Defoliation regrowth and dry matter partitioning in the two arid zone grasses, Aristida armata and Thyridolepis mitchelliana

1987 ◽  
Vol 38 (5) ◽  
pp. 881 ◽  
Author(s):  
RF Brown
Keyword(s):  
Seed Production ◽  
Dry Matter ◽  
Arid Zone ◽  
Plant Production ◽  
Pasture Management ◽  
Leaf Production ◽  
Dry Matter Partitioning ◽  
Intact Plants ◽  
Domestic Livestock ◽  
Total Plant

Plants of the desirable rangeland grass, Thyridolepis mitchelliana, and its undesirable companion, Aristida armata, were defoliated at various ages, and their subsequent regrowth and seed production compared with that of intact plants. Young plants of T. mitchelliana, but not A. armata, often failed to survive severe defoliation. Seed production by A. armata greatly exceeded that of T. mitchelliana and was much less affected by defoliation. In both defoliated and intact plants, the proportion of dry matter in inflorescences was several times greater for A. armata than T. mitchelliana, but the reverse occurred with leaf production. Root growth was little affected by defoliation, and there was no evidence of export of root material to support tops regrowth. Total plant production of both species was unaffected by the loss of half the tops, but was depressed by more severe defoliation. The differences between the two species in their reaction to defoliation seem sufficient to explain the displacement of T. mitchelliana by A. armata which followed the introduction of domestic livestock. Under grazing, A. armata is likely to have a reproductive advantage, and the implications of this for pasture management are examined.

Phenology, Reproductive-Biology and Seed Development in Four Rush and Sedge Species From Western Australia

1988 ◽  
Vol 36 (6) ◽  
pp. 711 ◽  
Author(s):  
KA Meney ◽  
KW Dixon
Keyword(s):  
Seed Production ◽  
Western Australia ◽  
Dry Matter ◽  
Matter Content ◽  
Dry Matter Content ◽  
Dry Matter Accumulation ◽  
Tissue Water ◽  
Dry Matter Partitioning ◽  
Study Species

Four species of Restionaceae and Cyperaceae from the Mediterranean-type climate region of Western Australia were studied to determine factor(s) limiting their reproductive performance. Ecdeiocolea monostachya (Ecdeiocoleaceae), Lepidobolus chaetocephalus (Restionaceae), Restio aff. sphacelatus (Restionaceae) and Mesomelaena pseudostygia (Cyperaceae) differed in the pattern of dry matter partitioning and phenological patterns. All species were moderately efficient at remobilising dry matter from senescing vegetative organs, maintaining constant tissue water to dry matter content in mature organs over the study period regardless of soil moisture availability. In situ nutrient and water supplements of study species did not elicit improved seed production or significant increases in dry matter accumulation (except for current and old culms of E. monostachya and spikelets of L. chaetocephalus). For all study species except L. chaetocephalus, seed production was low, while herbivore activity, insect predation andlor infection by a smut (Tolyposporium lepidiboli) reduced seed production potential in L. chaetocephalus and E. monostachya. Attempts at seed germination for all study species were not successful. Extracted embryos from mature seed of all species cultured in vitro grew rapidly, providing a reliable method for propagation of study species.

Resource Allocation to Asexual Gemma Production and Sexual Reproduction in South-Western Australian Pygmy and Micro Stilt-Form Species of Sundew (Drosera spp, Droseraceae)

1992 ◽  
Vol 40 (3) ◽  
pp. 353 ◽  
Author(s):  
PS Karlsson ◽  
JS Pate
Keyword(s):  
Resource Allocation ◽  
Sexual Reproduction ◽  
Seed Production ◽  
Asexual Reproduction ◽  
Western Australia ◽  
Dry Matter ◽  
Late Season ◽  
Plant Resource ◽  
Total Plant ◽  
Western Australian

Proportional allocations of current total dry matter (DM), N and P to early season asexual gemma production and late-season flowering and seed production were compared for eight pygmy rosette form and three micro stilt-form perennial pygmy sundews (Drosera spp.) in native habitat in south-western Australia. Mean allocations to gemmae for the smaller rosette species were 22% for DM, 60% for N and 38% for P versus 8, 20 and 23% (DM, N, P) respectively for the micro stilt forms. Allocations to mature fully formed seeds were extremely low, 1-8, 4.0 and 5.4% (DM, N, P) for the rosette forms, 0.7, 3-0 and 2.3% respectively for the micro stilt forms. The above values reflect the heavy bias towards gemma production, (8-52 propagules per plant per season across the 11 species) as opposed to that for seed (0-8 fully formed seeds per plant per season). Comparable information for the annual nongemmiferous pygmy sundew D. glanduligera showed end of season allocation of 66, 37 and 29% (DM, N, P) of total plant resource to inflorescences minus seeds, and additional amounts equivalent to 30, 59 and 69% to the 60 seeds produced per plant of this species in the study season. A detailed phenology of resource allocation across a full season of growth in second, third and fourth season plants of the rosette perennial D. closterostigma showed net seasonal losses in the total vegetative resource of N and of P in older plants attributable to apparent over commitment to asexual reproduction during the season of study.

scholarly journals Effect of harvest period on foliage production and dry matter distribution in five cassava cultivars during the second plant cycle

2006 ◽  
Vol 49 (6) ◽  
pp. 1007-1018 ◽  
Author(s):  
Edvaldo Sagrilo ◽  
Pedro Soares Vidigal Filho ◽  
Manoel Genildo Pequeno ◽  
Maria Celeste Gonçalves Vidigal ◽  
Carlos Alberto Scapim ◽  
...  
Keyword(s):  
Dry Matter ◽  
Rest Period ◽  
Matter Content ◽  
Plant Production ◽  
Dry Matter Content ◽  
Matter Distribution ◽  
Storage Roots ◽  
Leaf Production ◽  
Dry Matter Distribution ◽  
Cassava Plant

The objective of this work was to study the leaf production pattern and dry matter distribution in cassava during the second plant cycle. The completely randomized experimental design with four replications was used, with five cultivars in the main plots and ten harvest times in the sub-plots. Foliage production was affected by plant age, being higher in hot periods. Leaf blades and petioles dry matter content presented a linear increase due to a progressive decrease in the amount of young leaves and ontogenetic factors. The stems provided, temporarily, carbohydrates to the plant re-growth, delaying the availability and use of storage roots dry matter. The dry matter content in the storage roots was lower during the vegetative and higher during rest period. The storage roots diameter increased considerably when the amount of leaves was higher, indicating the importance of leaf area in the cassava plant production.

scholarly journals End-of-Day Light Quality Effects on Growth and Development of Watermelon Plants

HortScience ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 601E-601
Author(s):  
N.K. Damayanthi Ranwala ◽  
Dennis R. Decoteau
Keyword(s):  
Dry Matter ◽  
Light Quality ◽  
Distribution Patterns ◽  
Dry Mass ◽  
Matter Distribution ◽  
Dry Matter Partitioning ◽  
Dry Matter Distribution ◽  
Plant Parts ◽  
Total Plant ◽  
Plant Dry Mass

End-of-day (EOD) red (R) or far-red (FR) light treatments were used to study phytochrome-regulated growth and dry matter distribution in 2-week-old watermelon plants. Plants were exposed to low-intensity R or FR light for 15 min at the end of photoperiod for 9 consecutive days. End-of-day FR increased the petiole elongation in the first two leaves, which was accompanied by higher dry matter partitioning to the petioles after 3 days of treatments. However, total plant dry mass (above ground) in FR-treated plants increased significantly after 6 days of treatments. This indicates EOD FR regulated dry matter compensation among plant parts at the early stages of EOD light treatments, allowing plants to better adapt to the environment. Net CO2 assimilation rate in the second leaf of FR-treated plants also increased. Phytochrome involvement in these processes is suggested, since growth and dry matter distribution patterns were reversible when plants were treated with FR immediately followed by R.

Chrysanthemum dry matter partitioning patterns along irradiance and temperature gradients

1992 ◽  
Vol 72 (1) ◽  
pp. 307-316 ◽  
Author(s):  
M. G. Karlsson ◽  
R. D. Heins
Keyword(s):  
Dry Matter ◽  
Chrysanthemum Morifolium ◽  
Photon Flux ◽  
Dry Matter Accumulation ◽  
Strongly Correlated ◽  
Dry Matter Partitioning ◽  
Total Plant ◽  
Chrysanthemum Morifolium Ramat ◽  
Short Days ◽  
Matter Basis

The influence of photosynthetic photon flux (PPF, 1.8−21.6 mol d−1 m−2) and day (DT) and night (NT) temperature (10–30 °C) on dry matter accumulation and partitioning was studied in Chrysanthemum morifolium Ramat. ’Bright Golden Anne’. Total plant dry matter varied from 3.6 to 17.2 g at flowering. Plants with the greatest dry matter were from treatments with high PPF levels and temperatures. Accumulation of dry matter in roots, stems, leaves and flowers examined on a normalized time and normalized dry matter basis showed similar trends independent of DT, NT and PPF during development. Accumulated dry matter in roots, stems and leaves increased to a maximum and then decreased as the flowers were developing. Maximum leaf, root and stem dry matter was reached at 81, 85 and 91%, respectively, of required time from start of short days (SD) to flower. Proportion root dry matter increased and proportion leaf dry matter decreased in the plants as PPF increased. Partitioning to roots decreased as the DT increased. The root/shoot dry matter ratio decreased as plants developed from start of SD to flowering at all studied combinations of PPF, DT and NT. A positive difference between DT and NT (DIF) resulted in a higher percentage stem dry matter compared to plants grown at a negative DIF. Partitioning to flowers was not strongly correlated with the levels of PPF, DT and NT.Key words: Chrysanthemum morifolium, Dendranthema grandiflora, dry matter accumulation and partitioning, temperature, irradiance

Genotypic Variation in Transpiration Efficiency, Carbon-Isotype Discrimination and Carbon Allocation During Early Growth in Sunflower

1990 ◽  
Vol 17 (2) ◽  
pp. 207 ◽  
Author(s):  
JM Virgona ◽  
KT Hubick ◽  
HM Rawson ◽  
GD Farquhar ◽  
RW Downes
Keyword(s):  
Plant Growth ◽  
Dry Matter ◽  
Carbon Allocation ◽  
Genotypic Variation ◽  
Biomass Accumulation ◽  
Transpiration Efficiency ◽  
Dry Matter Partitioning ◽  
Matter Production ◽  
Total Plant ◽  
Selection For

Transpiration efficiency of dry matter production (W), carbon-isotope discrimination (�) and dry matter partitioning were measured on six sunflower (Helianthus annuus L.) genotypes grown for 32 days in a glasshouse. Two watering regimes, one well watered (HW) and the other delivering half the water used by the HW plants (LW), were imposed. Four major results emerged from this study. (1) There was significant genotypic variation in W in sunflower and this was closely reflected in Δ for both watering treatments. (2) The low watering regime caused a decrease in Δ but no change in W; nonetheless the genotypic ranking for either Δ or W was not significantly altered by water stress. (3) A positive correlation between W and biomass accumulation occurred among genotypes of HW plants. (4) Q, the ratio of total plant carbon content to leaf area, was positively correlated with W and negatively correlated with Δ. These results are discussed with reference to the connection between transpiration efficiency and plant growth. In short, Δ can be used to select for W among young vegetative sunflower plants. However, selection for W may be accompanied by changes in other important plant growth characteristics such as Q.

Dry Matter Partitioning and Vegetative Growth of Young Peach Trees Under Water Stress

1990 ◽  
Vol 17 (1) ◽  
pp. 23 ◽  
Author(s):  
SL Steinberg ◽  
JC Miller ◽  
MJ Mcfarland
Keyword(s):  
Water Stress ◽  
Biomass Production ◽  
Dry Matter ◽  
Root Production ◽  
Total Biomass ◽  
Leaf Production ◽  
Dry Matter Partitioning ◽  
Two Factors ◽  
The Difference ◽  
Peach Trees

Water stress affected the growth and dry matter partitioning of young peach trees grown in pots in a greenhouse. When the trees were subjected to four watering treatments, 100, 75, 50 and 25% of full water, total dry matter production was reduced with each incremental decrease in applied water. Despite large differences in biomass production, the difference in midday leaf water potential between the wettest and driest treatment was not greater than 0.6 MPa. This was partially attributed to lower leaf conductance in the drier treatments. A reduction or halting of lateral branching and new leaf production was observed soon after water stress was imposed, and these two factors were the major contributors to differences in tree biomass production. Root production was maintained at similar levels in all but the severest stress treatment. As a result, the root fraction of total biomass increased from 0.4 to 0.6 as the level of stress increased from 75 to 50% of full water. Currently growing leaves and internodes of the drier treatments reached maturity at a smaller size. In contrast to internode lengthening, leaf area expansion slowed in the final growth phase. This correlated well with leaf unfolding.

Sign in / Sign up

Export Citation Format

Share Document