DefinePK

Research Objective

To evaluate the impact of neem seeds extract (AENS) on soybean grains health after crops treatment in field conditions for the control against Asian rust (Phakopsora pachyrhizi and P. meibomiae).

Methodology

Experiment conducted in Mimetala and Nkometou (agroecological zone V, Cameroun) using three soybean varieties ("Locale", TGX 1835-10E, and TGX1910-14E). A completely randomized blocks design with five treatments was used: T0 (control/water), T1 (25 g/L AENS), T2 (50 g/L AENS), T3 (100 g/L AENS), and T4 (5.33 g/L Plantineb 80wp, chemical fungicide). Spraying occurred weekly starting at the 4th week after sowing (WAS) for five applications before harvest. Disease incidence on harvested grains was evaluated. Biochemical parameters (total proteins, globulin, albumin, glutelin, prolamin, and glucide) were extracted and quantified using standard spectrophotometric and colorimetric methods (Bradford, enthrone method). Data were analyzed using ANOVA and Duncan's test (P=0.05).

Methodology Flowchart

                        graph TD; A[Site Selection: Mimetala & Nkometou] --> B[Soybean Varieties & Treatments Setup]; B --> C[Treatments: T0 Control, T1-T3 AENS Doses, T4 Fungicide]; C --> D[Weekly Spraying 5 times starting 4 WAS]; D --> E[Harvesting of Ripe Pods]; E --> F[Pathogen Identification Phakopsora pachyrhizi]; F --> G[Evaluation of Disease Incidence on Grains]; G --> H[Extraction & Quantification of Biochemical Compounds]; H --> I[Statistical Analysis ANOVA, Duncan's Test]; I --> J[Conclusion on AENS Efficacy and Grain Quality Improvement];                    

Discussion

Aqueous extract of neem seeds (AENS) effectively reduced Asian rust development on crops and improved the health and biochemical quality of harvested grains. The highest AENS dose (T3) outperformed the chemical fungicide (T4) in enhancing protein and carbohydrate accumulation, suggesting that high concentrations of chemical fungicides might inhibit the synthesis and accumulation of these compounds. The observed differences in biochemical composition across varieties suggest inherent genetic variation influences nutrient accumulation, independent of disease control measures.

Key Findings

- Neem seeds extract (AENS) treatments significantly reduced Asian rust incidence on harvested grains compared to the control (T0: 35% incidence vs. T1, T2, T3: 1.14%, 1.07%, and 0.95% incidence, respectively).
- The highest dose of AENS (T3: 100 g/L) generally resulted in higher contents of all tested biochemical compounds (total proteins, reserve proteins, and glucides) in harvested grains compared to the chemical fungicide (T4).
- Variety TGX1910-14E consistently presented the highest content across most biochemical compounds tested.
- In T3 treatment, grain contents were: total proteins (415.17 mg/g DM), globulin (118.83 mg/g DM), albumin (118.33 mg/g DM), glutelin (44.43 mg/g DM), prolamin (36.53 mg/g DM), and glucide (10.83 mg/g DM).

Conclusion

The application of neem seeds extract (AENS) at the maximum dose (100 g/L) in field conditions successfully controlled Asian rust and improved the quality (biochemical composition) of harvested soybean grains compared to the control and the chemical fungicide treatment. Neem seed extract is recommended as a promoting bio-substance for integrated pest management of soybean against Asian rust.

Fact Check

1. The highest incidence of Asian rust in untreated plots (T0) was 35%. (Confirmed in Abstract)
2. The chemical fungicide (T4) was applied at a concentration of 5.33 g/L. (Confirmed in Methodology)
3. The study was conducted in Mimetala and Nkometou, located in agroecological zone V of Cameroun. (Confirmed in Abstract/Methodology)

Mind Map