TY  - PRO
AU  - Reis,E.M.
AU  - Casa,R.T.
AU  - Duveiller,E.|Dubin,H.J.|Reeves,J.|McNab,A.
AU  - Medeiros,C.A.
ED  - Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT), Mexico DF (Mexico)
TI  - Control of leaf blights of wheat by elimination of the inoculum source
SN  - 970-648-001-3
U1  - 633.1194 
PY  - 1998///
CY  - Mexico, DF (Mexico)
PB  - CIMMYT|UCL|BADC
KW  - Blights
KW  - Climatic factors
KW  - Disease control
KW  - Inoculation methods
KW  - Pathogens
KW  - Plant diseases
KW  - AGROVOC
KW  - Triticum
KW  - CIMMYT
N2  - The main inoculum sources of wheat leaf blights are infected seed and crop residues. Infected seeds introduce the pathogens into newly cultivated areas or to areas where the inoculum was eliminated through crop rotation with non-host crops. Disease transmission rate from seeds is high and very efficient. High sporulation on coleoptile tips confirm the potential of seed inoculum for causing epidemics, depending 01l climatic conditions during emergence to tillering. Such findings highlighted the need for eradication of seedborne inoculum. Once inoculum is introduced by seed, disease develops on above-ground plant parts where pathogens sporulate. Conidia are transported to new infection sites and to the soil by wind and rain splashes. Inoculum in the soil, as free dormant conidia (Bipolaris sorokiniana), increases with the amount of necrotic tissue. Sporulation continues in the residue until its complete decomposition. Dormant conidia may survive free in the soil for up to 37 months. Crop rotation may eliminate pathogens or reduce their inoculum to such an extent that they cannot cause an epidemic, even under favorable weather. Spot blotch may be economically controlled by treating seeds with fungicides and by rotating crops. In this case, epidemics do not reach the economical damage threshold level of 70-80% foliar incidence
ER  -