How low can you go? Estimating impacts of reduced pesticide use

Shadow prices of agrochemicals in the Chinese farming sector: A convex expectile regression approach

The use of agrochemical inputs has significantly enhanced agricultural yields in China; however, their excessive utilization has also caused a range of environmental issues. This paper examines the costs associated with reducing agrochemicals by employing shadow prices, which represent the value of the marginal product of agrochemicals, to further develop cost-effective environmental policy measures for reducing their usage. To this end, the shadow prices of agrochemicals have been assessed by adopting a newly developed convex expectile regression approach and using statistical data from 31 provinces in China spanning from 2005 to 2020. Furthermore, the present study investigates the disparities between shadow prices and market prices for different agrochemicals across various regions in China. The findings suggest that the costs of reducing chemical fertilizers are higher than those of reducing pesticides and plastic films. Moreover, the results indicate that central China exhibits relatively high potential for decreasing agrochemical usage. Finally, these findings can inform the Chinese government's restructuring of producer support and environmental policy in a cost-effective way to mitigate agrochemicals use in the future. Additionally, the research method employed in this study holds potential for extension to other agrochemicals-dependent countries.

Managing ecosystem services in oleaginous forests for bioenergy provision and climate change mitigation

Oleaginous forests provide diverse ecosystem services, including timber, seed yield (a vital feedstock for biodiesel production), and substantial carbon savings. These carbon savings encompass carbon sequestration related to timber growth and carbon savings resulting from substituting fossil fuel with biodiesel. However, oleaginous forests are vulnerable to seed wasp attacks (disservice), which significantly threaten both seed yield and carbon savings. Using an integrated ecological-economic model that includes Faustmann's Land Expectation Value model and a pest damage control model, we aim to understand the intricate relationship among multiple ecosystem services and disservices of oleaginous forests. The results reveal four distinct phases contingent on varying pesticide application rates: the pesticide under-use phase, substitution phase, complementary phase, and over-use phase. Notably, a potential avenue to minimize pest damage is identified during the complementary phase by reducing the optimal rotation age at the expense of decreased carbon sequestration and bioenergy provision, posing a challenge to climate change mitigation. These findings have implications for formulating policies to manage conflicting ecosystem services of energy forests, offering valuable insights into the intersection of sustainable forest management and climate policy.

Molecular mapping and transfer of a novel brown planthopper resistance gene bph42 from Oryza rufipogon (Griff.) To cultivated rice (Oryza sativa L.)

BACKGROUND

Brown planthopper (BPH), Nilaparvata lugens (Stål), is one of the most destructive pests of rice accounting for 52% of annual yield loss. The breakdown of resistance against known BPH biotypes necessitates the identification and deployment of new genes from diverse sources. The current study aimed at mapping and transfer of a novel BPH resistance gene from the wild species of rice O. rufipogon accession CR100441 to the elite rice cultivar against BPH biotype 4.

METHODS AND RESULTS

The phenotypic screening against BPH biotype 4 was conducted using the standard seedbox screening technique (SSST). Inheritance study using damage score caused by BPH infestation at the seedling stage indicated the presence of a single major recessive gene with the segregation ratio of susceptible to resistant plants in 3:1 (210:66, χ2c = 0.17 ≤ χ20.05,1 = 3.84). The genotyping of the mapping population was done using polymorphic microsatellite markers between PR122 and O.rufipogon acc.CR100441 spanning all the 12 chromosomes of rice. A total of 537 SSR markers were used to map a BPH resistance gene (designated as bph42) on the short arm of chromosome 4 between RM16282 and RM6659. QTL analysis identified a peak marker RM16335 contributing 29% of the phenotypic variance at 40.76 LOD.

CONCLUSIONS

The identified marker co-segregates with the bph42 and hence could be efficiently used for marker-assisted selection (MAS) for the transfer of resistance into elite rice cultivars. The introgression lines with higher yield and BPH resistance were identified and are under advanced yield trails for further varietal release.

Farmers' intention to reduce pesticide use: the role of perceived risk of loss in the model of the planned behavior theory

Numerous studies have examined how farmers are involved and behave in the use of pesticides, but what drives farmers' intention to diminish pesticide applications is mostly unknown. This study explored farmers' intention to minimize pesticide use, through the theory of planned behavior (TPB) and an adjusted form of the TPB, with perceived risk of loss as an additional variable to the original model. On a scale from 1 to 5, intention to reduce pesticide use had the lowest score of all variables (2.36), indicating that most farmers did not show intention to reduce pesticide use. Only 15.2% of the farmers were willing to reduce pesticide use, while 8.3% were undecided. Moreover, 58.2% of the farmers had high levels of perceived risk of loss by the reduction of pesticide use, which explained 37.3% of farmers' intention. From the three variables of the TPB, attitudes had the highest score (3.34), indicating slightly favorable attitudes toward pesticide reduction, while perceived behavior control had the lowest score (2.70), indicating poor control of pesticide reduction. Also, the three basic variables of the TPB were positively correlated (P < 0.01) with farmers' intention to reduce pesticides, while a negative correlation (P < 0.01) was noted between intention to reduce pesticides and perceived risk of loss. The three basic variables of the TPB were significant predictors of intention, capturing 54.7% of the variation in farmers' intention. Adding perceived risk of loss as a construct to the TPB improved the predictive ability of the original model. Poor control of pesticide reduction (high-perceived barriers) and high perceived risk of loss drive farmers' intention to reduce the use of pesticides. Advancing alternative crop protection methods focusing on agro-ecology and integrated pest management should be included in the work of extension services.

Developing a decision-making framework for insect pest management: a case study using Aphis glycines (Hemiptera: Aphididae)

BACKGROUND

The profitability of farming varies based on factors such as a crop's market value, input costs and occurrence of resistant pests, all capable of altering the value of pest management tactics in an integrated pest management program. We provide a framework for calculating expected yield and expected net revenue of pest management scenarios, using the soybean aphid (Aphis glycines) as a case study. Foliar insecticide and host-plant resistance are effective management tactics for preventing yield loss from soybean aphid outbreaks; however, pyrethroid-resistant aphid populations pose a management challenge for farmers. We evaluated eight scenarios relevant to soybean aphid management in Iowa with varying probabilities of aphid outbreaks and insecticide-resistant aphids occurring.

RESULTS

Our equation suggests that insecticide use is profitable when the probability of an aphid outbreak is ≥29%, and soybean production will become more costly with increasing probability of pyrethroid-resistant aphids. If farmers continue to use pyrethroids, they will not experience financial consequences from pyrethroid-resistant aphids until the chance of insecticide resistance is 48%. Aphid-resistant varieties provided consistent yield and offered the highest net revenue under all conditions.

CONCLUSION

This framework can be used for other crop-pest systems to evaluate the profitability of management tactics and investigate how resistance impacts revenue for farmers. Including the cost of resistance in crop budgets can help farmers and agronomic consultants comprehend these impacts and enhance decision-making to increase revenue and curb resistance development.

Farmer field schools for improving economic sustainability performance of Indonesian vegetable production

Purpose

A research and development project disseminated ecological technologies to approximately 3,250 vegetable farmers through farmer field schools (FFS) in four districts of Bali and East Java provinces of Indonesia. This article aims to assess the economic sustainability of vegetable production after FFS participation.

Design/methodology/approach

A survey randomly sampled 500 farmers, comprised of FFS participants (50%) and non-FFS participants (50%). Based on 1,000 farm operations, this analysis employed input-saving technology as the fundamental model examined using the double-difference method. Simultaneous reduction of agrochemicals and improvement of productivity represent indicators of economic sustainability.

Findings

Results indicate that pesticide use decreased without jeopardising farm productivity; moreover, vegetable production increased. These findings indicate that the ecological technologies transferred through FFS significantly improved economic sustainability performance.

Research limitations/implications

This study purposively selected farmers who grew tomato and chilli. Thus, the outcomes are not generalisable to other crops.

Practical implications

FFS continues to be an effective method for transferring agricultural technologies to farmer communities. Policymakers are recommended to use FFS for disseminating beneficial and sustainable technologies to broader agricultural communities.

Social implications

The adoption of ecological technologies provides positive economic and ecological milieus.

Originality/value

This study employs a double-differences approach to verify input-saving technological progress. Therefore, the performance of economic sustainability attributable to the project intervention is theoretically justified.

Bacillus thuringiensis Bioinsecticides Induce Developmental Defects in Non-Target Drosophila melanogaster Larvae

Bioinsecticides made from the bacterium Bacillus thuringiensis (Bt) are the bestselling bioinsecticide worldwide. Among Bt bioinsecticides, those based on the strain Bt subsp. kurstaki (Btk) are widely used in farming to specifically control pest lepidopteran larvae. Although there is much evidence of the lack of acute lethality of Btk products for non-target animals, only scarce data are available on their potential non-lethal developmental adverse effects. Using a concentration that could be reached in the field upon sprayings, we show that Btk products impair growth and developmental time of the non-target dipteran Drosophila melanogaster. We demonstrate that these effects are mediated by the synergy between Btk bacteria and Btk insecticidal toxins. We further show that Btk bioinsecticides trigger intestinal cell death and alter protein digestion without modifying the food intake and feeding behavior of the larvae. Interestingly, these harmful effects can be mitigated by a protein-rich diet or by adding the probiotic bacterium Lactobacillus plantarum into the food. Finally, we unravel two new cellular mechanisms allowing the larval midgut to maintain its integrity upon Btk aggression: First the flattening of surviving enterocytes and second, the generation of new immature cells arising from the adult midgut precursor cells. Together, these mechanisms participate to quickly fill in the holes left by the dying enterocytes.

Eco-efficiency as a strategy for optimizing the sustainability of pest management

Agricultural industrialization and the subsequent reliance on pesticides has resulted in numerous unintended consequences, such as impacts upon the environment and by extension human health. Eco-efficiency is a strategy for sustainably increasing production, while simultaneously decreasing these externalities on ecological systems. Eco-efficiency is defined as the ratio of production to environmental impacts. It has been widely adopted to improve chemical production, but we investigate the challenges of applying eco-efficiency to pesticide use. Eco-efficiency strategies include technological innovation, investment in research and development, improvement of business processes, and accounting for market forces. These components are often part of integrated pest management (IPM) systems that include alternatives to pesticides, but its implementation is often thwarted by commercial realities and technical challenges. We propose the creation and adoption of an eco-efficiency index for pesticide use so that the broad benefits of eco-efficient strategies such as IPM can be more readily quantified. We propose an index based upon the ratio of crop yield to a risk quotient (RQ) calculated from pesticide toxicity. Eco-efficiency is an operational basis for optimizing pest management for sustainability. It naturally favors adoption of IPM and should be considered by regulators, researchers, and practitioners involved in pest management. © 2019 Society of Chemical Industry.

Herbicide Resistance Management: Recent Developments and Trends

This review covers recent developments and trends in herbicide-resistant (HR) weed management in agronomic field crops. In countries where input-intensive agriculture is practiced, these developments and trends over the past decade include renewed efforts by the agrichemical industry in herbicide discovery, cultivation of crops with combined (stacked) HR traits, increasing reliance on preemergence vs. postemergence herbicides, breeding for weed-competitive crop cultivars, expansion of harvest weed seed control practices, and advances in site-specific or precision weed management. The unifying framework or strategy underlying these developments and trends is mitigation of viable weed seeds into the soil seed bank and maintaining low weed seed banks to minimize population proliferation, evolution of resistance to additional herbicidal sites of action, and spread. A key question going forward is: how much weed control is enough to consistently achieve the goal of low weed seed banks? The vision for future HR weed management programs must be sustained crop production and profitability with reduced herbicide (particularly glyphosate) dependency.