Studies on the growth and development of the rhizome and lateral rhizome buds in Elytrigia repens: some effects of parent shoot excision

1998 ◽  
Vol 76 (5) ◽  
pp. 769-776 ◽  
Author(s):  
G I McIntyre ◽  
A J Cessna
Keyword(s):  
Apical Dominance ◽  
Water Pressure ◽  
C:N Ratio ◽  
Dry Weight ◽  
Nitrate Content ◽  
Total N ◽  
Lateral Buds ◽  
Elytrigia Repens ◽  
Correlative Inhibition ◽  
Rhizome Buds

In experiments conducted under controlled conditions, excision of the shoot of Elytrigia repens (L.) Nevski increased the rate of rhizome elongation and promoted the growth of the lateral rhizome buds. Measurements with a transducer showed that the long-term growth response of the rhizome to shoot excision (4-6 days) was preceded by an immediate but transient (10 min) increase in growth rate. These various responses were associated with the occurrence of guttation from the rhizome apex, increases in the water content of the rhizome apex and lateral buds, and a 62% increase in rhizome water (pressure) potential. Parent shoot excision also induced a transition from rhizome to shoot development at the rhizome apex and caused lateral buds to develop as shoots instead of rhizomes when released from apical dominance. These developmental responses were associated with reductions in the dry weight of the rhizome apex and lateral buds and increases in the total N, amino-N, and nitrate content of the rhizome apex when expressed on a dry weight basis. These results provide evidence that, in E. repens, competition for water by the parent shoot may limit rhizome growth and contribute to the correlative inhibition of the lateral buds. They are also consistent with previous evidence that the C:N ratio may be an important morphogenetic factor in the mechanism controlling the path of bud and rhizome development.Key words: Elytrigia repens, water, nitrogen, rhizome, apical dominance.

Studies on the growth and development of Agropyron repens: interacting effects of humidity, calcium, and nitrogen on growth of the rhizome apex and lateral buds

1987 ◽  
Vol 65 (7) ◽  
pp. 1427-1432 ◽  
Author(s):  
Gordon I. McIntyre
Keyword(s):  
Apical Dominance ◽  
Water Status ◽  
Dry Weight ◽  
Apical Growth ◽  
High Humidity ◽  
N Supply ◽  
Lateral Buds ◽  
Low Humidity ◽  
Bud Growth ◽  
Agropyron Repens

A previous investigation of apical dominance in the rhizome of Agropyron repens showed that keeping the rhizome in a high humidity promoted the outgrowth of the lateral buds but strongly inhibited the growth of the rhizome apex. A study of these related responses demonstrated that the inhibition of apical growth was not prevented by excision of the lateral buds and was also induced when only the apex of the rhizome received the high humidity treatment. The necrotic lesions that developed in the arrested apices and the reduction of apical inhibition produced by various Ca treatments indicated that the inhibition of apical growth was caused by Ca deficiency. When the rhizome apex was exposed to low humidity, a localized high-humidity treatment of the lateral buds did not release the buds from apical dominance in low-N rhizomes but strongly promoted bud growth at a higher N level. When growth of the buds was induced at low humidity by increasing the N supply, the increase in bud weight was preceded by an increase in the water content of the bud when expressed on a dry weight basis. These results agree with those of previous investigations and suggest that the interacting effects of N and humidity on the water status of the buds may play a significant role in the mechanism of apical dominance.

Patterns of log decay in old-growth Douglas-fir forests

1987 ◽  
Vol 17 (12) ◽  
pp. 1585-1595 ◽  
Author(s):  
Phillip Sollins ◽  
Steven P. Cline ◽  
Thomas Verhoeven ◽  
Donald Sachs ◽  
Gody Spycher
Keyword(s):  
C:N Ratio ◽  
Dry Weight ◽  
Douglas Fir ◽  
Time Span ◽  
Western Hemlock ◽  
Tissue Type ◽  
Old Growth ◽  
Total N ◽  
Red Cedar ◽  
Western Red Cedar

Fallen boles (logs) of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), western hemlock (Tsugaheterophylla (Raf.) Sarg.), and western red cedar (Thujaplicata Donn) in old-growth stands of the Cascade Range of western Oregon and Washington were compared with regard to their physical structure, chemistry, and levels of microbial activity. Western hemlock and western red cedar logs disappeared faster than Douglas-fir logs, although decay rate constants based on density change alone were 0.010/year for Douglas-fir, 0.016/year for western hemlock, and 0.009/year for western red cedar. We were unable to locate hemlock or red cedar logs older than 100 years on the ground, but found Douglas-fir logs that had persisted up to nearly 200 years. Wood density decreased to about 0.15 g/cm3 after 60–80 years on the ground, depending on species, then remained nearly constant. Moisture content of logs increased during the first 80 years on the ground, then remained roughly constant at about 250% (dry-weight basis) in summer and at 350% in winter. After logs had lain on the ground for about 80 years, amounts of N, P, and Mg per unit volume exceeded the amount present initially. Amounts of Ca, K, and Na remained fairly constant throughout the 200-year time span that was studied (100-year time span for Na). N:P ratios converged toward 20, irrespective of tree species or wood tissue type. C:N ratios dropped to about 100 in the most decayed logs; net N was mineralized during anaerobic incubation of most samples with a C:N ratio below 250. The ratio of mineralized N to total N increased with advancing decay. Asymbiotic bacteria in fallen logs fixed about 1 kg N ha−1 year−1, a substantial amount relative to system N input from precipitation and dry deposition (2–3 kg ha−1 year−1).

scholarly journals Compost Feedstock and Compost Acidification Affect Growth and Mineral Nutrition in Northern Highbush Blueberry

HortScience ◽  
2019 ◽  
Vol 54 (6) ◽  
pp. 1067-1076 ◽  
Author(s):  
Ryan C. Costello ◽  
Dan M. Sullivan ◽  
David R. Bryla ◽  
Bernadine C. Strik ◽  
James S. Owen
Keyword(s):  
Root Growth ◽  
Mineral Nutrition ◽  
C:N Ratio ◽  
Dry Weight ◽  
Vaccinium Corymbosum ◽  
High Rate ◽  
Highbush Blueberry ◽  
Total N ◽  
Shoot Dry Weight ◽  
Northern Highbush Blueberry

New markets for organic northern highbush blueberry (Vaccinium corymbosum L.) have stimulated interest in using composts specifically tailored to the plant’s edaphic requirements. Because composts are typically neutral to alkaline in pH (pH 7 to 8), and blueberry requires acidic soil (pH 4.2 to 5.5), we investigated elemental sulfur (S0) addition as a methodology for reducing compost pH. The objectives were to 1) characterize initial compost chemistry, including the pH buffering capacity of compost (acidity required to reduce pH to 5.0), 2) measure changes in compost chemistry accompanying acidification, and 3) evaluate plant growth and mineral nutrition of blueberry in soil amended with an untreated or acidified compost. Ten composts prepared from diverse feedstocks were obtained from municipalities and farms. Addition of finely ground S0 reduced compost pH from 7.2 to 5.3, on average, after 70 d at 22 °C, and increased the solubility of nutrients, including K (from 22 to 36 mmol(+)/L), Ca (from 5 to 19 mmol(+)/L), Mg (from 5 to 20 mmol(+)/L), and Na (from 6 to 9 mmol(+)/L). Sulfate-S, a product of S0 oxidation, also increased from 5 to 45 mmol(−)/L. The composts were incorporated into soil at a high rate (30% v/v) in a greenhouse trial to evaluate their suitability for use in blueberry production. Shoot and root growth were strongly affected by compost chemical characteristics, including pH and electrical conductivity (EC). Potassium in compost was highly variable (2–32 g·kg−1). Concentration of K in the leaves increased positively in response to compost K, whereas shoot dry weight and root growth declined. Leaf Mg also declined in response to compost K, suggesting that elevated K concentrations in compost may cause Mg deficiency. Composts with the highest K were also high in total N, pH, and EC. Compost acidification to pH ≤ 6 improved growth and increased leaf Mg concentration. On the basis of these results, composts derived from animal manures or young plant tissues (e.g., green leaves) appear to be unsuitable for high-rate applications to blueberry because they usually require high amounts of S0 for acidification and are often high in EC and K, whereas those derived from woody materials, such as local yard debris, appear promising based on their C:N ratio, compost acidification requirement, and EC.

scholarly journals Pengaruh konsentrasi Si biogenic dan N-total terhadap pertumbuhan dan konsentrasi nitrat tanaman selada hidroponik

Jurnal Agro ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 130-141
Author(s):  
Salamet Ginandjar ◽  
Budy Frasetya Taufik Qurrohman ◽  
Panji Rahmatullah
Keyword(s):  
Plant Height ◽  
Analysis Of Variance ◽  
Rice Husk ◽  
Dry Weight ◽  
Nitrate Content ◽  
Plant Weight ◽  
Total N ◽  
Rice Husk Silica ◽  
Fresh Plant ◽  
N Concentration

Tanaman selada merupakan sayuran yang dikonsumsi dalam bentuk segar. Karakteristiknya sebagai tanaman akumulator nitrat perlu diimbangi pemupukan N dan aplikasi Silika (Si) sesuai kebutuhan tanaman. Penelitian ini bertujuan untuk mempelajari interaksi ekstrak silika sekam padi (ESSP) dan N-total, serta memperoleh konsentrasi  ESSP dan N-total yang tepat untuk menghasilkan panen selada yang tinggi tetapi aman bagi kesehatan. Rancangan penelitian yang digunakan adalah Rancangan Acak Lengkap Faktorial, faktor pertama adalah konsentrasi ESSP (0 ppm, 30 ppm, 60 ppm, 90 ppm) dan faktor kedua adalah konsentrasi N-total (100 ppm, 200 ppm, 300 ppm), setiap kombinasi perlakuan diulang 3 kali. Parameter yang diamati yaitu tinggi tanaman 35 hari setelah tanam (HST), luas daun, berat kering tanaman, berat segar tanaman, kandungan nitrat pada daun selada. Data dianalisis dengan analisis varians taraf 5% dilanjutkan dengan Uji Jarak Berganda Duncan pada taraf nyata 5%, sedangkan parameter kandungan nitrat dianalisis secara deskriptif. Berdasarkan hasil analisis varians konsentrasi ESSP dan konsentrasi N-total berinteraksi pada tinggi tanaman dan berpengaruh mandiri terhadap berat kering tanaman dan berat segar tanaman. Aplikasi ekstrak silika sekam padi 30 ppm meningkatkan hasil panen 28% lebih tinggi dan menurunkan 12% kandungan nitrat tanaman selada pada N total 100-300 ppm.AbstractLettuce is a freshly consumed vegetable. Its characteristics as a nitrate accumulator plant need to be balanced with N fertilization and Silica (Si) applications according to the plant required. This research aimed to study the interaction between rice husk silica extract (ESSP) and total N to obtain the right ESSP and total N concentrations to produce high yield lettuce and safely consumed it. This study used a factorial completely randomized design. The first factor was ESSP concentrations (0 ppm, 30 ppm, 60 ppm, 90 ppm) and the second factor was total N concentrations (100 ppm, 200 ppm, 300 ppm). Each treatment combination was repeated 3 times. The parameters observed were plant height in 35 days after planting, leaf area, plant dry weight, fresh plant weight, and nitrat e content in lettuce leaves. The  data  were  analyzed  by analysis of variance at the 5%, and post-test by DMRT at the 5% significant level, the nitrate content used descriptive analysis. Based on the analysis of variance, ESSP concentration and total N concentration interacted on plant height. The ESSP concentration and total N concentration independently affected plant dry weight and fresh plant weight. Application of 30 ppm rice husk silica extract increased 28% higher yield and decreased 12% nitrate content of lettuce plants at N-total of 100-300 ppm.

Effect of Nitrogen on the Glyphosate-Induced Inhibition of Rhizome Bud Growth in Quackgrass (Elytrigia repens)

Weed Science ◽  
1993 ◽  
Vol 41 (3) ◽  
pp. 426-433 ◽  
Author(s):  
James H. Hunter ◽  
Andrew I. Hsiao ◽  
Gordon I. Mcintyre
Keyword(s):  
Foliar Application ◽  
Dry Weight ◽  
Single Node ◽  
N Supply ◽  
Rhizome Growth ◽  
Lateral Buds ◽  
Elytrigia Repens ◽  
Bud Growth ◽  
Bud Position ◽  
Rhizome Bud

In experiments conducted under controlled conditions, glyphosate-induced inhibition of rhizome bud growth in quackgrass was reduced by increasing the nitrogen (N) concentration in the nutrient solution from 10.5 to 210 mg L−1either 2 or 4 d before foliar application of the herbicide, and for 7 d after the herbicide treatment. The additional N reduced the glyphosate-induced inhibition of rhizome growth on the intact plant at the lowest glyphosate dosage (2.8 μg per plant) but had no significant effect at higher dosages. Both the 2- and 4-d high N treatments significantly increased the length, dry weight, and water content of the lateral buds by the time the herbicide was applied. They also increased bud growth on the glyphosate-treated plants during the 7 d following the herbicide application and promoted release of the buds from inhibition during a subsequent bioassay of their regenerative growth on excised, single-node rhizome segments. These effects of N supply interacted significantly with glyphosate dosage, bud position on the rhizome, and duration of incubation. It is postulated that bud growth response to increased N supply may reduce the inhibiting effect of the herbicide by diluting the glyphosate concentration in the bud, or that the additional N may counteract the toxic action of glyphosate on amino acid metabolism or protein synthesis.

scholarly journals Effect of the Nitrate Reductase Genes (Nia) on the Quality of Different Lettuce Genotypes for Low Nitrate Content

2005 ◽  
Vol 10 (1) ◽  
pp. 41
Author(s):  
K.N. Al-Redhaiman
Keyword(s):  
Nitrate Reductase ◽  
Genotypic Variation ◽  
Positive Association ◽  
Dry Weight ◽  
Nitrate Content ◽  
Significant Positive Association ◽  
Total N ◽  
Nitrate Concentrations ◽  
Leaf Nitrate

Genotypic variation in nitrate concentrations of different lettuce genotypes belonging to four types (Butterhead, Cos/Romaine, Crisphead, and Stem lettuce) and its relationship to nitrate reductase genes (Nia) for low nitrate concentrations of leaves was investigated. The results showed that the Romaine genotype ' Lobjoit's Green' exhibited the lowest leaf nitrate concentration (4877.7 mg/kg dry weight). The highest nitrate levels were recorded in the Butterhead genotypes 'Augusta and Kennedy'. Nitrate concentrations in the roots were significantly higher in the Romaine genotype ' Little Gem' and the Butterhead genotypes 'Augusta and Merveille Des Quatre Saisons' than the other lettuce genotypes. Total N concentrations were higher in the Butterhead and Crisphead genotypes than in the Romaine and Stem lettuce genotypes. A significant positive association (r = 0.80, p > 0.01) was observed between leaf NO

scholarly journals INFLUENCE OF PESTICIDES ON NITROGEN CONTENT OF TOMATO PLANT S

HortScience ◽  
1993 ◽  
Vol 28 (4) ◽  
pp. 273D-273
Author(s):  
David N. Sasseville
Keyword(s):  
Nitrate Uptake ◽  
Calcium Nitrate ◽  
Dry Weight ◽  
Control Treatment ◽  
Nitrate Content ◽  
N Content ◽  
Total N ◽  
Tomato Plants ◽  
Growing Medium ◽  
Root Tissues

Tomato plants were grown in a greenhouse in a sand:soil mixture with six pesticide treatments applied weekly at 1 mg a.i./kg soil mixture as a soil drench. Plants were grown for six weeks with nitrogen applied weekly at 80 mg per plant as calcium nitrate. Glyphosate (Roundup) was toxic to plants with reduced dry weight of all tissues, but greater nitrate concentration in the leaf and root tissues. Captan produced the greatest dry weight, with mot tissues dry weights significantly greater than the control treatment. Captan resulted in significantly higher nitrate content in the tissues, but there was no difference between captan and the control on total N content. Both nitrapyrin (N-Serve) and sethoxydim (Poast) had significantly less growth and total N content than the control, as well as higher nitrate content in the growing medium. It appears that these two chemicals may inhibit nitrate uptake or cause other phytotoxic effects The other chemicals metalaxyl (Subdue) and etridiazole (Terrazole) had intermediate responses. While they both had reduced growth and total N content, these were not significantly different from the control treatment. Etridiazole had reduced nitrate content, but metalaxyl nitrate content was significantly greater than the control and comparable to captan, primarily because of high nitrate content in the leaves.

Developmental studies on Euphorbia esula. The influence of the nitrogen supply on the correlative inhibition of root bud activity

1972 ◽  
Vol 50 (5) ◽  
pp. 949-956 ◽  
Author(s):  
Gordon I. McIntyre
Keyword(s):  
Apical Dominance ◽  
Nitrogen Supply ◽  
Euphorbia Esula ◽  
Nitrogen Level ◽  
Developmental Studies ◽  
Subsequent Increase ◽  
Lateral Buds ◽  
Lateral Shoots ◽  
Correlative Inhibition ◽  
Low Nitrogen

When seedlings of leafy spurge (Euphorbia esula L.) were grown at a low nitrogen level (10.5 ppm) the growth of the lateral buds on the shoot was completely arrested by apical dominance while the buds on the roots, although also inhibited, showed considerably greater activity. At a higher nitrogen level (210 ppm) apical dominance was markedly reduced but the resulting outgrowth of the lateral buds increased the inhibiting capacity of the shoot, limiting root bud response. When the main shoot was decapitated the degree to which root bud growth was suppressed by a given number of lateral shoots was inversely related to the nitrogen supply. Inhibition of the root buds by the lateral shoots could be significantly reduced by growing the plants initially at a low nitrogen level so that growth of the lateral buds was arrested. A subsequent increase in the nitrogen supply strongly promoted the growth of the roots buds, some of which were sufficiently released from inhibition to emerge as leafy shoots.

The correlative inhibition of bud and shoot growth in flax. Anatomical changes associated with the release of lateral buds from inhibition

1974 ◽  
Vol 52 (11) ◽  
pp. 2269-2275 ◽  
Author(s):  
Gordon I. McIntyre ◽  
Shirley D. Larmour
Keyword(s):  
Apical Dominance ◽  
Shoot Growth ◽  
Vascular Tissue ◽  
Sand Culture ◽  
Quiescent Center ◽  
Staining Reaction ◽  
Linum Usitatissimum L ◽  
N Supply ◽  
Lateral Buds ◽  
Correlative Inhibition

Seedlings of flax (Linum usitatissimum L.) were grown in sand culture under controlled conditions and the bud at node 3 was released from apical dominance by increasing the concentration of N in the nutrient solution. Within 24 h of increasing the N supply the number of mitoses per bud had markedly increased and within 48 h the length of the bud was significantly greater than the controls. A distinctive group of cells (the "quiescent center"), characterized by enlarged nuclei with a reduced Feulgen staining reaction, was present at the apex of all inhibited low-N buds but rapidly disappeared when the buds were released from inhibition. Of the buds examined 48 h after the N supply was increased, about 50% had no xylem in the bud trace; the rest had only a single xylem strand and none had established a connection with the stele of the parent stem. Buds examined after 72 h showed a marked increase in the number of xylem strands, but more than 75% of these buds still lacked a complete xylem connection with the vascular tissue of the parent shoot.These results support the hypothesis that the release of lateral buds from apical dominance is not dependent on the prior strengthening of the xylem connections and that associated changes in vascular tissue development are the consequence rather than the cause of the release of the bud from inhibition.

scholarly journals Variation in Soil Properties Regulate Greenhouse Gas Fluxes and Global Warming Potential in Three Land Use Types on Tropical Peat

Atmosphere ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 465 ◽  
Author(s):  
Kiwamu Ishikura ◽  
Untung Darung ◽  
Takashi Inoue ◽  
Ryusuke Hatano
Keyword(s):  
Global Warming ◽  
Soil Moisture ◽  
Groundwater Level ◽  
Global Warming Potential ◽  
C:N Ratio ◽  
Co2 Flux ◽  
Nitrate Content ◽  
N2o Flux ◽  
Ch4 Flux ◽  
In The Beginning

This study investigated spatial factors controlling CO2, CH4, and N2O fluxes and compared global warming potential (GWP) among undrained forest (UDF), drained forest (DF), and drained burned land (DBL) on tropical peatland in Central Kalimantan, Indonesia. Sampling was performed once within two weeks in the beginning of dry season. CO2 flux was significantly promoted by lowering soil moisture and pH. The result suggests that oxidative peat decomposition was enhanced in drier position, and the decomposition acidify the peat soils. CH4 flux was significantly promoted by a rise in groundwater level, suggesting that methanogenesis was enhanced under anaerobic condition. N2O flux was promoted by increasing soil nitrate content in DF, suggesting that denitrification was promoted by substrate availability. On the other hand, N2O flux was promoted by lower soil C:N ratio and higher soil pH in DBL and UDF. CO2 flux was the highest in DF (241 mg C m−2 h−1) and was the lowest in DBL (94 mg C m−2 h−1), whereas CH4 flux was the highest in DBL (0.91 mg C m−2 h−1) and was the lowest in DF (0.01 mg C m−2 h−1), respectively. N2O flux was not significantly different among land uses. CO2 flux relatively contributed to 91–100% of GWP. In conclusion, it is necessary to decrease CO2 flux to mitigate GWP through a rise in groundwater level and soil moisture in the region.

Sign in / Sign up

Export Citation Format

Share Document