in-crop-weather State Indiana Crop Weather Week Ending Date August 23, 2009 IN-CW082409 AGRICULTURAL SUMMARY Some much needed rain fell across most of the state with heaviest amounts being reported in the northern and central districts, according to the Indiana Field Office of USDA’s National Agricultural Statistics Service. Reporters feel that this precipitation will help with pod fill in soybeans and will also be beneficial to grain weight in the corn crop. However, some irreversible crop damage has been sustained by the dry conditions over the last several weeks. White mold, aphids and sudden death syndrome (SDS) continue to be problems in some soybean fields. Cutting of tobacco and apple harvest began in some southern counties. FIELD CROPS REPORT There were 4.4 days suitable for field work during the week. Sixty-six percent of the corn is in dough compared to 69 percent last year and 85 percent for the 5-year average. Corn condition is rated 62 percent good to excellent compared with 64 percent last year at this time. Ninety-five percent of the soybean acreage is blooming compared with 95 percent last year and 98 percent for the 5-year average. Seventy-six percent of the soybean acreage is setting pods compared to 76 percent last year and 90 percent for the 5-year average. Soybean condition is rated 62 percent good to excellent compared with 59 percent last year at this time. The third cutting of alfalfa hay is 44 percent complete compared with 68 percent last year and 69 percent for the 5-year average. LIVESTOCK, PASTURE AND RANGE REPORT Pasture condition improved slightly and is now rated 66 percent good to excellent compared with 43 percent last year at this time. Livestock remain in mostly good condition. CROP PROGRESS TABLE Crop This Week Last Week Last Year 5-Year Avg. CROP CONDITION TABLE Crop Very Poor Poor Fair Good Excel-lent Percent SOIL MOISTURE & DAYS SUITABLE FOR FIELDWORK TABLE This Week Last Week Last Year Percent Crop Progress Table ------------------------------------------------------- : This : Last : Last : 5-Year Crop : Week : Week : Year : Avg ------------------------------------------------------- Percent Corn in Dough 66 42 69 85 Corn in Dent 9 NA 20 44 Soybeans Blooming 95 90 95 98 Soybeans Setting Pods 76 62 76 90 Alfalfa - 3rd Cutting 44 29 68 69 Crop Condition Table ---------------------------------------------------- : Very : : : : Excel- Crop : Poor : Poor : Fair : Good : lent ---------------------------------------------------- Percent Corn 3 8 27 50 12 Soybean 3 8 27 51 11 Pasture 2 7 25 47 19 Soil Moisture & Days Suitable for Fieldwork Table ---------------------------------------- : This : Last : Last : : Week : Week : Year : ---------------------------------------- Percent Topsoil Very Short 3 11 14 Short 12 24 40 Adequate 70 54 45 Surplus 15 11 1 Subsoil Very Short 4 8 12 Short 16 26 31 Adequate 67 55 55 Surplus 13 11 2 Days Suitable 4.4 5.9 6.6 Contact Information --Greg Preston, Director --Andy Higgins, Agricultural Statistician E-Mail Address: nass-in@nass.usda.gov http://www.nass.usda.gov/Statistics_by_State/Indiana/ ------------------------------------------------------------------------ Other Agricultural Comments And News WHITE MOLD (SCLEROTINIA STEM ROT) White mold of soybean, also called Sclerotinia stem rot, is present throughout most of the northern states. It is considered a minor disease in Indiana, but can cause significant damage in infested fields. The areas at greatest risk are northern Indiana (north of Interstate 70) and states further north. Cool, wet conditions during early reproductive stages favor disease development when the pathogen is present. The disease is often most severe in varieties that have a denser, faster-closing canopy. SYMPTOMS White mold first becomes apparent when single plants within a generally healthy canopy wilt and die rapidly in July and August. Leaves remain on the stem but turn brown, and the entire plant dies. Close inspection of the lower stem reveals a bleached area, often originating from a leaf axil and extending 2 to 6 inches in each direction along the stem. When a lesion girdles the stem, the tissue above it dies - not all the stem tissue will die, but all leaf tissue generally dies. Under moist conditions the bleached area may be covered with the fungus’ fluffy white mycelium. Eventually, black, oblong structures, from 1/8-inch to 3/4-inch long, may be visible in the center of the bleached area. These black structures, called sclerotia, also develop inside the stem, and can be easily seen when the stem is split in the bleached area. Sclerotia are the fungus’ survival structures. Sclerotia are initially soft, but harden with age. The sclerotia’s interior is white or pink. When cutting, the inside of the fungal bodies is clear. Infected plants may produce no seed. Yield loss from this disease in a field depends on the number of infected plants and the stage when the plants are killed. CAUSAL AGENT White mold is caused by Sclerotinia sclerotiorum, a fungus that has a wide host range, including alfalfa, beans, canola, clover, peppermint, potato, sunflower, and tomato. It can also infect several weed hosts, such as amaranths, castor bean, dandelion, lambsquarters, ragweed, and velvetleaf. DISEASE CYCLE Sclerotia can persist in the soil for several years. Although they decline over time, it apparently takes only a few to generate the density of ascospores needed for an epidemic. When conditions are favorable and the sclerotia are within 1 inch of the soil surface, light brown fruiting bodies of the fungus, called apothecia, emerge from the soil. The apothecia are 1/8-inch to 3/4-inch diameter, and consist of a cuplike structure on a short stalk. Spores are produced on the surface of the cuplike structure, and are forcefully ejected when they mature. Apothecia can be confused with the sporulating structures of bird’s nest fungi. Bird’s nest fungi are frequently observed on old corncobs found on the soil surface in minimum tillage systems. This fungus, although intriguing for its beauty, does not cause any disease on soybean. Wind currents transport the spores produced by white mold apothecia to soybean plants, where they can cause infections under wet, humid conditions. Spores can infect any part of the plant, but senescing flowers seem to be a common point of infection. When it infects a flower, the fungus grows down through the flower stalk (pedicel) and invades the stem. Floral infection explains why stem lesions are commonly centered at a node. They also appear to infect at points where dead flower parts adhere to the plant and provide a nutrient source for infection. Once in the plant, the fungus consumes plant nutrients and eventually girdles the stem, killing the tissue above the lesion. Sclerotia are similar in size and density to soybean seed and can easily end up in the grain bin when seed from an infected soybean crop is harvested. Some sclerotia are ejected from the combine in stem tissue, which can distribute sclerotia over more of the field. The combine can also transport sclerotia to uninfested fields following the harvest of an infested site. Because sclerotia survive in the soil, soil movement could also transport inoculum from one field to another. Once sclerotia find conducive conditions in the field and are about 1 to 2 inches from the soil surface, they will produce apothecia and initiate new infections. MANAGEMENT White mold management is difficult when environmental conditions are favorable for the disease. The sclerotia can remain in the soil for several years, and lose their viability slowly. The most effective defense against white mold is to keep the fungus out of a field, but this can be difficult. Avoid harvesting disease-infested fields before harvesting healthy fields unless the combine can be cleaned thoroughly. If a field with white mold is harvested, clean the combine before moving to fields with no history of the disease. If white mold is restricted to a portion of the field, that restricted area should be harvested last and independently from the rest of the field. If the disease is already present in a field, keep sclerotia out of the upper layer of the soil, and prevent the sclerotia from distributing over a wider area. PLANTING In infested fields, some have proposed spacing soybean rows wider apart than optimal for yield. Wider rows allow air to circulate to the soil surface while the crop is starting to flower. This promotes a drier soil surface and lower humidity around the base of the plants, which would interfere with sclerotia development, spore formation, and infection. However, if it is cool, overcast, and rainy, wide rows may not have any effect on white mold. Moreover, extremely wide rows (more than 30 inches) may actually increase spore dispersal by allowing more air movement near the soil surface. In the absence of the disease, plants grown in 30-inch rows will often not yield as much as those grown in narrow rows. But if the disease is severe in a field, moving to wide rows may provide some control. Still, while the incidence of white mold in wider rows may be reduced, the yield in wide row systems is seldom higher than narrow row systems. University of Wisconsin researchers advocate not going to 30-inch row spacing to avoid lower white mold potential. Instead, they recommend 15-inch row spacings. In white mold years, row width has little influence on white mold incidence. Lowering the plant population is a better approach. Avoid planting 200,000 plants per acre regardless of row width. In fields with a history of white mold, 125,000 to 150,000 plants per acre are recommended. TILLAGE Conventional wisdom suggests that burying sclerotia deeply by plowing will reduce white mold. If sclerotia are more than 2 inches below the soil surface, they do not produce apothecia. If a field where white mold was a problem is plowed, the soil should not be further disturbed in subsequent years. But if buried sclerotia are brought to the surface a year to two later, some will still be viable and can produce spores. However, in recent research in Wisconsin, no-tillage treatments that presumably leave sclerotia on the soil surface were reported to have lower apothecia numbers. Tillage that buries sclerotia would probably also reduce the number of spores produced but may result in greater canopy density compared to no-till, which may offset the benefit of burying sclerotia by increasing disease conduciveness of the canopy environment. ROTATION Rotating with nonhost crops can potentially reduce white mold incidence. But rotation must be carefully considered since the sclerotia are long-lived and do not necessarily decline sufficiently in one growing season to reduce disease pressure. Also, because of its wide host range, the fungus could reproduce on weeds, which would nullify the effectiveness of the nonhost crop. Introducing a small grain somewhere in rotation with soybean will eventually result in a lower incidence of white mold. Corn is not a good rotation crop, but small grains are. A corn-soybean-winter wheat rotation has a meaningful impact on white mold. A corn-soybean rotation poses a higher risk situation. RESISTANT SOYBEAN VARIETIES Partial resistance to white mold has been identified, and seed dealers provide ratings on the resistance levles of their varieties. Breeding efforts continue because partial resistance is prone to being overcome and other disease resistance characteristics may have priority when breeders develop new soybean varieties. CHEMICAL AND BIOLOGICAL CONTROL Several fungicides can provide some level of disease suppression, but proper timing and good canopy penetration are essential. Fungicide application may be more effective when disease pressure is no more than moderate. In addition to fungicides, there are reports that several beneficial organisms, when applied to soil, can degrade sclerotia faster than resident soil microbes can. Several of these microorganisms are currently being developed for commercial use. And are in the process of being introduced to the market. White mold is a severe disease of soybean in isolated areas of the Midwest. When a field has a history of white mold, a combination of strategies that includes resistant varieties, row spacing, tillage, and possibly fungicide applications, should be employed. Andreas Westphal, T. Scott Abney, and Gregory Shaner, Department of Botany and Plant Pathology, Purdue University and USDA-ARS. ------------------------------------------------------------------------ The INDIANA CROP & WEATHER REPORT (USPS 675-770), (ISSN 0442-817X) is issued weekly April through November by the USDA, NASS, Indiana Field Office, 1435 Win Hentschel Blvd, Suite 110, West Lafayette IN 47906-4145. For information on subscribing, send request to above address. POSTMASTER: Send address change to the USDA, NASS, Indiana Field Office, 1435 Win Hentschel Blvd, Suite 110, West Lafayette IN 47906-4145. ------------------------------------------------------------------------ Weather Information Table Week ending Sunday August 23, 2009 ----------------------------------------------------- | Past Week Weather Summary Data |--------------------------------- Station | Air | | Avg | Temperature | Precip. |4 in. |---------------|------------|Soil |Hi |Lo |Avg|DFN| Total| Days|Temp ---------------------------------------------------- Northwest (1) Chalmers_5W 90 53 71 -1 2.73 5 Francesville 90 53 70 +1 2.76 5 Valparaiso_AP_I 92 58 72 +2 0.77 5 Wanatah 91 55 70 +2 1.45 6 76 Winamac 90 55 72 +2 2.67 7 North Central(2) Plymouth 92 55 71 +1 2.38 7 South_Bend 92 57 71 +1 4.90 6 Young_America 86 54 69 -2 1.47 5 Northeast (3) Fort_Wayne 92 58 73 +2 3.84 4 Kendallville 93 60 73 +3 2.44 6 West Central(4) Greencastle 87 51 71 -3 1.40 4 Perrysville 92 54 72 +1 4.53 5 73 Spencer_Ag 89 56 73 +2 1.31 4 Terre_Haute_AFB 90 54 73 +2 1.97 2 W_Lafayette_6NW 90 51 71 +1 3.47 5 77 Central (5) Eagle_Creek_AP 90 58 74 +2 0.90 4 Greenfield 88 56 73 +2 2.39 5 Indianapolis_AP 90 57 75 +3 0.79 4 Indianapolis_SE 89 57 73 +0 1.14 4 Tipton_Ag 90 53 72 +3 1.78 4 81 East Central(6) Farmland 92 52 73 +4 0.83 4 77 New_Castle 86 56 72 +2 2.00 6 Southwest (7) Evansville 91 56 76 +1 0.59 4 Freelandville 90 57 74 +1 1.29 5 Shoals_8S 89 52 73 +0 0.36 2 Stendal 89 56 75 +2 0.55 3 Vincennes_5NE 91 60 76 +3 0.58 4 86 South Central(8) Leavenworth 90 58 75 +3 0.68 3 Oolitic 88 56 73 +2 0.25 5 77 Tell_City 89 59 76 +2 0.49 2 Southeast (9) Brookville 90 56 74 +3 1.03 5 Greensburg 91 58 74 +3 1.21 6 Seymour 89 54 74 +3 0.11 2 ----------------------------------------------------- Weather Information Table (Continued) Week ending Sunday, August 23, 2009 ------------------------------------------------- | Accumulation |-------------------------------- | April 1, 2009 thru Station | August 23, 2009 |-------------------------------- | Precipitation |GDD Base 50oF |-------------------------------- | | | | | |Total | DFN |Days|Total| DFN ------------------------------------------------- Northwest (1) | Chalmers_5W |19.10 +0.91 59 2089 -306 Francesville |20.11 +1.96 54 2035 -174 Valparaiso_AP_I |14.67 -4.13 55 2140 -44 Wanatah |17.25 -1.10 59 1948 -142 Winamac |16.10 -2.05 61 2102 -107 North Central(2)| Plymouth |18.04 -0.37 72 2017 -296 South_Bend |21.64 +3.96 55 2142 -31 Young_America |18.57 +1.23 47 2136 -131 Northeast (3) | Fort_Wayne |20.14 +3.75 58 2236 -34 Kendallville |17.96 +1.02 65 2256 +122 West Central(4) | Greencastle |29.13 +8.55 63 2093 -460 Perrysville |29.23 +9.65 61 2366 -19 Spencer_Ag |29.89 +8.81 64 2321 -87 Terre_Haute_AFB |22.53 +2.99 53 2575 +33 W_Lafayette_6NW |24.17 +6.01 60 2255 -5 Central (5) | Eagle_Creek_AP |26.61 +8.17 60 2530 +9 Greenfield |30.35 +10.03 63 2261 -154 Indianapolis_AP |29.93 +11.49 58 2609 +88 Indianapolis_SE |32.54 +13.41 63 2261 -244 Tipton_Ag |24.28 +5.82 63 2141 -55 East Central(6) | Farmland |16.78 -1.15 58 2174 +31 New_Castle |22.38 +2.79 61 2085 -109 Southwest (7) | Evansville |23.55 +4.89 58 2983 +53 Freelandville |29.08 +9.63 58 2601 -25 Shoals_8S |29.57 +8.46 55 2373 -165 Stendal |30.41 +9.54 56 2917 +158 Vincennes_5NE |28.14 +8.69 62 2711 +85 South Central(8)| Leavenworth |28.82 +7.19 78 2603 +75 Oolitic |26.54 +6.20 67 2381 -46 Tell_City |24.47 +3.15 54 2800 -1 Southeast (9) | Brookville |23.55 +3.81 60 2445 +142 Greensburg |30.33 +10.54 66 2548 +192 Seymour |27.42 +7.88 55 2359 -71 ------------------------------------------------------------------ Copyright 2009: Agricultural Weather Information Service, Inc. All rights reserved. DFN = Departure From Normal GDD = Growing Degree Days. Precipitation (Rainfall or melted snow/ice) in inches. Precipitation Days = Days with precip of .01 inch or more. Air Temperatures in Degrees Fahrenheit. For more weather inrformation, visit www.awis.com or call 1-888-798-9955.