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Illinois Fruit and Vegetable News:A Newsletter for Commercial Growers of Fruit and Vegetable Crops Vol. 11 , No. 3, March 18, 2005 |
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"We are what we repeatedly do. Excellence, then, is not an act, but a habit." --Aristotle Address any questions or comments regarding this newsletter to the individual authors listed after each article or to its editor, Rick Weinzierl, 217-333-6651, weinzier@uiuc.edu. To receive email notification of new postings of this newsletter, call or write the same number or address. This issue's words of wisdom ... which usually means the jokes ... are at the end of newsletter ... check the last page. In This Issue:Crop Reports and Regional Reports (from Elizabeth Wahle and Maurice Ogutu) Upcoming Meetings and Programs Notes from Chris Doll (spring temperatures, flower bud set and survival, planting new trees, notes on the Small Fruit and Strawberry School, apple cultivars) Degree-Days (a warm winter but a slow spring) Notes from Chris Doll (Wet weather, phenology, thinning, codling moth, and temperature trends) Vegetable Production and Pest Management (winter temperatures and corn flea beetles / Stewart's wilt, sweet corn hybrid observations from Dixon Springs) Fruit Production and Pest Management (new fungicides for small fruit crops, pheromone traps for fruit insects) University of Illinois Extension Specialists in Fruit & Vegetable Production & Pest Management Crop and Regional ReportsIn southern and southwestern Illinois, Field prep is underway throughout the southern region, and pruning of fruit trees continues. Temperatures have been all over the board--well above, well below, and sometimes right at the average temperature. Some of the early spring flowers have been tip burned by frost. Temperatures hovered around 20 degrees F in the St. Louis area on Sunday evening, March 13, but the next few days warmed up a bit--lows hover right around freezing with daytime highs in the 40s up to the 60s. Be sure to check the list of upcoming programs on the next page... twilight meetings, orchard tours, and viticulture workshops have been scheduled at various locations in or near the southern region. Elizabeth Wahle (618-692-9434; wahle@uiuc.edu) In northern Illinois, day temperatures in the upper 20s to 50s, and night temperatures in the low teens to low 30s characterized the first half of March. The area recorded unusually high temperatures on March 6, with highs in the 60s to low 70s. The region received about 0.2-0.3 inches of rainfall, and 0.6-3.0 inches of snow in early March. Pruning of brambles, grapes, and tree fruits is ongoing. Maurice Ogutu (708-352-0109; ogutu@uiuc.edu) Upcoming Meetings and ProgramsHere are a few dates to add to your calendar. Additional details for programs in the southern region will be posted as they become available at http://web.extension.uiuc.edu/regions/hort/ Contact: Elizabeth Wahle at wahle@uiuc.edu or 618-692-9434 April 9, 2005. Viticulture Workshop April 14, 2005. Twilight Meeting for Tree Fruit Growers May 13, 2005. Mississippi Valley Peach Orchard Tour (Kentucky's year to host, Illinois was last year) May 21, 2005. Viticulture Workshop May 26, 2005. Twilight Meeting for Tree Fruit Growers June 16, 2005. ISHS Summer Orchard Day June 25, Viticulture Workshop Elizabeth Wahle (618-692-9434; wahle@uiuc.edu) Notes from Chris DollWhat began as a potentially very early spring has now evolved into maybe a "normal" spring. March has been relatively cool, and recent days have seen lows near freezing. As a result, peach and apple buds show only slight swelling, and the early bloom of pussy willow has not gone much further. Chris Eckert has reported that green tip apple sprays were applied on March 16, 2004, and the Back 40 was sprayed on the 18th. We are both ready to spray when needed. My records show that the 1/2-inch green dates in recent years were 3/31/04, 3/25/03, 4/9/02 and 4/7/01. The rest period is over and the next warm spell will result in rapid bud growth. Several blocks of dwarfed apples were inspected during the past week, and flower bud set is excellent. M9 and B9 really induce flower bud set. For the more vigorous larger trees, the set is affected by last years crop and weather. Reports continue to come in about variable bud kill of peaches. Some blocks of Red Haven are 90 percent alive and others are nearly a total loss, with Loring in the same orchard showing enough live buds for a crop. The bud kill happened on January 17 at temps of 0 to +4, but only 5 days after a 70-degree day. Soil conditions have firmed and dried in March, and we have soils ready for planting. Early planting usually makes for optimum growth, especially if soil conditions are optimum. But I have seen mistakes from rushing the planting without proper soil preparation and tree placement at improper depth. Apple trees should be planted 1-2 inches deeper than grown in the nursery, and the bud union above the ground line far enough to prevent scion rooting in future years. Peach trees should be planted at near the same depth as they were in the nursery. Deep planting of peach trees can lead to trees failing to make brace roots for anchorage and therefore the trees tend to wallow. It is the time of the year that some branching induction attempts can be made on young, vigorous shoots of apple trees, especially varieties like Reds, Granny Smith and Fuji. Bud notching, the art of using a sharp knife to slice into the xylem just above a bud on a long (18-36 inch) shoot, is done sometime ahead of bud break. The second method is mix Promalin at 0.3 pint to 1.0 pint of latex paint with one percent nonionic wetting agent (Pennsylvania Tree Fruit Production Guide, page 46) and apply to one-year old shoots where branching is needed. Use a brush or sponge and time it when terminal buds begin to swell. Thornless blackberries need to be pruned and tied as soon as possible to avoid breaking off many of the emerging buds which will develop into the flowering shoots. The same reason is why grapes are pruned early, as the emerging grape buds are very easily knocked off. A few notes from the 2005 Illinois Small Fruit and Strawberry School are in order. An excellent Proceedings was published that included articles on blackberries, blueberries and plasticulture strawberries among others on varieties. It should be available from Bronwyn Aly at the Dixon Springs Agr. Center if she is contacted at baly@uiuc.edu. Dr. Barclay Poling of North Carolina said that good plastic laying is very important for success, as is freeze and frost control. Dr. John Strang of Kentucky described their trellising system for thornless blackberries and the use of Osmocote 15-9-12 for fertilizing blueberries. Our Dr. Elizabeth Wahle laid out the essentials for planting blueberries in Illinois, and Dr. Bob Skirvin of Illinois has included write-ups of varieties of strawberries, brambles, and grapes. The strawberry variety list includes Earliglow and Honeoye, which have been grown since 1975 and 1979 respectively. Apple variety enthusiasts should be interested in an article in the Journal of the American Pomological Society (Volume 59, Number 1, January 2005), titled "Performance of Apple Cultivars in the 1995 Ne-183 Regional Project Planting: III. Fruit Sensory Characteristics" (pages 28-43). It summarizes the work of 10 researchers across the U. S. and Canada on sensory scores and fruit appearance of 19 varieties. Under crispness, Creston was first, followed by Honeycrisp and Goldrush. For juiciness, Creston, Honeycrisp, and Shizuka were followed by Ginger Gold and Fuji Red Sport #2. Sweetness awards were taken by Orin and Fuji Red Sport #2, with Gold Rush being last. Honors for appearance tended toward Enterprise and Golden Supreme. However, the conclusion was that "no single cultivar developed superior sensory qualities across all sites." Chris Doll Degree-Day Accumulations
Average winter temperatures for 2004-05 were higher than they were last year and were warmer than normal. However, we are considerably behind in degree-day accumulations compared to one year ago. How is that possible you might ask? Temperatures in March thus far have been 2 to 6 degrees below normal across the state (Figure 1). Degree-day accumulations from January 1 through mid-March of 2004 and 2005 are compared in Table 1. Throughout the growing season you can check on degree-day accumulations on insects and growing degree-days for crops at the Degree-Day Calculator (www.ipm.uiuc.edu/degreedays).
The degree-day calculator is an internet tool developed to assist Illinois producers in making pest management decisions using pest development models and Illinois climate data. A collaborative effort between the Integrated Pest Management program (Department of Crop Sciences, University of Illinois) and the Illinois State Water Survey (Illinois Department of Natural Resources), the degree-day calculator provides users with the ability to determine degree-day accumulations for specific pests of field crops, fruits, and vegetables in Illinois. The calculator tracks and projects the growth of insect pests and crops in Illinois. It is designed to help the user determine when to monitor for specific insect stages that may be approaching in their region and aid in subsequent management decisions. Just as importantly, it provides this information in an up-to-date format that is designed to be user-friendly. Currently, degree-day calculations can be generated for 30 different insects at each of 19 weather sites. The degree-day calculator can also generate contour maps for specific insects and base temperatures. If the user wants to compare degree-day accumulations between different locations, the map function affords them this option. Whether determining degree-days at one site or creating a contour map, both of these functions can project degree-day accumulations one and two weeks into the future. Information is also provided to describe the relationship between insect developmental stages and degree-day accumulations as well as a background section on how degree-days are calculated. Additional information on the insects life cycle, potential injury, scouting procedures, and management can be found via a link to an insect fact sheet on the IPM web site. During the course of the spring and summer, we will make reference to degree-days and approaching insect stages. We hope that you too take advantage of this tool and use it to stay on top of developing insect problems. Kelly Cook (217-333-4424; kcook8@uiuc.edu) Vegetable Production and Pest ManagementWinter Temperatures and Corn Flea Beetle
Average winter temperatures for December through February in Illinois were approximately five degrees warmer than they were a year ago. These warmer winter temperatures favored increased survivorship of the corn flea beetle and the disease-causing bacteria it vectors. Corn flea beetles are the primary vector of Erwinia stewartii, the bacterium that causes Stewart's wilt of corn. The bacterium survives the winter in the gut of the corn flea beetle, and survival of the corn flea beetle is dependent on winter temperatures. Warmer winters result in greater survivorship of corn flea beetles, thus increasing the potential for Stewart's wilt. Using the average temperature of December, January, and February, the potential of Stewart's wilt can be predicted (Table 2).
Corn flea beetles become active in the spring when temperatures rise above 65°F. ;They feed on and transmit E. stewartii to seedling corn plants. The bacterium can spread systemically throughout the plant. Although most commercial field corn hybrids are resistant to Stewart's wilt, the disease is still a concern for susceptible seed corn inbreds and sweet corn hybrids. There are two phases of Stewart's wilt, the seedling wilt phase and the leaf blight phase. The seedling wilt stage occurs when seedlings become infected at or before the V5 stage. The growing point is easily infected. The vascular system becomes plugged with bacteria, causing the seedling to wilt, become stunted, and die. Infections of older corn plants usually result in the development of the leaf blight phase of Stewart's wilt. This phase is characterized by long, yellow to chlorotic streaks with wavy margins along the leaves. The late infection phase or "leaf blight phase" of Stewart's wilt occurs after tasseling and is generally not a concern in sweet corn because ears are harvested before damage occurs. Based on the recent winter temperatures from the Midwest Regional Climate Center, estimates of early season Stewart=s wilt are shown in Table 3. Remember, however, that these are only predictions; numbers of surviving corn flea beetles are not known. More information on the corn flea beetle and Stewart's wilt can be found on a new corn flea beetle fact sheet (http://www.ipm.uiuc.edu/vegetables/insects/corn_flea_beetle.pdf) and the sweet corn disease nursery website (http://sweetcorn.uiuc.edu/stewarts.html).
Kelly Cook (217-333-4424; kcook8@uiuc.edu) Sweet Corn Observation Trial: Extra-Tender and Super Sweet Hybrids In the spring of 2004, an extra-tender, super sweet sweet corn observation trial was established at the Dixon Springs Agricultural Center (DSAC). For this project, 10 different varieties, yellow, white, and bi-color, were evaluated for fruit qualities including ear size, weight, and tip fill. The corn was planted on May 21, 2004, using a Monasem planter with in-row spacing of 8 inches and between-row spacing of 30 inches, giving an estimated plant population of 26,000 plants per acre. Herbicide was also applied on May 21, 2004. One-inch seedling emergence was observed seven days later on May 28, 2004. Rows were side-dressed with ammonium nitrate (34-0-0) on June 4, 2004, and again on July 9, 2004. The second fertilizer application was needed because of excessive rainfall in June, and plants looked pale and somewhat stunted. Not only did this field receive excessive rainfall after planting, but no further irrigation was used later in the growing season. Deer and raccoon depredation was observed the week of harvest. Corn was harvested on August 6, 2004, and results are listed in Table 4 in the order they were harvested from the field. Table 5 lists the approximate yield per acre for each variety based on a plant population of 23,000 plants per acre.
Bronwyn Aly (618-695-2444; baly@uiuc.edu) Southern Illinois Pheromone Trap Data for Field Crop and Vegetable LepidopteraRon Hines of the University of Illinois Dixon Springs Ag Center maintains pheromone traps for several field crop / vegetable insects and posts weekly counts on his web site, "The Hines Report," on the University of Illinois Department of Crop Sciences IPM site at http://www.ipm.uiuc.edu/pubs/hines_report/comments.html. Fruit Production and Pest ManagementPheromone Traps for Fruit InsectsThis lengthy summary will look a lot like one from this newsletter in March of 2004 ... and 2003 for that matter. It must be that time of year again ... For apple, peach, and grape growers, NOW is the time to order pheromone traps for key insects if you've not already done so. Although traps are available and useful for monitoring many insects of fruit crops, the ones listed in the table that follows are probably the most important for most Illinois fruit growers. Other pests that may be worth monitoring with traps include dogwood borer, spotted tentiform leafminer, redbanded leafroller, and obliquebanded leafroller in apples and peachtree borer in peaches. Contact me if you want more information on these insects. What kind of traps should I use? A few companies manufacture traps, and all have a similar range of designs. Trece is still the best known, so I'm using their models as examples, but there=s no reason not to use other traps as long as they are pretty much identical in shape and size, and the lesser-known competitors may provide equal quality for a lower price. The standard sticky trap for most orchard insects has been the Pherocon IC. The inside surface of the bottom - the "floor" of the trap - is coated with stickum or tanglefoot, and the bottom hangs from the top by wires. Spacers on the wires hold the bottom slightly below the top or roof so that there is an opening all along the sides as well as the ends of the IC trap. Although this trap has been used for monitoring flights of most orchard insects, a slightly different trap, Trece's Pherocon ICP, was recommended most often for several years for codling moth trapping. Although the trap top is the same as the one used for the IC, the bottom of the ICP trap is slightly smaller than the IC bottom, and it is attached without spacers so that it slides under the sides of the trap top, leaving a closed trap except for the ends. The ICP trap (or an identical model from other suppliers) is the one I used for several years to monitor codling moth flights around Illinois. A few years ago, Trece began selling a new trap, the Pherocon VI, and it differs from the other two described above primarily in that it=s quick to set up (the user doesn't have to assemble the top and bottom with wires), and it uses a separate sticky bottom or "liner" that slides in and out. Its main benefit is that it is MUCH faster to change sticky liners on this trap than it is to change the bottoms of the IC or ICP. I compared these three traps at the University of Illinois orchards in 2002 and found no difference in how many codling moths they captured over the season as a whole. The IC bottoms caught more extraneous things (insects and debris) than the other two, but otherwise there was no difference in their performance. I find the Pherocon VI to be so much easier and faster to handle than the others, so I recommend using it (or a similar trap from another manufacturer) for monitoring codling moth, Oriental fruit moth, grape berry moth, lesser peachtree borer, leafrollers, etc.
What attracts moths to traps? For all the moths typically monitored using sticky pheromone traps, the trap must be baited with a pheromone lure - usually a small piece of rubber or plastic containing a synthetic blend of chemicals that is very similar to compounds used by female moths to attract males. When traps capture male moths, that serves as an indication that females are also present, and mating and egg-laying are occurring. When you order pheromone traps, you also must order lures for the specific insect(s) you wish to monitor. (Sometimes you may order "kits" that come with a combination of traps and enough extra sticky liners and lures to last the season.) Remember that although you may use the same type of trap to monitor different pests, you must use only a single lure per trap ... it does not work to put lures for codling moth and tufted apple bud moth in the same trap. Depending on the pest species, lures usually last 2 to 8 weeks (suppliers can tell you the effective life of the lures they sell), so you have to order enough lures to last through the whole season. What about apple maggot? For apple growers in the northern half of Illinois, monitoring the flight of apple maggot flies also is necessary. Traps for apple maggot flies rely on appearance (the color and shape of a bright red apple) and the use of a food odor ("apple volatiles") instead of a pheromone, and they are designed to capture female apple maggot flies ready to lay eggs on fruit. All the major suppliers of insect traps carry these kinds of traps. Growers should order the red spheres, tubes or tubs of stickum or tanglefoot, and the food lures recommended by the supplier. Apple maggot traps may be used without any food lures; counts are interpreted accordingly.
How many traps should I use? There are no precise answers, but in general, for the moths that are pests in Midwest fruit crops, use 2 to 3 pheromone traps per pest species per each block of trees or vineyard up to 15 acres in size. Guidelines often recommend at least 3 traps per pest species for any orchard up to 15 acres in size and 1more trap for every 3 to 5 acres above 15. To monitor 50 acres of trees in 3 or 4 separate blocks, use at least 3 traps per block and at least 9-10 traps total. Always use at least 3 apple maggot traps (red spheres) per block of trees. See the table below regarding placement of traps. If you have only one block of trees, you may want to order 3-trap "kits" that suppliers package for each of the major pests. Kits with "standard" lures will include 3 lures per trap, but because the lures for most will have to be replaced every 4 weeks. most Illinois growers will need yet another 2 extra lures per pest species per trap to get through the entire season. Suppliers also sell these extra lures and extra "liners" (the sticky trapping surface) for traps. If you operate an orchard larger than 20 to 30 acres, you'll need more traps; don't "mess with" 3-trap kits; contact the suppliers and make plans to order supplies in bulk. "Long-life" lures are available for the codling moth and the Oriental fruit moth (and some other species) ... these lures last 8 weeks between changes and are the best choice for almost all Illinois growers. Apple growers in southern Illinois ... a few years ago we saw some problems with tufted apple bud moth in orchards treated pretty much exclusively with organophosphates. With greater reliance on alternative chemistries in recent years, this pest has not reached outbreak levels in any Illinois orchards in the last 3-4 years (to my knowledge), but I'm including it in the table on the next page because it still warrants attention in some orchards. Pheromone trapping guidelines
Suppliers of pheromone traps include:
Rick Weinzierl (217-333-6651; weinzier@uiuc.edu) New Fungicides Registered for Use on Vegetable and Small Fruit Crops
Mohammad Babadoost (217-333-1523; babadoos@uiuc.edu) This issue's words of wisdom ...Cowboy in distress A drunken cowboy lay sprawled across three entire seats in the posh Amarillo Theater. When the usher came by and noticed this, he whispered to the cowboy, "Sorry, sir, but you're only allowed one seat." The cowboy groaned but didn't budge. The usher became more impatient: "Sir, if you don't get up from there I'm going to have to call the manager." Once again, the cowboy just groaned. The usher marched briskly back up the aisle, and in a moment he returned with the manager. Together the two of them tried repeatedly to move the cowboy, but with no success. Finally they summoned the police. The Texas Ranger surveyed the situation briefly then asked, "All right buddy, what's your name?" "Sam," the cowboy moaned. "Where ya from, Sam?" asked the Ranger. With terrible pain in his voice, and without moving a muscle, Sam replied, "... the balcony." University of Illinois Extension Specialists in Fruit and Vegetable Production & Pest Management
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 Integrated Pest Management College of Agricultural, Consumer and Environmental Sciences Crop Sciences | Entomology Natural Resources & Environmental Sciences Illinois Natural History Survey |
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| Illinois Fruit and Vegetable News Copyright © 2004 University of Illinois at Urbana-Champaign |
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