|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
![]() |
The New Agriculture Network's on-line newsletter with seasonal advice for field crop and vegetable growers interested in organic agriculture.
Next issue will be posted August 23, 2006. Read previous issues through our calendar of issues.Canola: An oilseed for organic and sustainable crop rotations? Sieg Snapp and Russell Freed There has been new interest recently in an old oilseed crop, canola. Canola was developed by Canadian plant breeders that made selections from rapeseed that had low erucic acid and glucosinolate levels – less than 2% erucic acid and less than 30 micro-moles of glucosinolate in the meal. As a member of the Brassica family, canola could be an important crop to help diversify our region’s agriculture, complement our cropping systems, and maintain a vibrant rural sector. Canola has tremendous potential to have an impact on our economic, health, environment and agricultural systems. Some of canola’s attributes are: |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
One of the challenges of producing alternative crops is identifying a secure market. There is a small and volatile organic canola market and increasing interest in growing canola as a potential component of biodiesel (In Europe there are biodiesel plants that process canola oil, but this market is not yet developed in the United States). The export and domestic demand for canola is not consistent and attention to marketing is important. Canola will provide diversity in terms of flowers, plant residues with unique biochemical compounds and reduced host potential for many plant parasitic nematodes. Another attribute of Brassica family plants often discussed is the potential for bio-fumigation. Many Brassica species such as mustards produce chemical compounds in the roots and leaves, which have biocide effects that inhibit soil-borne diseases. If managed as a green manure crop, where green residues are chopped and incorporated, then a mustard or oilseed radish may improve the root health of subsequently grown cash crops. For more information, see the recent MSU Extension bulletin: Snapp, S.S. K. Date, K. Cichy and K. ONeil. 2006. Mustards: A Brassica Cover Crop for Michigan. Michigan State University Extension Bulletin E2956. It is important to realize that canola grown in a crop rotation is not expected to have the same effects as a mustard grown as a green manure or cover crop. The glucosinolates have been bred out of the canola varieties; these are the plant biochemical compounds that have biofumigation effects. Also, growing a crop to maturity and removing the seed will leave older residues and roots that may have minimal effects on soil organisms compared to incorporating a fresh, green vegetative cover crop. However, canola will provide very different types of root inputs than other plant families such as legumes (soybean, dry bean) and grasses (corn, wheat, oats), and crop diversification promotes a healthy soil community. Canola production
Wet and poorly drained soils are not suitable for production of canola and this is a primary consideration in choosing a field for canola – there should be no standing water problems. It is also important to have no wild mustard weed infestation problems. For the seeding rate of a specific canola variety, check with the seed source. A general recommendation is to plant 5 to 7 lbs per acre with a drill used for planting small grains. Canola has a small seed and produces a small seedling that initially may be susceptible to weed competition, so a management strategy for pre-plant and pre-emerge control of weeds is important. Once canola is established, it has a broad leaf and will suppress many weeds. Pest problems are generally minimal although there are some potential disease and insect issues that are summarized by the Great Lakes Canola Association, at http://www.agry.purdue.edu/ext/canola/. A potential problem is Western Beet Yellows virus, which has the potential to be transferred between sugar beets and canola, so do not produce canola in sugar beet-producing areas. Canola can be combined directly by a small grain combine, at about 9 to 10 percent seed moisture. Generally, about 95 percent of the pods will have turned brown and seed in the pods will be black at maturity. Slow combine speed should be used to enhance seed cleanliness. To maintain high seed oil quality is important, and processors and market outlets should be consulted to learn of specific harvest or post-harvest storage recommendations. Resources A recent guide on organic production of canola was produced in Australia. For a copy of this review, type ‘Canola’ into the search engine at: www.dpi.vic.gov.au/dpi/nreninf.nsf. Note that the organic production method described is somewhat ‘substitution’ oriented, as organic mined sources of nutrients are described and limited information is provided on building soil fertility with cover crops. It was also developed for a drier climate than the upper Midwest as the annual rainfall is about 15 inches in the region of Australia where organic canola is primarily produced. |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| back to top |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
United States and regional supply of certified organic fruits and vegetables Jennifer Dennis and Corinne Alexander, Department of Agricultural Economics, |
According to the Nutrition Business Journal (2004), organic produce accounted for $4.3 billion in sales with fresh produce accounting for over 80% of sales. Organic fruits and vegetables continue to be the “gateway” products to organic purchases (Oberholtzer, Dimitri, and Greene, 2005) and one of the key contributors to the success of the organic movement. This article summarizes the currently available information on the United States and regional supply of certified organic fruit and vegetables. The USDA, Economic Research Service has published survey data on certified organic operations through 2003 (ERS, 2005). U.S. trends in certified organic fruit Regional trends in certified organic fruit
U.S. trends in certified organic vegetables Regional trends in certified organic vegetables
Conclusions References |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| back to top |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Key diseases in organically produced tomatoes: septoria leaf spot and early blight Margaret Tuttle McGrath, Cornell University (Editor’s note: This article was first published by IPM News at Cornell University.) |
Septoria leaf spot and early blight are the most common of several important foliar diseases affecting tomatoes grown in the northeastern United States. They are both caused by fungi that can be seed-borne, produce abundance of spores dispersed by wind or water, and can survive in soil thereby perpetuating on a farm once introduced. Their common occurrence even in small home gardens isolated from other tomatoes indicates the ease with which the fungi causing these diseases can be dispersed. Other important foliar diseases in the northeast are late blight, bacterial speck, bacterial spot, bacterial canker, leaf mold, powdery mildew, and tomato spotted wilt virus. Symptoms of both diseases are small, circular, dark brown to black leaf spots that first form on lower leaves. These spots can have yellow borders. Black leaf spots also develop with bacterial speck and spot, but these are more often on upper leaves when the disease starts to develop. Spots caused by Septoria lycopersici develop a characteristic gray center maintaining dark brown at the border, and they develop tiny black structures in the gray tissue that are visible with a hand lens. Water-dispersed spores ooze out of these black structures under humid conditions, which can be obtained by putting leaves on damp paper towel in a plastic bag over night. In contrast, leaf spots due to early blight become larger and often develop concentric rings that give these spots their characteristic target appearance. Tomato spotted wilt virus can also induce brown leaf spots with rings. Usually these plants will have other symptoms, including dieback of growing tips and brown discoloration on fruit. Dark, leathery, sunken spots sometimes with a velvety spore covering can develop on fruit of plants affected by early blight. Symptoms also develop on stems, petioles and fruit calyx with Septoria leaf spot and early blight. Collar rot can occur with early blight when stem lesions at ground level continue to enlarge causing plants to become girdled, resulting in death. Accurate diagnosis is critical with any disease so that appropriate management practices are implemented. Pictures are available at:
When uncontrolled under favorable conditions, both Septoria leaf spot and early blight can cause extensive death of leaves. Defoliation before fruit are mature results in fruit with poor flavor because sugar content is lower due to reduced photosynthesis. Also, without protective leaves, fruit are exposed to sun and can be injured (sunscald). Fruit production will also decline. Septoria leaf spot and early blight can be effectively managed with cultural practices that start before planting and rescue treatments beginning at the first sign of these diseases. Select early blight resistant varieties when suitable. Early-blight resistance has been incorporated into the Mountain series, which includes Mountain Pride, Supreme, Gold, Fresh and Belle. This resistance is controlled by several genes, thus these varieties have moderate but stable resistance. These varieties unfortunately produce smaller fruit than others and are not as suitable for the northeast because they are late maturing; however, where early blight has been severe, these might be worth considering. In the near future, perhaps as early as 2007, varieties will begin to be released by the Cornell Breeding Program that are suitable for the northeast with early blight and late blight resistance. Note that early maturing varieties tend to develop early blight symptoms before other varieties and to become more severely affected, and indeterminant varieties tend to be less severely affected than determinant ones. Purchase seed and transplants from a reliable supplier. Hot water treat seed right before planting (methods are on-line at: http://vegetablemdonline.ppath.cornell.edu/NewsArticles/All_BactSeed.htm). Inspect purchased transplants for symptoms. Select a field that has not been planted to tomatoes for at least 3 years. Plastic or organic mulch forms a barrier between the pathogen overwintering in the soil and the crop. Mulch with hairy vetch might induce resistance, as demonstrated recently through research. Provide optimum growing conditions. Severity of early blight can be lower when soil fertility is high. As with most foliar plant diseases caused by fungi, development of Septoria leaf spot and early blight are favored by wet leaf tissue because moisture is needed for spore germination and growth into the leaf. Therefore these diseases will be less severe where cultural practices are used to minimize the time that leaves are wet. Plant rows parallel to prevailing wind. Use wide row and plant spacing. Stake or trellise plants; disinfect used stakes. Control weeds and volunteer tomato plants, which can serve as a source of inoculum as well as promote moist conditions by restricting air movement when allowed to grow unrestricted. Irrigate with drip preferably or overhead irrigate when leaf wetness period will be minimally extended. Work when foliage is dry to minimize movement of Septoria spores. Inspect plants at least weekly so that rescue treatments can be started at the beginning of disease development. Look thoroughly about a week after favorable conditions (couple days of rain or long dew periods when temperature is 75-85°F). Starting treatment early is critical because once established, diseases are difficult to suppress even with conventional fungicides. There are disease forecasting systems developed for early blight that have also proven useful for Septoria leaf spot and Anthracnose: TomCAST, FAST, CUFAST, and TomFAST. These use temperature and moisture measurements (RH, Rain, leaf wetness, and/or dew) to determine favorability of conditions. Severity values are assigned to each favorable period and accumulated until threshold has been reached, at which point treatment is recommended because conditions have been sufficiently favorable that infection would have occurred if spores were present. Commercial products are available with sensors and software with a forecast program. With these systems it has been possible to achieve similar disease control to a weekly spray program with as much as 50% fewer applications, but note that these experiments have been conducted with conventional fungicides. These systems are not a substitute for crop inspection because there are other diseases, in particular those caused by bacteria, which have different favorable conditions. There are OMRI-approved fungicides and products exempt from EPA registration that can be used for rescue treatments. OMRI-approved fungicides labeled for early blight in tomato include OxiDate, Sonata, Serenade Max, and the copper-based fungicide Champion. Champion is also labeled for Septoria leaf spot. In New York and other states that require the target pest/pathogen be specified on the label, these products registered through EPA as fungicides can only be used legally for these diseases unless a FIFRA 2(ee) recommendation has been approved for another pathogen. There are also several products defined as minimum risk pesticides through FIFRA Section 25(b) rule because their active and inert ingredients are generally recognized as safe (GRAS). These consequently are exempted from the regulation requirements of FIFRA and thus can be used on any labeled crops for any target since they do not need to be registered as a pesticide. Several products for managing early blight and Septoria leaf spot in organically-produced tomato have been evaluated in replicated experiments. In Ohio in 2003, early blight and Septoria leaf spot were suppressed most by treatments with copper (Bordeaux mixture, Champion, Storox alternated with Champion) based on disease severity on 26 Sep and AUDPC, which is a summation value for disease severity over time. Based on just AUDPC, Garlic Barrier, Serenade, seaweed extract (SW-3), and Trilogy were also effective. Biodynamic 508, Humega, Kaligreen, Sonata, Storox, Timor and Timorex were ineffective. In an experiment conducted in Iowa in 2003 where both bacterial spot and Septoria leaf spot occurred, disease severity was significantly lower and yield significantly higher in tomato treated with Champion than tomato treated with Serenade or either compost tea tested, which were not significantly different from non-treated tomato grown on straw or plastic mulch. In Massachusetts in 2000, copper hydroxide suppressed early blight and Septoria leaf spot while the microbial-based treatments (Biostart Agricola, Deny, and compost tea) did not. In a series of 3 experiments conducted on a certified organic farm in western New York, foliar disease symptoms were reduced significantly compared with the non-treated control with foliar applications of Trilogy and also Plantshield applied as a soil drench after transplanting when early blight was the predominant disease and conditions were at most moderately favorable for disease development. (Note that Plantshield currently is labeled for use as a greenhouse drench for root diseases). During a cooler, wetter season when Septoria leaf spot was the dominant disease, foliar application of Champion WP was the only treatment that significantly decreased disease compared with the control. Trilogy (foliar), SW-3 (drench and foliar) and Humega (soil) appeared to provide some suppression of Septoria leaf spot, but while severity was not significantly different from that of Champion-treated plants, it was also not different from the non-treated control plants. Foliar diseases (combination of Septoria leaf spot, powdery mildew, and bacterial speck) were not suppressed by any of the treatments evaluated on Long Island, NY, in 2003 and 2004, which included preventive applications of Sonata and/or compost tea and rescue treatments of JMS Stylet-oil and Champion that followed preventive compost tea applications. Destroy plant debris at the end of the season to reduce the quantity of inoculum that can survive over winter. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| back to top |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Is soybean yield affected by introducing cereal rye in the rotation? Matías L. Ruffo, Donald G. Bullock and Germán A. Bollero* Crop Sciences Department, University of Illinois |
The inclusion of cereal rye as winter cover crop following corn is a valuable nutrient management tool in the typical corn–soybean rotation of the United States Midwest. However, scientists from the Crops Sciences Department at the University of Illinois suggest that little information is available on the effects of rye WCC on the soybean crop. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| back to top |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Reports from our organic growers | Indiana report Illinois Report West Central Illinois—Anne Patterson It’s all pretty much harvesting at this point, with the exception of weekly lettuce transplants. A University of Wisconsin Dept of Ag field study is showing fertilizing hazelnuts is resulting in poorer results than not fertilizing. This is contrary to what I have read. I’m finding out that growing hazelnuts in the Midwest is a true experiment with not enough scientific or field knowledge. The most important factor seems to be adequate water, which I haven’t had in the five years since I planted them. So watering is more important than anything else, besides deer browsing prevention. I’m glad I haven’t yet put manure on hazels this year. In the next two weeks we will be clearing old beds and waiting until September to put in a winter cover crop. We also will be working on new woodland plant propagation beds, which have been started, but not finished. We will continue harvesting. West Suburban Chicago—Steve Tiwald Current activities include: In the next two weeks we will finish the potato harvest and set it up to cure in the corn crib loft. We’ll also be harvesting onions and setting them up to cure in the hayloft on drying racks. Transplanting: Finish transplanting the fall crops of pac choi, continue the successions of lettuce, continue the harvesting and seeding of lettuce and cultivation. Northern Illinois—Dave Campbell I finished combining oats last week; yields were disappointing in the 65 bu/A range. I finished combining wheat a week and a half ago with yields in the 75 bu/A range, and quality was good as well. I also just finished baling oats and wheat straw last week. I will start cultivating beans for the third time tomorrow. Within the next day or two I will start walking soybeans to cut out broadleaf weeds in the rows. I will put up second hay cutting, hopefully soon, once I get my baler fixed. I will also be cutting weeds along with trimming around field borders and waterways. Iowa report I am still trying to finish up combining flax. Where the weeds were bad, the rain on the windrows is a problem. They don’t dry underneath and are starting to mold. If it rains on them again I think the flax will be unusable. I only have about five acres left. Yields are surprisingly good considering the conditions—about 20 bu/A. I am also trying to finish up some cover crop planting. I can finally do that since it has rained. Over the next two weeks I have a lot of manure to haul. Solid from a neighbor that will be composted and liquefied. Manure from my pigs will be knifed in on small grain fields going to corn next year. Michigan report East Michigan—John Simmons Currently we are continuing harvest of spelt, pasture rotation and painting the barn. In the next two weeks we will finish spelt harvest and harvest oats and rye. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| back to top |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||