Population Dynamics of Pratylenchus brachyurus in Maize Treated with Inorganic Fertilizer

Field studies were conducted in the early and late season of 2010 in the tropical rainforest zone of Nigeria to investigate the effects of NPK fertilizer as an inorganic soil amendment at 75 kg/ha and 150 kg/ha in four replications on population densities of Pratylenchus brachyurus and on crop yield of maize. Seeds of maize variety, DMR LSR-Y were collected from Institute of Agricultural Research and Training, Ibadan. The experimental field was naturally infested with Pratylenchus spp. due to subsequent continuous cultivation of susceptible crop on the field. Seeds were planted and NPK was applied around the roots of maize plants 3 weeks after seedling emergence. Soil samples were taken on treatment plots at planting and harvest to determine the percentage change in nematode population. At the end of experiment, NPK application resulted in the increase in the nematode population. However, the grain yield of maize was not reduced by the increased nematode densities. The results of this study suggests that the usage of NPK caused a surge in the nematode reproduction on the field due to the availability of more feeding sites on the actively growing root system of the crop.

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Selection in the M2 Generation of Soybeans (Glycine Max (L.) Merill) irradiated with Cobalt – 60 Gamma Irradiation in the Guinea Savannah Agroecology of Ghana

Ghana Journal of Science, Technology and Development ◽

10.47881/127.967x ◽

2019 ◽

Vol 6 (1) ◽

pp. 30-37

Author(s):

Isaac Kwahene ADDAI

Keyword(s):

Gamma Irradiation ◽

Grain Yield ◽

Gamma Ray ◽

Agricultural Research ◽

Atomic Energy Commission ◽

Block Design ◽

Seedling Emergence ◽

Field Studies ◽

Cropping Season ◽

60Co Source

Field studies were conducted at the research fields of the University for Development Studies, Ghana from July to November, 2014 and June to October 2015. The studies were aimed at investigating the effect of gamma irradiation on growth and grain yield of soybean. Seeds of soybean variety Jenguma were subjected to gamma irradiation at 150, 200, 250 and 300 Gy from the 60Co source at the Biotechnology and Nuclear Agricultural Research Institute of the Ghana Atomic Energy Commission in Accra, Ghana. The irradiated seeds and some unirradiated control (0 Gy) were planted during the 2014 cropping season in a randomized complete block design with three replications. At harvest, all M1 seeds for respective gamma ray doses were harvested and composited, and advanced to the M2 generation during the cropping season of 2015. In M1, gamma irradiation significantly (P < 0.05) affected seedling emergence. There was significant reduction in survival of seedlings especially from the 150 Gy. Seedling heights of the irradiated species were significantly (P < 0.05) reduced. Number of days to 50% flowering was also significantly (P < 0.05) affected. In M2, more desired traits were found from plants irradiated with the 200 Gy and 250 Gy doses, with only few in the 150 Gy and 300 Gy treated plants. There was a potential for total grain yield improvement. Numbers of pods per plant and seed weight were the key parameters found to influence grain yield. Maturity period was also found to be shorter in the selected plants. The shattering resistance of plants in the 200 Gy and 250 Gy was found to be a potential improvement over the parental variety ‘Jenguma’ which was originally bred for that purpose. Selected plants would be advanced into M3 generation for further studies and results will be published

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Performance of Seed Treatments Applied on Bt and Non-Bt Maize Against Fall Armyworm (Lepidoptera: Noctuidae)

Environmental Entomology ◽

10.1093/ee/nvaa088 ◽

2020 ◽

Vol 49 (5) ◽

pp. 1137-1144 ◽

Cited By ~ 1

Author(s):

Dionei S Muraro ◽

Regis F Stacke ◽

Gisele E Cossa ◽

Daniela N Godoy ◽

Cínthia G Garlet ◽

...

Keyword(s):

Seed Treatment ◽

Fall Armyworm ◽

Field Studies ◽

F1 Hybrids ◽

Seed Treatments ◽

Bt Maize ◽

Maize Seeds ◽

Natural Infestation ◽

Maize Plants ◽

Lepidoptera Noctuidae

Abstract Fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), is the main pest of maize in Brazil, attacking plants from emergence to reproductive stages. Here, we conducted studies to evaluate the efficacy of two seed treatments (chlorantraniliprole alone and imidacloprid combined with thiodicarb) on Bt and non-Bt maize in laboratory bioassays with distinct FAW strains that are susceptible, selected for resistance to Bt-maize single (Cry1F) or pyramided (Cry1A.105 + Cry2Ab2) events and F1 hybrids of the selected and susceptible strains (heterozygotes), and in the field against a natural infestation. In the laboratory, leaf-discs from seed treated Bt-maize plants at 7 d after emergence (DAE) increased the mortality of FAW resistant, heterozygote, and susceptible strains up to 24.8%, when compared with the respective maize grown without a seed treatment. In the field against natural infestations of FAW, Bt maize with a seed treatment had ~30% less FAW damage than non-Bt maize with the same seed treatment at 7 and 14 DAE. No differences in FAW damage was observed between Bt and non-Bt maize grown with and without a seed treatment at 21 DAE. Maize seeds treated with chlorantraniliprole alone or imidacloprid and thiodicarb combined presented limited protection against early infestations of FAW strains under laboratory and field studies.

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Precrop Effect of Red Clover (Trifolium pratense L.) and Alfalfa (Medicago sativa L.) on the Population Development of the Northern Root-Knot Nematode Meloidogyne hapla Chitwood, 1949 and on Succeeding Crops—A Pot Study

Agronomy ◽

10.3390/agronomy11040722 ◽

2021 ◽

Vol 11 (4) ◽

pp. 722

Author(s):

Renata Dobosz ◽

Roman Krawczyk

Keyword(s):

Population Density ◽

Medicago Sativa ◽

Trifolium Pratense ◽

Red Clover ◽

Continuous Cultivation ◽

Nematode Population ◽

Meloidogyne Hapla ◽

Root Knot Nematode ◽

Crop Species ◽

Tomato Growth

The northern root-knot nematode, Meloidogyne hapla, is a major pest of many crop species. The objective of the study was to determine how M. hapla population dynamics is affected by two precrops, i.e., Trifolium pratense and Medicago sativa, in three crop durations: one, two and three years of continuous cultivation. Moreover, we set ourselves the task of evaluating the effect of the legume precrop soil on the growth of the succeeding tomato plant (Solanum lycopersicum) and on the nematode population. The experiment was performed outdoors in pots with naturally infected soil. Both precrop species investigated were found to modify the J2 nematode population density in the soil. The galls and nematode females with egg masses were observed on the roots of both studied plant species at the end of each growing season. They appeared to be more abundant on the red clover roots than on those of the alfalfa. The obtained data indicate that the spring soil sampling is more appropriate for the estimation of the M. hapla population density in the red clover precrop soil. The legume precrop soil had a limiting effect on tomato growth and fruit yield. The nematode population negatively influenced tomato growth. The experiment revealed that tomato plants could be planted in alfalfa precrop soil following at least three years of continuous alfalfa cultivation. The same cannot be said of the cultivation of red clover as a precrop for tomatoes.

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Influence of chaff and chaff lines on weed seed survival and seedling emergence in Australian cropping systems

Weed Technology ◽

10.1017/wet.2020.142 ◽

2020 ◽

pp. 1-22

Author(s):

Michael J. Walsh ◽

Annie E. Rayner ◽

Annie Rutledge ◽

John C. Broster

Keyword(s):

Cropping Systems ◽

Seedling Emergence ◽

Field Studies ◽

Wild Oat ◽

Weed Seed ◽

Weed Species ◽

Environment Effect ◽

Seed Survival ◽

Cropping Seasons ◽

Rigid Ryegrass

Abstract Chaff lining and chaff tramlining are harvest weed seed control (HWSC) systems that involve the concentration of weed seed containing chaff material into narrow (20 to 30 cm) rows between or on the harvester wheel tracks during harvest. These lines of chaff are left intact in the fields through subsequent cropping seasons in the assumption that the chaff environment is unfavourable for weed seed survival. The chaff row environment effect on weed seed survival was examined in field studies, while chaff response studies determined the influence of increasing amounts of chaff on weed seedling emergence. The objectives of these studies were to determine 1) the influence of chaff lines on the summer-autumn seed survival of selected weed species; and 2) the influence of chaff type and amount on rigid ryegrass seedling emergence. There was frequently no difference (P>0.05) in survival of seed of four weed species (rigid ryegrass, wild oat, annual sowthistle and turnip weed) when these seed were placed beneath or beside chaff lines. There was one instance where wild oat seed survival was increased (P<0.05) when seed were placed beneath compared to beside a chaff line. The pot studies determined that increasing amounts of chaff consistently resulted in decreasing numbers of rigid ryegrass seedlings emerging through chaff material. The suppression of emergence broadly followed a linear relationship where there was approximately a 2.0% reduction in emergence with every 1.0 t ha-1 increase in chaff material. This relationship was consistent across wheat, barley, canola and lupin chaff types, indicating that the physical presence of the chaff was more important than chaff type. These studies indicated that chaff lines may not affect the over summer-autumn survival of the contained weed seeds but the subsequent emergence of weed seedlings will be restricted by high amounts of chaff (>40 t ha-1).

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Effect of foliar application of chelated copper and manganese on yield components and fibre properties of Egyptian cotton (Gossypium barbadense)

The Journal of Agricultural Science ◽

10.1017/s0021859600077066 ◽

1993 ◽

Vol 121 (2) ◽

pp. 193-198 ◽

Cited By ~ 4

Author(s):

Z. M. Sawan ◽

M. H. Mahmoud ◽

B. R. Gregg

Keyword(s):

Yield Components ◽

Agricultural Research ◽

Foliar Application ◽

Field Studies ◽

Gossypium Barbadense ◽

Research Centre ◽

Fibre Properties ◽

Foliar Sprays ◽

Egyptian Cotton ◽

Cotton Cultivar

SUMMARYA decline in supplies of organic manures and the increased use of chemical fertilizers has led to a decrease in the micronutrient content of the soil, with attendant effects on yield.Field studies were conducted in 1986 and 1987 at the Giza Agricultural Research Centre, Egypt, to determine the effect of Cu-EDTA and Mn-EDTA foliar sprays on growth, mineral content, yield components and fibre properties of the Egyptian cotton cultivar Giza 75 (Gossypium barbadense L.).All combinations used significantly increased the uptake of Cu and Mn and the dry matter yield. The earliness of harvest and the value of yield components were all increased by the application of Cu or Mn; 25 mg/1 of both Cu and Mn gave the highest values. Lint percentage and fibre properties were not significantly affected.This study indicated that the yield of cotton, grown under otherwise standard conditions, may be increased by foliar sprays of Cu-EDTA and Mn-EDTA combined.

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Crotalaria species in succession to soybean for the management of Pratylenchus brachyurus

Ciência Rural ◽

10.1590/0103-8478cr20190645 ◽

2020 ◽

Vol 50 (7) ◽

Author(s):

Thays Torquato Cruz ◽

Guilherme Lafourcarde Asmus ◽

Rodrigo Arroyo Garcia

Keyword(s):

Production Systems ◽

High Capacity ◽

Suppressive Effect ◽

Nematode Population ◽

Agricultural Crop ◽

Root Lesion Nematode ◽

Soil Pathogens ◽

Mato Grosso ◽

Pratylenchus Brachyurus ◽

Lesion Nematode

ABSTRACT: Soybean is the main agricultural crop in the State of Mato Grosso do Sul, Brazil. It is primarily cultivated in a crop succession system, in wich soybean is grown in spring/summer, followed by corn or graminaceous pastures in autumn/winter as a second crop. Due to the intensive cultivation, new phytosanitary problems have arisen, among them the root-lesion nematode, Pratylenchus brachyurus, which besides causing damage to plant roots, can be important gateway for other soil pathogens. The recent occurrence of high nematode population densities has brought great concern due to the limited resistant soybean genotypes available. Besides, the use of nematicides only reduces nematodes populations temporarily. A viable alternative for the control of soil nematodes could be the use of Crotalaria spp. in succession or rotation with soybean. Crotalaria is immune or a bad host to the nematode, besides having high capacity of biological nitrogen fixation. Thus, the objective of the present research was to define the best way of insertion of this legume as a second crop in soybean production systems to reduce the population density of the root-lesion nematode. Two experiments were carried out: one in the field, in an infested area, and other in a greenhouse. In both experiments, the treatments were: 1) Zea mays, 2) Brachiaria brizantha cv. Xaraés,, 3) Z. mays + Crotalaria spectabilis, 4) Z. mays + C. ochroleuca, 5) B. brizantha cv. Xaraés + C. spectabilis, 6) B. brizantha cv. Xaraés + C. ochroleuca, 7) C. spectabilis, and 8) C. ochroleuca. The effect of the treatments was evaluated by estimating the number of nematodes in the roots of autumn/winter crops, as well as in the roots of the soybean cultivated in the sequence. The cultivation of both Crotalaria species provided suppression of the nematode population. However, when intercropped with corn or Xaraés palisade grass, the suppressive effect of Crotalaria was supplanted by corn and Xaraés palisadegrass susceptibility to the root-lesion nematode.

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Adaptability of prospective spring barley cultivars bred in Federal Agricultural Research Center of the North-East

BIO Web of Conferences ◽

10.1051/bioconf/20213601013 ◽

2021 ◽

Vol 36 ◽

pp. 01013

Author(s):

Irina N. Shchennikova ◽

Olga N. Shupletsova ◽

Irina Yu. Zaytseva ◽

Larissa P. Kokina ◽

Rimma I. Vyatkina

Keyword(s):

Agricultural Research ◽

Spring Barley ◽

Culture Method ◽

Field Studies ◽

Tube Formation ◽

Yield Potential ◽

High Yield ◽

Barley Cultivars ◽

North East ◽

Yield Capacity

Based on the statistical assessment of long-term field studies, in competitive variety tests, barley cultivars were identified adaptive to the conditions of the region, promising for transfer to the State variety test. As a result of the studies, a promising breeding material was created. The efficiency of using various methods of creating a new initial material, in particular, the cell culture method, is shown. A statistically significant correlation was established between the value of the hydrothermal coefficient (GTK) in the period “leaf tube formation - heading” and the yield capacity of a cultivar (r = 0.520). High variability (V = 24.4%) in the duration of the inter-stage period “leaf tube formation - heading” was revealed in the cultivars of competitive variety testing. Cultivars 94-13 and 38-15 are distinguished by a high yield potential (up to 6.4… 6.9 t/ha) and the duration of inter-stage periods, at which the main stages of organogenesis occur at the most favorable combination of heat and moisture for the potential development of plant features and properties. Cultivars 207-15, 38-15, and regenerant 550-08, characterized by high annual average yield capacity (5.9…5.7 tons/ha) and adaptability, are promising for transfer to the Russian Federation State variety test.

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Impact of Fungal Endophyte Colonization of Maize (Zea mays L.) on Induced Resistance to Thrips- and Aphid-Transmitted Viruses

Plants ◽

10.3390/plants9040416 ◽

2020 ◽

Vol 9 (4) ◽

pp. 416 ◽

Cited By ~ 1

Author(s):

Simon Kiarie ◽

Johnson O. Nyasani ◽

Linnet S. Gohole ◽

Nguya K. Maniania ◽

Sevgan Subramanian

Keyword(s):

Integrated Management ◽

Management Strategies ◽

Fungal Endophyte ◽

Eastern Africa ◽

Maize Seeds ◽

Fungal Isolates ◽

Chlorotic Mottle Virus ◽

Maize Chlorotic Mottle Virus ◽

Chlorotic Mottle ◽

Maize Plants

In eastern Africa, Maize lethal necrosis (MLN) is caused by the co-infection of maize plants with Maize chlorotic mottle virus (MCMV) (Tombusviridae: Machlomovirus) and Sugarcane mosaic virus (SCMV) (Potyviridae: Potyvirus). With the disease being new to Africa, minimal effective management strategies exist against it. This study examined the potential of 10 fungal isolates to colonize maize plants and induce resistance against MCMV and SCMV. Maize seeds were soaked in fungal inoculum, sown and evaluated for endophytic colonization. Fungus-treated plants were challenge-inoculated with SCMV and/or MCMV to assess the effects of fungal isolates on the viruses in terms of incidence, severity and virus titers over time. Isolates of Trichoderma harzianum, Trichoderma atroviride and Hypocrea lixii colonized different plant sections. All plants singly or dually-inoculated with SCMV and MCMV tested positive for the viruses by reverse transcription-polymerase chain reaction (RT-PCR). Maize plants inoculated by T. harzianum and Metarhizium. anisopliae resulted in up to 1.4 and 2.7-fold reduced SCMV severity and titer levels, respectively, over the controls but had no significant effect on MCMV. The results show that both T. harzianum and M. anisopliae are potential candidates for inducing resistance against SCMV and can be used for the integrated management of MLN.

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Efficacy of some new genearation insecticides and a botanical against mustard aphid and their toxicity to coccinellid predators and foraging honeybees

Bangladesh Journal of Agricultural Research ◽

10.3329/bjar.v41i4.30704 ◽

2016 ◽

Vol 41 (4) ◽

pp. 725-734 ◽

Cited By ~ 1

Author(s):

NK Dutta ◽

SN Alam ◽

M Mahmudunnabi ◽

MF Khatun ◽

YJ Kwon

Keyword(s):

Agricultural Research ◽

Field Studies ◽

Aphid Population ◽

Lipaphis Erysimi ◽

Agricultural Research Institute ◽

Mustard Aphid ◽

Honeybee Population ◽

New Generation ◽

Treated Plot ◽

Research Institute

Field studies were carried out to evaluate the efficacy of four new generation insecticides along with a botanical against mustard aphid (Lipaphis erysimi Kalt.) and their toxicity to coccinellid beetles and foraging honeybees during 2014-15 at Bangladesh Agricultural Research Institute (BARI), Gazipur, Bangladesh. Buprofezin 40 SC was found to be the most effective against aphid offering the lowest aphid population (1.56/ top10cm central twig) at 7 days after spraying (DAS) which was statistically identical to Diafenthiuron 500SC (1.85/ top10cm central twig). Among the treatments, Azadiractin 1EC appeared to be safest to coccinellid beetles and foraging honeybees because it recorded the highest number of beetle (7.50 /5 plants) and honeybee (9.64 /plot/5 min) population at 7 DAS, although honeybee population did not vary statistically with that of Buprofezin 40 SC and Lufenuron 5EC treated plots. Indoxacarb 145SC was found to be the most toxic against honeybees. However, the highest yield was obtained from Buprofezin 40 SC (1.57 t ha-1) treated plot although this was statistically identical to that Diafenthiuron 500SC (1.52 t ha-1) and Azadiractin 1EC (1.48 t ha-1) treated plots.Bangladesh J. Agril. Res. 41(4): 725-734, December 2016

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Potential for transmission of Stenocarpella macrospora from inoculated seeds to maize plants grown under controlled conditions

Journal of Seed Science ◽

10.1590/2317-1545v32n2904 ◽

2014 ◽

Vol 36 (2) ◽

pp. 154-161 ◽

Cited By ~ 5

Author(s):

Carolina da Silva Siqueira ◽

José da Cruz Machado ◽

Ellen Noly Barrocas ◽

Mirella Figueiró de Almeida

Keyword(s):

Transmission Rate ◽

Climatic Conditions ◽

Inoculum Potential ◽

Ear Rot ◽

Total Rate ◽

Maize Cultivars ◽

Maize Seeds ◽

Two Temperatures ◽

Maize Plants ◽

Biological Methods

Maize seeds infected by Stenocarpella macrospora can cause stalk and ear rot and leaf spot. Transmission of this pathogen through seeds may vary according to the cultivar, climatic conditions, and virulence of the pathogen among other factors. The aim of this study was to assess the transmission rate of S. macrospora from seeds of the maize cultivars C1-RB9308YG and C2-RB9108 using artificially infected seeds grown under two temperatures (20 ºC and 25 ºC). Seeds were inoculated by the osmotic conditioning method for 24 h (inoculum potential - P1), 48 h (P2), 72 h (P3) and 96 h (P4). After inoculation, 25 seeds were distributed individually in plastic cups with substrate, with 4 replicates per treatment. At the end of twenty-eight days of daily assessments, all plants were analyzed for the presence of the pathogen by biological methods, and some were sampled at random and analyzed Bio-PCR. The maximum percentages of dead seeds/seedlings in pre-emergence were 74.5% and 82.5% for P3 and P4, respectively. The highest total rate of transmission of the pathogen under study was 85.8% for seeds of the cultivar C1 at the highest inoculum potential (P4), grown at the temperature of 20 ºC.

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