scholarly journals (122) Simulation of Poor Quality Irrigation Waters in Subirrigation and Top-watering using Mixture Experiments

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1084E-1085
Author(s):  
Matthew W. Kent ◽  
David W. Reed

The effects of cations vs. anions in salinity studies cannot be separated by traditional means. Analysis of mixture experiments allows ionic ef-fects to be analyzed individually by varying proportions of ions without changing their total concentrations. A series of mixture experiments were performed in the greenhouse to determine the effects of the anions bicarbonate, chloride, and sulfate, given a constant and equal concentration of the cation sodium, on vinca `Pacifica Red' grown with different irrigation systems and leaching fractions. In subirrigation, increasing total ion concentrations from 30 to 60 meq/L total ion concentrations (TIC) caused a general decrease in shoot fresh and dry weights, with bicarbonate contributing to the greatest degree of reduction, and sulfate the least. Root dry weight was similarly decreased with increasing TIC, but the differences between individual ion effects were more subtle. SPAD data, an indication of chlorophyll concentration, showed a sharp decrease with increase in bicarbonate, but not with sulfate or chloride. Medium pH increased as TIC increased, being influenced primarily by bicarbonate. Conversely, growing medium EC was influenced most by sulfate and chloride, and least by bicarbonate with increasing TIC. At 30 meq/L TIC, top-watered treatments with a leaching fraction (LF) of 5% generally had reduced shoot and root dry weight without regard to ion species, while a leaching fraction of 35% produced results more similar to those of subirrigation. While medium EC and pH varied with layer and irrigation method, bicarbonate generally affected EC least and pH most.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1069c-1069
Author(s):  
William R. Graves

Root hydraulic conductance is often expressed on the basis of dry weight or surface area of leaves or roots of plants produced in solution or aggregate culture. In this study, biomass partitioning and its influence on the interpretation of root hydraulic conductance data were compared in 21- to 63-day-old Gleditsia triacanthos inermis Willd. (honey locust) seedlings grown in solution and sand cultures. The ratio of lamina to root dry weight decreased as seedlings aged but was always greater for solution-grown plants than for sand-grown plants. Expressed on the basis of root dry weight, steady-state water fluxes at applied pressures ≥ 0.28 MPa and hydraulic conductivity coefficients declined with root system age, with a sharp decrease among solution-grown plants between ages 21 and 35 days. Such a difference was not detected using data expressed on lamina surface area or dry weight, illustrating that caution must be exercised when reporting and comparing the conductance of roots cultured in different media.


Author(s):  
K.H. Widdup ◽  
T.L. Knight ◽  
C.J. Waters

Slow establishment of caucasian clover (Trifolium ambiguum L.) is hindering the use of this legume in pasture mixtures. Improved genetic material is one strategy of correcting the problem. Newly harvested seed of hexaploid caucasian clover germplasm covering a range of origins, together with white and red clover and lucerne, were sown in 1 m rows in a Wakanui soil at Lincoln in November 1995. After 21 days, the caucasian clover material as a group had similar numbers of emerged seedlings as white clover and lucerne, but was inferior to red clover. There was wide variation among caucasian clover lines (48-70% seedling emergence), with the cool-season selection from cv. Monaro ranked the highest. Recurrent selection at low temperatures could be used to select material with improved rates of seedling emergence. Red clover and lucerne seedlings produced significantly greater shoot and root dry weight than caucasian and white clover seedlings. Initially, caucasian clover seedlings partitioned 1:1 shoot to root dry weight compared with 3:1 for white clover. After 2 months, caucasian clover seedlings had similar shoot growth but 3 times the root growth of white clover. Between 2 and 5 months, caucasian clover partitioned more to root and rhizome growth, resulting in a 0.3:1 shoot:root ratio compared with 2:1 for white clover. Both clover species had similar total dry weight after 5 months. Unhindered root/ rhizome devel-opment is very important to hasten the establishment phase of caucasian clover. The caucasian clover lines KZ3 and cool-season, both selections from Monaro, developed seedlings with greater shoot and root growth than cv. Monaro. KZ3 continued to produce greater root growth after 5 months, indicating the genetic potential for improvement in seedling growth rate. Different pasture estab-lishment techniques are proposed that take account of the seedling growth characteristics of caucasian clover. Keywords: establishment, genetic variation, growth, seedling emergence, Trifolium ambiguum


2018 ◽  
Vol 7 (1) ◽  
pp. 28
Author(s):  
Yetti Elidar

Research on the response of roots of palm sugar palm seeds (Arenga pinnata) in nurseries at doses and intervals of Nasa liquid organic fertilizer. Aims to determine the dosage, interval and combination of dosages and fertilization intervals with Nasa liquid organic fertilizer which can provide the best dry weight of the roots in the nursery. The research design used was a Completely Randomized Design (CRD) with 3x3 factorial experiments and each treatment was repeated 8 (eight) times, consisting of: the first factor was the treatment of POC Nasa dose in a concentration of 3 cc POC Nasa per liter of water (D) consists of 3 levels, namely: d1 = 300 ml POC Nasa, d2 = 400 ml POC Nasa, d3 = 500 ml POC Nasa, while the second factor is the treatment of POC Nasa Interval (I) consisting of 3 levels, namely: i1 = 2 once a week, i2 = once every 3 weeks, i3 = once every 4 weeks. The results of the POC Nasa dose study had a significant effect on leaf wet weight, leaf dry weight, root wet weight and root dry weight. The best dose at this level are: d2 (400 ml of Nasa liquid organic fertilizer), the interval of liquid organic fertilizer Nasa has a significant effect on leaf wet weight, leaf dry weight, root wet weight and root dry weight. The best dose at this level is: i1 (once every 2 weeks). The treatment combination has no significant effect on all parameters. 


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Admas Alemu ◽  
Tileye Feyissa ◽  
Marco Maccaferri ◽  
Giuseppe Sciara ◽  
Roberto Tuberosa ◽  
...  

Abstract Background Genetic improvement of root system architecture is essential to improve water and nutrient use efficiency of crops or to boost their productivity under stress or non-optimal soil conditions. One hundred ninety-two Ethiopian durum wheat accessions comprising 167 historical landraces and 25 modern cultivars were assembled for GWAS analysis to identify QTLs for root system architecture (RSA) traits and genotyped with a high-density 90 K wheat SNP array by Illumina. Results Using a non-roll, paper-based root phenotyping platform, a total of 2880 seedlings and 14,947 seminal roots were measured at the three-leaf stage to collect data for total root length (TRL), total root number (TRN), root growth angle (RGA), average root length (ARL), bulk root dry weight (RDW), individual root dry weight (IRW), bulk shoot dry weight (SDW), presence of six seminal roots per seedling (RT6) and root shoot ratio (RSR). Analysis of variance revealed highly significant differences between accessions for all RSA traits. Four major (− log10P ≥ 4) and 34 nominal (− log10P ≥ 3) QTLs were identified and grouped in 16 RSA QTL clusters across chromosomes. A higher number of significant RSA QTL were identified on chromosome 4B particularly for root vigor traits (root length, number and/or weight). Conclusions After projecting the identified QTLs on to a high-density tetraploid consensus map along with previously reported RSA QTL in both durum and bread wheat, fourteen nominal QTLs were found to be novel and could potentially be used to tailor RSA in elite lines. The major RGA QTLs on chromosome 6AL detected in the current study and reported in previous studies is a good candidate for cloning the causative underlining sequence and identifying the beneficial haplotypes able to positively affect yield under water- or nutrient-limited conditions.


2021 ◽  
Vol 4 (2) ◽  
pp. 291
Author(s):  
Indri Elang Mayanti ◽  
Basir Achmad

The areas of tropical forests in Indonesia always decrease every year, so that efforts are needed to cultivate plants efficiently for the supply of seedlings. Sungkai (Peronema canescens) has good quality wood that can be used for various purposes, either for construction, furniture, plywood or the leaves can be used for medicine. The purpose of this study was to analyze the growth of stem cuttings of sungkai based on the number of latent buds by calculating the root dry weight, bud dry weight, and total dry weight. This study used a factorial complete randomized design. There were two factors studied, namely the number of buds consisting of 2 levels: 2 buds and 1 bud, and the stem split factor. Each treatment was replicated 3 times and each experiment unit used 5 cuttings. The growth of sungkai cuttings in the treatment of two buds had a total dry weight of 170.04 grams, while the treatment of one bud had a total dry weight of 98.30 grams. The results of this study indicated that the more the number of latent buds, the more root and bud growth of cuttings.Keywords: Coppice; Latent buds; Cuttings; Sungkai


2021 ◽  
Vol 51 (3) ◽  
Author(s):  
Claudyanne do Nascimento Costa ◽  
Jadson Emanuel Lopes Antunes ◽  
João Pedro Alves de Aquino ◽  
Ingrid Sthephanie da Costa Silva ◽  
Angela Celis de Almeida Lopes ◽  
...  

ABSTRACT: This study evaluated the activity of rhizobia isolates inoculated in large (18 mm) and small (11 mm) seeds on lima bean growth, nodulation and N fixation. Selected rhizobia isolates were compared with a reference strain CIAT899 and two controls without inoculation. Large seeds contributed for highest plant growth, nodulation and N fixation than small seeds. The isolates UFPI-59, UFPI-18 and UFPI-38 promoted the highest values of shoot and root dry weight, respectively. The isolates UFPI-32 promoted the highest values of nodule number, while UFPI-59 promoted the highest values of nodule dry weight. The isolates UFPI-38 and UFPI-59 promoted the highest accumulation of N. This study showed that seed size really influences lima bean growth, nodulation and BNF. Considering rhizobia isolates, UFPI-59, UFPI-38, and UFPI-18 contributed for plant growth, promoted better nodulation and effectiveness on biological N fixation.


1996 ◽  
Vol 6 ◽  
pp. 163-166
Author(s):  
J. Van den Bosch ◽  
C.F. Mercer

Root-knot nematode (Meloidogyne sp.) reduces growth and nutrition of white clover (Trifolium repens L.) in New Zealand, and breeding resistant cultivars (with low galls per gram of root) is the preferred control method. Resistant and susceptible selections were bred from a wide range of white clover lines for three generations. In the third generation there were significant differences between seed lines from the selections for number of galls, root dry weight, visual growth score and galls/gram of root dry weight. Resistant selections had 43% of the susceptible selections' galls per gram, and 50% of the number of galls. Germplasm showing resistance to Meloidogyne spp. in the USA showed partial resistance to the local Meloidogyne sp. Two resistant and two susceptible genotypes were also compared for nematode egg production; resistant genotypes had a mean of 3,460 eggs/plant, compared to 25,030 for susceptible genotypes. Keywords: breeding, Meloidogyne sp., resistance, rootknot nematode, screening, selection, Trifolium repens, white clover


2008 ◽  
Vol 68 (4) ◽  
pp. 875-883 ◽  
Author(s):  
LH. Sipaúba-Tavares ◽  
AML. Pereira

Large-scale lab culture of Ankistrodesmus gracilis and Diaphanososma birgei were evaluated by studying the biology and biochemical composition of the species and production costs. Ankistrodesmus gracilis presented exponential growth until the 6th day, with approximately 144 x 10(4) cells.mL-1, followed by a sharp decrease to 90 x 10(4) cells.mL-1 (8th day). Algae cells tended to increase again from the 11th day and reached a maximum of 135 x 10(4) cells.mL-1 on the 17th day. D. birgei culture showed exponential growth until the 9th day with 140 x 10² individuals.L-1, and increased again as from the 12th day. Algae A. gracilis and zooplankton D. birgei contain 47 to 70% dry weight protein and over 5% dry weight carbohydrates. The most expensive items in the context of variable costs were labor and electricity. Data suggested that temperature, nutrients, light availability and culture management were determining factors on productivity. Results indicate that NPK (20-5-20) may be used directly as a good alternative for mass cultivation when low costs are taken into account, promoting adequate growth and nutritional value for cultured A. gracilis and D. birgei.


2020 ◽  
Vol 25 (3) ◽  
pp. 349-355
Author(s):  
Fitri Krismiratsih ◽  
Sugeng Winarso ◽  
Slamerto Slamerto

Efforts to increase production potential can be carried out by extensification in a less productive saline land. Salinity is a major problem in the growth of most plants. Azolla is a plant that is sensitive to salinity, but if it is applied well, it can grow optimally at high salinity levels. The purpose of this study is to obtain an azolla application technique that is effective in increasing the adaptation of rice plants to NaCl saline soil conditions. The experimental design used was Randomized Block Design (RBD) with 2 factors and 3 replications. The first factor was the azolla application technique consisted of 3 levels: fresh azolla composted, fresh azolla immersed, and fresh azolla as a ground cover. The second factor was the levels of NaCl salt stress consisted of 4 levels: control DHL 0, 2, 4, and 8 dS m-1. The adaptation ability of rice plants based on variable plants height growth rate, number of tillers, strove dry weight, root dry weight, stomata density, leaf chlorophyll (SPAD), age of flowering, number of paddy grain, and harvest index. The results showed how to test content up to 2 dS m-1 which increased rice growth especially the application of azolla composted. Increasing stress to 4 and 8 dS m-1showed bad effects on vegetative, physiology, and yields of rice components. The stronger of salt stress the higher all plants growth variables except the age of flowering that actually showed the acceleration of flowering. Application of composted azolla can increase the root dry weight and azolla as a ground cover can increase the numbers of paddy grains.   Keywords: azolla, NaCl, rice, stress


2021 ◽  
Vol 8 ◽  
Author(s):  
Rosemary Kate Steinberg ◽  
Emma L. Johnston ◽  
Teresa Bednarek ◽  
Katherine A. Dafforn ◽  
Tracy D. Ainsworth

Ocean warming driven bleaching is one of the greatest threats to zooxanthellate cnidarians in the Anthropocene. Bleaching is the loss of Symbiodiniaceae, chlorophyll, or both from zooxanthellate animals. To quantify bleaching and recovery, standardised methods for quantification of Symbiodiniaceae and chlorophyll concentrations have been developed for reef-building scleractinian corals, but no such standard method has been developed for octocorals. For stony corals, quantification of Symbiodiniaceae and chlorophyll concentrations often relies on normalisation to skeletal surface area or unit of biomass [i.e., protein, ash-free dry weight (AFDW)]. Stiff octocorals do not change their volume, as such studies have used volume and surface area to standardise densities, but soft-bodied octocorals can alter their size using water movement within the animal; therefore, Symbiodiniaceae and chlorophyll cannot accurately be measured per unit of surface area and are instead measured in units of Symbiodiniaceae and chlorophyll per μg of host protein or AFDW. Though AFDW is more representative of the full biomass composition than host protein, AFDW is more time and resource intensive. Here, we provide a streamlined methodology to quantify Symbiodiniaceae density, chlorophyll concentration, and protein content in soft-bodied octocorals. This technique uses minimal equipment, does not require freeze-drying or burning samples to obtain ash weight, and is effective for down to 0.2 g wet tissue. Bulk samples can be centrifuged, the Symbiodiniaceae pellet washed, and the supernatant saved for protein analysis. This efficient technique allows for clean, easy to count samples of Symbiodiniaceae with minimal animal protein contamination. Chlorophyll a and c2 extractions occurs at different rates, with chlorophyll a taking 24 h to extract completely at 4°C and chlorophyll c2 taking 48 h. Finally, we found that where necessary, wet weight may be used as a proxy for protein content, but the correlation of protein and wet weight varies by species and protein should be used when possible. Overall, we have created a rapid and accurate method for quantification of bleaching markers in octocorals.


Sign in / Sign up

Export Citation Format

Share Document