Effects of cutting and grazing on newly sown plants of Phalaris aquatica cv. Sirosa at Tamworth, New South Wales

2007 ◽  
Vol 47 (11) ◽  
pp. 1351 ◽  
Author(s):  
G. M. Lodge
Keyword(s):  
Stem Elongation ◽  
Tiller Number ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Phalaris Aquatica ◽  
Basal Cover ◽  
South Wales ◽  
Water Soluble Carbohydrates ◽  
Plant Frequency ◽  
Fertiliser Application

A field study was conducted (1994–97) to investigate defoliation time and frequency effects on a newly sown stand of phalaris (Phalaris aquatica cv. Sirosa). Defoliation treatments were applied from spring 1994 to autumn 1995 and effects on plant frequency and basal cover monitored until June 1997. The experimental design was a randomised split-plot in three replicates, with 45 main plots and 90 subplots. Main plots included three types of defoliation (two cutting heights or grazing with Merino sheep) applied at four different times (early stem elongation, anthesis, end of summer and end of autumn) and an undefoliated control. The main plots were divided into two subplots for frequency of defoliation (once only or cut every 8 weeks). In September 1995, none of the treatments had a significant effect on plant frequency, basal cover, green tiller weight and weight of individual tillers. However, there were significant (P < 0.05) effects of defoliation type on green tiller number, defoliation time on basal bud weight and water soluble carbohydrates and defoliation type and frequency on basal bud water soluble carbohydrates. In February and April 1996, there were significant effects of defoliation time on green tiller number and weight, basal bud weight and water soluble carbohydrates. In 1996, Sirosa phalaris plant frequency and basal cover values were generally higher (P < 0.05) in the undefoliated control compared with those defoliated at early stem elongation. However, despite fertiliser application and moderate grazing, Sirosa phalaris plant frequency had declined to a mean of 23.6% by February 1997 and to <10% by June 1997.

The regrowth of swards of S24 perennial rye-grass subjected to different pretreatments

1966 ◽  
Vol 67 (1) ◽  
pp. 139-144 ◽  
Author(s):  
Alison Davies
Keyword(s):  
Tiller Number ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Root Weight ◽  
Nitrogen Levels ◽  
Rye Grass ◽  
Water Soluble Carbohydrates

In an experiment in which plots of S24 perennial rye-grass grown at a 2 in. spacing were subjected to pretreatments involving two different nitrogen levels and three different cutting frequencies it was found that subsequent regrowth was most strongly related to total stubble weight. Other significant correlations were obtained with root weight, tiller number and weight of water-soluble carbohydrates in roots and stubble.The relationships between cultural treatments and sward condition, and between sward condition and regrowth are discussed in the light of the results from this and other experiments.

scholarly journals Response of Bromus valdivianus (Pasture Brome) Growth and Physiology to Defoliation Frequency Based on Leaf Stage Development

Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2058
Author(s):  
Iván P. Ordóñez ◽  
Ignacio F. López ◽  
Peter D. Kemp ◽  
Daniel J. Donaghy ◽  
Yongmei Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Stomatal Conductance ◽  
Root Growth ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Leaf Stage ◽  
Water Soluble Carbohydrates ◽  
Stage Development ◽  
Defoliation Frequency ◽  
Root Growth Rate

The increase in drought events due to climate change have enhanced the relevance of species with greater tolerance or avoidance traits to water restriction periods, such as Bromus valdivianus Phil. (B. valdivianus). In southern Chile, B. valdivianus and Lolium perenne L. (L. perenne) coexist; however, the pasture defoliation criterion is based on the physiological growth and development of L. perenne. It is hypothesised that B. valdivianus needs a lower defoliation frequency than L. perenne to enhance its regrowth and energy reserves. Defoliation frequencies tested were based on B. valdivianus leaf stage 2 (LS-2), leaf stage 3 (LS-3), leaf stage 4 (LS-4) and leaf stage 5 (LS-5). The leaf stage development of Lolium perenne was monitored and contrasted with that of B. valdivianus. The study was conducted in a glasshouse and used a randomised complete block design. For Bromus valdivianus, the lamina length, photosynthetic rate, stomatal conductance, tiller number per plant, leaf area, leaf weights, root growth rate, water-soluble carbohydrates (WSCs) and starch were evaluated. Bromus valdivianus maintained six live leaves with three leaves growing simultaneously. When an individual tiller started developing its seventh leaf, senescence began for the second leaf (the first relevant leaf for photosynthesis). Plant herbage mass, the root growth rate and tiller growth were maximised at LS-4 onwards. The highest leaf elongation rate, evaluated through the slope of the lamina elongation curve of a fully expanded leaf, was verified at LS-4. The water-soluble carbohydrates (WSCs) increased at LS-5; however, no statistical differences were found in LS-4. The LS-3 and LS-2 treatments showed a detrimental effect on WSCs and regrowth. The leaf photosynthetic rate and stomatal conductance diminished while the leaf age increased. In conclusion, B. valdivianus is a ‘six-leaf’ species with leaf senescence beginning at LS-4.25. Defoliation at LS-4 and LS-5 was optimum for plant regrowth, maximising the aboveground plant parameters and total WSC accumulation. The LS-4 for B. valdivianus was equivalent to LS-3.5 for L. perenne. No differences related to tiller population in B. valdivianus were found in the different defoliation frequencies.

scholarly journals Changes in root porosity and water soluble carbohydrates in rice (Oryza sativa L.) under submergence stress

2019 ◽  
Vol 17 (4) ◽  
pp. 539-544
Author(s):  
Md Juiceball Hassan ◽  
Md Masudul Karim ◽  
Md Amirul Islam ◽  
Md Habibur Rahman Pramanik ◽  
Md Alamgir Hossain
Keyword(s):  
Stress Condition ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Soluble Carbohydrate ◽  
Susceptible Cultivar ◽  
Rice Cultivars ◽  
Root Porosity ◽  
Submergence Stress ◽  
Water Soluble Carbohydrates ◽  
Water Soluble Carbohydrate

Submergence stress at early vegetative stage is one of the most important constraints in the productivity of rice in Bangladesh. Submergence causes yield loss of rice at Aman season in Bangladesh and therefore, it is necessary to develop submergence tolerant rice cultivars. A pot experiment was conducted at the net house of Department of Crop Botany, Bangladesh Agricultural University, during Aman season from July to December, 2017 to evaluate the changes in root porosity and water soluble carbohydrates (WSCs) associated with submergence tolerance in rice. The experiment consisted of two factors—(i) Rice cultivars (Binadhan-11, Binadhan-12, BRRI dhan51 and BRRI dhan52 as tolerant and BRRI dhan49 as susceptible) and(ii) Submergence stress: Submergence for 14 days at vegetative stage and control. Submergence stress was imposed by dipping of pots into a water tank with about 90 cm depth of water while the control plants are maintained in the pot house of the field laboratory. The plants were sampled at seven days interval during submergence to determine the changes in root porosity and to examine the contribution of shoot reserves for their survival. The root porosity was measured by pycnometer method and water soluble carbohydrate was measured by the anthrone method. Tolerant cultivars showed greater root porosity development in both control and stress condition but the susceptible cultivar showed significantly lower root development in stress condition. Higher root porosity might help tolerant cultivars to survive in submergence stress more efficiently. Tolerant rice cultivars had high initial soluble carbohydrate than the susceptible one. Under submergedcondition, the tolerant cultivars showed slow depletion of water soluble carbohydrate compared to susceptible cultivar. Higher carbohydrate contents in tolerant cultivars might act as buffer stock during submergence for their better survival and growth. J Bangladesh Agril Univ 17(4): 539–544, 2019

scholarly journals Harvest interval affects lucerne ( Medicago sativa L.) taproot total yield, starch, nitrogen and water‐soluble carbohydrates

2020 ◽  
Vol 206 (5) ◽  
pp. 619-629 ◽  
Author(s):  
Meredith L. Mitchell ◽  
Stephen G. Clark ◽  
Kym L. Butler ◽  
Zhongnan Nie ◽  
Vivianne F. Burnett ◽  
...  
Keyword(s):  
Medicago Sativa ◽  
Total Yield ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Water Soluble Carbohydrates ◽  
Medicago Sativa L
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