|
Illinois Fruit and Vegetable News:A Newsletter for Commercial Growers of Fruit and Vegetable Crops Vol. 15, No. 3, April 17, 2009 |
"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. In This Issue:Upcoming Programs (Illinois Tree Nut Association spring meeting; Illinois Summer Horticulture Day; 2009 Sustainable Ag tours)) Regional Updates (from Elizabeth Wahle, Bronwyn Aly and Jeff Kindhart, and Maurice Ogutu) Notes from Chris Doll (on fruit development stages, Apogee, and thinning) Fruit Production and Pest Management (winter injury in northern IL grapes; notes on tree fruit insecticides and insects) Vegetable Production and Pest Management (early-season vegetable insect pests) University of Illinois Extension Specialists in Fruit & Vegetable Production & Pest Management Upcoming Programs
Regional UpdatesIn southwestern Illinois, for the most part it has remained wet and cool, and we had a "hold your breath" moment at the end of last month when overnight temperatures dropped just below freezing two nights in a row. Although peach stage ranged from full boom to shuck split, apple from bud burst to tight cluster, cherry from swollen bud to bloom, no significant damage to crop potential has been identified yet. Since then, there have been a few other nights just below freezing, resulting in many peach growers delaying or foregoing bloom thinning. Spring so far has been running below average in temperature, so bloom periods have been really extended. It's not unusual this year to see a peach tree in full bloom for several weeks or to see an apple branch with multiple blooms in all stages; from pink all the way to petal fall. Scab and fire blight in apples should be on grower's minds now. When a fire blight infection period is predicted, strep sprays need to go on before a rain event, and if that doesn't happen, within 24 hours after the beginning of the rain event. Apogee is an option for reducing twig blight infection, and the initial application to susceptible and vigorous cultivars should be timed for petal fall of king bloom. Remember tree foliage is necessary for good uptake and it takes about 10 days for shoot extension growth to slow. The effect will last 2 to 4 weeks, and subsequent applications should be made when first few shoots show sign of re-growth. A potential negative side effect is a significant increase in fruit set and a corresponding decrease in fruit size, requiring a more aggressive thinning program by increasing thinner rate 5 to 10%. There should be at least a 2- to 4-day interval between application of Apogee and application of chemical thinners. For traditionally difficult varieties to thin -- such as Fuji, Golden Delicious, Lodi, Rome, and Wealthy -- plan to thin early (petal fall to 7mm) to allow time for follow-up sprays if necessary. For moderate to heavy thinning of difficult varieties, the first thinning spray could be applied at petal fall using Sevin (1 lb) + spray oil (1 qt) per 100 gallon dilute. Follow that with a combination spray at 7mm-12mm if needed. For moderate thinning, consider Sevin plus NAA or Sevin plus 6BA. For heavy thinning, consider combining Sevin with 6BA and spray oil. A few reminders about NAA ... high rates and later timing increase the risk of pigmy fruit for Delicious, Fuji, and Gala. Do not apply NAA and BA to the same trees of Delicious or Fiji, or excessive formation of pygmy fruit may result. See the 2009 Midwest Tree Fruit Spray Guide for Commercial Growers athttp://www.extension.iastate.edu/Publications/PM1282.pdf for additional recommendations, or for a more detailed discussion see the Pennsylvania Tree Fruit Production Guide http://www.extension.iastate.edu/Publications/PM1282.pdf On the vegetable production side, some emerged early planted sweet corn was nipped by freezing temperatures, but additional plantings followed soon after. Horseradish harvest is ongoing. Elizabeth Wahle (618-692-9434; wahle@illinois.edu) At the Dixon Springs Agricultural Center, nearby growers anxiously await drier field conditions to prepare ground and plant sweet corn. High tunnel and low tunnel tomatoes have been planted and are off and growing. At DSAC, we have planted tomatoes and are protecting them with hot caps, cage cloches, and a low tunnel. We are looking to see if there is any significant difference in these three "low tech" methods of early production.
Plasticulture strawberry plants sent for viral analysis at Agdia came back negative, and at this point the crop looks exceptional for much of southern Illinois. These plants have spent a great deal of time under the row covers this spring, as threats of frost have been very common. Growers need to remember to continue to apply nitrogen through the drip system to these plantings.
Matted row strawberry plantings are beginning to bloom, and there has been some loss to frost on early varieties that are on sites that warm early in the spring. In general, the matted row strawberries also still look like they have great potential for the 2009 season. Blueberry, blackberry, apple, and peach plantings in southern Illinois look good to excellent. The blueberry plantings at DSAC have a surprisingly high bloom count based on the fact that last year was also a bumper crop. Bronwyn Aly & Jeff Kindhart (618-695-2444; baly@illinois.edu, jkindhar@illinois.edu) In northern Illinois, day temperatures in the low 40s to mid 50s and night temperatures in the upper 20s to mid 30s have characterized early through mid April. The ground is still wet in most of the region, limiting field operations. Pruning and training of small fruits and tree fruits continues, and most apples were at silver tip to green tip on April 15. Maurice Ogutu (708-352-0109; ogutu@illinois.edu) Notes from Chris DollCool temperatures and saturated soils tell most of the story in SW Illinois at this time. What began as a fairly early spring and some early bloom of tree fruits has turned into a cool and wet spring, with plant development a little behind "normal." In the last 21 days, there were no 70-degree temperatures, 13 days with minimums in the 30's, three days with maximums in the mid 40's, and 3.7 inches of rain. Most field work is at a standstill.
As soon as the peach set is determined, the rest of the fertilizer can be applied. Chris Doll Fruit Production and Pest ManagementWinter Injury in Northern Illinois GrapesThe winter of 08-09 will probably be remembered in northern Illinois as a persistently cold one that helped us sort out which grape varieties should be planted here. On January 16 and the following couple of nights, temperatures bottomed out at levels that were colder than the previous 5-10 winters. In northeastern Illinois, most rural sites were below minus 20oF, and some were colder than minus 30oF. Actual temperatures in vineyards may have differed from nearby weather stations in the rolling hills of northwestern Illinois, as cold air settled in low areas. Fortunately, the vines were conditioned to be in full dormancy by the gradual development of cold temperatures. Dormant plants will respond to slowly lowering temperatures by descending into full dormancy. Each variety has its limitations though. It is not unusual for tender hybrids to be hardier than European grapes but to be injured by temperatures in the -15 to -20oF range. The popular cultivars Chambourcin and Chardonel are examples of such hybrids. Hardier hybrids may be able to withstand much colder temperatures. The varieties coming from Minnesota's breeding program or the private breeder Elmer Swenson of Eau Claire, WI, may be able to withstand temperatures that drop to -35 to -40oF. Even some French hybrids, such as Marechal Foch, can take temperatures colder than -30oF if conditioned properly. Unfortunately, many vineyards in northern Illinois may not have been conditioned properly last winter. This isn't necessarily due to poor management. Last season was a very challenging season. We were generally low on heat units across northern Illinois because of prevailing cloudy, wet conditions. The frequent rainfall led to high disease pressure. Also, an unusually challenging infestation of Japanese beetles led to vegetative canopies being ravaged. All of this led to low levels of photosynthesis and reduced energy available to the vine for storage into winter. This could have been exacerbated in some vineyards by excessive crop loads, and by the fact that the previous growing season had similar conditions. Being aware of the relative strength of vines and their limitations will be a key to growing grapes in the northern part of Illinois. Brad Taylor of SIU and I are collecting dormant cane material from different vineyards in Illinois to determine the bud survival rates in those varieties. More information on this will come later.
Growers were busily pruning vineyards in late March and early April, and many have now finished, and the process of pruning should reveal winter damage. Many canes hanging from cordons may have a gray, desiccated appearance. They may feel soft and light, and when cutting through while pruning, they will show no green color in the cambium layer just below the thin bark. These are canes that have died back. Some dieback is normal at the tips of canes where wood is thin. Where the wood is pencil-sized in thickness it should survive if the variety's minimum cold tolerance is not exceeded. If canes of good thickness are not showing good green color in the cambium layer, the vine has suffered dieback, either due to excessive cold or lack of energy, or both. This season may have been a watershed for determining variety suitability in Illinois, particularly in the north. Growers should record the extent of damage they experienced in each variety they grow and assess the reason for the damage. If management led to vines that were in less than optimal condition, then corrective measures should be taken. Vine health is critical to the long-term investment in a vineyard. If management was optimal or at least suitable, and vines had sufficient energy going into the fall, growers should consider the possibility that the variety is not appropriate for their site. There is no area of Illinois where suitable wine grape varieties cannot be grown. However, every area of Illinois can serve as a site for making poor variety choices. Mother Nature will be the judge. Growers with damaged vines will need to make decisions about the future for those varieties. If the varieties are suitable, the growers will need to rehabilitate vines. Next issue will have some discussion on bringing vines back into optimal health. Bill Shoemaker (630-584-7254, wshoemak@illinois.edu) Notes on Tree Fruit Insects
(Rick Weinzierl; 217-244-2126; weinzier@uiuc.edu) Vegetable Production and Pest ManagementVegetable Insect ManagementRepeating a note from late April last year (history may not repeat itself, but one can sure hear echoes) ... Cold weather so far has meant little to write about insect development or problems. Some creatures to be on the lookout for as temps rise and planting and transplanting finally ramp up include seed and root maggots in cool soils, asparagus beetle and cutworms on asparagus spears, Colorado potato beetle on potatoes and other nightshades, and several flea beetle species on a variety of vegetable crops. Background information on these insects is available by "googling" them on the web and in the book Vegetable Insect Management, edited by Rick Foster and Brian Flood (Meister Media, Willoughby, OH; http://www.meisterpro.com/vim/. Brief sampling and threshold information, along with listings of insecticides registered for the control of these insects, are presented in the Midwest Vegetable Production Guide, available on-line at http://btny.purdue.edu/Pubs/ID/ID-56/. Illustrations of a few of the insects mentioned above (and credits to their sources):
(Rick Weinzierl; 217-244-2126; weinzier@uiuc.edu) Less seriouslyFrom Practical Orcharding on Rough Lands, 1911, forwarded by Chris Doll. (And by the way, the things they sprayed in 1911 pretty certainly would not pass EPA muster almost 100 years later in 2009.) If we have the scale from San Jose, or other pest, be what it may ... While we laze around they're feedin'; while we're swearin' they're a breedin'; plenty poison's what we're needin' ... Lay a stock of Paris Green in; don't forget the kerosenin' ... Into crevices go huntin'; stop the hoppers cheerful jumpin'; what we've got to do is pumpin' ... Pupa, nymphs, and millers; fungi mixed with caterpillars ... Be they plump or thin or flaccid; bring to bear on them the acid ... University of Illinois Extension Specialists in Fruit and Vegetable Production & Pest Management
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
 Integrated Pest Management College of Agricultural, Consumer and Environmental Sciences Crop Sciences | Entomology Natural Resources & Environmental Sciences Illinois Natural History Survey |
|
| Illinois Fruit and Vegetable News Copyright © 2004 University of Illinois at Urbana-Champaign |
||
