000			03119nam a22004697a 4500
001			G65769
003			MX-TxCIM
005			20190401213003.0
008			121211s ||||f| 0 p|p||0|| |
020			_a968-6923-93-4
040			_aMX-TxCIM
072		0	_aF01
072		0	_aH50
082	0	4	_a633.153 _bEDM
100	1		_aSantos, M.X. _uDeveloping Drought- and Low N-Tolerant Maize. Proceedings of a Symposium; El Batan, Mex. (Mexico); 25- 29 Mar 1996
110	2		_aCentro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT), Mexico DF (Mexico)
245	0	0	_aDrought and low N status limiting maize production in Brazil
260			_aMexico, DF (Mexico) _bCIMMYT : _c1997
340			_aPrinted
520			_aThe Brazilian territory has an area of approximately 8.5 million km2, which is divided into five main regions with particular characteristics related to average climatic conditions and natural soil fertility. Climatic variations may be very accentuated within each particular region, but a common feature is the irregular distribution of rains, which causes droughts of variable intensities. Maize is an important crop in most Brazilian regions, occupying approximately 13 million ha and producing annually 28-30 million tons of grain. It has been estimated that drought problems, depending on year and intensity, reduce maize production by 14% to 28%. Another limiting factor for maize production in Brazil is the low natural fertility of the soils, especially in nutrients like phosphorus and nitrogen (N). It has been estimated that 80% of the soils in Brazil are deficient in N. Although fertilization is a common solution to this problem, its high costs make this option inaccessible to many farmers. The amount of supplemental N applied to maize in Brazil is low (36 kg N/ha), and of this only 50% to 60% is utilized by the crop. Considering that low N availability and drought are severe constraints to maize crops in Brazil, the National Maize and Sorghum Research Center (CNPMS/EMBRAPA) has initiated breeding programs aimed at the development of germplasm that performs more efficiently under these two limiting conditions. Several genotypes have been developed on the basis of anthesis-silking interval selection for drought tolerance, and a variety is being developed for soils with low fertility where N is the most limiting nutrient.
546			_aEnglish
591			_a9801|AGRIS 9702
593			_aJose Juan Caballero
595			_aCPC
650	1	0	_aBrazil
650	1	0	_aClimatic factors _91048
650	1	0	_aDrought resistance
650	1	0	_91081 _aDrought stress _gAGROVOC
650	1	0	_aNitrogen content
650	1	0	_aPlant production _91212
653	0		_aCIMMYT
650	1	0	_91314 _aZea mays _gAGROVOC
650	1	0	_91952 _aSoil fertility _gAGROVOC
700	1		_aCoelho, A.M., _ecoaut.
700	1		_aEdmeades, G.O.|Banziger, M.|Mickelson, H.R.|Pena-Valdivia, C.B. _eeds.
700	1		_aFranca, G.E., _ecoaut.
700	1		_aGama, E.E.G., _ecoaut.
700	1		_aGuimaraes, P.E.O., _ecoaut.
700	1		_aLopes, M.A., _ecoaut.
700	1		_aParentoni, S.N., _ecoaut.
942			_cPRO
999			_c3673 _d3673