Invited Synthesis Paper: Regulation of Tillering by Apical Dominance: Chronology, Interpretive Value, and Current Perspectives

Murphy, Jeffrey S.; Briske, David D.

doi:10.2307/4002896

Cited by 94 publications

(80 citation statements)

References 75 publications

(83 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Da primavera para o verão, a massa de colmos aumentou, provavelmente como resposta estímulo ao perfilhamento decorrente da desfolhação (Butler & Briske, 1988). Além disso, outras variáveis ambientais além da luminosidade (temperatura, condição hídrica) podem atuar no perfilhamento e ser tão importante quanto fatores hormonais no desenvolvimento de gemas e no estímulo ao perfilhamento (Murphy & Briske, 1992).…”

Section: Resultsunclassified

Acúmulo de forragem durante a rebrotação de capim-xaraés submetido a três estratégias de desfolhação

Pedreira

Silva

2009

R. Bras. Zootec.

View full text Add to dashboard Cite

RESUMO -Objetivou-se comparar a dinâmica do acúmulo de forragem em pastos de capim-xaraés [Brachiaria brizantha (A. Rich.) Stapf. cv. Xaraés] submetidos a três estratégias de desfolhação intermitente, uma baseada no calendário (pastejo a cada 28 dias) e duas na interceptação luminosa (IL), aos 95 ou 100% de interceptação luminosa. A massa de forragem (MF) pré-pastejo foi maior na estratégia de desfolhação aos 100% de interceptação de luz. Os piquetes pastejados aos 95% de interceptação de luz e a cada 28 dias apresentaram menores massas de forragem e não diferiram entre si na primavera. O pastejo aos 95% de interceptação de luz aumentou a proporção de folhas, apesar das menores massas pré-pastejo. O pastejo aos 100% de interceptação de luz resultou na menor porcentagem de folhas na massa de forragem, indicando que a maior produção total de forragem foi ocasionada pelo maior alongamento de colmos, o que está associado à competição por luz entre as plantas no interior do dossel. O prolongamento do período de descanso para além dos 95% de interceptação da luz incidente aumenta a massa de forragem na entrada dos animais no momento do pastejo (100% IL ou a cada 28 dias durante o verão), porém, esse aumento é resultado do acúmulo de colmos e material morto e pode afetar negativamente o valor nutritivo da forragem produzida e o desempenho animal. Pre-graze forage mass (FM) was higher for 100% LI pastures. Pastures grazed at 95% LI and 28-d resulted in similar pregraze FM in the spring, both lower than that of the 100%-LI treatment. Grazing at 95% LI resulted in higher leaf percentage in pre-graze forage, although total pre-graze FM was lower. Forage produced in paddocks grazed at 100% LI had lower pregraze leaf percentage, indicating that the higher forage accumulation in that treatment was a result of higher stem elongation, likely due to light competition within the canopy. Rest periods beyond the point where swards achieved 95% LI (100% LI or 28-d during the summer) resulted in higher accumulation and higher pre-graze FM, although this corresponded mainly to large amounts of stem and dead material, which could negatively affect the nutritive value of the forage produced and animal performance.Key Words: leaf area index, light interception, plant part composition, sward height IntroduçãoA produtividade e a perenidade das pastagens decorrem, entre outros fatores, da capacidade de reconstituição e manutenção da área foliar após a desfolhação. Assim, diferentes freqüências e intensidades de desfolhação têm forte impacto sobre a condição das plantas, determinando sua velocidade de crescimento, produtividade e persistência (Nabinger & Pontes, 2001).A caracterização da forragem ofertada aos animais, com base no crescimento e desenvolvimento durante determinado período de rebrotação, pode ser feita por meio do fracionamento da forragem acumulada em estratos horizontais do dossel e também nos componentes morfológicos (folhas, colmos e material morto), possibilitando a caracterização dos padrões e das alterações morfológicas ...

show abstract

Section: Resultsunclassified

Acúmulo de forragem durante a rebrotação de capim-xaraés submetido a três estratégias de desfolhação

Pedreira

Silva

2009

R. Bras. Zootec.

View full text Add to dashboard Cite

show abstract

“…Defoliation, however, decreased both realized and potential tiller recruitment via depression of axillary bud numbers. Axillary buds probably set a meristematic limit on future yields because they are the source of new tillers (Murphy and Briske 1992) and defoliation probably has a larger impact on potential yields than water stress.…”

Section: Discussionmentioning

confidence: 99%

“…El Perennial forage grasses in the Northern Great Plains are often grazed when moisture is limiting. If apical or intercalary meristems are removed by grazing, production of new tillers through activation of axillary buds is crucial to reestablish the photosyn-thetic canopy (Jewiss 1972 However, axillary bud numbers are important, because, as a source of new tillers, they set a meristematic limit for future yields in perennial grasses, (Murphy and Briske 1992). Grazing and drought may adversely affect the ability of these axillary buds to initiate new tillers, and negatively affect stand persistence (Busso et al 1989 (Lawrence and Ashford 1966).…”

Section: Introductionmentioning

confidence: 99%

Intermediate wheatgrass and Russian wildrye responses to defoliation and moisture

Hendrickson¹,

Berdahl²

2002

REM

View full text Add to dashboard Cite

Perennial forage grasses in the Northern Great Plains are often grazed under water-limiting conditions. The effects of defoliation and soil moisture dynamics on herbage yield, tiller recruitment and number of crown positions for 2 perennial forage grasses were evaluated in a greenhouse experiment at Mandan, N.D.Intermediate wheatgrass (Thinopyrum intermedium (Host) Barkw 62 and 50 % of the number of crown positions of control seedlings, respectively. Water stress decreased (P = 0.004) number of crown positions at 40% of field capacity but only when crown positions of both parent and daughter tillers were pooled. In this experiment, defoliation had a greater effect than water stress. Moisture level mainly affected tiller size not numbers. The interaction between defoliation and water stress should be examined in field studies to foster improved management of these 2 grasses.Key Words: (Psathyrostachys juncea), (Thinopyrum intermedium) ((Fisch.) Nevski) a 75, 50, 0 40% de la capacidad de campo y se dejaron como controles sin defoliar o defoliados, a intervalos de 10 dias a 8-4-cm de altura. La produccion herbacea acumulativa mostro interacciones entre el nivel de defoliacion y la humedad del suelo (P = 0.0001) y entre especie y defoliacion (P = 0.007). La produccion disminuyo con el aumento en la intensidad de la defoliacion al 75 y 50% de la capacidad de campo, pero al 40% de la capacidad de campo, solo el nivel mas severo de defoliacion tuvo un efecto significativo. P. juncea produjo mas hierba (1.97 g planta'') que T. intermedium (1.36 g planta'') en condiciones de defoliacion severa. El aumento en la intensidad de defoliacion (P = 0.0001) y no la disponibilidad de agua (P > 0.05) produjo una reduccion en el numero de macollas. Combinando todos los tratamientos, P. juncea produjo 10 macollas por planta mientras que T. intermedium produjo 7 (P = 0.0001). Esto puede explicar parcialmente la mayor tolerancia al pastoreo de P. juncea. El numero de posiciones en la corona (posiciones potenciales de yemas axilares en los 20 mm basales de la planta) fue similar entre las especies, to que sugiere que el mayor numero de macollas en P. juncea ocurrio debido a que sus yemas axilares fueron activadas mas facilmente que las de T. intermedium. La defoliacion moderada y severa redujo el numero de posiciones en la corona en las plantas progenitoras solo en un 62 y 50% del numero de posiciones en la corona en las plantas usadas como control, respectivamente. El estres hidrico disminuyo (P = 0.004) el numero de posiciones en la corona en el 40% de la capacidad de campo, pero solo cuando se combinaron las posiciones en la corona de la macolla madre con las de la hija. En este experimento la defoliacion tuvo mayor efecto que el estres hidrico. El nivel de humedad afecto especialmente el tamano de las macollas pero no el numero de ellas. La interaccion entre la defoliacion y el estres hidrico deberia ser examinada en estudios de campo para ayudar en el mejoramiento del manejo de estas 2 especies de pasto.U.S. Departmen...

show abstract

“…The apical meristem was apparently removed by mowing, necessitating development of new tillers for regrowth. Adequate moisture and optimum temperatures must exist before tiller buds are activated (Morrow and Power 1979;Busso et al 1989); light quantity and quality may also influence axillary bud activation (Olson and Richards 1988a;Murphy and Briske 1992). Conditions for emergence of new tillers were not met until the spring following defoliation.…”

Section: Discussionmentioning

confidence: 99%

Regrowth of crested wheatgrass (Agropyron cristatum [L.] Gaertn.) following defoliation

Romo¹,

Harrison²

1999

Can. J. Plant Sci.

View full text Add to dashboard Cite

] Gaertn.) on the amount of time required to reach peak regrowth, the lag period for regrowth to begin, regrowth biomass, tiller survival and replacement, and carryover effects of defoliation the following year were investigated. Regrowth of crested wheatgrass was determined during the summers of 1990, 1991 and 1992 in central Saskatchewan following a single defoliation to a 5-cm stubble height at eight stages of growth. Crested wheatgrass regrew 54-130 g m -2 of biomass when defoliated tillers had ≤3.6 leaves. Regrowth began accumulating within 3-53 growing degree-days (GDD) and peaked in 705-875 GDD. Rates of leaf development after defoliation (218-252 GDD phyllochron -1 ) equaled or were faster than control (218-330 GDD phyllochron -1 ). Regrowth biomass accounted for 35-76% of total annual production. Total annual production was greatest when plants were defoliated during vegetative growth or at peak growth. In 1991 and 1992, etiolated growth in the spring following defoliation was reduced by defoliation in the previous year. Tiller replacement was not affected by defoliation and averaged 1.2 tillers tiller -1 (SE = 0.1) in 1991 and 1.5 tillers tiller -1 (SE = 0.1) in 1992. Two periods of grazing can be expected from crested wheatgrass if it is grazed when tillers have ≤3.6 leaves; however, the impacts of a second grazing must be determined. If crested wheatgrass is grazed late in the growing season, only one period of grazing can be expected, and production will likely be less the following growing season, necessitating a rest period for plants to regain their production potential. ] Gaertn) sur la durée de repos avant la reprise de la croissance, sur le temps nécessaire pour atteindre la repousse maximale, sur la biomasse de la repousse, sur la survie et sur le renouvellement des talles, ainsi que les arrière-effets sur la croissance l'année suivante. La repousse de la graminée était mesurée au cours des étés 1990, 1991 et 1992 dans le centre de la Saskatchewan à la suite d'une seule fauche à la hauteur de 5 cm, effectuée à 8 stades de croissance. La repousse atteignait 54 à 130 g de biomasse au mètre carré (m 2 ) quand les talles étaient coupées lorsqu'elles ne portaient pas plus de 3,6 feuilles chacune. Elle commençait à s'accroître au bout de 3 à 53 degré-jours de croissance (DJC), pour atteindre son maximum aux alentours de 705-875 DJC. Le taux de croissance foliaire après défoliation, soit 218 à 252 DJC par feuille, était égal ou plus rapide que celui observé dans les parcelles témoins (218-330 DJC). La biomasse de la repousse représentait de 35 à 76 % de la production annuelle totale. Cette dernière était à son maximum lorsque la fauche avait été exécutée durant la phase végétative ou au niveau de croissance maximum. En 1991 et en 1992, la croissance étiolée au printemps suivant l'année de défoliation était diminuée. Le renouvellement des talles n'était pas touché par le régime de fauche et se maintenait aux alentours de 1,2 talles par talle morte (ET = 0,1) en 1991 et à 1,5 en 1992. On peut donc obt...

show abstract

Invited Synthesis Paper: Regulation of Tillering by Apical Dominance: Chronology, Interpretive Value, and Current Perspectives

Cited by 94 publications

References 75 publications

Acúmulo de forragem durante a rebrotação de capim-xaraés submetido a três estratégias de desfolhação

Acúmulo de forragem durante a rebrotação de capim-xaraés submetido a três estratégias de desfolhação

Intermediate wheatgrass and Russian wildrye responses to defoliation and moisture

Regrowth of crested wheatgrass (Agropyron cristatum [L.] Gaertn.) following defoliation

Contact Info

Product

Resources

About