Produção estacional, índice de área foliar e interceptação luminosa de cultivares de alfafa sob pastejo

Ferragine, M. D. C.; Pedreira, Carlos Guilherme Silveira; Otani, Lyssa; Tonato, F.

doi:10.1590/s0100-204x2004001000013

Cited by 4 publications

(2 citation statements)

References 8 publications

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“…Ferragine et al (2004), in São Paulo, showed bigger survival in Alfagraze (25.9%) comparing to ABT 805 (10.7%) when grazed, enhancing this hypothesis. The authors pointed similarities between the productions of ABT 805 (17,600 kg DM/ha/year) and Crioula (18,300 kg DM/ha/year), significantly higher than Alfagraze (13,300 kg DM/ha), with rotated stocking rate.…”

Section: Resultsmentioning

confidence: 80%

Grazing resistance mechanisms in alfalfas of different aptitude in the juvenile stage

Scheffer-Basso

Muniz

2010

R. Bras. Zootec.

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-This study aimed at verifying whether juvenile plants of alfalfa cultivars with different aptitude (grazingtype: Alfagraze and ABT 805; hay-type: Crioula) show morphophysiological differences in order to develop a protocol for early selection for grazing persistence. Two experiments were conducted in a greenhouse, in completely randomized design and three repeplicates. In Experiment 1, plants were evaluated from successive destructive harvests at 60, 90, 120 and 150 days of age. In Experiment 2, plants at 150 days of age were cut to a 10-cm stubble and harvested at 15 and 30 days of regrowth. In Experiment 1, Alfagraze showed the lowest height (19 cm), internode length (1.4 cm) and apical bud accessibility (15.3 cm). Grazing-type cultivars did not differ significantly for subterranean hypocotyl diameter (3.5 mm) on the mean ages, and at 120 days of age they had lower number of leaves (56/ Para estes caracteres a seleção precoce é possível e a Alfagraze pode ser utilizada como testemunha.Palavras-chave: ABT 805, Alfagraze, Crioula, evitamento (escape), tolerância R. Bras.

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Section: Resultsmentioning

confidence: 80%

Grazing resistance mechanisms in alfalfas of different aptitude in the juvenile stage

Scheffer-Basso

Muniz

2010

R. Bras. Zootec.

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“…A altura do dossel no pré-corte foi afetada pela interação cultivar × frequência × estação (P<0,0001 -----------------------------------cm ----------------------------- -------------------------o em relação a horizontal-------------------- ----------------------------------------% ----------------------------- ----------------------------------------% ----------------------------- ----------------------------------kg MS m -3 ----------------------------- 1956;ETHREDGE et al, 1973;PEDREIRA et al 1999;MANDEBVU et al,1999 (FAGUNDES et al, 1999;GERDES et al, 2000;SOARES FILHO et al, 2002;FERRAGINE et al, 2004;. Nesse sentido, a menor estacionalidade de produção do capim Vaquero é resultado da baixa produção de forragem na primavera e verão e não por acentuada produção de forragem no outono e inverno (Tabela 4).…”

Section: Altura Do Dossel No Pré-corteunclassified

Desempenho produtivo e análise de crescimento de capins do gênero Cynodon em resposta à frequência de desfolhação

Silva¹

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Productive performance and growth analysis of Cynodon grasses in response to frequency of defoliation In Brazil, forage production is key because it is the main feed resource used to feed the largest commercial cattle herd in the world. Thus, it is essential to know the management factors that influence forage production, and that can be uses in decision-making within the production system. However, for some forages, suchas grasses of the genus Cynodon, technical and scientific information are still scarce in tropical regions, especially for recentlyintroduced genotypes, such as Jiggs and Vaquero bermudagrasses. This narrows the range of opportunity for efficient use of these materials, since differences between Cynodons, for subtle they are, suggest the need forgenotype-specific management so that each grass can be used to its full potential. The study of forages harvested under different frequencies of defoliation can help differentiate yield potential and best utilization methods of species and cultivars under such managements if they are established from information on the ecophysiological limits resulting from the management proposed. The objective of this study was to describe and explain productive, morphological and structural traits, Tifton 85, Jiggs and Vaquero bermudagrasses, and growth patterns of Tifton 85 and Jiggs bermudagrasses in response to frequencies of defoliation (every 14, 28 and 42 days). The trial was carried out at Escola Superior de Agricultura "Luiz de Queiroz", USP, in Piracicaba-SP, from December 21, 2010 through December 21, 2011. A completely randomized design was used with a factorial arrangement, with four replications. Responses measured included total and seasonal yield, plant-part composition of the forage harvested and canopy characteristics, pre-harvest sward height, LAI and light interception of Tifton 85, Jiggs and Vaquero bermudagrasses. Growth analysis was also performed on Tifton 85 and Jiggs bermudagrasses, including crop growth rate (CGR), relative growth rate (RGR), net assimilation rate (NAR), morphological characteristics and harvest efficiency (HE). In spring and summer, Jiggs bermudagrass is as productive as Tifton 85, but Tifton 85 forage is leafier. Under the 42-d frequency Jiggs is more productive than the other cultivars for total forage production (25.96 Mg MS ha-1), but is similar to Tifton 85 at the frequency of 28 days (16.64 Mg MS ha-1). For optimal forage production and leaf / stem ratio, in summer and spring, Jiggs and Tifton 85 should be harvested every 28 days, and Vaquero every 42 days. Vaquero has a less pronounced seasonal growth, mainly because poor forage production in spring and summer. Regardless of the clipping frequency, Jiggs had great net assimilation rate (NAR) (10.56 g m 2 day-1). Plant-part composition and canopy structure make for high relative growth rates (RGR) of Jiggs, similar to that of Tifton 85 in spring and summer. Grasses with similar level of production in the growing season may have important differences in canopy structure ...

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Validating the NAAIC alfalfa grazing tolerance standard test and assessing physiological responses to grazing in a tropical environment

Pedreira

Silva

Ferragine³

et al. 2020

Crop Science

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The North American Alfalfa Improvement Conference (NAAIC) is the curator of a series of standard tests that allow validation of any alfalfa (Medicago sativa L.) cultivar's pest resistance and agronomic attributes. One NAAIC test is for grazing tolerance, an important trait in the tropics. Our objectives were to validate the NAAIC grazing tolerance test and to describe physiological characteristics related to alfalfa grazing persistence in a tropical environment. Treatments were combinations of five cultivars (varying in fall dormancy and grazing tolerance) and two grazing methods, applied from March 2001 to January 2002 (330 d) in Piracicaba, Brazil. Plots were grazed every 7 d (mimicking continuous stocking) or every 28/42 d in springsummer/autumn-winter (graze-rest scheme of rotational stocking), always to 7-cm stubble. 'Alfagraze' (fall dormant, tolerant) and 'ABT 805' (fall nondormant, tolerant) had greater survival under both grazing environments compared with the nontolerant checks 'Pioneer 5432' (fall dormant, intolerant) and 'CUF101' (fall nondormant, intolerant). The widely used Brazilian cultivar 'Crioula' showed poor survival, suggesting that adaption did not affect the test, and Crioula is now described as grazing intolerant. Rotational stocking favored persistence of even the tolerant checks. This was related to maintenance of carbohydrate reserve pools, which declined by 80% in roots and by 85% in plant crowns when plots were grazed every 7 d, but only by 46 and 59%, respectively, under the 28/42 d grazing regime. The NAAIC standard test should be useful to screen cultivars for grazing tolerance in tropical or temperate environments. The use of rotational stocking is best for even grazing-tolerant cultivars.

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Produção estacional, índice de área foliar e interceptação luminosa de cultivares de alfafa sob pastejo

Cited by 4 publications

References 8 publications

Grazing resistance mechanisms in alfalfas of different aptitude in the juvenile stage

Grazing resistance mechanisms in alfalfas of different aptitude in the juvenile stage

Desempenho produtivo e análise de crescimento de capins do gênero Cynodon em resposta à frequência de desfolhação

Validating the NAAIC alfalfa grazing tolerance standard test and assessing physiological responses to grazing in a tropical environment

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