Yield loss caused by bacterial streak in the wheat

( Xanthomonas translucens pv. translucens )

Bacterial leaf streak (BLS) - Black chaff

-: المرض أهمية لــ تـصل خسائر يسبب الحاالت بعض والية% 40فى امريكا .idahoفى فى بنسبة للسنابل عقم يسبب بالرش% .10-5ايضا الرى عند فى تكمن المرض )- خطورة ) الحبوب: البذور فى الكامنة االمراض من

– ) الشعير حبوب تنتج التى النباتات جميع يصيب حيث واسع الـعوائلى مداه – ( درجات – – النباتات لهذه المصاحبة الحشائش بعض القمح الشوفان

هى له المناسبة ذات 30-15الحرارة دافئة و رطوبة بها التى المناطق درجةـــدرجات – فى فجائى تغير بها التى المناطق فى ينتشر كذلك باردة ليالى

الحرارة بها ينتشر الذى - :- الدول - - - - بيرو- البرازيل االرجنتين المكسيك ـكندا أمريكا

- - - - - - - - - ليبيا- تنزانيا تركيا اليمن اسرائيل سوريا الهند ايران باـكستان الصين. - - استراليا- موروكو زامبيا مدغشقر

البرودة لشدة اوروبا وسط فى ينتشر ال

Symptoms

Bacterial leaf streak (BLS) - Black chaff

( Disease cycle of Xanthomonas translucens pv. translucens)

Condensed summary of the Zadoks two-digit code system for growth staging in wheat with corresponding Feekes scale

Zadoks code

Description CorrespondingFeekes code

Principalstage

Secondarystage

3 Stem elongation 1 First node detectable 6 2 Second node detectable 7 3 Third node detectable 7 Flag leaf just visible 8 9 Flag leaf collar just visible 9

4 Boot 1 Flag leaf sheath extending 3 Boot just beginning to swell 5 Boot swollen 10

7 Flag leaf sheath opening

9 First awns visible 5 Head emergence

1 First spikelet of head just visible 10.1 3 One-fourth of head emerged 10.2 5 One-half of head emerged 10.3 7 Three-fourths of head emerged 10.4 9 Head emergence complete 10.5

6 Flowering (not readily visible in barley)

1 Beginning of flowering 10.5.1 5 Half of florets have flowered 10.5.2 9 Flowering complete

7 Milk development in kernel 1 Kernel watery ripe 10.5.4 3 Early milk

5 Medium milk 11.1

7 Late milk 8 Dough development in kernel

3 Early dough 5 Soft dough 11.2 7 Hard dough, head losing green color 9 Approximate physiological maturity

9 Ripening

1 Kernel hard (difficult todivide with thumbnail) 11.3

2 Kernel cannot be dented bythumbnail, harvest ripe 11.4

TilleringSTAGE 1-5

Stem extensionSTAGE 6-10

HeadingSTAGE

10.1-10.5

Ripening

STAGE 11

مرحلة التسميد

بالمبيدات المعاملة فترةالفطرية

Head at approximately physiological maturity when the kernels have attained maximum dry weight. Note the green color is gone from the peduncle and head parts

Soft dough Hard doughKernel watery ripe

Milk Dough

Stage (10.5.4 – 11.2)

Relationship between the grain weight per spike and the severity of bacterial streak at GS10.5.4 caused by Xanthomonas translucens pv. translucens in the winter wheat cultivar Savannah inBaton Rouge, Louisiana, in 1993 and 1994.

Relationship between the number of kernels per spike and the severity of bacterial streak atGS 10.5.4 caused by Xanthomonas translucens pv. translucens in the winter wheat cultivar Savannahin Baton Rouge, Louisiana, in 1993 and 1994.

Relationship between the grain weight per spike and the severity of bacterial streak at GS 10.5.4 caused by Xanthomonas translucens pv. translucens in the winter wheat cultivar Florida 304 in Alexandria and Baton Rouge, Louisiana.

Data were analyzed with the GLM procedure of SAS(SAS Institute, Cary, NC) using the fixed model :

Yijk = µ+R(L) ij + Lj +Tk + TLkj + Eijk

Yijk is the response of treatment (T) k in replication (R)i within location (L)j ; µ is the overall mean: TLkj is the interaction between treatments and locations ; and Eijk is the residual.

Severity (%)of leaf rust on the flag leaf

10 25 40 65 100

Growth stage… ……………

…………% Yield loss… …………………

……………

Flowering 10 15 20 30 35

Milk 2 5 8 14 20

Soft dough 1 3 4 7 10

Hard dough 1 1 1 3 5

Approximate percent loss of yield caused by leaf rust at combinations of leaf rust severity and growth stage of wheat