Wheat Cultivars: Response to Irrigation and Sowing Dates

Abstract

This study was carried out in an Alfisol-Oxisol transition sandy-clay texture, using six wheat cultivars (Triticum aestivum, L.): two tall and tolerant to soil aluminium toxicity (BH-1146, and IAC-18), and four semi-dwarf cultivars - Anahuac, IAC-162, IAC-24, and IAC-60 - of which only the first two are sensitive to soil aluminium toxicity. Two minimum soil water potentials (ys) levels were used: 1. watered, when Ys reached about -0.05 MPa; 2. dry, when the water potential reached around -1.5 MPa. Two sowing dates, 05/22/92 and 06/11/92, were used. The results showed that Anahuac and IAC-60 are the most indicated cultivars for the studied region; when irrigated all cultivars presented similar yield level under no irrigation conditions; the irrigation was not sufficient to avoid yield differences between the two growing seasons; differences in rainfall were important for the crop in the dry treatment for both seasons.<br>Este trabalho foi desenvolvido em um solo Alfisol intergrade para Oxisol, textura areno-argilosa, utilizando-se seis cultivares de trigo (Triticum aestivum, L.): dois de porte alto e tolerantes ao alumínio tóxico do solo (BH-1146 e IAC-18) e quatro de porte semi-anão (Anahuac, IAC-162, IAC-24 e IAC-60, sendo apenas os dois primeiros sensíveis ao alumínio tóxico do solo). Dois potenciais de umidade do solo (Ys) mínimos definiam dois tratamentos de umidade do solo: 1. Úmido, as plantas eram irrigadas quando Ys atingia as imediações de -0,05 MPa; e 2. Seco, quando as plantas receberiam irrigação com Ys em torno de -1,5 MPa. Duas épocas de plantio foram usadas: 22/05/96 e 11/06/96. Os resultados permitiram as seguintes conclusões principais: os cultivares Anahuac e IAC-60 são os mais indicados para a regão estudada; todos os cultivares apresentaram produtividade semelhante quando não se procedeu à aplicação artificial de água; a irrigação não foi suficiente para para evitar diferenças de rendimento entre as duas épocas de plantio deste ensaio; as diferenças que ocorreram nas precipitações pluviométricas entre as duas épocas afetaram a produtividade das plantas no tratamento que não recebeu irrigação

Effect of Nitrogen Fertilizer and Supplementary Irrigation on Yield and Quality of Some Local Bread Wheat Varieties

“…Cultivars showed significant differences in these characters at both locations, IPA-99 variety recorded highest number of spike/m 2 at Telkaef site, while Iraq cultivar gave highest value for number of grain/spike at both locations which was significantly different from other cultivars this was related with reduction in number of spike/m 2 which led to minimize the competition on nutrient absorption from soil and those synthesized in plant as well. These results are in general agreement to those of Klar and Hossokawa (1996) and Saleem et al (2003) . The effect of interaction between irrigation and fertilizer was insignificant for number of spikes/m 2 at Telkaef location, although it caused a remarkable increment with (SI) or N fertilizer or both which was significant at Mosul location, maximum number of spike/m 2 was recorded for the combination of (SI) with N fertilizer which was (341.8-380) spikes/m 2 at Telkaef and Mosul respectively, number of grain/spike was increased at both locations with (SI) alone or (SI) with N fertilizer which reached 51.28 and 42.51 at Telkaef and Mosul, while least number of grain/spike was recorded with no irrigation and fertilizer which was 42.72 and 39.07 for both locations, respectively.…”

“…It is well known that the moisture is the major limiting factor determining grain yield potential under arid and semi-arid regions .Cultivars were also significantly different in grain yield, IPA-99 gave highest grain yield at both location which were 4623, 4250 kg/ha at Telkaef and Mosul, respectively, while minimum yield was for Abu-Ghraib/3 and Iraq at both location. Differences between cultivars have been also reported by Klar and Hossokawa (1996) Al-Samaray (2002) Boehm et al (2004( ) Beuerlein et al (2004. Such differences are mainly due to their genetic potential, production capacity, and efficiency in speed of nitrogen absorption .…”