Field Assessment of the Potential Role of Fusarium Species in the Pathogenesis of Coffee Wilt Disease in Democratic Republic of Congo

Aim: To determine the probable role of 3 species of Fusarium (F. falciforme, F. solani and                       F. stilboides) in the pathogenesis of Coffee Wilt Disease (CWD). Study Design: The field trial was performed using a Randomized Completed Block Design (RCBD) replicates three times. Place and Duration of the Study: The study was conduct in the Experimental Garden of Department of Biology, Faculty of Sciences, University of Kinshasa in Democratic Republic of Congo, between November 2005 and February 2006. Methodology: Four Fusarium species (F. falciforme, F. solani, F. stilboides and F. xylarioides) were inoculated alone, or the first three strains were inoculated in combination with F. xylarioides in coffee seedlings 10 months old. Observations were focused on the time of expression of main CWD symptoms, the rate of each symptom observed, and the presence of each pathogen in dead woods of inoculated seedlings.   Results: Results obtained showed that all Fusarium species induced main symptoms of CWD at varying moment and degrees. Chronologically, leaf yellowing appeared an average 25 dai, followed by leaf browning (46 dai), leaf drying (61 dai), mortality (75 dai) and defoliation (77 dai). Significant differences (P = .05) were observed between treatments considered. All Fusarium induced seedlings mortality and were isolated in dead woods at 1 – 4 cm from the point of inoculation. In general, the search of synergistic interaction between Fusarium spp. inoculated in combination with F. xylarioides showed enhanced ability to induce various symptoms of CWD when species are used together.  Conclusion: The present study demonstrates that CWD could be reconsidered as a parasitic complex, and in natural conditions all Fusarium species used present a danger for coffee growing

Field Assessment of the Potential Role of Fusarium Species in the Pathogenesis of Coffee Wilt Disease in Democratic Republic of Congo

Aim: To determine the probable role of 3 species of Fusarium (F. falciforme, F. solani and                       F. stilboides) in the pathogenesis of Coffee Wilt Disease (CWD). Study Design: The field trial was performed using a Randomized Completed Block Design (RCBD) replicates three times. Place and Duration of the Study: The study was conduct in the Experimental Garden of Department of Biology, Faculty of Sciences, University of Kinshasa in Democratic Republic of Congo, between November 2005 and February 2006. Methodology: Four Fusarium species (F. falciforme, F. solani, F. stilboides and F. xylarioides) were inoculated alone, or the first three strains were inoculated in combination with F. xylarioides in coffee seedlings 10 months old. Observations were focused on the time of expression of main CWD symptoms, the rate of each symptom observed, and the presence of each pathogen in dead woods of inoculated seedlings.   Results: Results obtained showed that all Fusarium species induced main symptoms of CWD at varying moment and degrees. Chronologically, leaf yellowing appeared an average 25 dai, followed by leaf browning (46 dai), leaf drying (61 dai), mortality (75 dai) and defoliation (77 dai). Significant differences (P = .05) were observed between treatments considered. All Fusarium induced seedlings mortality and were isolated in dead woods at 1 – 4 cm from the point of inoculation. In general, the search of synergistic interaction between Fusarium spp. inoculated in combination with F. xylarioides showed enhanced ability to induce various symptoms of CWD when species are used together.  Conclusion: The present study demonstrates that CWD could be reconsidered as a parasitic complex, and in natural conditions all Fusarium species used present a danger for coffee growing

Occurrence of Cassava Mosaic Disease Related to Agro-ecosystem in Farmer’s Fields located in Kongo Central Province, Democratic Republic of Congo

Aim: To assess the Cassava Mosaic Disease (CMD) pressure by analyzing its incidence, severity and gravity, and to characterize agro-ecosystems where cassava farmers’ fields are established. Place and Duration: The study was conducted in three different localities (Mvuazi, Ndembo and Pompage) in Kongo Central province, Democratic Republic of Congo, from June to December 2016. Methodology: One hundred and fifty farmers’ fields randomly selected were investigated during epidemiological survey, with 50 fields in each locality. In each field selected, 30 cassava plants randomly selected in a square of 10 m x 10 m were analyzed. The CMD incidence, severity and gravity were collected, and agronomic and environmental factors relative to cassava fields were analyzed. Results: In general, CMD was observed in the three localities, with pressure depending upon to localities and fields. The distance between two neighboring fields could vary from 5 to 35 or even 50m. Pathological parameters show significant difference (P = .05) among fields for the same locality. The lowest pressure was recorded in Mvuazi locality (with 12.8% for incidence, score 2 for severity, and 15% for gravity), while the highest pressure was recorded in Pompage (with 20% for incidence, score 3 for severity, and 32% for gravity). Data recorded on agro-environmental factors show that farmers of the three localities used almost the same agricultural practices. Analysis of data reported suggest that the origin and the type of cassava material cuttings used can play a principal role in the propagation and development of CMD in most of cassava cultivation regions. Conclusion: The results of the present study revealed that CMD was present in different localities surveyed, and its pressure varies among localities, and from one field to another for the same locality. Agricultural practices used by farmers can play an important role in the propagation of CMD in different regions of cassava cultivation

Sanitary Status of Soybeans Seeds Produced in Democratic Republic of Congo

Soybean is one of the main food crops in Democratic Republic of Congo (DRC). Its production is ensured mainly by farmers who use seeds of various origins. However, yields obtained with this crop remain low because of seed-borne diseases that also affect the quality of the seeds.&#x0D; Twenty – two batches of seeds collected in the Democratic Republic of Congo were analyzed. The average values ​​of weight purity recorded ranged from 79 to 100 %, germination rates from 0 % to 86.6 % and seed weight from 71.1 to 152 g. Several phytopathogenic agents have been identified on both certified variety and landraces. The fungus Fusarium solani F.sp Glycine, Aspergillus sp, Rhizoctonia solani, Phomopsis longicola, Xanthomonas axonopodis pv. Glycine and Pseudomonas syringae pv Glycine have been identified.</jats:p

Use of Essential Oil of Eucalyptus globulus Leaves against Sitophilus zeamais Motsch

Aim: To assess in laboratory conditions, the efficacy of essential oil of Eucalyptus globulus leaves against the infestation due to maize weevil Sitophilus zeamais, the main insect pest of stored maize grains.  &#x0D; Study Design: This study was conducted as two separate trials. Each trial was performed using a completely randomized design with 5 treatments repeated 3 times.&#x0D; Place and Duration of the Study: The study was conducted in the laboratory Unit of Phytopathology and Crop protection, Faculty of Agronomy, University of Kinshasa, between February and April 2018. &#x0D; Methodology: Two trials (in Petri dishes and in cotton bags) were conducted separately from each other, while treatments used were the same. Trials were conducted according to a completely randomized design with 5 treatments repeated 3 times. Treatments used corresponded to 5 different volumes (0, 15, 20, 25 and 30 ml) of essential oil of Eucalyptus globulus leaves. In each trial, data collected were the rate of S. zeamais mortality and percentage of maize grains damaged. &#x0D; Results: In general, statistical analysis showed significant differences (P&lt;0.05) among treatments used. There was variation over time of the percentage of S. zeamais mortality as a function of the volume of essential oil of E. globulus. The volume of 30ml of essential oil caused higher mortality compared to other treatments. The percentage of maize grains damaged increased on control, while it decreased on maize grains treated with essential oil of E. globulus leaves.     &#x0D; Conclusion: The results of the present study revealed that essential oil of E. globulus leaves can help to protect maize grains stored against infestation due to maize weevil, Sitophilus zeamais.</jats:p

Field Assessment of Some Agronomic Traits of Four Groundnuts (Arachis hypogaea L.) Varieties from the Germplasm of Gimbi Research Station

Aim: To evaluate under agro-environmental conditions of Gimbi research station, some agronomic traits of four groundnut varieties from germplasm of PNL.&#x0D; Study Design: This study was conducted using a randomized complete block design with four treatments repeated three times.&#x0D; Place and Duration of the Study: The study was conducted in Gimbi research station between October 2019 and January 2020 (i.e. 4 months). &#x0D; Methodology: Trial was conducted using four treatments with three replications. Data collected concerned percentage of seedlings emerged, number of days between sowing and flowering 50%, dry pod weight, weight of unsorted seed, weight of sorted seeds, percentage of good seeds, shelling percentage, average weight of 1,000 seeds and grain yield per hectare. All data were submitted to analysis of variance at 5% probability level.   &#x0D; Results: The rate of seedlings emerged recorded on each groundnut variety was overall less than 50%. All varieties flowered 32 days after sowing. The highest average weight of dry pods (410.8g) was noted on A1408, while the lowest value of dry pod weight (310.6g) was observed on JL24. The highest weight of unsorted seeds (360.9g) was recorded on A1408, while the lowest value (260.7g) was observed on JL24. Variety A1408 presented the highest weight of stored seeds (350.5g), while the lowest value (250.8g) was noted on variety JL24. The highest percentage of good seeds (97.3) was obtained on A1408, while variety Sivi presented the lowest percentage of good seeds (93.2). The highest shelling percentage of groundnut pods (87.6) was obtained on A1408, while the lowest shelling percentage (83.5) was noted on JL24. The lowest weight of 1,000 seeds was noted on Sivi variety (484.6g), and the highest value was recorded on A1408 (522.6g). The highest grain yield (912.9Kg.ha-1) was obtained on variety A1408, while the lowest grain yield was noted on JL24 (690Kg.ha-1).&#x0D; Conclusion: Seeds of all varieties presented a very low rate of emergence (less than 50%). Variety A1408 was more productive than other varieties, and variety JL24 used as control should be regarded as having degenerated.</jats:p