CEREAL RUST BULLETIN
 Final Report
 August 15, 1996
 
 Issued by: 
 Cereal Rust Laboratory, Agricultural Research Service, 
 U.S. Dept. of Agriculture
 University of Minnesota, St. Paul, MN 55108
 (612) 625-6299    FAX (612) 649-5054
 Internet: markh@puccini.crl.umn.edu
 CRL web page:  http://www.umn.edu/rustlab/
 
 
 * Wheat stem rust was widespread throughout the U.S. wheat growing area in 
 1996.  The most significant damage was caused in the northern soft red winter 
 wheat area east of the Mississippi River.
 
 * Wheat leaf rust was widespread in winter wheat throughout the U.S., but 
 incidence and severity were less than normal because of the dry conditions in 
 the southern plains and less overwintering in the central plains.
 
 * Wheat stripe rust in the Pacific Northwest was effectively controlled by 
 adult plant resistance in most varieties, although susceptible varieties were 
 heavily infected and losses were more severe than last year.
 
 * Oat stem rust in 1996 was very light throughout the oat-growing area, which 
 may be due to the decline in oat production.
 
 * Oat crown rust was severe throughout much of the northern oat-growing area 
 where the buckthorns provided the initial inoculum for rust infection.
 
 * Barley stem rust did not reach damaging levels in the northern plains due to 
 the low levels of the barley attacking race, QCCJ, farther south.
 
 * Barley leaf rust was found throughout the northern barley-growing area, but 
 severities were too low to affect yields.
 
 * Barley stripe rust is now firmly established throughout the Pacific 
 Northwest where the climate is most favorable for its development.  Fungicide 
 applications were needed to prevent losses in yield and quality.
 
 
 Most of the small grains in the northern Great Plains are in good condition 
 and near normal in maturity.   Scab is lighter than last year in western 
 Minnesota and eastern North Dakota spring wheat fields.  Barley, oat and 
 winter wheat harvest has begun in northeastern North Dakota and northeastern 
 Montana.
 
 
 Wheat stem rust
 
 This year, wheat stem rust was found scattered in plots and fields throughout 
 the southern Plains and the lower Mississippi Valley wheat-growing area.  In 
 all of these areas, losses to wheat stem rust were minimal, but these fields 
 did provide stem rust inoculum for susceptible wheats and barleys farther 
 north.
 
 During 1996, wheat stem rust overwintering sites were found in southern Texas,  
 southern Louisiana and southern Illinois.   During the first week in April, 
 traces of stem rust were found in winter wheat fields southwest of Houston and 
 southern Louisiana.  Stem rust development in southern Texas and Louisiana in 
 1996 was less than in 1993, the last year with significant wheat stem rust in 
 the U.S.  1993 and other recent years, with greater than average stem rust, 
 generally had warmer late winter and early spring weather with more rainfall 
 than occurred in 1996.  In late April, traces of wheat stem rust were observed 
 on susceptible cultivars in southern and central Texas nurseries.  In early 
 June, traces of stem rust were found in plots and a field in east central 
 Arkansas.  During the second week in June, wheat stem rust severities ranged 
 from trace to l% in fields of soft red winter wheat in southern Illinois, and 
 in wheat plots in central Indiana.  In late June, traces of stem rust were 
 found on soft red winter wheat plants throughout southern Wisconsin and 
 southern Michigan.  In early July, stem rust severities were light to moderate 
 in fields in south central Wisconsin.  By late July, severely rusted fields of 
 soft red winter wheat were observed in northwestern Illinois, northeastern 
 Wisconsin and east central Michigan.  In Indiana, the most stem rust was found 
 since 1986 .  In those northern soft red winter wheat areas where moisture 
 conditions were good for the infection process to occur, there were 
 significant losses to stem rust.  
 
 During the second week in June, traces of stem rust were observed in central 
 and northeastern Kansas plots.  The  date of the first stem rust observation 
 was two weeks later than normal for the northeastern Kansas location.   During 
 late June, wheat stem rust was found at trace-40% severities in plots and 
 trace-l% severities in fields of susceptible cultivars in northern Kansas and 
 southern Nebraska.  The first stem rust infections in this area occurred when 
 stem rust spore-laden rains fell in early June.  The hot dry weather in mid-
 June in this area was not conducive for rust increase.
 
 In mid-July, traces of wheat stem rust were found in plots and fields of 
 winter wheat in southeastern South Dakota and east central North Dakota.  At 
 that time, traces of wheat stem rust were found also in plots of the 
 susceptible spring wheat Baart in west central Minnesota, eastern South Dakota 
 and central North Dakota.  A more severe case of wheat stem rust, 20% 
 severity, was observed on the susceptible spring wheat cultivar Max in a 
 southeastern North Dakota plot.  In mid-July, the durum cultivar, Mindum, 
 which was released over 50 years ago, had traces of stem rust in plots in east 
 central North Dakota.  By mid-July, in an east central South Dakota nursery, 
 some the of the late planted susceptible cultivars were destroyed by rust.
 
 Several factors delayed stem rust development in the central Great Plains.  
 First, stem rust overwintering in the southern Plains was less than normal.  
 Then, cool, dry conditions in late winter in the southern Plains and hot dry 
 weather in early June in the central plains were not conducive for rust 
 increase.  In spite of this, sufficient quantities of stem rust spores spread 
 from the central Great Plains to initiate stem rust foci in susceptible spring 
 wheat plots in the northern Great Plains.  Stem rust from these foci developed 
 normally. The stem rust resistance in the spring wheats remains highly 
 effective in the northern plains.  Without this highly developed stem rust 
 resistance, spring wheats would have suffered significant losses throughout 
 the northern plains.  
  
 By mid-July, hot spots (1-20% stem rust severities) were reported in winter 
 wheat plots in the Palouse area of Washington.  In mid-July, traces of stem 
 rust were found on winter wheat in plots in western New York.  
 
 To date, race Pgt-TPMK is the predominant stem rust race identified in 1996 as 
 it was in 1995 (Table 1).  Presented in Table 1 are the preliminary wheat stem 
 rust race identifications (many isolates will be rerun to confirm race 
 identification).
 
 
 TABLE 1.  Preliminary identification of wheat stem rust races through 
 August 14, 1996
 _____________________________________________________________________________
 
              Number of                Number of isolates of Pgt race*
        _____________________   ______________________________________________
 State  collections  isolates   GFCS  GFBS  QCCS  QCCJ  QCMS  QFCS  RTRS  TPMK
 AR          2          6                                                   6
 IL          5         15                                                  15
 IN          2          6                     1                             5
 KS         14         40         4           1           6     5     3    21
 LA          4         12                                                  12
 NE          7         21               1                       2          18
 TX          9         26         3                  2          4          17
 _____________________________________________________________________________
 * Virulence formula:
 GFCS - Sr21,8a,9g,17,9a,9d,10   QCMS - Sr5,21,9g,36,17,9a,9d,10
 GFBS - Sr21,8a,9g,9a,9d,10      QFCS - Sr5,21,8a,9g,17,9a,9d,10
 QCCS - Sr5,21,9g,17,9a,9d,10    RTRS - Sr5,21,7b,11,6,8a,9g,36,9b,17,9a,9d,10
 QCCJ - Sr5,21,9g,17,9d,10       TPMK - Sr5,21,9e,7b,11,8a,9g,36,17,9d,10,Tmp
 
 
 Wheat leaf rust
 
 Southern Plains - Overwintering of leaf rust was lower than normal throughout 
 most of the southern U.S. in 1995-96.  During the last week in March, 20% leaf 
 rust severities were observed on lower leaves of wheat plants in southern 
 Texas fields and traces were observed in central Texas nursery plots.  
 Generally, by late March, leaf rust was severe in nursery plots throughout 
 southern Texas and moderate in central Texas, but the cool, dry weather kept 
 the rust in check.  By mid-April, leaf rust severities were lower than normal 
 throughout the southern U. S.   In southern Texas fields, rust was light and 
 in southern Texas plots of susceptible cultivars, 40% severities were observed 
 which is much less than normal.  During the third week in April, no wheat leaf 
 rust was observed in fields and  plots in north central Texas.  By the first 
 week in May, 30% rust severities were observed on susceptible cultivars in 
 central Texas nursery plots and traces were found in north central Texas 
 fields (Fig. 1).   During the third week in May, traces of leaf rust were 
 found in south central Kansas and north central Oklahoma.  In this area, leaf 
 rust development was minimal because little or no rust overwintered and little 
 rust inoculum arrived from areas farther south where drought conditions 
 existed.  
 
 Central Plains -In contrast to the 1994-95 winter, when leaf rust overwintered 
 throughout Kansas, very little rust overwintered in Kansas in 1995-96.  In 
 early June, traces of leaf rust were found in plots and fields of susceptible 
 cultivars throughout Kansas.  Most of the rust pustules were concentrated on 
 upper leaves indicating that the rust developed from exogenous spore sources.  
 During the third week in June, leaf rust was widespread throughout Kansas on 
 wheat plants where there still was green tissue.  Severities ranged from 
 trace-5% on cultivars in plots and traces in fields in northeastern Kansas.  
 The leaf rust loss estimate in Kansas in 1996 is less than 1% which is 
 significantly less than the 5% loss in 1995.  During the third week in June, 
 20-40% severities were found on susceptible wheat cultivars in east central 
 Nebraska plots.  In late June, 40% leaf rust severities were observed in a few 
 fields and plots of susceptible cultivars in southern Nebraska.  In this area, 
 losses will vary with local conditions. 
 
 Northern Plains - On June 28, traces of wheat leaf rust were found in west 
 central Minnesota, east central South Dakota and Winnipeg, Canada nurseries.  
 This was two weeks later than the normal first date of observation of wheat 
 leaf rust at these three locations.  During early July, traces of leaf rust 
 were found in spring wheat plots in central and east central North Dakota and 
 traces in a winter wheat field in east central North Dakota.  In mid-July, 
 trace to 5% severities were common on flag leaves in plots and fields of 
 winter wheat in east central and eastern South Dakota and southeast North 
 Dakota winter wheat plots and fields.  Leaf rust severities in the northern 
 plains were much lower than normal this year, because leaf rust development in 
 the southern and central plains was also much less than normal.  Initial leaf 
 rust development in the northern plains comes mainly from windborne spores 
 from the south that are deposited with rains on wheat fields in the north.  In 
 mid-July, in susceptible spring wheat plots, trace-5% severities were common, 
 while in spring wheat fields no leaf rust was observed in the northern Great 
 Plains.  By early August, in susceptible spring wheat plots, trace-10% 
 severities were common.  Due to resistance, only traces of leaf rust developed 
 in commercial fields and therefore losses were minimal in spring wheats.  No 
 rust was reported on durum wheat.
  
 Southeast - In the southeast U.S., during late March, leaf rust severities 
 were generally light on susceptible southern soft red winter wheat in plots 
 and fields.  By mid-April, wheat leaf rust was severe in nursery plots in 
 southeastern Louisiana and light in plots in the panhandle of Florida.  By 
 late April, leaf rust was severe on susceptible cultivars in nurseries and 
 light in fields in central Louisiana and southern Georgia (Fig. 1).  The 
 winter rainfall in the Florida panhandle and southern Georgia was normal, 
 creating favorable conditions for rust infection.  Cool temperatures in 
 February and March slowed rust development, but warm temperatures and moist 
 conditions in early April were favorable for rust buildup.  These rust 
 infected plants provided leaf rust inoculum for wheats farther north.  In late 
 April, traces of leaf rust were found in an east central Arkansas field where 
 leaf rust had survived the extremely cold winter.  In mid-May, traces of leaf 
 rust were reported in nurseries from east central North Carolina to east 
 central Arkansas.  
 
 Midwest -  In early June, light leaf rust was observed on soft red winter 
 wheat from eastern Virginia to southern Illinois (Fig. 1).   In mid-June, 
 trace to 15% severities were observed in soft red winter wheat fields and 
 nurseries at the soft dough stage throughout Indiana and Illinois.   In the 
 third week in June, traces of leaf rust were observed in fields in the Thumb 
 area and central Michigan.  In Michigan the leaf rust that developed was from 
 spores that were deposited with rain from southern inoculum sources and not 
 overwintering sources.  In early July, leaf rust was severe in susceptible 
 cultivars growing throughout Michigan.
 
 California - During the last week in March, 15%  leaf rust severities were 
 reported on fall-sown spring wheat cultivars growing in nurseries and fields 
 in the San Joaquin Valley in California.   By the last week in April, moderate 
 to severe leaf rust was found on wheat cultivars growing in nurseries and 
 fields in the San Joaquin Valley in California (Fig. 1).  By the first week in 
 May, 60% leaf rust severities were reported on wheat cultivars growing in 
 nurseries and in some fields in the Sacramento Valley in California.  
 Generally, fields in the Sacramento Valley had moderate severities of leaf 
 rust.   Leaf rust losses on wheat occurred on the majority of cultivars 
 throughout the state except for Express and RSI 5, which displayed excellent 
 resistance. 
 
 Northwest - During mid-May, leaf rust was found throughout the state of 
 Washington and the Columbia basin with 40% severities being reported on 
 susceptible cultivars in nurseries.  This was more severe leaf rust than 
 normal for mid-May.  In early June in the Pacific Northwest, wheat leaf rust 
 was increasing rapidly.  In central Washington, 90% severities were reported 
 on susceptible cultivars and in the Palouse area of Washington, leaf rust was 
 light to moderate.  There was some spraying to control leaf rust on soft white 
 wheat.  An emergency label was obtained for the use of Folicur on wheat in 
 Washington, because supplies of Bayleton ran low.  Leaf rust development in 
 eastern Oregon and Washington and northern Idaho was delayed by dry weather 
 during early June, but rains in mid-June allowed for a rapid buildup of leaf 
 rust in winter wheats in late June.  Rains in eastern Washington and eastern 
 Oregon during the last week in June created ideal conditions for rust increase 
 and in mid-July, leaf rust was light to moderate in spring wheat plots.  In 
 the Pacific Northwest, the ideal moisture conditions for rust infection and 
 endogenous rust inoculum created conditions for losses to leaf rust to occur 
 in some areas.
 
 Northeast - During the first week in July, leaf rust severities ranged from 
 trace to 10%  on winter wheats across the state of New York.
 
 The wheat leaf rust races identified so far in the 1996 survey are presented 
 in Table 2.  All of the races identified were also found in 1995.  Because of 
 the light leaf rust this year, the rust collections that were made were less 
 than one-half the normal number. 
 
 TABLE 2.  Preliminary identification of wheat leaf rust races 
 through August 14, 1996
 ______________________________________________________________
                                    Number of isolates by state
                                   ____________________________
 Prt code   Virulence formula*       GA      LA      TX      CA
 ______________________________________________________________
 MBB         1,3                              2
 MBB-10      1,3,10                           1
 MBG-10      1,3,10,11                1               2
 MBR-10      1,3,3Ka,10,11,30                 2       5
 MCB-10      1,3,10,26                                        2
 MCD-10      1,3,17,26                        4       2
 MGB-10      1,3,10,16                                2
 MLR-10,18   1,3,3Ka,9,10,11,18,30                    2
 TBG-10      1,2a,2c,3,10,11                  2
 TDB-10      1,2a,2c,3,10,24                          2
 TDG-10      1,2a,2c,3,10,11,24                       5
 TLG-18      1,2a,2c,3,9,11,18                2
 _____________________________________________________________
 No. of Isolates                     1       13      20      2
 No. of Collections                  1        8      12      2
 _____________________________________________________________
 * Single gene resistance evaluated: 
            Lr1,2a,2c,3,3Ka,9,10,11,16,17,18,24,26,30
 
 
 Wheat stripe rust
 
 By the second week in April, moderate severities of wheat stripe rust were 
 observed in the San Joaquin Valley and traces were found in the Sacramento 
 Valley of California.  During early May, traces of wheat stripe rust were 
 found in wheat fields in the Sacramento Valley in California.  
 
 By early May, wheat stripe rust was found throughout the state of Washington 
 where environmental conditions were ideal for rust development.  Sixty-percent 
 severities were reported on susceptible cultivars in western Washington plots 
 and 10% severities in eastern Washington plots.  The earliest planted hard red 
 winter wheat fields in central Washington were sprayed in early May for stripe 
 rust control.  By the third week in May, stripe rust was widespread throughout 
 the Pacific Northwest and increased to epidemic levels on susceptible 
 cultivars.  The moist cool conditions this spring were ideal for rust 
 development.  By early June, wheat stripe rust was increasing.  Stripe rust 
 was found on spring wheats, but cultivars with adult plant resistance were not 
 seriously damaged.  Growers used large amounts of fungicide to control stripe 
 rust on the susceptible cultivars of hard red and club wheats.  Dry weather 
 during the first 2 weeks of June delayed stripe rust development in eastern 
 Oregon and Washington and northern Idaho.  During early July, rust buildup on 
 the soft white wheats was light since most of the major cultivars are 
 resistant to stripe rust.  In early July, stripe rust was severe in plots of 
 susceptible winter wheat in the Palouse area of Washington, but stripe rust 
 was not a problem in commercial fields with adult plant resistance.  Stripe 
 rust in the Pacific Northwest was severe this year and losses were greater 
 than last year.
 
 In early July, light amounts of stripe rust were detected in the Gallatin 
 Valley in Montana, but hot, dry weather prevented further increase. 
 
 No wheat stripe rust was found in the central U.S. this year.
 
 
 Oat stem rust
 
 In mid-April, traces of oat stem rust were found in a nursery in southeastern 
 Louisiana.  Usually, by early April oat stem rust was severe in these plots, 
 but the cooler than normal weather in March slowed the disease progress.  By 
 early May, 20-30% oat stem rust severities were observed on susceptible 
 cultivars in central Louisiana, which was less than normal.  In mid-May, trace 
 to 80% rust severities were observed on oat cultivars in southern Louisiana 
 plots.
 
 In late April, traces of oat stem rust were found in nurseries in central 
 Texas.  During the last week in June, the first detection of oat stem rust in 
 the central plains was traces of oat stem rust in north central Kansas fields.  
 By mid-July, traces of oat stem rust were found in plots in south central 
 Minnesota and southeastern South Dakota and in one field in southeastern South 
 Dakota as well as on wild oats (Avena  fatua) in southeastern North Dakota.  
 In early August, traces of oat stem rust were found in plots in northwestern 
 Minnesota and northeastern North Dakota.  Much less oat stem rust has been 
 found in the northern Great Plains the past two years than in previous years.  
 The reduced amount of oat stem rust seems to be associated with a decline in 
 oat production.
 
 In early May, 30% rust severities were found on oats growing in plots and 
 traces on wild oats in the Sacramento Valley in California.
 
 Race NA-27, virulent to Pg-1,2,3,4, and 8 remains the predominant race of the 
 oat stem rust population (Table 3).
 
 TABLE  3.  Preliminary identification of oat stem rust races 
 through August 14, 1996
 ______________________________________________________________
 
               Number of            Number of isolates of race*
        _____________________       ___________________________
 State  collections  isolates       NA-10      NA-16      NA-27
 ______________________________________________________________
 CA          2          4             4
 KS          1          3                                    3
 LA          3          9                        1           8
 TX         10         27                        3          24
 ______________________________________________________________
 
 * Virulence formula:
 NA-10 Pg-2,3,15
 NA-27 Pg-1,2,3,4,8
 NA-16 Pg-1,3,8
 
 
 Oat crown rust
 
 During the last week in March, traces of crown rust were found in plots in 
 southern Texas, but none was found in commercial fields.  During mid-April, 
 crown rust was light in southern Texas fields and plots.  In late April, crown 
 rust was light in central Texas fields and plots.  This area provided very 
 little crown rust inoculum for oat-growing areas farther north.
 
 By the second week in April, oat crown rust was found in a southeastern 
 Louisiana nursery and 15% severities were reported in spreader rows.  By early 
 May, the severity of oat crown rust in central Louisiana was much less than 
 normal.
 
 During mid-May, light to moderate numbers of aecial infections were found on 
 buckthorns growing in south central Wisconsin.  Buckthorns are the alternate 
 hosts for crown rust and generally provide the initial spores for crown rust 
 infection of the northern oat crop.  During the third week in May, light 
 aecial infections were found in the St. Paul, Minnesota buckthorn nursery.  By 
 early June, light to moderate numbers of aecial infections were found on 
 buckthorns growing in south central Minnesota and east central North Dakota.  
 Aecial infections were 2 -3 weeks later than normal in this area.  During the 
 third week in June, traces of crown rust were found on oats in fields in south 
 central Wisconsin and Iowa and in plots in  south central Minnesota and east 
 central South Dakota.  Crown rust was beginning to build up on susceptible oat 
 lines near buckthorn at the St. Paul, Minnesota, by early June.  By early 
 July, crown rust was light to moderate in southern Wisconsin and southern 
 Minnesota oat fields.  During the second week in July, traces of crown rust 
 were found in a oat field in west central Minnesota and in the same field, 20% 
 severities were found on wild oat plants.  In mid-July, trace-40% crown rust 
 severities were found on oat flag leaves in plots and fields throughout the 
 Dakotas and southern Minnesota.  In plots in southeastern South Dakota, 40% 
 severities were common, while in central North Dakota plots, trace severities 
 were common.  On wild oats (Avena fatua), 20-40% severities were common in 
 southeastern North Dakota fields.  Crown rust was reported light to moderate 
 in south central and southeastern Wisconsin.  The most severe crown rust was 
 found where rust occurred early and conditions were conducive for rust 
 development.  Buckthorn growing in close proximity to oat fields provided the 
 initial inoculum in these areas, i.e., southeastern South Dakota and southern 
 Minnesota.  In early August, crown rust was severe in northern Wisconsin 
 fields.  Losses were more severe than last year in the northern oat-growing 
 area with the latest planted fields suffering the most damage.  
 
 During mid-April, traces of crown rust were found on wild oats growing in the 
 Sacramento Valley of California.
 
 
 Barley stem rust
 
 Barley stem rust was found for the first time this year in mid-July at trace 
 amounts in plots in west central Minnesota, in a field in south central South 
 Dakota and in plots and fields in southeastern North Dakota.  Traces also were 
 found on wild barley (Hordeum jubatum) growing on the roadside in northeastern 
 South Dakota.  In early August, traces of stem rust were found in plots and 
 fields in eastern North Dakota.   Much less barley stem rust was found in the 
 northern plains than last year, which correlates to less wheat stem rust race 
 QCCJ  (the race which infects barley)  being found as part of the stem rust 
 population throughout the United States.
 
 
 Barley leaf rust
 
 By the last week in March, severe leaf rust caused by Puccinia hordei  was 
 observed in one plot in south Texas.  In the other plots in the same nursery, 
 lighter amounts were found.  This year no barley leaf rust was found in 
 eastern Virginia, which is unusual because barley leaf rust has overwintered 
 there nearly every year.  In early June, traces of barley leaf rust were found 
 in plots in southern Illinois.  During the second week in June, leaf rust was 
 starting to increase in winter barley plots in Guelph, Canada, where it likely 
 overwintered.  
 
 By the third week in June traces of barley leaf rust were found in southern 
 Minnesota plots.  In late June, traces of barley leaf rust were observed in 
 plots in east central South Dakota and west central Minnesota.  In early July, 
 traces of leaf rust were found in a barley field in west central Minnesota.  
 During mid-July, traces of barley leaf rust were found on wild barley (Hordeum 
 jubatum) growing on the roadside in southern Minnesota and northeastern South 
 Dakota.  
 
 This year losses to barley leaf rust were minimal in the United States.
 
 
 Barley stripe rust
 
 By the third week in March, barley stripe rust was found in Central Valley, 
 Sacramento Co. and Sutter Co., California nurseries.  By the last week in 
 April, barley stripe rust was severe on susceptible cultivars growing in 
 nurseries and fields in the San Joaquin and Sacramento valleys of California.  
 Most of the released cultivars were susceptible to barley stripe rust, but 
 some of the lines in the nursery were resistant to the rust.  
 
 In mid-April, barley was heavily infected with barley stripe rust in winter 
 trial plots in northwestern Oregon at Corvallis.  The rust first developed in 
 susceptible border rows and then spread quickly to other cultivars in the 
 plots.  The most heavily rusted plants had 100% stripe rust on the bottom 
 three leaves.  By early May, stripe rust infection centers were observed in 
 northeastern Oregon winter and spring barley varietal trials (Fig. 2).  In 
 early May, 40% severities were reported in eastern Washington barley plots.  
 In mid-May, severe barley stripe rust was reported in experimental plots on 
 the western side of the Cascades in Washington.  In fields in eastern 
 Washington, moderate levels of barley stripe rust were found.  By early June, 
 in the Pacific Northwest barley stripe rust severities as high as l00% were 
 recorded in some western Washington winter barley plots.  Traces of barley 
 stripe rust were observed on spring barley in western Washington.   In mid-
 June, stripe rust was severe on winter barley in irrigated plots in north 
 central Oregon and in winter wheat plots and fields in northern Idaho and in  
 southwest Idaho plots.  An emergency label was obtained for use of Folicur to 
 control stripe rust on barley in the Pacific Northwest.  During the first week 
 in July, stripe rust was increasing in spring barley fields and plots in 
 northern Idaho and eastern Washington and in mid-July, rust was severe in 
 susceptible cultivars in this area.  In early August, light stripe rust was 
 reported in a spring barley trial plot in the Flathead Valley of northern 
 Montana.  In the Pacific Northwest this year, a range in adult plant 
 resistance was observed in different cultivars to barley stripe rust. 
 
 In 1996, severe barley stripe rust was reported from California and throughout 
 Oregon and Washington  Barley stripe rust is now firmly established in the 
 Pacific Northwest, where the climate is most favorable for its development.  
 As stated last year, this is a perfect example of a disease finding its niche 
 and increasing at a fast rate over a large area.
 
 
 Barley crown rust
 
 In mid-June, 15% crown rust severities were reported on barley plants in an 
 east central South Dakota nursery and by mid-July severities had reached 60%.  
 In mid-July, trace to 25% barley crown rust severity readings were reported  
 in barley plots and fields and wild barley in southeastern North Dakota.   By 
 late July, severities reached 40% in susceptible cultivars in the North Dakota 
 plots.  
 
 
 Rye stem rust
 
 In early August, traces of rye stem rust were found in a plot in west central 
 Minnesota.  
 
 
 Rye leaf rust
 
 In late April, trace-10% rye leaf rust severities were observed in central 
 Texas plots.  During the third week of June, traces of rye leaf rust were 
 found in southern Minnesota plots.   In early July, leaf rust was heavy on the 
 lower leaves of rye plants in a west central Wisconsin field.   In mid-July, 
 20% rye leaf rust severities were observed in a plot of the spring rye 
 cultivar Prolific in east central Minnesota.
 
 
 Crown rust on Buckthorn
 
 During the second week in June, light to moderate aecial infections were found 
 on buckthorn in east central Illinois, southern Minnesota and east central 
 South Dakota.  Due to the cool spring, infections on buckthorn appeared 2 to 3 
 weeks later than normal throughout this area.  During the last week in June, a 
 new wave of aecia were found on buckthorn growing in hedges in St. Paul, 
 Minnesota.  This is the latest that actively sporulating aecia were found on 
 buckthorn in Minnesota in the last 8 years.  Oats growing near these hedges 
 were heavily infected with crown rust.  
 
 In mid-June, aecial development was severe in the Guelph, Canada, area and 
 losses occurred in the latest maturing oat fields.  
 
 
 Stem rust on Barberry
 
 During mid-May, the aecial stage of stem rust was found on common barberry  
 (Berberis vulgaris) bushes in south central Wisconsin.  In early June, the 
 aecial stage was found on common barberry  in southeastern Minnesota.
 
 
 This is the last issue of the Cereal Rust Bulletin for the 1995-96 growing 
 season.  I would like to thank all of those who helped with the bulletin this 
 year, especially Mark Hughes who coordinates its distribution through the CRL 
 web page (http://www.umn.edu/rustlab/), e-mail (markh@puccini.crl.umn.edu) and 
 the post.  As most universities and research facilities now have access to the 
 Internet, we would like to use this system for exchanging information.  Any 
 reports of rust that you find in your area will be appreciated and this 
 information will be added to the CRB and possibly our web page. 
 Your comments on any aspect of the Cereal Rust Bulletin CRL web page are 
 welcome.
 
 David L. Long 
 (davidl@puccini.crl.umn.edu)
 
 Special Note:
 
 This and previous 1994-96 rust bulletins can be viewed on the Cereal Rust 
 Laboratory's web page (http://www.umn.edu/rustlab).  Several summary 
 statements of the cereal rust situation in specific regions this year have 
 been provided by cooperators in those regions.  The reports can be found on 
 our web page under the Cereal Rust: Bulletins, Updates section.