Phytosanitary and Technical Quality Challenges in Export Fresh Vegetables and Strategies to Compliance with Market Requirements: Case of Smallholder Snap Beans in Kenya

Integrating Metarhizium anisopliae entomopathogenic fungi with border cropping reduces black bean aphids (Aphis fabae) damage and enhances yield and quality of French bean

French bean growers, rely mainly on pesticides for pest management. The acceptable tolerance for pesticides residue in French beans is a major concern and has led to several tonnes of the crop continuously rejected and listed as unsafe for human consumption. There is growing demand for alternative approaches and products that are effective at managing pests without the side-effects associated with reliance on pesticides. A field study to determine the combined effects of Metarhizium anisopliae, (Metarril WP E9 and Biomagic) biopesticides and border crops (Sunflower and wheat) on aphid population, damage severity, growth, yield and quality of French bean. A two-factor experiment was conducted at the Egerton University, Kenya. First factor included two border crops (sunflower and wheat) and no border crop (control). Second factor included spraying Metarril WPE9 (2 × 108 cfu/g), Biomagic (2 × 108 cfu/ml) biopesticides, alpha-cypermethrin (synthetic insecticide) and water. Data on growth, yield and quality parameters were collected and analyzed using the SAS version 9.4M8. Results showed that M. anisopliae and border crop significantly (p < 0.0005) enhanced growth, yield and quality of French bean in both seasons. French bean grown with wheat or sunflower borders showed a significant reduction in aphid population (p < 0.0001) and damage severity (p < 0.0001) when sprayed with various treatments compared to the control. Plots with wheat border caused an increase in collar diameter of French bean. The plots (Metarril and wheat border) caused a 4 % and 5 % increase in marketable yield, a 2 % and 12 % reduction in non-marketable yield. To exploit the benefits of biopesticides, the study recommends their integration with and border crops. Thus, French bean growers could benefit more from fungal-based biopesticides in aphid-IPM approach, as it reduces pre-harvest intervals and residues compared to synthetic insecticides.

The dual impacts of specialized agricultural services on pesticide application intensity: Evidence from China

BACKGROUND

Specialized agricultural services are a new trend in agricultural production around the world, especially in developing countries. However, the growing impacts of specialized agricultural services on pesticide application intensity are unclear. In regions facing pesticide overuse, do specialized agricultural services exacerbate or mitigate the problem?

RESULTS

Based on province-level panel data from China from 2004 to 2018, this study examines the impact of specialized agricultural services on pesticide application intensity, considering both direct and indirect (i.e. spatial spillover) effects. The dual impacts of specialized agricultural services on pesticide application intensity in China are identified. First, specialized agricultural services directly increase pesticide application intensity, likely due to increased cultivation and specialized management of land that was previously abandoned or marginally managed. Second, there is a negative indirect or spatial spillover effect of specialized agricultural services on pesticide application intensity, likely due to technology and efficiency diffusion enabled by the cross-regional provision of specialized agricultural services. The net impact of specialized agricultural services on pesticide application intensity is negative.

CONCLUSION

Crop protection services are regarded as the core force to promote the reduction of pesticide application intensity. Steps should be taken to promote the research and development, demonstration, and promotion of new technologies and equipment for crop protection services, particularly the development of crop protection by drones. © 2022 Society of Chemical Industry.

Efficacy of hot water treatment for postharvest control of western flower thrips, Frankliniella occidentalis, in French beans

BACKGROUND

The western flower thrips, Frankliniella occidentalis, is a quarantine pest of French beans that requires phytosanitary treatment to meet quarantine requirements for strict lucrative markets. In this study, the efficacy of hot water treatment against F. occidentalis eggs and its effects on the postharvest physicochemical quality parameters of French beans was evaluated.

RESULTS

The immersion time of 8.01 min (95% critical limits CL 7.77-8.24) was predicted by the probit model as the minimum time required to achieve a 99.9968% control level. Confirmatory tests with a large number of F. occidentalis eggs were performed to validate the estimated time to achieve probit-9 control level, and there were no survivors from the 50 103 eggs treated. Likewise, none of the 55 364 eggs exposed to 45 ± 0.2 °C for 7 min (observational time) survived. The effect of the treatment schedule on French beans quality parameters was assessed and there were no differences in weight loss, moisture content, total soluble solids, titratable acidity, pH, and reducing sugars between treated and untreated samples.

CONCLUSION

Our results indicate that hot water treatment (at 45 ± 0.2 °C for a duration of 8.01 min is an effective phytosanitary treatment for the control of Frankliniella occidentalis on French beans, with no significant impact on pods quality. © 2022 Society of Chemical Industry.

Correlation between Irradiation Treatment and Metabolite Changes in Bactrocera dorsalis (Diptera: Tephritidae) Larvae Using Solid-Phase Microextraction (SPME) Coupled with Gas Chromatography-Mass Spectrometry (GC-MS)

The metabolites produced by the larvae of Bactrocera dorsalis (Diptera: Tephritidae) exposed to different doses of irradiation were analyzed using solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS), and a metabonomic analysis method of irradiated insects based on GC-MS was established. The analysis revealed 67 peaks, of which 23 peaks were identified. The metabolites produced by larvae treated with different irradiation doses were compared by multivariate statistical analysis, and eight differential metabolites were selected. Irradiation seriously influenced the fatty acid metabolic pathway in larvae. Using the R platform combined with the method of multivariate statistical analysis, changes to metabolite production under four irradiation doses given to B. dorsalis larvae were described. Differential metabolites of B. dorsalis larvae carried chemical signatures that indicated irradiation dose, and this method is expected to provide a reference for the detection of irradiated insects.

Improving Access to Export Market for Fresh Vegetables through Reduction of Phytosanitary and Pesticide Residue Constraints

The horticultural sector is a key contributor to Kenya’s gross domestic product through the export of fresh-cut flowers, fruits and vegetables to various niche markets. It employs over 350,000 people, while about six million depend on it. However, the sector is constrained by the strict technical and phytosanitary quality requirements set by the export markets. The phytosanitary concerns include the presence of pests and microbial contaminants, while the presence of chemical residues constitute the major technical challenge. These constraints cause the interception and rejection of produce at the export destinations. The fresh produce should be free of quarantine and regulated non-quarantine pests, pest damage, pesticides above the stipulated maximum residue levels (MRLs) and phytosanitary certification. This review discusses the following four-tiered approach to compliance with phytosanitary and pesticide residue requirements: (i) use of alternative pest management approaches, including biocontrol options, cultural and physical practices; (ii) collaboration among regulatory agencies, institutions, producers and regional countries in the enforcement of standards; (iii) investment in research and the adoption of innovative technologies; (iv) awareness creation and training of actors along the fresh vegetable value chain. It is envisaged that this approach will contribute to sustainable fresh vegetable value chains, leading to improved access to export markets, and increased export volumes and income to smallholder farmers and other actors in the fresh vegetable value chain.