The ecological significance of plasticity in root weight ratio in response to nitrogen: Opinion

1996 ◽  
Vol 185 (1) ◽  
pp. 75-97 ◽  
Author(s):  
H. L. Reynolds ◽  
C. D'Antonio
Keyword(s):  
Weight Ratio ◽  
Root Weight ◽  
Ecological Significance ◽  
Root Weight Ratio

scholarly journals Needle-Clipping Longleaf Pine and Top-Pruning Loblolly Pine in Bareroot Nurseries

1998 ◽  
Vol 22 (4) ◽  
pp. 235-240 ◽  
Author(s):  
David B. South
Keyword(s):  
Loblolly Pine ◽  
Seedling Survival ◽  
Longleaf Pine ◽  
Weight Ratio ◽  
Dry Weight ◽  
Root Weight ◽  
Root Weight Ratio ◽  
Root Dry Weight ◽  
Percentage Points ◽  
Average Survival

Abstract Studies have shown that clipping needles of longleaf pine before outplanting can increase average seedling survival by 13 percentage points. Under some situations, the increase in survival might be due to a reduction in transpiration. For loblolly pine, top-pruning in the nursery might increase average survival by 6 percentage points. Benefits of pruning appear greater when seedlings experience stress after planting and when nonpruned seedlings have low root weight ratios (root dry weight/total seedling dry weight). On some droughty sites, a seedling with a 0.3 root weight ratio might have an 80% chance of survival, while a seedling with a 0.2 root weight ratio might only have a 53% chance of survival. In most studies where heights were measured after 3 yr in the field, pruned seedlings were the same height as nonpruned seedlings (± 7 cm). South. J. Appl. For. 22(4):235-240.

scholarly journals Effect of Wind and Soil Moisture on the Growth of `Bluecrop' (Vaccinium corymbosum L.)

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 648c-648
Author(s):  
W. Alan Erb ◽  
Mark Pyeatt
Keyword(s):  
Soil Moisture ◽  
Leaf Area ◽  
Weight Ratio ◽  
Dry Weight ◽  
Root Weight ◽  
Total Leaf Area ◽  
Root Weight Ratio ◽  
Leaf Weight Ratio ◽  
Canopy Volume ◽  
Temperature Experiment

This study was conducted in the greenhouse by running two experiments at different temperature regimes (22°C day and 13°C night and 33°C day and 22°C night). One-year-old tissue culture propagated plants were irrigated at three different soil moisture tension levels (5, 15, and 30 cnbars) and either exposed to moving or still air. The moving air treatment was created by two 51-cm-diameter fans running at either low (5.6 mph) or medium (8.2 mph) speed. Each experiment included, forty-eight plants arranged in a randomized complete block design. Each block consisted of a greenhouse bench containing two fans, a plastic dividing wall and two plant replications for each treatment. Canopy volume measurements were taken at the beginning, middle and end of each experiment to estimate growth rate. At the end of each experiment, total leaf area and leaf, stem and root dry weight data were collected. In the moderate temperature experiment, the still air treated plants had the highest canopy volume and leaf weight ratio while the moving air treated plants had the highest stem weight ratio. The only difference for the moisture treatments was the 5-cnbar treatment had the highest canopy volume. In the high temperature experiment, the still air treated plants had the highest canopy volume, total leaf area, leaf dry weight, shoot/root ratio, leaf weight ratio and leaf area duration while the moving air treated plants had the highest root weight ratio. The 5-cnbar treatment had the highest canopy volume and biomass accumulations. The 30-cnbar treatment had the highest root weight ratio.

Growth of Lotus creticus creticus and Cynodon dactylon under two levels of irrigation

2002 ◽  
Vol 53 (12) ◽  
pp. 1375 ◽  
Author(s):  
O. R. Vignolio ◽  
C. Biel ◽  
F. de Herralde ◽  
J. P. L. Araújo-Alves ◽  
R. Savé
Keyword(s):  
Leaf Area ◽  
Hydraulic Resistance ◽  
Cynodon Dactylon ◽  
Weight Ratio ◽  
Net Photosynthesis ◽  
Green Leaf ◽  
Shoot Biomass ◽  
Root Weight ◽  
Root Weight Ratio ◽  
Green Leaf Area

Soils with scarce plant covering are very susceptible to water and wind erosion. Two species recommended for permanent cover of soil are Lotus creticus creticus and Cynodon dactylon. The performance of both species cultivated in pure stands and in mixture and with 2 watering regimes, high (12.64 L/bag) and low (8.36�L/bag), was analysed in polyethylene bags between March and July in greenhouse conditions. With low watering the growth of both species was lower but mortality of plants was not observed. Growth of stems in L.�creticus and stolons in C. dactylon did not stop with low watering. The growth of C. dactylon was higher than that of L. creticus at both watering regimes. Total root and green shoot biomass of each species was affected by watering. Green leaf area, root weight ratio, root hydraulic resistance, and watering efficiency (g biomass/L watering) differed with the combination of species. Green leaf area, root hydraulic resistance, and watering efficiency were higher in C. dactylon than in L. creticus. Root weight ratio was higher in L. creticus than in C. dactylon, but the specific length and area of roots were higher in C. dactylon than in L. creticus. Net photosynthesis rate of each species was only affected by watering regime. Performance of both species was not affected by the mixture and it has the potential to be a successful ground cover.

scholarly journals Testing the potential of LEDs to enhance growth and quality characteristics of Salvia fruticosa

2019 ◽  
Vol 46 (No. 2) ◽  
pp. 98-106 ◽  
Author(s):  
Filippos Bantis ◽  
Kalliopi Radoglou
Keyword(s):  
Root Biomass ◽  
Weight Ratio ◽  
Dry Weight ◽  
Total Phenolic ◽  
Root Weight ◽  
Light Emitting ◽  
Shoot Dry Weight ◽  
Radiation Spectra ◽  
Salvia Fruticosa ◽  
Developmental Characteristics

The effect of light-emitting diodes (LED) with broad radiation spectra on developmental, physiological, and phytochemical characteristics of Greek sage (Salvia fruticosa L.) seedlings was assessed. Fluorescent (FL – control) tubes and four LED lights [AP67 (moderate blue, red and far-red), L20AP67 (moderate blue, red and far-red, high green), AP673L (moderate blue, high red) and NS1 (high blue and green, low red, high red : far-red, 1% ultraviolet)] were used in a growth chamber. Seedlings grown under FL, L20AP67 and AP673L exhibited the best morphological and developmental characteristics. FL led to inferior root biomass formation compared to all LEDs. AP67 promoted greater root-to-shoot dry weight ratio and dry-to-fresh overground and root weight ratios, but induced the least morphological and developmental characteristics. NS1 performed well regarding the root biomass production. Total phenolic content and the root growth capacity were not significantly affected. The present study demonstrates that L20AP67 and AP673L LEDs performed equally to FL light regarding the developmental characteristics. AP67 and NS1 may have the potential to be used for compact seedling production.

Effects of Plant Population on Sole-crop Cassava in Sierra Leone

1978 ◽  
Vol 14 (3) ◽  
pp. 239-244 ◽  
Author(s):  
W. Godfrey-Sam-Aggrey
Keyword(s):  
Sierra Leone ◽  
Yield Components ◽  
Dry Matter ◽  
Weight Ratio ◽  
Land Plant ◽  
Plant Population ◽  
Root Weight ◽  
Plant Populations ◽  
Sole Crop ◽  
Yield And Yield Components

SUMMARYEffects of plant population on mean yield and yield components of 2-year sole cassava crops were studied on Njala upland soils of Sierra Leone in two experiments. Increasing plant population of multi-shoot Cocoa cassava over 7000/ha decreased all the parameters studied except top/root weight ratio, which increased. The observed effects were attributed to competition for environmental resources, since area of land/plant unit decreased as plant population increased. The relations between plant populations and yields of fresh root and cortex dry matter were asymptotic, indicating that the respective yields were products of the vegetative phase of cropping.

scholarly journals SKRINING GALUR KAPAS (Gossypium hirsutum L.) TOLERAN TERHADAP KEKERINGAN DENGAN PEG-6000 PADA FASE KECAMBAH

2020 ◽  
Vol 19 (3) ◽  
pp. 139 ◽  
Author(s):  
SIWI SUMARTINI ◽  
EMY SULISTYOWATI ◽  
SRI MULYANI ◽  
ABDURRAKHMAN ABDURRAKHMAN
Keyword(s):  
Gossypium Hirsutum ◽  
Root Length ◽  
Arable Land ◽  
Weight Ratio ◽  
Root Weight ◽  
Cotton Production ◽  
Gossypium Hirsutum L ◽  
Drought Susceptibility Index ◽  
Peg 6000 ◽  
Susceptibility Index

<p>ABSTRAK<br />Daerah pengembangan kapas di Indonesia umumnya lahan kering<br />dengan keterbatasan air. Penelitian ini bertujuan untuk mendapatkan galur-<br />galur kapas toleran kekeringan menggunakan PEG-6000 pada fase<br />kecambah. Penelitian dilaksanakan di Laboratorium Pengujian Benih Balai<br />Penelitian Tanaman Pemanis dan Serat, mulai bulan April sampai Juni<br />2012. Perlakuan disusun dalam rancangan Petak Terbagi dan diulang dua<br />kali. Petak utama adalah perlakuan PEG-6000 (-3 bar) dan tanpa PEG-<br />6000 (air), sedangkan anak petak adalah 13 galur kapas dan varietas<br />Kanesia 14. Setiap perlakuan terdiri dari lima pot masing-masing ditanam<br />sepuluh biji. Benih kapas dicampur dengan fungisida Mancozeb 80% 2<br />g/kg benih sebelum ditanam. Parameter pengamatan meliputi daya<br />berkecambah, panjang kecambah dan akar, bobot kecambah dan akar,<br />rasio  panjang  akar/kecambah,  serta  indeks  kerentanan  terhadap<br />kekeringan. Kecambah dihitung sebagai kecambah normal jika panjang<br />lebih dari 0,5 cm. Perlakuan PEG-6000 berpengaruh sangat nyata terhadap<br />penurunan daya berkecambah, panjang kecambah dan akar, serta bobot<br />kecambah dan akar. Sebaliknya, rasio panjang akar/kecambah lebih tinggi<br />pada perlakuan PEG-6000 dibandingkan dengan perlakuan tanpa PEG-<br />6000. Respon ketahanan galur kapas yang dihitung dengan indeks<br />kerentanan kekeringan berbeda pada masing-masing parameter yang<br />diamati. Dari nilai rata-rata indeks kerentanan kekeringan semua<br />parameter, tidak ada galur yang tahan terhadap kekeringan (S&lt;0,50).<br />Terdapat delapan galur yang agak tahan kekeringan (0,50&lt;S&lt;1,0) dan<br />lebih tahan dibandingkan dengan Kanesia 14, yaitu 03002/12, 03006/1,<br />03008/7, 03008/24, 03012/17, 03014/12, 03017/13, dan 03017/15.<br />Kata kunci: Gossypium hirsutum L., tahan kekeringan, PEG-6000,<br />perkecambahan, galur</p><p>ABSTRACT<br />Cotton production areas in Indonesia are arable land with lack of water<br />availability. The aim of this study was to obtain cotton lines tolerant to<br />drought using PEG-6000 at germination stage. The experiment was<br />conducted at the Seed Testing Laboratory in Indonesian Sweetener and<br />Fiber Crops Research Institute, from April to June 2012. Treatments were<br />arranged in a Split Plots design with two replications. The main plot was<br />PEG-6000 (-3 bar) and without PEG-6000 (water), while the subplot was<br />13 cotton lines and Kanesia 14 variety. Seed cotton was treated with 80%<br />Mancozeb fungicide dose of 2g/kg seed before sowing. Parameters<br />observed were germination percentage, shoot and root length, shoot and<br />root weight, ratio of root/shoot length, and drought susceptibility index.<br />Seedling was counted as normal if its length more than 0.5 cm. PEG-6000<br />treatment gives very significant effect on the decline on seed germination,<br />shoot and root length, shoot and root weight. Otherwise, ratio of root/shoot<br />length was higher in the PEG-6000 than without PEG-6000 treatment.<br />Response of cotton lines to drought which calculated with a drought<br />susceptibility index were different among parameter observed. Mean<br />drought susceptibility index of all parameters showed that none of cotton<br />line tolerant to drought (S &lt; 0,50) was achieved from the study. There<br />were eight moderately drought-resistant lines (0, 50 &lt; S &lt; 1,0) achieved<br />namely 03002/12, 03006/1, 03008/7, 03008/24, 03012/17, 03014/12,<br />03017/13, and 03017/15 which more resistance than Kanesia 14.<br />Key words: Gossypium hirsutum L., drought tolerant, PEG-6000,<br />germination, lines</p>

Response of a Red Fescue-Kentucky Bluegrass Turf to Three Consecutive Annual Applications of Amidochlor, Mefluidide, and Ethephon

Weed Science ◽  
1987 ◽  
Vol 35 (1) ◽  
pp. 95-98 ◽  
Author(s):  
Prasanta C. Bhowmik
Keyword(s):  
Adverse Effects ◽  
Phosphonic Acid ◽  
Root Length ◽  
Poa Pratensis ◽  
Weight Ratio ◽  
Kentucky Bluegrass ◽  
Root Weight ◽  
Festuca Rubra ◽  
Red Fescue ◽  
Greenhouse Study

A red fescue (Festuca rubraL.)- Kentucky bluegrass (Poa pratensisL.) turf was treated annually with amidochlor {N-[(acetylamino)methyl]-2-chloro-N-(2,6-diethylphenyl)acetamide} at 2.2, 2.8, and 3.4 kg ai/ha, mefluidide {N-[2,4-dimethyl-5-[[(trifluoromethyl)sulfonyl] amino] phenyl] acetamide} at 0.4 kg ai/ha, and ethephon [(2-chloroethyl) phosphonic acid] at 5.6 kg ai/ha for three consecutive years. Recuperative potential of treated turfgrass was determined in the field and in a greenhouse study. Amidochlor and mefluidide treatments injured turfgrass (11 to 64%) four weeks after application. However, turfgrass recovered after eight weeks. Amidochlor at 2.8 to 3.4 kg/ha and mefluidide at 0.4 kg/ha suppressed (75 to 100%) seedhead development. Ethephon at 5.6 kg/ha was ineffective. Turfgrass recovered normally each spring after amidochlor treatments, with no delay in spring green-up. Root length, root weight, and root:shoot weight ratio of the plugs from the greenhouse study were unaffected by three consecutive annual applications of amidochlor, mefluidide, and ethephon. One annual spring application of amidochlor, mefluidide, and ethephon for three consecutive years caused no adverse effects that would limit their use on red fescue-Kentucky bluegrass turf.

scholarly journals Increasing Cell Size and Reducing Medium Compression Enhance Lettuce Transplant Quality and Field Production

HortScience ◽  
1996 ◽  
Vol 31 (2) ◽  
pp. 184-189 ◽  
Author(s):  
Silvana Nicola ◽  
Daniel J. Cantliffe
Keyword(s):  
Cell Size ◽  
Sandy Soil ◽  
Shoot Growth ◽  
Weight Ratio ◽  
Dry Weight ◽  
Root Weight ◽  
Growth Ratio ◽  
Root Dry Weight ◽  
Total Dry Weight ◽  
Initial Root

`South Bay' lettuce (Lactuca sativa L.) seedlings were grown in a greenhouse during winter, spring, and fall to investigate the effect of cell size and medium compression on transplant quality and yield. Four Speedling planter flats (1.9-, 10.9-, 19.3-, 39.7-cm3 cells) and two medium compression levels [noncompressed and compressed (1.5 times in weight)] were tested. The two larger cell sizes and compression of the medium led to increased plant shoot growth. Conversely, root weight ratio [RWR = (final root dry weight ÷ final total dry weight + initial root dry weight ÷ initial total dry weight) ÷ 2] was highest with the smaller cells without medium compression. Lettuce transplants were field-grown on sand and muck soils. The larger cells delayed harvest by >2 weeks for plants grown on muck soil, but yield was unaffected. When grown on sandy soil, earliness was enhanced from plants grown in 19- and 40-cm3 cells, but head weights were not affected in the spring planting. In fall, heads were heavier for plants grown in 11-, 19-, or 40-cm3 cells compared with those from 2-cm3 cells. On sandy soil, harvest was delayed 13 days in spring and 16 days in fall for plants grown in the smallest cell size. Using the two smaller cell sizes saved medium and space in the greenhouse and increased the root growth ratio, but it led to reduced plant growth compared to using the bigger cells. Yield and earliness were more related to season and soil type than to transplant quality. On sandy soil, plants grown in 2- and 11-cm3 cells matured later, and yield was significantly decreased (8.6%) in fall by using plants from the 2-cm3 cells compared to the other sizes. From our results, compressing the medium in the cells was not justified because it is more costly and did not benefit yield in the field.

scholarly journals Seedling Growth of Catawba Rhododendron. I. Temperature Optima, Leaf Area, and Dry Weight Distribution

HortScience ◽  
1994 ◽  
Vol 29 (11) ◽  
pp. 1298-1302 ◽  
Author(s):  
D. Bradley Rowe ◽  
Stuart L. Warren ◽  
Frank A. Blazich
Keyword(s):  
Leaf Area ◽  
Seedling Growth ◽  
Weight Ratio ◽  
Dry Weight ◽  
High Elevation ◽  
Root Weight ◽  
Root Dry Weight ◽  
Leaf Weight Ratio ◽  
Leaf Weight ◽  
Total Plant

Catawba rhododendron (Rhododendron catawbiense Michx.) seedlings of two provenances, Johnston County, N.C. (35°45′N, 78°12′W, elevation = 67 m), and Yancey County, N.C. (35°45′N, 82°16′W, elevation = 1954 m), were grown in controlled-environment chambers for 18 weeks with days at 18, 22, 26, or 30C in factorial combination with nights at 14, 18, 22, or 26C. Shoot and root dry weights and total leaf areas of seedlings of the Yancey County provenance (high elevation) exceeded (P ≤ 0.05) those of the Johnston County (low elevation) provenance at all temperature combinations. Leaf area was maximal at 22/22C, 18/26C, and 22/26C and minimal at 30/14C (day/night). Shoot dry weight responded similarly. Root dry weight decreased linearly with increasing day temperature, but showed a quadratic response to night temperature. Leaf weight ratio (leaf dry weight: total plant dry weight) increased, while root weight ratio (root dry weight: total plant dry weight) decreased with increasing day temperature. Leaf weight ratio was consistently higher than either stem or root weight ratios. Day/night cycles of 22 to 26/22C appear optimal for seedling growth.

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