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Celaya, Mexico

Valencia-Botin A.J.,Produccion de Semillas | Valencia-Botin A.J.,University of Guadalajara | Mendoza-Onofre L.E.,Produccion de Semillas | Silva-Rojas H.V.,Produccion de Semillas | And 3 more authors.
Spanish Journal of Agricultural Research | Year: 2011

The effect of Pseudomonas syringae subsp. syringae on seed yield, aerial biomass production and partitioning in wheat (Triticum aestivum L.) is unknown. A field experiment was carried out in two locations of the Mexican Highlands (Montecillo and Chapingo) to evaluate the response of two wheat cultivars ('Seri M82' and 'Rebeca F2000') to four inoculum rates (106,8,10 cfu mL-1, plus a control without inoculum). Disease incidence and severity, seed yield, seed number and seed size were measured. At flowering and seed physiological maturity, aerial biomass production and distribution of main stem, secondary stems and total plant were recorded. Source-sink relationships during the grain filling period were estimated. Higher values of disease incidence and severity were observed at Chapingo; the same traits were also greater in 'Seri' than in 'Rebeca' at both sites (p < 0.05). Seed yield, seed number and seed size of 'Rebeca' were higher (p < 0.05) than that of 'Seri'. The pathogen reduced (p < 0.05) plant height, seed yield, seed yield components, and biomass production of most organs of main and secondary stems. The magnitude of the reductions was similar in both cultivars at both sites. The effect of the bacteria at each location was higher (p < 0.05) at greater doses affecting seed number more than seed weight. Stems prevailed as sink organs, while laminae, sheaths, spikes, and other vegetative parts predominated as source organs. Plant disease records should complement crop physiological variables to evaluate and to explain bacterial disease effects.

Solis-Moya E.,Programa de Trigo | Huerta-Espino J.,Instituto Nacional de Investigaciones Nucleares | Rodriguez-Garcia M.F.,Instituto Nacional de Investigaciones Nucleares | Hector E. Villasenor-Mir,Instituto Nacional de Investigaciones Nucleares | And 3 more authors.
Agrociencia | Year: 2013

Leaf rust caused by Puccinia triticina is one of the main diseases of wheat (Triticum spp. L.) in México. Through breeding it is possible to incorporate resistance genes in seedling and adult plant that maintain resistance to leaf rust for long periods of time. The objective of this study was to postulate genes of seedling and determine adult plant resistance to leaf rust in wheat varieties recommended for El Bajío, México. The genes in seedlings were postulated, under greenhouse conditions, in 11 varieties and in the field adult plant resistance was determined. In durum wheat, genes Lr10 and 23 were postulated and one not identified. Lr10 and 23 in seedling and adult plant are ineffective to race BBG/BN that overcame the resistance of durum wheat varieties grown in México. In the eight bread wheat varieties the resistance genes Lr1, 3, 3bg, 10, 13, 14a, 16, 17, 23, 27 and 31, alone or in combinations were postulated. These do not differ substantially from those postulated in the varieties released in México until 1990. In the field tests adult plant resistance was identified as different from that of the seedling, but at levels that should be improved with larger number of durable resistance genes and diversifying the sources of resistance.

Ledesma-Ramirez L.,Programa de Trigo | Solis-Moya E.,Programa de Trigo | Suaste-Franco M.P.,Programa de Trigo | Rodriguez-Caracheo J.F.,Programa de Trigo | de la Cruz-Gonzalez M.L.,Programa de Trigo
Agrociencia | Year: 2012

El Bajío is one of the principal wheat (Triticum spp.) producing areas in México, as it contributes 28 % of the national total. Among the principal problems affecting wheat production in El Bajío is lack of water, given that the groundwater balance presents an important deficit. Through genetic breeding it is possible to obtain genotypes with high yields, under normal and restricted irrigation. The objective of the present study was to analyze the genotype-by-environment interaction of eight wheat cultivars in three irrigation calendars in Celaya, Guanajuato, México, with the GGE biplot model. In the fall-winter agricultural cycles of 1999 to 2008, five flour wheat (Triticum aestivum L.) cultivars were evaluated, and three of crystalline wheat (Triticum durum Desf.) with two, three and four irrigations (0-55, 0-45-75 and 0-45-75-100 d after sowing). The experimental design was complete randomized blocks with three replicates. For the analysis of phenotypic stability, the GGE biplot model was used. The model explained 78 % of the combined effects of genotypes and of the genotype-by-environment interaction, the CPI 63 % and the CP2 15 % of the variability due to genotypes and the genotype-by-environment interaction. According to the model, Bárcenas S2002 was the most productive cultivar in 24 environments, Eneida F94 was outstanding in two and Camón 5 in one. Salamanca S75 and Saturno S86 obtained the lowest values of the CP2; therefore, this model classified them as the most stable. The results obtained showed that Bárcenas S2002 was the best both under normal and restricted irrigation, and that phenotypic stability is useful only when it is considered together with yield through environments.

Suaste-Franco M.P.,Programa de Trigo | Solis-Moya E.,Programa de Trigo | Ledesma-Ramirez L.,Programa de Trigo | de la Cruz-Gonzalez M.L.,Programa de Trigo | And 2 more authors.
Agrociencia | Year: 2013

Wheat (Triticum aestivum L.) yields depend on date, method and sowing density. The objective of this research was to study the effect of the method and sowing density on intermediate and late sowing dates on the grain yield of two wheat cultivars. In the fall-winter seasons of 2006-2008, two sowing dates (December 22 and January 12), four sowing methods (conventional flat sowing of four and six rows and raised bed sowing of two and three rows), four plant densities (60, 120, 180 and 240 kg seed ha-1) and two cultivars (Bárcenas S2002 and Josecha F2007), were evaluated. The experimental design was a randomized block with a split-plot arrangement with four replications. The highest yield was obtained in the first sowing date in the two cycles (p≤0.01). The conventional flat methods outperformed the sowing in rows (p≤0.01). The seeding rate of 180 kg ha-1 exceeded densities of 60 and 120 and equaled or exceeded that of 240 kg ha-1. The variety Josecha F2007 outperformed Bárcenas S2002 in 2006-2007. Sowings in late December and early January with 180 kg ha-1 seed outperformed the regional control with 240 kg ha-1 and that recommend for this region with 120 kg ha-1.

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