scholarly journals Soybean Leaf Age and Plant Stage Influence Expression of Resistance to Velvetbean Caterpillar and Fall Armyworm

2021 ◽  
Author(s):  
Bruno Henrique Sardinha de Souza ◽  
Eduardo N. Costa ◽  
Zulene A. Ribeiro ◽  
Bruno Perlatti ◽  
Mara C. P. Cruz ◽  
...  
Keyword(s):  
Management Strategies ◽  
Leaf Age ◽  
Fall Armyworm ◽  
Anticarsia Gemmatalis ◽  
Growth Stages ◽  
Velvetbean Caterpillar ◽  
Resistant Genotype ◽  
Plant Parts ◽  
Plant Stage ◽  
Antibiosis Resistance

Abstract Numerous species of herbivorous insects are associated with soybeans, including the specialist velvetbean caterpillar (VBC), Anticarsia gemmatalis, and the generalist fall armyworm (FAW), Spodoptera frugiperda. Expression of plant resistance is influenced by factors intrinsic to host plants, such as leaf age and plant stage, which can differentially affect specialist and generalist insects due to varying levels of plant defense and corresponding insect adaptation. In this study four experiments were carried out to test the hypotheses that levels of antibiosis-resistance to VBC and FAW in the resistant genotype PI 227687 and susceptible genotype IGRA RA 626 RR are related to leaf age and plant stage of soybean. Furthermore, the concentrations of nutrients and selected flavonoids were quantified to give insights on possible chemical mechanisms underlying the resistance. As results, development of VBC and FAW were negatively affected when larvae fed leaves of the resistant genotype, older leaves from the lower part of plants, or leaves from reproductive-stage soybeans. The effects were partly different for each insect species, and the generalist FAW was more affected by higher resistance levels in the older leaves of soybean than the specialist VBC. Distribution and concentrations of nutrients and flavonoids in soybean in function of leaf age and plant stage may explain the varying levels of antibiosis-resistance to VBC and FAW. These results can benefit developments of specific protocols for screening resistant soybean genotypes and pest management strategies focused in plant parts and growth stages that insect-resistance levels are lowest.

scholarly journals Soybean leaf age and plant stage influence expression of resistance to velvetbean caterpillar and fall armyworm

Chemoecology ◽  
2021 ◽  
Author(s):  
Bruno H. S. Souza ◽  
Eduardo N. Costa ◽  
Zulene A. Ribeiro ◽  
Bruno Perlatti ◽  
Mara C. P. Cruz ◽  
...  
Keyword(s):  
Leaf Age ◽  
Fall Armyworm ◽  
Velvetbean Caterpillar ◽  
Plant Stage ◽  
Soybean Leaf

scholarly journals Nontarget Effects of Soil-Applied Chlorpyrifos on Defoliating Pests and Arthropod Predators in Peanut1

1990 ◽  
Vol 17 (2) ◽  
pp. 113-117 ◽  
Author(s):  
J. E. Funderburk ◽  
L. B. Braxton ◽  
R. E. Lynch
Keyword(s):  
Spodoptera Frugiperda ◽  
Solenopsis Invicta ◽  
Fall Armyworm ◽  
Anticarsia Gemmatalis ◽  
Red Imported Fire Ant ◽  
Velvetbean Caterpillar ◽  
Nontarget Effects ◽  
Arthropod Predators ◽  
Solenopsis Invicta Buren ◽  
Imported Fire Ant

Abstract Studies determined the effects of granular chlorpyrifos on densities of nontarget arthropods in peanuts. A portion of several commercial fields was treated during the early pod stage of peanut growth in 1987 and 1988; then, densities of defoliating pests and arthropod predators were estimated weekly. Populations of Helicoverpa spp. were significantly increased in 1987 by chlorpyrifos application, but were not significantly affected in 1988. Densities of the velvetbean caterpillar, Anticarsia gemmatalis Hubner, were low on most sample dates. On dates when densities were great, populations were directly suppressed by chlorpyrifos application. Densities of the fall armyworm, Spodoptera frugiperda (J. E. Smith), were always low, and were not affected by chlorpyrifos application. Arthropod predators sampled included the red imported fire ant, Solenopsis invicta Buren; spiders (Aranaea: Araneidae); ground beetles (Coleoptera: Carabidae); earwigs (Dermaptera: Labiduridae); damsel bugs (Hemiptera: Nabidae); and bigeyed bugs (Hemiptera: Lygaeidae). Densities of spiders were significantly decreased by chlorpyrifos application. The other predators were not significantly affected. These results demonstrate that chlorpyrifos application results in nontarget effects on defoliating pest populations. Treated fields should be scouted regularly, because such fields may have an increased potential for outbreaks of some defoliating pests.

Resistance in Eight Peanut Genotypes to Foliar Feeding of Fall Armyworm, Velvetbean Caterpillar, and Corn Earworm

1991 ◽  
Vol 18 (1) ◽  
pp. 38-40 ◽  
Author(s):  
James W. Todd ◽  
R. M. Beach ◽  
W. D. Branch
Keyword(s):  
Fall Armyworm ◽  
Pupal Stage ◽  
Common Species ◽  
Corn Earworm ◽  
Anticarsia Gemmatalis ◽  
Pupal Weight ◽  
Test Field ◽  
Velvetbean Caterpillar ◽  
Percent Survival ◽  
Curly Leaf

Abstract A laboratory feeding bioassay was used to test field-grown foliage of eight peanut (Arachis hypogaea L.) genotypes for foliar feeding resistance to three common species of defoliating caterpillars: velvetbean caterpillar (VBC), Anticarsia gemmatalis Hübner; fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith); and corn earworm (CEW), Helicoverpa zea Boddie. The eight peanut genotypes studied were: Southern Runner, Florigiant, Curly Leaf, GPNC 343, Robut 33–1, NC6, Tifton-8, and Florunner. Percent survival of both FAW and VBC was very high (84–100%) when reared on any of the genotypes tested. Development to the pupal stage was slowest for FAW reared on Florunner, NC 6, and Tifton-8, and for VBC reared on Florunner and Tifton-8. Percent survival of CEW larvae was reduced on both NC 6 and Tifton-8 (36% survival). Differences in development to pupation and pupal weight were less distinct for CEW. When CEW larvae were provided ten peanut blooms each 48 hours in addition to unlimited foliage, development to pupation was significantly shorter in Florunner, NC 6, Robut 33–1, GPNC 343, and Curly Leaf than when larvae were fed only foliage. Similarly, CEW pupal weights were heavier in Florunner and GPNC 343 treatments, indicating that feeding on peanut blooms of most peanut genotypes tested was of benefit to CEW. In terms of overall response of the three insect species tested, NC 6 and Tifton-8 appeared to be the most resistant while Robut 33–1, Curly Leaf, and Florigiant appeared to be the most susceptible.

scholarly journals DAMAGING NATURE OF FALL ARMYWORM AND ITS MANAGEMENT PRACTICES IN MAIZE: A REVIEW

2020 ◽  
Vol 1 (2) ◽  
pp. 82-85
Author(s):  
Shirisa Acharya ◽  
Subham Kaphle ◽  
Jaya Upadhayay ◽  
Abina Pokhrel ◽  
Sabina Paudel
Keyword(s):  
Crop Production ◽  
Management Practices ◽  
Management Practice ◽  
Management Strategies ◽  
Fall Armyworm ◽  
Growth Stages ◽  
Agricultural Crop ◽  
Vegetable Crops ◽  
Young Leaves ◽  
Ecologically Sustainable

Fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is a polyphagous pest which is arising as one of the major threats to agricultural crop production. It has around 80 host species that cause severe damage to cereals and vegetable crops. This pest was first discovered in Africa (2016) and first collected and reported in Nepal at Nawalparasi district on 9th may 2019. The larvae of FAW are found on young leaves, leaf whorls, tassels or cobs according to their growth stages. First instar larvae scrape leaves and shows pin-hole symptoms and window-pane feeding symptoms whereas in the later vegetative stages, damage results in skeletonised leaves and heavily windowed whorls. If climatic condition for pest establishment is suitable this pest could cause approximately 100% crop loss in maize if not managed in time. Regular scouting, push and pull method, black light traps, commonly available botanicals like neem locally available materials like ash and some recommended insecticides with recommended dose can be used for the control of fall armyworm. There is an urgent need for developing ecologically sustainable, economically profitable, and socially acceptable integrated pest management strategies to mitigate the impacts of the fall armyworm and not just rely on single management practice.

Peanut Fungicides: Effect on Survival and Development of the Corn Earworm, Fall Armyworm, and Velvetbean Caterpillar1

1996 ◽  
Vol 23 (2) ◽  
pp. 116-123 ◽  
Author(s):  
Robert E. Lynch
Keyword(s):  
Spodoptera Frugiperda ◽  
Helicoverpa Zea ◽  
Fall Armyworm ◽  
Corn Earworm ◽  
Anticarsia Gemmatalis ◽  
Velvetbean Caterpillar ◽  
Survival And Development ◽  
Comparable Concentration ◽  
Terminal Buds ◽  
Army Worm

Abstract The fungicides chlorothalonil, tebuconazole, and propiconazole commonly used for control of peanut diseases were evaluated for activity against the corn earworm [Helicoverpa zea (Boddie)], fall armyworm [Spodoptera frugiperda (J. E. Smith)], and velvetbean caterpillar (Anticarsia gemmatalis Hübner). Chlorothalonil most adversely affected early establishment and survival of neonates of all three insect species on peanut terminal buds. Chlorothalonil also decreased the weight of larvae of all three species at 10 d and extended the time to pupation for fall armyworm and velvetbean caterpillar larvae. Similarly, tebuconazole adversely affected early survival and establishment, decreased 10-d weight and extended time to pupation of corn earworm and velvetbean caterpillar larvae, but had little effect on fall armyworm larvae. Propiconazole had no effect on establishment and survival of corn earworm and fall armyworm larvae on peanut terminals, and actually increased the weight of 10-d-old larvae for all three insects over that recorded for the untreated control. Orthogonal comparisons of the activity of five chlorothalonil-based fungicides against the fall army-worm showed that the activity was due to chlorothalonil rather than to formulation. At equivalent concentrations used in the field, Bravo Ultrex® was significantly more active against larvae of the fall armyworm than was a comparable concentration of Bravo 72®. However, regression lines did not differ for the two fungicides for any of the developmental parameters measured when larvae of all three species were fed different concentrations of Bravo 720® and Bravo Ultrex® in their meridic diet.

scholarly journals Growth and Phenology of Vulpia Myuros in Comparison with Apera Spica-Venti, Alopecurus Myosuroides and Lolium Multiflorum in Monoculture and in Winter Wheat

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1495
Author(s):  
Muhammad Javaid Akhter ◽  
Bo Melander ◽  
Solvejg Kopp Mathiassen ◽  
Rodrigo Labouriau ◽  
Svend Vendelbo Nielsen ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Weed Management ◽  
Lolium Multiflorum ◽  
Management Strategies ◽  
Integrated Weed Management ◽  
Growth Stages ◽  
Neighborhood Design ◽  
Alopecurus Myosuroides ◽  
Winter Cereals ◽  
Arable Weed

Vulpia myuros has become an increasing weed problem in winter cereals in Northern Europe. However, the information about V. myuros and its behavior as an arable weed is limited. Field and greenhouse experiments were conducted in 2017/18 and 2018/19, at the Department of Agroecology in Flakkebjerg, Denmark to investigate the emergence, phenological development and growth characteristics of V. myuros in monoculture and in mixture with winter wheat, in comparison to Apera spica-venti, Alopecurus myosuroides and Lolium multiflorum. V. myuros emerged earlier than A. myosuroides and A. spica-venti but later than L. multiflorum. Significant differences in phenological development were recorded among the species. Overall phenology of V. myuros was more similar to that of L. multiflorum than to A. myosuroides and A. spica-venti. V. myuros started seed shedding earlier than A. spica-venti and L. multiflorum but later than A. myosuroides. V. myuros was more sensitive to winter wheat competition in terms of biomass production and fecundity than the other species. Using a target-neighborhood design, responses of V. myuros and A. spica-venti to the increasing density of winter wheat were quantified. At early growth stages “BBCH 26–29”, V. myuros was suppressed less than A. spica-venti by winter wheat, while opposite responses were seen at later growth stages “BBCH 39–47” and “BBCH 81–90”. No significant differences in fecundity characteristics were observed between the two species in response to increasing winter wheat density. The information on the behavior of V. myuros gathered by the current study can support the development of effective integrated weed management strategies for V. myuros.

Lethal and Sublethal Effects of Eucalyptus camaldulensis and Mentha piperita Essential Oils on the Khapra Beetle (Coleoptera: Dermestidae) in Terms of Feeding Inhibition, Oviposition, and Seed Damage

2021 ◽  
Author(s):  
Ehsan Borzoui ◽  
Ramin Khaghani ◽  
Gadir Nouri-Ganbalani
Keyword(s):  
Essential Oils ◽  
Sublethal Effects ◽  
Management Strategies ◽  
Eucalyptus Camaldulensis ◽  
Choice Test ◽  
Mentha Piperita ◽  
Growth Stages ◽  
Fumigant Toxicity ◽  
Khapra Beetle ◽  
Wheat Seeds

Abstract Trogoderma granarium Everts, the Khapra beetle, is a major pest of stored products, especially grains. In this study, fumigant toxicity and sublethal effects of Eucalyptus camaldulensis Dehnh. (Myrtaceae) and Mentha piperita L. (Lamiaceae) essential oils (EOs) were investigated against different growth stages of T. granarium. To assess the sublethal effects, insects were exposed to an LC20 or LC50 concentration of each essential oil, and the ability of these oils to deter feeding, oviposition, and damage to wheat seeds and overall mass were surveyed. At LC50 concentrations, M. piperita EO showed higher fumigant toxicity than E. camaldulensis EO against eggs, 2nd instar larvae, 4th instar larvae, and adults of T. granarium. Furthermore, the adults were more sensitive to the tested EOs than immatures. In free-choice tests, both larvae and adults showed a preference for control-treated wheat seeds than for seeds treated with an LC20 or LC50 concentration of EOs from E. camaldulensis or M. piperita. In a no-choice test, adult females exposed to EOs showed lower fecundity and fertility in comparison to control females not exposed to EOs. Treatment of wheat seeds with E. camaldulensis or M. piperita EOs resulted in a dose-specific reduction in the number of damaged seeds and seed weight loss when compared to control. According to our results, both tested EOs, especially EOs extracted from M. piperita, showed good potential for use in integrated pest management strategies against T. granarium.

scholarly journals Impact of an Exotic Invasive Pest, Spodoptera frugiperda (Lepidoptera: Noctuidae), on Resident Communities of Pest and Natural Enemies in Maize Fields in Kenya

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1074
Author(s):  
Bonoukpoè Mawuko Sokame ◽  
Boaz Musyoka ◽  
Julius Obonyo ◽  
François Rebaudo ◽  
Elfatih M. Abdel-Rahman ◽  
...  
Keyword(s):  
Natural Enemies ◽  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
Invasive Pest ◽  
Growth Stages ◽  
Insect Communities ◽  
Exotic Invasive Species ◽  
Before And After ◽  
Exotic Invasive ◽  
Lepidoptera Noctuidae

The interactions among insect communities influence the composition of pest complexes that attack crops and, in parallel, their natural enemies, which regulate their abundance. The lepidopteran stemborers have been the major maize pests in Kenya. Their population has been regulated by natural enemies, mostly parasitoids, some of which have been used for biological control. It is not known how a new exotic invasive species, such as the fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera, Noctuidae), may affect the abundance and parasitism of the resident stemborers. For this reason, pest and parasitism surveys have been conducted, before and after the FAW invaded Kenya, in maize fields in 40 localities across 6 agroecological zones (AEZs) during the maize-growing season, as well as at 3 different plant growth stages (pre-tasseling, reproductive, and senescence stages) in 2 elevations at mid-altitude, where all maize stemborer species used to occur together. Results indicated that the introduction of the FAW significantly correlated with the reduction of the abundance of the resident communities of maize stemborers and parasitoids in maize fields; moreover, the decrease of stemborer density after the arrival of FAW occurred mostly at both reproductive and senescent maize stages. It also suggests a possible displacement of stemborers by FAW elsewhere; for example, to other cereals. However, since this study was conducted only three years after the introduction of the FAW, further studies will need to be conducted to confirm such displacements.

scholarly journals First report of Diaporthe ueckerae causing stem canker on soybean (Glycine max L.) in Colombia

Plant Disease ◽  
2021 ◽  
Author(s):  
Nathali López-Cardona ◽  
YUDY ALEJANDRA GUEVARA ◽  
Lederson Gañán-Betancur ◽  
Carol Viviana Amaya Gomez
Keyword(s):  
Management Strategies ◽  
Elongation Factor ◽  
Morphological Characteristics ◽  
Aerial Mycelium ◽  
Stem Canker ◽  
Growth Stages ◽  
Internal Transcribed Spacer Region ◽  
First Report ◽  
Glycine Max L ◽  
Soybean Plants

In October 2018, soybean plants displaying elongated black to reddish-brown lesions on stems were observed in a field planted to the cv. BRS Serena in the locality of Puerto López (Meta, Colombia), with 20% incidence of diseased plants. Symptomatic stems were collected from five plants, and small pieces (∼5 mm2) were surface sterilized, plated on potato dextrose agar (PDA) and incubated for 2 weeks at 25°C in darkness. Three fungal isolates with similar morphology were obtained, i.e., by subculturing single hyphal tips, and their colonies on PDA were grayish-white, fluffy, with aerial mycelium, dark colored substrate mycelium, and produced circular black stroma. Pycnidia were globose, black, occurred as clusters, embedded in tissue, erumpent at maturity, with an elongated neck, and often had yellowish conidial cirrus extruding from the ostiole. Alpha conidia were observed for all isolates after 30 days growth on sterile soybean stem pieces (5 cm) on water agar, under 25ºC and 12 h light/12h darkness photoperiod. Alpha conidia (n = 50) measured 6.0 – 7.0 µm (6.4 ± 0.4 µm) × 2.0 – 3.0 µm (2.5± 0.4 µm), were aseptate, hyaline, smooth, ellipsoidal, often biguttulate, with subtruncate base. Beta conidia were not observed. Observed morphological characteristics of these isolates were similar to those reported in Diaporthe spp. by Udayanga et al. (2015). DNA from each fungal isolate was used to sequence the internal transcribed spacer region (ITS), and the translation elongation factor 1-α (TEF1) gene, using the primer pairs ITS5/ITS4 (White et al. 1990) and EF1-728F/EF1- 986R (Carbone & Kohn, 1999), respectively. Results from an NCBI-BLASTn, revealed that the ITS sequences of the three isolates (GenBank accessions MW566593 to MW566595) had 98% (581/584 bp) identity with D. miriciae strain BRIP 54736j (NR_147535.1), whereas the TEF1 sequences (GenBank accessions MW597410 to MW597412) had 97 to 100% (330-339/339 bp) identity with D. ueckerae strain FAU656 (KJ590747). The species Diaporthe miriciae R.G. Shivas, S.M. Thomps. & Y.P. Tan, and Diaporthe ueckerae Udayanga & Castl. are synonymous, with the latter taking the nomenclature priority (Gao et al. 2016). According to a multilocus phylogenetic analysis, by maximum likelihood, the three isolates clustered together in a clade with reference type strains of D. ueckerae (Udayanga et al. 2015). Soybean plants cv. BRS Serena (growth stages V3 to V4) were used to verify the pathogenicity of each isolate using a toothpick inoculation method (Mena et al. 2020). A single toothpick colonized by D. ueckerae was inserted directly into the stem of each plant (10 plants per isolate) approximately 1 cm below the first trifoliate node. Noncolonized sterile toothpicks, inserted in 10 soybean plants served as the non-inoculated control. Plants were arbitrarily distributed inside a glasshouse, and incubated at high relative humidity (>90% HR). After 15 days, inoculated plants showed elongated reddish-brown necrosis at the inoculated sites, that were similar to symptoms observed in the field. Non-inoculated control plants were asymptomatic. Fungal cultures recovered from symptomatic stems were morphologically identical to the original isolates. This is the first report of soybean stem canker caused by D. ueckerae in Colombia. Due to the economic importance of this disease elsewhere (Backman et al. 1985; Mena et al. 2020), further research on disease management strategies to mitigate potential crop losses is warranted.

scholarly journals Relación entre el peso freco y el peso seco del rastrojo de maíz en diferentes estados fenológicos del cultivo.

2016 ◽  
Vol 8 (1) ◽  
pp. 20 ◽  
Author(s):  
M. Bänziger ◽  
G. O. Edmeades ◽  
J. Bolaños
Keyword(s):  
Dry Matter ◽  
Dry Weight ◽  
Important Variable ◽  
Growth Stages ◽  
Simple Method ◽  
Plant Parts ◽  
Maturity Period ◽  
Area Unit ◽  
Drying Conditions ◽  
The Relationship

The amount of dry matter produced during various stages of corn growth is a important variable to be taken into consideration. However, the lack of drying facilities makes its measurement a difficult task in the fields. A simple method to convert the fresh weight of a crop in the field into dry weight, could be an answer to that problem. In this study, we calculated the relationship between fresh and dry weight of corn stovers, over several, growth, stages of eight corn cultivars of different vigour and maturity period, at two Mexican locations. The differences between cultivars were for percent stover dry weight (%SDW) most evident in the second half of the grain growth stage, when late cultivars showed less humidity than the early ones. The % SDW was regressed against the phenological developmental stage and expressed as a ratio against antesis (R, days to sampling /days to 50% antesis). The equations (R2 = 0.97 - 0.99) with best results were: Early maturing cultivars: %SDW = 12.6 + 0.94R2 + 1.68R4; Late: %SDW = 16.1 - 4.00 R2 + 3.36R4. There were no consistant differences among cultivars with different vigour levels, even though certain differences were noted among the locations and they were attributed to differences in relative humidity. We describe a protocol for determining the dry weight of corn stover by area unit (t/ha) when drying conditions are not available, by utilizing only a scale and a ruler.We also suggest a method to calculate percent dry matter for a real plant parts (including grain).

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