Competitiveness-shifts from weeds to crops using arbuscular fungi

Non-Peer ReviewedArbuscular fungi (AF) colonize ca. 80% of terrestrial plant roots and typically improve their growth by enhancing nutrient uptake, reducing disease severity and/or imparting resistance to abiotic stress. Therefore, AF-colonized crop cultivars exhibit early vigor and superior growth compared to cultivars not colonized by AF. However, routine AF inoculation of crops is limited because of their obligate nature. Nevertheless, there are strategies that can be readily adopted by growers to exploit the indigenous AF community. Our project aimed at determining the relationship between the mycorrhizal dependency of crops and crop competitiveness against weeds. The mycorrhizal dependency of eight barley and eight wheat cultivars on an AF mixture resembling that of an indigenous AF community was evaluated in natural soil. There were significant differences between the cultivars in their response to AF. The most and least mycorrhizal cultivar (based on biomass) were evaluated for their competitiveness against wild oat at four crop:weed density levels (1:0.5; 1:1; 1:2; 1:4) in soil with and without the AF mixture. Results showed that the most AF dependent cultivar in both crops exhibited superior growth and competitiveness against wild oat up to a level of 1:1 crop:weed density. This confirms that mycorrhizal dependency is partially linked to crop competitiveness against weeds and that the choice of cultivar may be a strategy which can enhance crop competitiveness while reducing chemical herbicide use

Arbuscular mycorrhizal fungi influence competition between barley and wild oat

Non-Peer ReviewedArbuscular mycorrhizal fungi (AMF) are soil fungi that intimately associate with most crops and influence their productivity. This study determined (i) the mycorrhizal dependency of eight barley cultivars and (ii) whether barley competitiveness against wild oat was linked to its mycorrhizal dependency. Of the eight cultivars tested, Virden was the most dependent on AMF whereas CDC Earl was the least dependent; Earl and Virden were therefore evaluated for competitiveness against wild oat at weed density ratios of 1:0.5, 1;1, 1:2 and 1:4 with or without AMF. Regardless of the AMF treatment, the total shoot dry weight of both barley varieties decreased with increasing crop:weed ratio. Earl derived 32% less benefit than Virden at a crop:weed ratio of 1: 0.5, and at a crop:weed ratio of 1:1, the total shoot dry weight of wild oat competing against Virden was significantly lower than that of wild oat competing against Earl. Regardless of the crop:weed ratio, (i) both barley varieties responded positively to the AMF mixture, (ii) the total shoot dry weight of AMF-inoculated Virden was 13% higher than that of AMF-inoculated Earl, and (iii) the shoot dry matter ratio of barley:wild oat was greater for AMF-inoculated Virden than Earl. At crop: weed ratios of up to 1:1, AMF-inoculated Virden plants had significantly more total shoot biomass than uninoculated Virden, whereas this was not the case with Earl. In general, wild oat competing against AMF-inoculated Virden had the least shoot dry matter at all the crop:weed ratios compared to all other treatments. These results suggest that the highly mycorrhizal Virden appeared to be more competitive than Earl and indicates that barley competitiveness may be partially linked to its mycorrhizal dependency

Fame profiles of Rhizobium leguminosarum strains isolated from Saskatchewan soils

Non-Peer Reviewe

Fontes de lipídios na dieta de poedeiras: desempenho produtivo e qualidade dos ovos Lipids sources on layer hen diet: performance and egg quality

Os efeitos de fontes de lipídios na dieta de poedeiras sobre o desempenho produtivo e a qualidade do ovo foram verificados em dois experimentos. Foram utilizados quatro tratamentos, definidos de acordo com a fonte lipídica adicionada nas rações: óleo de soja, óleo de girassol, óleo de linhaça e ração controle (sem adição de óleo). Os experimentos foram realizados com poedeiras de 20 e 54 semanas de idade, respectivamente, com duração de oito semanas. Avaliaram-se os parâmetros produtivos - consumo de ração, conversão alimentar, produção e peso dos ovos - e de qualidade do ovo - porcentagens de gema, albúmen e casca, sólidos da gema, unidades Haugh, pH do albúmen, e cor da gema. Somente o peso do ovo de poedeiras jovens foi afetado pela inclusão de óleos vegetais na ração. Esses ovos apresentaram maior peso e maior porcentagem de gema que os produzidos pelas poedeiras jovens alimentadas com ração-controle. Concluiu-se que a utilização de diferentes fontes de lipídios na ração de poedeiras não altera o desempenho produtivo e a qualidade interna dos ovos, com exceção do peso do ovo de poedeiras novas, que aumenta com a utilização de óleos vegetais.<br>The effects of different sources of fat in the diet of layer hens on performance and egg quality were recorded in two experiments. Four treatments were defined by the lipid source added to the diets: soybean oil, sunflower oil, linseed oil and control diet (without oil added). The experiments were carried out with layers from 20 to 54 weeks of age, respectively, for eight weeks. Production parameters (feed intake, feed conversion, egg production, and egg weight) and quality of eggs (percentages of yolk, albumen, and shell; total solids of yolk; Haugh units; pH of albumen; and yolk color) were evaluated. Among the parameters of production and quality of the eggs, only the weight of eggs and percentage of yolk of young hens were affected by the inclusion of vegetable oils in the diet. These eggs were significantly heavier and had higher percentage when compared with the eggs of hens fed the control diet. It was concluded that the utilization of different sources of oils in layers diet did not change performance and egg quality , except egg weigh of young layers, that increased with the utilization of vegetables oils

Desempenho de frangos de corte alimentados com ingrediente de alta digestibilidade nas fases de criação pré-inicial e inicial Performance of broilers fed with highly digestible ingredient in the prestarter and starter raising periods

O objetivo deste trabalho foi avaliar o efeito de dieta, com inclusão de um núcleo energético-proteico (NEP) de alta digestibilidade, no desempenho produtivo e características de carcaça de frangos de corte. O NEP constituiu-se de composto de óleo degomado de soja, milho pré-gelatinizado, soja biprocessada, mananoligossacarídeos e peptídeos. O total de 864 pintainhos machos, da linhagem AgRoss 508, com um dia de idade, foram pesados individualmente e distribuídos em blocos ao acaso. Os tratamentos consistiram de suplementos com diferentes teores de NEP, com oito repetições com 27 aves cada: T1, controle, 0% de NEP; T2, 7% de NEP (1-7 dias) e 3,5% de NEP (8-21 dias); T3, 14% de NEP (1-7 dias) e 7% de NEP (8-21 dias); e T4, 21% de NEP (1-7 dias) e 10,5% de NEP (8-21 dias). Aos 21 dias de idade, o peso corporal, ganho de peso, consumo médio de ração, conversão alimentar e rendimento de carcaça e cortes não foram afetados significativamente pelos tratamentos experimentais. A utilização de NEP na dieta de frangos de corte não altera o desempenho das aves e não interfere nas variáveis de características de carcaça.<br>The objective of this work was to evaluate the effect of the diet, with the inclusion of an energetic-protein nucleus (EPN) composed of highly digestible ingredients, on the productive performance and carcass traits of broiler chicks. The nucleus was composed by degummed soybean oil, pre-gelatinized corn, twice-processed soybean, mannanoligosaccharides and peptides. The total of 864 male AgRoss 508 broiler, with one day of age, were weighed individually and distributed in a randomized block design. Treatments consisted of: T1, control, 0% EPN; T2, 7% EPN (1-7 days) and 3.5% EPN (8-21 days); T3, 14% EPN (1-7 days) and 7% EPN (8-21 days); and T4, 21% EPN (1-7 days) and 10.5% EPN (8-21 days of age). At 21 days of age, body weight, weight gain, average feed intake, feed conversion and carcass and cut-ups yield were not significantly affected by treatments. The EPN inclusion in the diets did not influence the performance, carcass traits and cut-ups of broilers