Soybean Integrated Pest Management Research Articles

Integration of Sclerotinia sclerotiorum-Targeted Biofungicides Coniothyrium minitans and Bacillus amyloliquefaciens into Season-Long Soybean Pest Management Practices in Indiana

Two biofungicides, Coniothyrium minitans and Bacillus amyloliquefaciens, are commercially available and have been shown to limit or suppress Sclerotinia sclerotiorum in soybean. S. sclerotiorum is a soilborne pathogen of soybean that can cause significant yield losses under cool and wet environmental conditions. Integrated soybean pest management practices can include the application of herbicides, fungicides, and insecticides at various times during the growing season to minimize yield losses. However, limited information is available regarding how these biofungicides can be successfully incorporated into a soybean-integrated pest management program. To assess the sensitivity of C. minitans and B. amyloliquefaciens biological activity on S. sclerotiorum to pesticides commonly used in soybean-production systems, a poison plate assay and soil plate and growth chamber experiments were conducted. In the poison plate assay, C. minitans was most sensitive to the preemergence herbicide flumioxazin and the synthetic fungicides boscalid and fluazinam, whereas B. amyloliquefaciens was sensitive only to the synthetic fungicide fluazinam. In the soil plate assay, the mycoparasitic activity of C. minitans on S. sclerotiorum was sensitive to flumioxazin, metribuzin, glyphosate, picoxystrobin, and boscalid. In the controlled environment experiments, none of the pesticides tested decreased the efficacy of B. amyloliquefaciens. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

New Decision-Making Control System for Caterpillars on Soybean Fields

Decision-making systems are essential to integrated pest management (IPM) programs, particularly in the context of soybean (Glycine max), the world’s most cultivated legume. As agricultural practices change, including adopting new cultivars, planting seasons, and planting regions, the challenges in pest management, mainly caterpillars (Lepidoptera larvae), also change. To address this, this study aimed to devise an updated decision-making approach tailored to the current soybean field conditions. Over two years, caterpillar densities were evaluated in 38 commercial soybean fields. The beating tray sampling technique was superior in precision and efficiency compared to the direct counting and beating cloth techniques. This technique involved assessing 61 plants per field to determine caterpillar density. Economic thresholds were determined at 7.11 caterpillars per beating tray for vegetative stages and 3.60 for reproductive stages. The new proposed sampling system was validated and demonstrated more precise and representative caterpillar density determination than the standard beating cloth system. Both methods exhibited similar costs and execution times. Therefore, this refined decision-making system has the potential for incorporation into soybean IPM programs due to its accuracy, representativeness, feasibility, speed, and cost-effectiveness. This study underscores the viability of integrating the newly developed decision-making system to enhance soybean pest management strategies.

Biological Control as Part of the Soybean Integrated Pest Management (IPM): Potential and Challenges

Biological Control as Part of the Soybean Integrated Pest Management (IPM): Potential and Challenges

Protocol for assessing soybean antixenosis to Heliothis virescens

AbstractLarvae of Heliothis virescens (Fabricius) (Lepidoptera: Noctuidae) often infest soybean crops, Glycine max (L.) (Fabaceae), causing significant yield losses in important soybean‐producing regions. The use of soybean varieties resistant to lepidopteran larvae is a major approach in soybean integrated pest management. However, standardization and optimization of bioassays that are used to screen genotypes for insect resistance are essential for high‐throughput phenotyping. Methodologies for screening were assessed to determine the most effective method for discriminating levels of antixenosis to H. virescens in soybean plants. Feeding and oviposition preference assays were performed to determine optimal densities of larvae and adults, and optimal plant structures and growth stages for conducting assays. In addition, trichome densities, and fiber and lignin contents were quantified in plant structures of soybean cultivars differing in resistance. Resistance levels of cultivars were best differentiated using nine neonate larvae and two 6‐day‐old larvae, and by using young leaves of plants at the vegetative stage. This was likely due to the more pronounced differences in lignin and fiber contents in young leaves of vegetative‐stage plants. Density of adult pairs, plant structure, and growth stage did not affect ability to distinguish differences in oviposition preference by H. virescens. Higher numbers of eggs were found on the leaves, which were the plant structures that exhibited the lowest trichome densities. The protocol developed in this work will benefit future evaluations of soybean genotypes for antixenosis against H. virescens.

Challenges for Adoption of Integrated Pest Management (IPM): the Soybean Example.

Soybean is considered one of today's most important crops. Planted on millions of hectares worldwide, the management of soybean pests usually requires large amounts of chemicals. However, a key component to meet the increasing demand for food due to the rapidly growing global population is protecting crops from pests while maintaining environmental quality through ecologically and economically sound integrated pest management (IPM) practices. Not only can IPM result in more profitable agriculture due to the reduction of pest control costs but also assures equitable, secure, sufficient, and stable flows of both food and ecosystem services. Despite those ecological and economic benefits, the vast areas of cultivated soybean as well as the convenience of spraying insecticides are encouraging the adoption of prophylactic pest control as a relatively inexpensive safeguard compared to IPM practices. Thus, in this forum, we discuss the reasons for soybean IPM not reaching its potential. We give examples of how we can revive this once successful pest management program with a focus on experiences in Brazil and the USA. We analyze IPM case studies to illustrate the need for growers to have easy and fast access to IPM information on its medium- and long-term benefits. Overall, this forum highlights the importance of IPM for agricultural sustainability including ecological and financial benefits.

Below‐ground nematode herbivory of resistant soybean cultivars impairs the performances of an above‐ground caterpillar and its parasitoid

1. Interactions between below‐ and above‐ground organisms have attracted interest in recent years, but less is known about the effect of root‐feeding nematodes on above‐ground trophic interactions between herbivores and their natural enemies.2. This study examined whether the presence of the soybean cyst root nematode Heterodera glycines influences the performance of the above‐ground leaf‐chewing tobacco cutworm Spodoptera litura on soybeans, Glycine max, and whether this in turn affects the success of its parasitoid, Meteorus pulchricornis. Using three soybean cultivars that varied in the level of constitutive resistance to the tobacco cutworm, the study determined whether feeding by the nematode altered the developmental and reproductive performances of the caterpillar and its parasitoid.3. Root feeding by the nematode slowed tobacco cutworm larval development time and reduced adult body weight. Root feeding by the nematode also had a negative effect on the caterpillar's parasitoid, by prolonging development time, decreasing adult body size and reducing fecundity. These effects increased in a linear trend and varied in magnitude depending on levels of soybean constitutive resistance.4. These findings demonstrate that root feeding by the nematode can prime soybean plants with negative impacts on their herbivore and its parasitoid, and that the impact may vary in magnitude depending on levels of soybean constitutive defence. The results emphasise the need to integrate soybean constitutive and root nematode‐induced defences for a better understanding of below‐ and above‐ground organism interactions, and to allow insights to be gained into the improvement of soybean integrated pest management programmes.

The use of soybean integrated pest management in Brazil: a review

The adoption of integrated pest management (IPM) in soybean is a great example of how this technology is essential to guarantee crop sustainability and productivity. In Brazil, up to 1970, soybean was cultivated with the use of pesticides applied without the adoption of any economic threshold to base this decision. As a consequence, a six-insecticide spraying per crop season used to be the average insecticide dosage. With the introduction of Soybean-IPM, the use of pesticides was reduced to approximately two applications per season. Comparing these two contrasting situations, the advantages of using IPM methods cannot be ignored, since they are economically and mostly environmentally feasible. Despite the benefits provided by Soybean- -IPM, this program was abandoned in Brazil, and its principles were almost forgotten, and, as a consequence, insecticide use increased. The success and failures of Soybean-IPM in Brazil will be further analyzed in this review in an attempt to point out how safe this technology is and whether there is any risk in fully adopting this approach.

Assessment of a more conservative stink bug economic threshold for managing stink bugs in Brazilian soybean production

The objective of this study was to assess the stink bug economic threshold for soybean integrated pest management decisions. For this purpose, a replicated experiment was implement in a commercial soybean crop located in Arapongas, Parana State, Brazil, during two crop seasons: 2010/2011 and 2011/12. Treatments consisted of different stink bug densities triggering the application of insecticides, ¼ of the economic threshold (ET) (= 0.5 stink bugs m−1) and ET (= 2 stink bugs m−1), and without applying an insecticide (control). The stink bugs were quantified weekly and all specimens were identified to the species level. At harvest, yield and quality of the seeds were also measured. In all crops, Euschistus heros was the most abundant species. The highest yield and percentage of viable seeds were found in the 'BMX Power RR′ cultivar (indeterminate growth cultivar), indicating a better seed quality. At the end of the experiment, there was no observed difference in yield between different stink bug management thresholds, indicating the effectiveness of the control when adopting ET. This study demonstrates that decreasing the economic threshold increased the number of required insecticide applications, but did not increase yield or bean quality neither the net income when an economic analysis was performed.

Economic Thresholds in Soybean-Integrated Pest Management: Old Concepts, Current Adoption, and Adequacy.

Increasing global demands for food underline the need for higher crop yields. The relatively low costs of the most commonly used insecticides in combination with increasing soybean market prices led growers and technical advisors to debate the adequacy of recommended economic thresholds (ETs). The adoption of ETs and pest sampling has diminished in Brazil, leading to excessive pesticide use on soybean. The reduced efficacy of natural biological control, faster pest resurgence, and environment contamination are among the side-effects of pesticide abuse. To address these problems and maximize agricultural production, pest control programs must be guided by a proper integrated pest management (IPM) approach, including the ET concept. Therefore, the most appropriate time to initiate insecticide spraying in soybean is indicated by the available ETs which are supported by experiments over the last 40years in different edapho-climatic conditions and regions with distinct soybean cultivars. Published scientific data indicate that preventive insecticide use is an expensive and harmful use of chemicals that increases the negative impact of pesticides in agroecosystems. However, the established ETs are for a limited number of species (key pests), and they only address the use of chemicals. There is a lack of information regarding secondary pests and other control strategies in addition to insecticides. It is clear then that much progress is still needed to improve ETs for pest management decisions. Nevertheless, using the current ETs provides a basis for reducing the use of chemicals in agriculture without reducing yields and overall production, thereby improving sustainability.

History and Contemporary Perspectives of the Integrated Pest Management of Soybean in Brazil

The integrated pest management (IPM) of soybean developed and implemented in Brazil was one of the most successful programs of pest management in the world. Established during the 1970s, it showed a tremendous level of adoption by growers, decreasing the amount of insecticide use by over 50%. It included outstanding approaches of field scouting and decision making, considering the economic injury levels (EILs) for the major pests. Two main biological control programs were highly important to support the soybean IPM program in Brazil, i.e., the use of a NPVAg to control the major defoliator, the velvet bean caterpillar, Anticarsia gemmatalis Hübner, and the use of egg parasitoids against the seed-sucking stink bugs, in particular, the southern green stink bug, Nezara viridula (L.). These two biological control programs plus pests scouting, and the use of more selective insecticides considering the EILs supported the IPM program through the 1980s and 1990s. With the change in the landscape, with the adoption of the no-tillage cultivation system and the introduction of more intense multiple cropping, and with the lower input to divulge and adapt the IPM program to this new reality, the program started to decline during the years 2000s. Nowadays, soybean IPM is almost a forgotten control technology. In this mini-review article, suggestions are made to possibly revive and adapt the soybean IPM to contemporary time.

Podisus nigrispinus (Heteroptera: Pentatomidae) and IAC-24 Soybean Cultivar Are Compatible

<p>The main tactics of soybean integrated pest management combine plant resistance and biological control. The impact of insect resistant IAC-24 soybean cultivar [caterpillars of <em>Anticarsia gemmatalis</em> Hübner (Lepidoptera: Noctuidae) in UFVS-2006 soybean cultivar susceptible to insects and water compared to <em>A. gemmatalis</em> in IAC-24 soybean cultivar resistant to insects and water] on the nymphal and adult stages of the predator <em>Podisus nigrispinus</em> Dallas (Heteroptera: Pentatomidae) was evaluated. The duration and survival of the instars and nymphal stage and the body mass of nymphs, males and females of this predator were similar between treatments. The periods of pre-oviposition, oviposition, post-oviposition and egg incubation; interval between egg clutch; number of egg clutch per female, eggs per egg clutch, eggs per female, nymphs per female, nymphs per egg clutch and percentage of nymph eclosion and male and female longevity were also similar between treatments. The use of insect resistant IAC-24 soybean cultivar on <em>P. nigrispinus</em> was found to be safe because that legume did not have any deleterious effects on the referred predator.</p>

Population Dynamics and Dispersion Patterns of Nymphal Threecornered Alfalfa Hoppers (Homoptera: Membracidae)

Seasonal abundance and dispersion characteristics of nymphal threecornered alfalfa hopper (TCAH), Spissistilus festinus (Say), were determined for soybean fields located in Alabama and Florida to contribute to a better soybean integrated pest management program. Four fields were sampled in 1985 and two fields were sampled in 1986. Populations were present in each field from vegetative stages of crop growth until senescence. Nymphal populations of two complete generations occurred in each field, with populations broadly overlapping. Population dynamics were similar to that reported from Louisiana, indicating a similar phenology for TCAH throughout the southern U.S. Results also indicate that TCAH is an occasional pest of soybean in the region. Dispersion statistics of variance/mean ratio and Taylor's power law were calculated for nymphal sample estimates. Populations were aggregated most of the time. The Taylor's power law relationships were used to calculate the number of shake-cloth samples needed to estimate nymphal TCAH density at the 10 and 25% precision levels. A large number of samples are needed to estimate density at the 10% precision level, but fewer than 15 samples are needed at the 25% precision level when nymphal densities are > 4 per m of row.

An Economic Analysis of Soybean Integrated Pest Management

AbstractThe type ofpest management strategy a farmer chooses is influenced by the amount of risk associated with alternative strategies. This paper examines the attractiveness of alternative pest management strategies used on a representative Virginia soybean farm. Probability distfibutions of net revenue associated with alternative pest control options are simulated and then compared using generalized stochastic dominance criteria. Results suggest risk‐averse and, in some cases, risk‐preferring farmers would prefer strategies which incorporate an integrated pest management approach to pest control rather than one which relies completely on chemical pest control.