommendations, and planting cover crops. Cover cropping a site the year before planting is an excellent way to increase organic matter and reduce weed problems. Several cover crops are available for fall planting, and mid to late September is the time to plant in most areas of the state. A favorite among growers is winter rye because it performs very well under Indiana conditions. Rye not only adds large amounts of organic matter to the soil, but also suppresses the development of many annual and perennial weeds. There are several other cover crops and the choice depends on the growerÕs specific preferences and needs. -Bordelon Perennial Weed Control: Late summer and fall is an excellent time to control troublesome perennial weeds by spot spraying with suitable herbicides. Perennial weeds tend to become established within the rows in fruit plantings because they are not fully controlled by the normal weed management program. Once established, these plants can be difficult to eliminate. Glyphosate (e.g. Roundup) is a particularly good herbicide for controlling perennial weeds in the fall. As perennial plants begin to slow growth and harden off for winter, carbohydrates are translocated to the roots for storage. Fall applied systemic herbicides will be similarly transported to the root system which leads to excellent control. Fall application works equally well on hard to control herbaceous perennial weeds such as thistle, dock, smartweed, and morning glory, as well as woody perennials such as poison ivy, Virginia creeper, multiflora rose, mulberry, blackberry and so on. The plants do not have to be actively growing for good results but should have sufficient active leaf area to take up the herbicide. Check the manufacturerÕs product label for specific recommendations. NOTE: Desirable crop plants are also translocating carbohydrates to the roots and can be severely injured by fall applied systemic herbicides. Be extra careful when spot treating to AVOID ANY CONTACT with desirable plants. -Bordelon Fall Weed Management: Fall is a good time to do a weed survey and determine the weed problems in your plantings. This information can be used to tailor your weed management plan. There are several advantages to fall applications of pre-emergent herbicides in fruit crops. Dry soil conditions in the fall allow for equipment travel without compaction, weather conditions are more stable giving the grower greater flexibility in application times, and there is less likelihood of heavy rains to cause runoff. Fall applications provide control of winter annual weeds and can eliminate the need for a post emergent herbicide application the following spring. Though weed control from fall applications can last shorter into the following growing season than spring applications, a split application can help eliminate this problem. Several herbicides registered for use on fruit crops have a recommendation for fall or fall/spring split applications. Materials such as Surflan, Devrinol, Princep, Karmex and Kerb perform well in fall or fall/spring split applications. See ID-168 and ID-169 for complete weed control recommendations. -Bordelon Subscribing electronically: To subscribe (or unsubscribe) to Facts for Fancy Fruit, send a message to fff@lists.hort.purdue.edu with the subject or body ÒsubscribeÓ (or ÒunsubscribeÓ). You can also use the form at the web site http://www.hort.purdue.edu/fff/mailinglist.html to submit your subscription. Electronic access is free of charge. Coming Meetings: October 21, 1999 - The Second Annual Pawpaw Field Day. Kentucky State University Research Farm, Frankfort, KY. Contact Kirk Pomper at 502-227-5942 or kpomper@gymail.kysu.edu. Check out the website at www.pawpaw.kysu.edu October 23, 1999 - Kentucky Vineyard SocietyÕs annual meeting. MakerÕs Mark Conference Center, Loretto, KY/ Contact Mitchell Wagner at 502-459-6958 or mitch@kort.com November 3-4, 1999 - Southeast Strawberry Expo. McKimmon center, Raleigh, NC Contact the North Carolina Strawberry Association at 919-542-3687 November 8-9, 1999 - MSU Blueberry School. Kellogg Biological Station, Hickory Corners, MI. Contact Eric Hanson 517-355-2261 or hansone@pilot.msu.edu November 10-11, 1999 - National Blueberry Conference & Exposition & MBG Annual Meeting and Awards Banquet. Grand Rapids, MI. Contact MBG at 616-434-6791 or 800-367-7292 or www.blueberries.com January 3-4, 2000 - KSHS/KVGA Annual Meeting and Trade Show. Holiday Inn North, Lexington, KY January 16-20, 2000 - 5th International Symposium on Cool Climate Viticulture and Enology. Melbourne, Australia. Contact the symposium secretary at ICMS Pty. Ltd., 84 Queensbridge St., Southbanc, VIC 3006 Australia. Phone: 61 3 9862 0244 or check out the website at www.icms.com.au/coolclimate January 24-26, 2000 - Indiana Horticultural Congress. AdamÕs Mark Hotel, Indianapolis. February 10-12, 2000 - North American FarmersÕ Direct Marketing Association meeting. Cincinnati, OH February 13-15, 2000 - Ohio Grape-Wine Short Course. Columbus, OH ---------------------------------------------------------------------------- Bruce Bordelon, 1165 Dept. of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907-1165, 317/494-1301, e-mail: bordelon@hort.purdue.edu Peter Hirst, 1165 Dept. of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907-1165, 317/494-1323, e-mail: hirst@hort.purdue.edu Paul Pecknold, 1155 Dept. of Botany & Plant Pathology, Purdue University, West Lafayette, IN 47907-1155, 317/494-4628, e-mail: Pecknold@btny.purdue.edu Rick Foster, 1158 Dept. of Entomology, Purdue University, West Lafayette, IN 47907-1158, 317/494-9572, e-mail: Rick_Foster@entm.purdue.edu Disclaimer: Reference to products in this publication is not an endorsement to the exclusion of others that may be similar. Any person using products listed in this newsletter assumes full responsibility for their use in accordance with current label directions of the manufacturer.