The physiology of tiller death in grasses.

Abstract

A reproducible method of causing tiller death on individual ryegrass (Lolium perenne L., cv. S23) plants is described. This was achieved by subjecting whole plants grown previously for 7 weeks in full light (100%) and full nutrient (100^^) to either light stress {11-5% or 2-5%) or nutrient stress (10% or 0%) or various combinations of light and nutrient stress. Detailed records were made of tiller appearance, position and weight, and the probability of tiller death was calculated. Analysis of each plant indicated that the smallest tiller, which was often, but not always the youngest, was the most vulnerable when the whole plant was stressed. Tiller position was relatively unimportant in determining survival. The results are discussed in relation to tiller mortality in natural populations and crop communities.Tiller death in grasses 203 BROUGHAM R.W. (1958) Interception of light by the foliage of pure and mixed stands of pasture piants.

Effect of Post-Grazing Sward Height, Sire Genotype and Indoor Finishing Diet on Steer Intake, Growth and Production in Grass-Based Suckler Weanling-to-Beef Systems

“…Furthermore, the longer regrowth interval [ 61 ] and a tendency for the higher sward density for PGSH-4 than PGSH-6 also contributes to a higher herbage accumulation for PGSH-4. The lower sward density for PGSH-6 could be attributed to the decreased tiller numbers as a result of lower light penetration to the base of the sward [ 62 ].…”

Functional Traits, Morphology, and Herbage Production of Vernalised and Non-Vernalised Chicory cv. Choice (Cichorium intybus L.) in Response to Defoliation Frequency and Height

“…Frequent defoliation might remove the apical domination of the main stem and thus remove the growth inhibition of other crown buds allowing lateral crown shoots to be relatively further advanced before one shoot became dominant [48]. The other explanation is related to a shading effect, as young vegetative shoots of 600 GDD plants likely died because of lack of sufficient light to maintain growth as taller reproductive shoots capture most radiation [49,50]. Even though our results showed an increased photosynthetic capacity of leaves in 600 GDD plants (higher SPAD values), it might not have been sufficient to compensate for the reduced radiation interception by lateral shoots for sustaining growth which therefore resulted in premature senescence of lower leaves.…”

“…This is probably because chicory is a winter dormant plant, which utilises stored WCS for its survival during winter [13,21]. The plant is also transitioning to a reproductive stage after vernalisation, which requires greater energy resources [49].…”

Interactions Between Environment and Genetic Diversity in Perennial Grass Phenology: A Review of Processes at Plant Scale and Modeling

“…Tiller regression usually occurs during the elongation of reproductive tillers and can reduce tiller population by 50% ( Colvill and Marshall, 1984 ). Regressing tillers are mainly vegetative young tillers (age < 40 days), which experience an increasing competition for light and assimilates with larger and taller reproductive tillers ( Ong, 1978 ; Colvill and Marshall, 1984 ; Sachs et al, 1993 ). After summer, reproductive tillers die after seed dispersion and the remaining vegetative tillers start to produce new leaves and tillers again until canopy closure is reached once again during the next growing season ( Figure 4 ; Jewiss, 1972 ; Matthew et al, 2000 ).…”