000			02820nam a22004097a 4500
001			G70467
003			MX-TxCIM
005			20211006075510.0
008			121211s ||||f| 0 p|p||0|| |
020			_a92-9146-058-3
040			_aMX-TxCIM
072		0	_aH20
090			_aLook under series title
100	1		_aVan Dyk, K. _uRegional Wheat Workshop for Eastern, Central and Southern Africa, 10; University of Stellenbosch, South Africa; 14-18 Sep 1998
110	2		_aCentro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT), Addis Ababa (Ethiopia)
245	0	0	_aPatchy stunting of wheat and barley in Tanzania -- preliminary results
260			_aAddis Ababa (Ethiopia) _bCIMMYT : _c1999
340			_aPrinted
500			_aAbstract only
520			_aPatchy stunting (PS) of cereals has been observed on wheat farms of the Hanang Wheat Complex, Tanzania, since the early 1970s and recently also on farms at West Kilimanjaro and Karatu. Estimated yield losses amount to approximately 5-30%, but could be as high as 40-50% during drier years on newly-broken land. A survey was conducted to determine the incidence of the PS pathogen (Rhizoctonia solani AG-6) and other pathogenic fungi in the main production areas and in different soil types. Potentially pathogenic fungal species comrnonly isolated from roots and crowns of wheat and barley included: Bipolaris sorokiniana, Fusarium equiseti, F. nygamai, F. oxysporum, F. solani, Periconia macrospinosa and Rhizoctonia spp. Roots yielded mainly Fusarium spp., whereas B. sorokiniana was predominantly and almost exclusively isolated from crowns. The incidence of fungi in the various soil types and production areas did not differ significantly. Contrary to crater disease of wheat in South Africa, PS occurs not only in black montmorillonitic clay soils, but also in clay, clay loam and sandy clay soils. However, the disease is more pronounced in the predominating black clay soils. Chemical analysis of the different soil types revealed significantly higher levels of Ca, Mg and Na and a lower K content in the black soil compared to the other soil types. Accordingly, in vitro growth of R. solani AG-6 was stimulated by increasing levels of Ca, Mg and Na, whereas high concentrations of K inhibited the organism.
546			_aEnglish
591			_a0007|AGRIS 0101|AL-Wheat Program
593			_aJose Juan Caballero
595			_aCPC
650	1	0	_aBarley _91018
650	1	7	_aDisease resistance _gAGROVOC _2 _91077
650	1	0	_aPathogens _91197
650	1	7	_aPlant diseases _gAGROVOC _2 _91206
650	1	0	_aRhizoctonia solani
650	1	0	_aTanzania
653	0		_aCIMMYT
650	1	7	_aTriticum _gAGROVOC _2 _91295
700	1		_aDu Toit Meiring, J.J., _ecoaut.
700	1		_aKuwite, C.A., _ecoaut.
700	1		_aMeyer L., _ecoaut.
942			_cPRO
999			_c4521 _d4521