scholarly journals Effects of Sublabeled Rates of Dazomet and Metam-Sodium Applied Under Low-Permeability Films on Calonectria Microsclerotia Survival

Plant Disease ◽  
2018 ◽  
Vol 102 (4) ◽  
pp. 782-789 ◽  
Author(s):  
Dalia Aiello ◽  
Alessandro Vitale ◽  
Rafael F. Alfenas ◽  
Acelino C. Alfenas ◽  
Gabriella Cirvilleri ◽  
...  
Keyword(s):  
Red Clover ◽  
Low Permeability ◽  
Infested Soil ◽  
Metam Sodium ◽  
Primary Inoculum ◽  
Application Rates ◽  
Different Seasons ◽  
Leaf Tissues ◽  
Field Plots ◽  
Plastic Containers

Infested soil is the primary inoculum source for Calonectria spp. for initiating disease in ornamental and forestry crops. The effects of dazomet and metam-sodium on survival of microsclerotia of 28 isolates belonging to 19 Calonectria spp. were evaluated in this study under nursery conditions. Two experiments with exotic Calonectria spp. in plastic containers in a greenhouse and three trials with endemic species in field plots were performed during different seasons. The containers and plots were artificially infested with Calonectria microsclerotia differentiated on carnation leaf tissues. Basamid (dazomet) was applied at 100, 160, 200, 400, and 500 kg/ha, while Divapan (metam-sodium) was applied at 250, 350, 400, 700, and 1,000 liters/ha in both the containers and plots. The fumigants were applied under virtually and totally impermeable films. Fungal survival was evaluated after 21 days using leaf tissues collected from treated soil and plated on potato dextrose agar, and the ability of microsclerotia to cause infection was tested on red clover. The survival of Calonectria inocula and microsclerotia decreased with increasing fumigant rates. In the greenhouse trials, where Basamid was applied at 200, 400, and 500 kg/ha and Divapan at 400, 700, and 1,000 liters/ha, no viable microsclerotia were recovered for 14 exotic Calonectria spp., whereas viable inocula of Calonectria hongkongensis, C. naviculata, and C. sulawesiensis were retrieved from the fumigated plots. Low rates of Basamid (100 and 160 kg/ha) and Divapan (250 and 350 liters/ha) were less effective at reducing Calonectria viability and, for these treatments, the rate of microsclerotia survival was highly variable among the different isolates and species. Furthermore, totally impermeable film significantly enhanced fumigant performance. Relative to endemic Calonectria spp., all of the treatments killed microsclerotia of C. polizzii and C. pauciramosa independent from fumigant, rate, and film. This research demonstrated the possibility of reducing the application rates by up to 160 kg/ha for Basamid and 400 liters/ha for Divapan under low-permeability films (virtually impermeable film or totally impermeable film) for eradicating or reducing the primary inoculum of Calonectria spp. in soil.

Fate of the nitrification inhibitor dicyandiamide (DCD) sprayed on a grazed pasture: effect of rate and time of application

Soil Research ◽  
2012 ◽  
Vol 50 (4) ◽  
pp. 337 ◽  
Author(s):  
Dong-Gill Kim ◽  
Donna Giltrap ◽  
Surinder Saggar ◽  
Thilak Palmada ◽  
Peter Berben ◽  
...  
Keyword(s):  
Half Life ◽  
Nitrification Inhibitor ◽  
Plant Canopy ◽  
Time Of Application ◽  
Grazed Pasture ◽  
N Source ◽  
Pasture Soil ◽  
Application Rates ◽  
Different Seasons ◽  
Field Plots

The objectives of this study were to improve our understanding of seasonal variation in the biophysical disappearance of the nitrification inhibitor dicyandiamide (DCD) in soil and the key regulatory factors. Changes in DCD concentrations in the soil and plant canopy were measured following application to dairy-grazed pasture soil and non-grazed pasture soil. Treatments included two levels of DCD alone (10 and 20 kg ha–1) applied to non-grazed pasture field plots, and DCD (10 kg ha–1) applied with urine and with urea fertiliser. DCD (10 kg ha–1) was also applied in grazed farmlets following grazing. About 4–40% of the DCD applied was intercepted and stayed on the plant canopy from <6 and up to 16 days, depending on the subsequent timing and intensity of rainfall. In this poorly drained soil, <10% of applied DCD leached below 10 cm depth. Neither the level of DCD nor the N source had any significant effect on the half-life of DCD in soil. The half-life of DCD did vary with season, ranging from 7 to 13 days in March to November respectively, and showed a linear decrease with observed increase in soil temperature between 10.7 and 16.5°C. The results suggest that to maintain an optimum effective DCD concentration in soil, different DCD application rates and frequency may be required in different seasons.

scholarly journals Incidence and Survival of Cylindrocladium parasiticum in Peanut Seed

Plant Disease ◽  
2003 ◽  
Vol 87 (7) ◽  
pp. 867-871 ◽  
Author(s):  
D. L. Glenn ◽  
P. M. Phipps ◽  
R. J. Stipes
Keyword(s):  
Seed Storage ◽  
Infested Soil ◽  
Ambient Temperatures ◽  
Growing Seasons ◽  
Commercial Seed ◽  
Cylindrocladium Parasiticum ◽  
High Incidence ◽  
Normal Seed ◽  
Pathogen Recovery ◽  
Field Plots

Sixty-three commercial seed lots of peanut produced in Virginia were examined for the presence of seed with speckled testae. Speckled seed were present in seed lots from the 1998, 1999, and 2000 growing seasons at average rates of 3, 1.2, and 0.6%, respectively. Speckled and normal seed from 19 seed lots were assayed on a medium selective for C. parasiticum. The fungus was isolated from speckled seed at rates ranging from 40 to 96%. C. parasiticum was isolated only from a single normal seed from one seed lot. The pathogen was recovered at high rates from speckled seed immediately after pods had been dried in commercial drying trailers at temperatures up to 35°C. Ambient temperatures during winter seed storage that fluctuated from -10 to 28°C in 1999 and -8 to 33°C in 2000 greatly reduced pathogen recovery in speckled seed stored for 16 or 24 weeks. In field plots with naturally infested soil, the number of speckled seed harvested was directly correlated to the number of symptomatic plants in plots on 29 September. Based on this finding, the harvest of seed peanuts in areas of a field with high incidence of Cylindrocladium black rot (CBR) should be avoided. Adoption of this policy is expected to lower the number of speckled seed entering commercial seed lots and reduce the risk for spread of CBR.

scholarly journals Evaluation of Unmanned Multicopters’ Performance Indicators for Pesticide and Agrochemical Application

2021 ◽  
Vol 15 (3) ◽  
pp. 55-62
Author(s):  
V. P. Asovskiy ◽  
A. S. Kuzmenko ◽  
O. V. Khudolenko
Keyword(s):  
Performance Indicators ◽  
Estimation Error ◽  
Technical Information ◽  
General Description ◽  
Traffic Patterns ◽  
Agricultural Industry ◽  
Application Rates ◽  
Methodological Approaches ◽  
The Impact ◽  
Field Plots

The authors considered the use of unmanned aerial vehicles as one of the promising innovative directions for the development of economic and social sectors. The authors touched upon the prospects for their use in agriculture, especially for pesticide and agrochemical application, where accuracy, quality and timeliness are important. The relevance of multicopter performance assessment was noted. (Research purpose) The authors aim to develop and test a methodology for the evaluation of multicopters’ performance indicators for pesticide and agrochemical application in the agricultural industry. (Materials and methods) The authors used scientific and technical information and experimental materials, applied methods of system, statistical and functional-cost analysis, mathematical modeling, object and process parameter optimization, as well as previously developed methodological approaches to studying the aerial distribution of substances. (Results and discussion) The authors presented a general description and content of the developed methodology and means for assessing multicopter performance when applying working solutions that provide for an estimation error of up to 7 percent.The typical options for field plots and their treatment were specified. The authors analyzed the results of testing the methodology and software for a typical hexacopter with the payload of up to 10 kilograms. The authors analyzed the impact of working speed of up to 10 meters per second, application rates of 2-30 liters per hectare, the size and characteristics of the field plot up to 200 hectares, traffic patterns and other factors on productivity and multicopter treatment cost.  (Conclusions) The authors confirmed the efficiency of implementing complex multi-factor assessment of multicopter performance indicators for working fluids application in agricultural production. The authors determined the appropriate area of  applying multicopters with a payload of up to 10 kilograms in the field plots up to 50-60 hectares with a rut length of up to 800-900 meters with different treatment performance: flight – up to 10.5 hectares per flight hour, working – up to 7.5 hectares per hour, daytime – up to 55 hectares. Proposals and recommendations for the provision, organization and implementation of this work were formulated. 

Cultivation practices improving seed productivity of tetraploid red clover

2019 ◽  
Author(s):  
М. Новосёлов ◽  
Л. Дробышева ◽  
О. Старшинова ◽  
Э. Рекашус ◽  
А. Одноворова
Keyword(s):  
Ammonium Nitrate ◽  
Red Clover ◽  
Nodule Bacteria ◽  
Seed Productivity ◽  
Mineral N ◽  
Yield Increase ◽  
Seed Inoculation ◽  
Application Rates ◽  
Yield Capacity ◽  
Clover Seed

В статье изложены результаты исследований влияния инокуляции клубеньковыми бактериями и внекорневых обработок бором и минеральным азотом на семенную продуктивность клевера лугового сорта Марс. Цель работы определить оптимальные варианты внекорневой обработки растений бором и минеральным азотом, в том числе в сочетании с инокуляцией клубеньковыми бактериями, обеспечивающие максимальную семенную продуктивность клевера лугового сорта Марс. Установлено, что внекорневые подкормки минеральным азотом и бором в фазу начала цветения, а также инокуляция эффективным штаммом клубеньковых бактерий повышали его семенную продуктивность. Обработка растений бором повысила урожайность семян на 8,2. Совместное применение бора и инокуляции увеличило эффективность приёма до 20,0 к инокулированному и до 34,4 к неинокулированному контролю. Внекорневое опрыскивание аммиачной селитрой в чистом виде было эффективно в дозах 2,5 и 3,0 кг/га: прибавка к контролю составила соответственно 11,8 и 16,7. Комплексное применение бора и минерального азота наибольшую прибавку урожая семян дало в варианте B N3,0, которая составила 36,6. Инокуляция комплементарным штаммом Rh. trifolii увеличила урожайность семян клевера на 12,0. Обработка растений бором и аммиачной селитрой в различных концентрациях на фоне инокуляции была эффективной во всех вариантах (12,331,4 к инокулированному и 25,847,1 к неинокулированному контролю). Рекомендуется для повышения семенной продуктивности тетраплоидных сортов типа Марс проводить внекорневое опрыскивание растений в фазу начала цветения бором в дозе 0,4 кг/га в комплексе с аммиачной селитрой из расчёта 3,0 кг/га действующего вещества или инокулировать семена перед посевом комплементарными штаммами с последующей внекорневой подкормкой бором (0,4 кг/га) совместно с минеральным азотом (3,0 кг/га). This paper reports on red clover seed productivity affected by the inoculation with nodule bacteria and topdressing with B and mineral N. The aim was to determine optimal treatment rates and combinations leading to the highest seed productivity of clover Mars. Topdressing with B and N at flowering time combined with bacterium inoculation increased its yield capacity. B application improved seed yield by 8.2. B treatment together with inoculation improved clover performance by up to 20.0 and 34.4 compared to the inoculated and non-inoculated controls, respectively. Application rates of 2.5 and 3.0 kg ha-1 showed the best effect when topdressing by pure ammonium nitrate: yield increase amounted to 11.8 and 16.7, respectively. Variant B N3.0 provided the highest yield increase of 36.6. Seed inoculation with Rh. trifolii increased seed productivity by 12.0. Topdressing with different concentrations of B and ammonium nitrate was effective in all the variants on the background of bacterium inoculation (12.331.4 and 25.847.1 compared to inoculated and non-inoculated controls, respectively). Spraying with B (0.4 kg ha-1) and ammonium nitrate (3.0 kg ha-1) with or without seed inoculation by nodule bacteria are recommended to improve tetraploid clover performance.

Magnesium metabolism in the dairy cow IV. The availability of the magnesium in various feedingstuffs

1962 ◽  
Vol 59 (2) ◽  
pp. 225-232 ◽  
Author(s):  
J. A. F. Rook ◽  
R. C. Campling
Keyword(s):  
Early Stage ◽  
Red Clover ◽  
Barley Straw ◽  
Mature Stage ◽  
Stages Of Growth ◽  
Oil Cakes ◽  
Dietary Magnesium ◽  
Different Seasons ◽  
Daily Intakes ◽  
Protein Rich

1. The ‘availability’ of the magnesium of diets consisting solely of roughage or succulent feeds, including herbages cut at different seasons and at different stages of growth, and of diets of hay supplemented with various concentrate feeds, was assessed in metabolism trials conducted with two non-pregnant, non-lactating Shorthorn cows.2. The highest daily intakes of magnesium (1720 g./day) were provided by a diet of red clover: grasses and hays generally gave a considerably lower intake of magnesium (8–10 g./day), and most of the other diets provided intermediate amounts. However, with timothy hay and barley straw, intakes of 5 and 2 g./day, respectively, were recorded. Supplements to a diet of hay of dairy cubes or of oilcakes rich in protein gave a massive increase in magnesium intake but a supplement of flaked maize provided little additional magnesium.3. The ‘availability’ of the magnesium of the diets was generally low, within the range of 5–30%. With diets of single feeds no clear distinction between the various roughages and succulents in the ‘availability’ of their magnesium was established, though within the group of herbages the lowest values tended to occur with grasses cut at an early stage of growth and the highest values at the mature stage. A supplement of flaked maize increased the ‘availability’ of dietary magnesium and one of protein-rich oil cakes decreased the ‘availability’ of dietary magnesium.4. The results are discussed in relation to the development of hypomagnesaemia in cattle grazing spring pasture.

scholarly journals Eradication of Phytophthora ramorum and Other Pathogens from Potting Medium or Soil by Treatment with Aerated Steam or Fumigation with Metam Sodium

2008 ◽  
Vol 18 (1) ◽  
pp. 106-110 ◽  
Author(s):  
R.G. Linderman ◽  
E.A. Davis
Keyword(s):  
Infected Plant ◽  
Selective Medium ◽  
Phytophthora Ramorum ◽  
Steam Treatment ◽  
Infested Soil ◽  
Pythium Irregulare ◽  
Metam Sodium ◽  
Potting Medium ◽  
Potting Media ◽  
Polyethylene Bags

Phytophthora ramorum survived in potting media infested with sporangia or chlamydospores, allowing the pathogen to remain undetected while disseminated geographically. Chlamydospores or oospores of P. ramorum, Pythium irregulare, Thielaviopsis basicola, and Cylindrocladium scoparium produced in vermiculite culture were used to infest potting media. Infested media in plastic plug flats were treated with aerated steam mixtures from 45 to 70 °C for 30 min. In a second experiment, infested media were fumigated in polyethylene bags with a concentration series of metam sodium ranging from 0.25 to 1.0 mL·L−1. Survival of the pathogens was determined by selective baiting or direct plating the infested media on PARP selective medium. Assays indicated that all pathogens in the infested potting media were killed by aerated steam heat treatments of 50 °C or higher. Metam sodium concentrations of 1.0 mL·L−1 of medium or greater also eradicated all pathogens from the potting medium and soil. These results show that aerated steam treatment or fumigation with metam sodium can effectively sanitize soil-less potting media infested with P. ramorum or other soilborne pathogens, as well as P. ramorum-infested soil beneath infected plant containers. In addition, steam treatments to 70 °C did not melt plastic plug trays.

scholarly journals Fertilizer Source and High Tunnel Production Environment Affect Antioxidant Levels of Pac Choi

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1000D-1001 ◽  
Author(s):  
Xin Zhao ◽  
Edward E. Carey ◽  
Takeo Iwamoto
Keyword(s):  
Open Field ◽  
Production Environment ◽  
Organic Fertilization ◽  
Fertilizer Rate ◽  
High Tunnel ◽  
Phytochemical Content ◽  
Application Rates ◽  
High Tunnels ◽  
Pac Choi ◽  
Field Plots

An experiment was conducted at Olathe, Kan., in Spring 2004 to investigate the influence of organic and conventional fertilizer sources and application rates on antioxidant levels of pac choi (Brassica rapa L. cv. Mei Qing) in open fields and poly-covered high-tunnel plots. Organic plots received pre-plant application of composted cattle manure and alfalfa (Hu-More 1–1–1) at 0 kg/ha N, 156 kg/ha N, or 314 kg/ha N, and conventional plots received preplant application of 13N–13P–13K at 0 kg/ha N, 78 kg/ha N, or 156 kg/ha N. Antioxidant levels were measured using the oxygen radical absorbance capacity (ORAC) assay. There were significant effects of fertilizer source and high-tunnel environment on the antioxidant capacity of pac choi. Organic fertilization significantly increased hydrophilic ORAC of pac choi in open field plots, but not in high tunnels. Regardless of the fertilizer source, pac choi grown in the open field had significantly higher hydrophilic ORAC than that grown in tunnels. Lipophilic ORAC was significantly increased by organic fertilization but was not affected by high-tunnel production. Total ORAC (hydrophilic + lipophilic) was significantly higher in pac choi from organic or open-field plots, compared to conventional and high-tunnel plots, respectively. Although fertilizer rate did not show significant impact on antioxidant level of pac choi, hydrophilic and total ORAC seemed to decrease as the fertilizer rate increased, especially under conventional fertilization, while lipophilic ORAC reached the highest level at the medium fertilizer rate. Differences in antioxidant levels were likely associated with the enhanced phytochemical content of pac choi from organically fertilized and open-field plots.

Crop rotation can confer resistance to potatoes from Phytophthora erythroseptica attack

2005 ◽  
Vol 85 (2) ◽  
pp. 523-528 ◽  
Author(s):  
R. D. Peters ◽  
A. V. Sturz ◽  
M. R. Carter ◽  
J. B. Sanderson
Keyword(s):  
Crop Rotation ◽  
Spring Barley ◽  
Red Clover ◽  
Disease Suppression ◽  
Susceptible Host ◽  
Minimum Tillage ◽  
Potato Plants ◽  
Pink Rot ◽  
Phytophthora Erythroseptica ◽  
Field Plots

The influence of 2- and 3-yr crop rotations and conservation tillage practices on the severity of pink rot of potato (causal agent: Phytophthora erythroseptica) was examined in Prince Edward Island, Canada. The 2-yr rotation crops included spring barley and potato (cv. Russet Burbank), and the 3-yr rotation was comprised of barley (undersown with red clover), red clover and potato. In the potato year only, the main plots were split to examine conventional and minimum tillage (sub-plot) treatments. Soil samples and potato tubers were extracted from field plots 6-7 yr after the initiation of the field trial. Following post-harvest inoculation of field-grown tubers with P. erythroseptica, we determined that pink rot disease development was significantly (P = 0. 05) less pronounced in potatoes from 3-yr rotational than from 2-yr rotational soils. The effect of tillage management was not significant. Potato plants grown in greenhouse trials in 3-yr rotational soils (from field plots) were significantly (P = 0.05) less diseased than those grown in 2-yr rotational soils following inoculation with P. erythroseptica. These results suggest that potato plants grown in soils managed under a 3-yr rotation are intrinsically more resistant to pathogen attack than those managed under a 2-yr rotation. We confirmed that crop rotation provides disease control benefits beyond those normally associated with pathogen population decline in the absence of the susceptible host. The possibility that beneficial soil microflora and tuber endophytes were involved in disease suppression is discussed. Key words: Phytophthora erythroseptica, pink rot, potato, Solanum tuberosum, crop rotation, minimum tillage, beneficial endophytes, biocontrol

PRELIMINARY STUDIES OF THE TRANSFER OF FOUR STRAINS OF DITYLENCHUS DIPSACI (KÜHN 1858) FILIPJEV 1936

1937 ◽  
Vol 15c (4) ◽  
pp. 168-174
Author(s):  
R. J. Hastings ◽  
Wm. Newton
Keyword(s):  
Host Range ◽  
Host Specificity ◽  
Pacific Northwest ◽  
Red Clover ◽  
Infested Soil ◽  
The Pacific ◽  
Limited Host Range ◽  
Ditylenchus Dipsaci ◽  
Tissue Reactions ◽  
Test Plants

The bulb and stem nematode, Ditylenchus dipsaci, attacks narcissus, iris, red clover and strawberry in the Pacific Northwest. The isolations from each of these important crops are herein described as strains.Preliminary studies of the transfer of these strains establish the existence of three strains of D. dipsaci in the Pacific Northwest, viz.:(i) Red clover strain; characterized by causing swollen crowns and stunt in red clover seedlings.(ii) Strawberry strain; characterized by a limited host range, swollen crowns in strawberry seedlings, and entrance into red clover seedlings without visible tissue reactions.(iii) Narcissus and iris strain; characterized by a wide host range and entrance into clover and strawberry seedlings without visible tissue reactions.No satisfactory technique of establishing the host range of the biological strains of D. dipsaci has been developed. The clamping of glass rings filled with a nematode suspension in moist pulverized peat to the foliage of test plants did not affect the test plants in a constant manner. The examination of seedlings after clarification in a lacto-phenol solution containing acid fuchsin gave more constant results. The seedlings were removed from infested soil shortly after they appeared above ground.The reports of host specificity of the red clover strain were not confirmed, for the red clover strain entered white clover and alfalfa, hitherto considered resistant. Likewise, the reports of host specificity of the narcissus strain were not supported by our experimental results. The narcissus strain entered red clover and oats, also considered resistant hitherto.

The influence of spring nitrogen on yield, yield components and glucosinolate content of autumn-sown oilseed rape (Brassica napus)

1993 ◽  
Vol 120 (2) ◽  
pp. 219-224 ◽  
Author(s):  
P. E. Bilsborrow ◽  
E. J. Evans ◽  
F. J. Zhao
Keyword(s):  
Protein Content ◽  
Oilseed Rape ◽  
Seed Yield ◽  
Yield Components ◽  
Glucosinolate Content ◽  
Nitrogen Application ◽  
Application Rates ◽  
Different Seasons ◽  
Glucosinolate Concentration ◽  
Low Erucic Acid

SUMMARYThe response of low glucosinolate, low erucic acid (double low) cultivars of oilseed rape to spring nitrogen application was examined at Cockle Park, Northumberland in three successive seasons (1987–90). Seed yield and protein content increased in response to increasing nitrogen application. In each season over 85% of the maximum recorded yield was obtained with an application of 150 kg N/ha. In the absence of spring nitrogen, seed yield varied considerably over the three seasons. The variation in seed yield and protein content between 1987/88 and 1988/89 can partly be explained by differences in the availability of soil nitrogen in the different seasons. Seed glucosinolate concentration was significantly increased withnitrogen applications between 0 and 150 kg/ha. Increasing nitrogen beyond 150 kg/ha hadlittle or no effect on seed glucosinolate concentration. The results are examined with reference to the varying effects of increasing nitrogen application rates on seed glucosinolate concentrations reported previously.

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