scholarly journals Development of Strategies to Evaluate Brassica oleracea L. Vegetable Crops for Wirestem Caused by Rhizoctonia solani

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 621c-621
Author(s):  
Mark W. Farnham ◽  
Anthony P. Keinath
Keyword(s):  
Rhizoctonia Solani ◽  
Field Experiments ◽  
Effective Means ◽  
Field Studies ◽  
Field Trials ◽  
Alternative Methods ◽  
Environment Interaction ◽  
Vegetable Crops ◽  
Respective Field ◽  
Controlled Environments

Wirestem, caused by Rhizoctonia solani, is a destructive disease of B. oleracea cole crops and is distributed worldwide. Effective means of wirestem control include soil fumigation and soil treatment with pentachloronitrobenzene, which are increasingly expensive and environmentally undesirable. As a consequence, alternative methods of wirestem control are needed. Thus, we conducted controlled-environment and field experiments to develop methodology to study host-plant resistance and possibly biocontrol agents as potential wirestem control alternatives. Seedlings of 12 cultivars (three each of cauliflower, broccoli, cabbage, and collard) at the four- to five-leaf stage were transplanted to trays in a growth room or into field plots and covered with soil infested with R. solani AG-4 sclerotia. Disease progression (percent of plants healthy, diseased, and dead) was observed every 3 days for 2 weeks in the controlled environments and for 3 weeks in field trials. At the end of two studies, plants were dug with roots intact and rated for disease using a 1 to 10 scale. In all trials, percent healthy plants stabilized at about 2 weeks after inoculation. Incidence of wirestem disease varied among experiments ranging from 70% to 100% diseased, dead plants in controlled environments, and from 51% to 88% and 33% 65% in the two respective field studies. Disease rating was always negatively and significantly correlated with percent healthy plants. Although a genotype × environment interaction was observed, some cultivars (i.e., `Snowcone' and `Snowcrown' cauliflowers) were always severely diseased, while others (i.e., `Viking' broccoli and `Blue Max' collard) were consistently among the least diseased.

scholarly journals Optimizing Sowing Depth of Tef for Irrigated Mediterranean Conditions: From Laboratory to Field Studies

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1983
Author(s):  
Shiran Ben-Zeev ◽  
Shane Kerzner ◽  
Onn Rabinovitz ◽  
Yehoshua Saranga
Keyword(s):  
Field Experiments ◽  
Field Studies ◽  
Field Trials ◽  
Eragrostis Tef ◽  
Sowing Depth ◽  
New Crops ◽  
Different Depths ◽  
Plant Emergence ◽  
Increasing Demand ◽  
Mediterranean Conditions

Developing new crops adapted to arid conditions is a promising approach to meet the increasing demand for food production under expanding aridity. Tef [Eragrostis tef (Zucc.) Trotter] is a C4 cereal crop cultivated mainly in Ethiopia and the Horn of Africa, and known for its high resilience to stressful environments. Due to their tiny size, tef seeds are traditionally sown by broadcasting and lightly covering with soil. Under semiarid Mediterranean conditions, a deeper sowing may guarantee seedling establishment while saving on irrigation water. The objective of this study was, therefore, to determine the effects of sowing depth on tef emergence, development, lodging, and productivity. Tef seeds were sown at different depths in test tubes and pots, and in two field experiments. In tubes and pots, time from sowing to emergence increased about twofold and emergence rate decreased in the deepest sowing (3 cm) treatment compared to controls (0 cm). In the pot and field trials, deep sowing (3 cm) significantly reduced plant height, shoot and root biomass, and lodging. Sowing depths of 1–2 cm allowed successful plant establishment while not exacting penalties on plant emergence or development; hence this range appears to be optimal for sowing irrigated tef.

scholarly journals Differential Cultivars and Criteria for Evaluating Resistance to Rhizoctonia solani in Seedling Brassica oleracea

Plant Disease ◽  
1997 ◽  
Vol 81 (8) ◽  
pp. 946-952 ◽  
Author(s):  
Anthony P. Keinath ◽  
Mark W. Farnham
Keyword(s):  
Rhizoctonia Solani ◽  
Brassica Oleracea ◽  
Field Experiments ◽  
Field Trials ◽  
Plant Weight ◽  
Progress Curve ◽  
Growth Room ◽  
Differential Cultivars ◽  
Field Plots ◽  
Sand Cultures

Growth-room and field experiments were conducted to develop methods of studying resistance in Brassica oleracea crops to Rhizoctonia solani anastomosis groups (AG) 2-1 and 4, causal agents of wirestem. Seedlings of 12 cultivars (3 each of broccoli, cauliflower, cabbage, and collard) at the four- to five-leaf stage were transplanted to trays in a growth room and covered with steamed soil infested with cornmeal-sand cultures or sclerotia of R. solani or to fumigated field plots infested with sclerotia. The percent healthy, diseased, and dead plants was assessed every 3 to 5 days for 2 weeks in the growth room and for 3 weeks in field trials. At harvest, plants were dug out with roots intact and rated for wirestem severity. In most experiments, wirestem incidence (percent diseased and dead plants) stabilized within 10 to 14 days after inoculation. Inoculation with cornmeal-sand cultures of both AGs and sclerotia of AG-4 resulted in severe wirestem in all experiments, whereas sclerotia of AG-2-1 were less effective in the growth room and not effective in the field. Percent healthy and surviving (healthy plus diseased) plants, area under the disease progress curve (AUDPC), and wirestem severity all separated the most susceptible from the partially resistant cultivars more consistently than fresh weight of inoculated plants expressed as a percentage of noninoculated plant weight. Wirestem severity and AUDPC were always negatively and significantly (P ≤ 0.01) correlated with percent healthy plants. Although genotype by environment interactions were observed, the cauliflower cvs. Snowcone and Snow Crown were severely diseased in all experiments, whereas collard cv. Blue Max was consistently and significantly (P ≤ 0.05) less diseased.

scholarly journals Efficacy of Bacterial or Fungal Soil Amendments on Vegetables Following Peanut

HortScience ◽  
2006 ◽  
Vol 41 (6) ◽  
pp. 1395-1399
Author(s):  
Vincent M. Russo
Keyword(s):  
Mycorrhizal Fungi ◽  
Field Experiments ◽  
Nutrient Content ◽  
Field Trials ◽  
Growth Cycle ◽  
Bell Pepper ◽  
Vegetable Crops ◽  
Marketable Yield ◽  
Navy Bean ◽  
Fertilizer Rate

Amendment of soil with microorganisms during the growth cycle of one crop may affect development of succeeding crops. Species of Rhizobium bacteria or abuscular-mycorrhizal fungi were added alone to, or in combination with, potting soil in pots in a greenhouse. Controls were no amendments. Seed of peanut (Arachis hypogaea L.) were planted and two levels of a combination NPK fertilizer, the recommended and one-fourth the recommended rate, were applied. After harvest of peanut and remoistening of soil, seed of the bell pepper (Capsicum annuum L.) or navy bean (Phaseolus vulgaris L.) were sown into the same planting medium in pots without additional inoculation with microbes. Dry weights of above-ground vegetative and edible portions of crops were determined. Inoculum type only affected peanut top and total dry weights. The recommended fertilizer level did not affect peanut yield but did cause improvement in bell pepper and navy bean yield over that of the deficient fertilizer rate. In field experiments, peanut was planted into soil receiving Rhizobium spp. bacteria, or arbuscular-mycorrhizal fungi alone or in combination. Controls consisted of no amendment. Only the recommended fertilizer rate was used. In the next 2 years, bell pepper or navy bean were established in plots without use of additional microbial amendment. Yields and nutrient contents of crops were determined. Type of inoculum did not affect yield or nutrient content in any crop. Bell pepper marketable yield was unaffected by year, and navy bean seed yield was higher in 2004 than in 2005. In both years, navy bean yields were below U.S. averages. Concentrations of most nutrients in edible portions of bell pepper and navy bean were lower in 2004 than in 2005. Results of the field trials were generally similar to those of greenhouse studies. Use of inocula did not provide substantial benefits to yield or nutrient content of peanut or vegetable crops that followed.

scholarly journals Root phenotypes of young wheat plants grown in controlled environments show inconsistent correlation with mature root traits in the field

2020 ◽  
Vol 71 (16) ◽  
pp. 4751-4762 ◽  
Author(s):  
Sarah M Rich ◽  
Jack Christopher ◽  
Richard Richards ◽  
Michelle Watt
Keyword(s):  
Plant Development ◽  
Field Experiments ◽  
Primary Root ◽  
Root Traits ◽  
Field Trials ◽  
Controlled Environment ◽  
Nodal Root ◽  
Controlled Environments ◽  
Root Types ◽  
Mature Root

Abstract Using a field to lab approach, mature deep-rooting traits in wheat were correlated to root phenotypes measured on young plants from controlled conditions. Mature deep-rooting root traits of 20 wheat genotypes at maturity were established via coring in three field trials across 2 years. Field traits were correlated to phenotypes expressed by the 20 genotypes after growth in four commonly used lab screens: (i) soil tubes for root emergence, elongation, length, and branching at four ages to 34 days after sowing (DAS); (ii) paper pouches 7 DAS and (iii) agar chambers for primary root (PR) number and angles at 8 DAS; and (iv) soil baskets for PR and nodal root (NR) number and angle at 42 DAS. Correlations between lab and field root traits (r2=0.45–0.73) were highly inconsistent, with many traits uncorrelated and no one lab phenotype correlating similarly across three field experiments. Phenotypes most positively associated with deep field roots were: longest PR and NR axiles from the soil tube screen at 20 DAS; and narrow PR angle and wide NR angle from soil baskets at 42 DAS. Paper and agar PR angles were positively and significantly correlated to each other, but only wide outer PRs in the paper screen correlated positively to shallower field root traits. NR phenotypes in soil baskets were not predicted by PR phenotypes in any screen, suggesting independent developmental controls and value in measuring both root types in lab screens. Strong temporal and edaphic effects on mature root traits, and a lack of understanding of root trait changes during plant development, are major challenges in creating controlled-environment root screens for mature root traits in the field.

Controlling Bamboo (Phyllostachys spp.) with Herbicides

2007 ◽  
Vol 21 (1) ◽  
pp. 80-83 ◽  
Author(s):  
Mark A. Czarnota ◽  
Jeffrey Derr
Keyword(s):  
Field Experiments ◽  
Field Studies ◽  
Field Trials ◽  
Grass Species ◽  
Bamboo Shoot ◽  
Bamboo Species ◽  
Limited Information ◽  
Single Application ◽  
Fresh Weight ◽  
Greenhouse Experiments

Bamboos are grass species that can escape cultivation and invade lawns, landscapes, and other areas. Limited information is available on ways to control invasive bamboo species. Greenhouse and field studies were initiated to determine the level of bamboo control provided by a single application of selected PRE and POST herbicides. Bamboo species included in the study were golden bamboo in greenhouse experiments and red-margined bamboo in field experiments. In greenhouse trials, MSMA, quinclorac, dithiopyr, clethodim, fenoxaprop, and sethoxydim did not control either species. Glyphosate, glufosinate, and fluazifop significantly reduced bamboo-shoot fresh weight, although regrowth occurred after a single application. In field trials, bamboo control with dichlobenil in the 2002 and 2004 experiments was less than 23%. For the study initiated in 2002, glyphosate and imazapyr provided 76% and 98% bamboo control, respectively, at 58 wk after treatment (WAT). By 161 WAT (approximately 3 yr after treatment), bamboo-control ratings were 40% with glyphosate and 85% with imazapyr. For the study initiated in 2004, at 61 WAT, glyphosate and imazapyr provided 46 and 88% control of bamboo, respectively.

Fungicide seed dressings: their effects on emergence of soybean and nodulation of pea and soybean

1980 ◽  
Vol 20 (105) ◽  
pp. 497 ◽  
Author(s):  
GE Stovold ◽  
J Evans
Keyword(s):  
Field Experiments ◽  
Soybean Seed ◽  
Field Trials ◽  
Inhibitory Effect ◽  
Alternative Methods ◽  
Seedling Disease ◽  
Rhizobium Inoculation ◽  
Treated Seed ◽  
Inoculant Carrier ◽  
Seedling Diseases

A range of fungicides was tested for their efficacy as seed treatments for the control of seedling diseases of soybeans. Thiram, captan and captafol at rates of 2000 ppm a.i. w/w or 3000 ppm a.i. w/w provided the most consistent protection in field trials conducted for 3 years at three separate sites. Of these three fungicides, thiram had the least effect on nodulation by Rhizobium applied to the seed, but an inhibiting effect did occur in some years. Several other fungicides had little effect on nodulation but were inconsistent in controlling seedling diseases. In a glasshouse pot trial, the fungicides did not reduce nodulation even though some were consistently toxic in the field experiments. In field trials with peas and soybeans, the inhibitory effect of a toxic fungicide (captan) on nodulation by seed-borne Rhizobium was avoided by using alternative methods of inoculation which separated Rhizobium from the treated seed. A water suspension of peat-based rhizobial inoculant, or sand particles coated with peat inoculant introduced to the furrow together with the seed, were effective methods of inoculation. A large-particle inoculant carrier (heat-killed soybean seed) was unsuitable. For control of soybean seedling disease we recommend the use of thiram fungicide at a rate of 2000 ppm a.i. w/w, and where practicable the use of alternative methods of Rhizobium inoculation to separate the inoculum from the treated seed.

Corrosion and performance of dust palliatives : laboratory and field studies

2021 ◽  
Author(s):  
Lulu Edwards ◽  
Charles Weiss ◽  
J. Newman ◽  
Fred Nichols ◽  
L. Coffing ◽  
...  
Keyword(s):  
Field Experiments ◽  
Field Studies ◽  
Field Trials ◽  
Ground Vehicle ◽  
Wind Speeds ◽  
Corrosion Studies ◽  
Air Impingement ◽  
And Performance ◽  
Rotary Wing

This report details laboratory and field experiments on BioPreferred® dust suppressants to assess performance and corrosion characteristics. Numerous bio-based dust suppressant products are marketed, but little data are available to assess performance for dust abatement and corrosion of common metals. A laboratory study used an air impingement device and the Portable In-Situ Wind ERosion Laboratory (PI-SWERL) to simulate wind speeds similar to those in field conditions for rotary wing aircraft. Laboratory corrosion studies used metal coupons imbedded in soil treated with dust palliative. Field trials were conducted using ground vehicle traffic to minimize cost and lower safety concerns while increasing surface wear from repetitive traffic. These studies clearly show that bio-based products demonstrate low corrosion potential with similar dust abatement performance to synthetic-based agents.

scholarly journals EVALUATION OF THE INFLUENCE OF ARBUSCULAR MYCORRHIZAL FUNGI ON ECONOMICALLY VALUABLE INDICATORS OF ONION

Ekosistemy ◽  
2020 ◽  
Vol - (21) ◽  
pp. 101-108
Author(s):  
S. F. Abdurashytov ◽  
V. I. Nemtinov ◽  
E. V. Puzanova ◽  
K. S. Gritsevich ◽  
I. V. Belova ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
Field Experiments ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Field Studies ◽  
Dry Mass ◽  
Initial Assessment ◽  
Vegetable Crops ◽  
Bulb Formation ◽  
Southern Chernozem

Allium cepa L. is one of the main vegetable crops. It is actively used in food industry and medicine. The biochemical composition of plants, both bulbs and green leaves, in different periods of growth changes depending on the variety, environmental and agrotechnical conditions of plant cultivation. Representatives of the genus Allium are highly sensitive to the presence of arbuscular mycorrhiza (AM) in soil due to root development features. The aim of our work was to identify effective associations of AM fungi to increase the productivity and quality of onions in the conditions of southern chernozem. Pot and field experiments were carried out with associations of AM fungi and onion varieties from the collection of the Research Institute of Agriculture of Crimea. The initial assessment of the AM fungi collection was conducted in the pot with a sterile substrate under artificial lighting conditions according to the intensity of mycorrhizal colonization and the accumulation of phytomass of the storage plant. Field studies were carried out on southern carbonate chernozem in 2019. It is established that the AM fungi association M9 significantly exceeds the referent in the arbuscules abundance by 13.3 %. Association 1–16 showed the most considerable abundance of vesicles, which was 11.1–13.3 % higher than other variants of this experiment. The dry mass of onion shoots had a significant increase of 11.719.7 mg per plant (38.865.8 %) from inoculation by associations AM S1-4, 1-16 and M9. The positive effect of the AM fungi association 1-16 on the accumulation of phytomass in the onset phase of bulb formation and onion productivity of the onion variety Yaltinskiy plus and line 11A with an increase by 0.690.8 g / plant (31.351.7 %) and 1.11.3 t / ha (14.114.9 %), respectively, and an increase in the content of ascorbic acid by 18.524.4 % to the variant without treatment are shown.

scholarly journals The Influence of Light on Relationships Between Sclerotinia Stem Rot of Soybean in Field and Controlled Environments

Plant Disease ◽  
2008 ◽  
Vol 92 (11) ◽  
pp. 1510-1514 ◽  
Author(s):  
A. J. Peltier ◽  
C. R. Grau
Keyword(s):  
Light Intensity ◽  
Growth Stage ◽  
Field Performance ◽  
Field Trials ◽  
Growth Chamber ◽  
Disease Assessment ◽  
Environment Interaction ◽  
Sclerotinia Stem Rot ◽  
Field Interaction ◽  
Controlled Environments

Interaction phenotypes between soybean and Sclerotinia sclerotiorum observed in controlled and field environments often do not correlate. Resistant and susceptible accessions were selected to study light intensity as a variable that influences interaction phenotype. Objectives were to investigate whether light intensity within a controlled environment influences the ability to: i) distinguish resistant and susceptible accessions; ii) predict field interaction phenotypes; and iii) determine whether the method used for disease assessment influences the outcome of results. Six accessions were evaluated in growth chamber and field disease nursery trials. Five environments ranging from 146 to 434 μmol·m–2·s–1 of photosynthetically active radiation were established in the growth chamber. Inoculum was delivered to cut petioles at the R1 growth stage and interaction phenotypes were assessed for 11 days. For field trials, individual plants were rated at growth stage R7. The breeding line W04.1002 had less disease than NK S19-90 in field environments. Rank correlations of field and light environment interaction phenotypes indicate that light intensity affected the prediction of field performance. Evaluations conducted at 337 μmol·m–2·s–1 of light were most predictive of field interaction phenotypes (rs = 0.83 to 0.94; P = 0.05 to < 0.005). Controlling light intensity is critical to facilitate the identification of resistance to S. sclerotiorum in soybean.

scholarly journals Genotype by environment interaction for main winter triticale varieties characteristics at two levels of technology using additive main effects and multiplicative interaction model

Euphytica ◽  
2021 ◽  
Vol 217 (2) ◽  
Author(s):  
Jan Bocianowski ◽  
Anna Tratwal ◽  
Kamila Nowosad
Keyword(s):  
Field Experiments ◽  
Block Design ◽  
Interaction Model ◽  
Field Trials ◽  
Genotype By Environment Interaction ◽  
Environment Interaction ◽  
Multiplicative Interaction ◽  
Winter Triticale ◽  
Genotype By Environment ◽  
Main Effects

AbstractThe aim of this study was to assess genotype by environment interaction for grain yield, plant height and thousand-grain weight in winter triticale cultivars by the additive main effects and multiplicative interaction (AMMI) model. The study comprised of ten winter triticale varieties i.e.: Algoso, Baltiko, Grenado, Magnat, Moderato, Pawo, Todan, Trimester, Trismart and Witon. Field trials were performed at seven locations in three years (21 environments) in a randomized complete block design, with two replicates at two levels of cultivation technology (standard – A1 and intensive – A2). Field experiments were carried out as part of Post Registration Variety Trials in Wielkopolska region. AMMI analyses revealed significant genotype and environmental effects as well as genotype by environmental interaction with respect to all three observed traits in both levels of cultivation intensity. The cultivars Algoso, Baltiko and Trimester are recommended for further inclusion in the breeding programs because of their stability and good average values of observed traits.

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