Tomato (Solanum lycopersicum L.) is one of the most important vegetables in Togo. Unfortunately, tomatoes are susceptible to many diseases, among which bacterial wilt caused by Ralstonia solanacearum causes major yield losses. In this study, incidence of bacterial wilt and its distribution was evaluated in the central region of Togo, the major tomato producing area in the country. Overall, 16 localities were surveyed in four prefectures. In each locality, three fields were visited, and the incidence of the disease was recorded, and diseased samples were collected for laboratory investigation. The results showed that bacterial wilt occurred in all the fields visited, indicating a field incidence of 100%, whereas the plant incidence ranged from 10.00±00% to 43.33±3.33%, with an average of 20.94±1.77%. The antibody based Immunostrip test was positive for R. solanacearum in 100% of the visited fields. From 144 samples collected from fields, 45 R. solanacearum isolates were isolated on Modified SMSA media. This survey results show that tomato bacterial wilt is a real threat to tomato production in the central region of Togo.

Objectives: Facing severe attacks of anthracnose on D. alata in Togo and in order to develop an effective and sustainable control method, this work aims to evaluate the resistance of different cultivars of yams to Colletotrichum gloeosporioides, the pathogen of the disease. Methodology and Results: Severity and incidence of anthracnose were assessed on 14 local and 10 improved varieties of D. alata in field under natural infection conditions and in greenhouse by inoculation using two isolates of C. gloeosporioides. Trials were arranged in random blocks with 3 repetitions. A highly significant difference was observed between the varieties for the severity of anthracnose in the field (P = 0.006) and in the greenhouse (P <0.001). The hierarchical ascending classification (CAH) of the anthracnose severity average indicated that the local varieties Kabanga, Kéfou, Tsrokpa, Lotossou and the improved varieties TDa 99/00199, TDa 99/00169, Hawaii, were tolerant. Conclusion and application of results: 4 local varieties and 3 improved varieties were tolerant to anthracnose and could, after multilocal tests, be distributed directly to the producers for the control of the disease or serve as parents for the varietal improvement of D. alata against this disease. These results demonstrate that, despite the high pressure of C. gloeosporioides in the production areas of D. alata, there are sources for resistance to anthracnose in populations of this yam species in Togo. This suggests the need to continue yam screening to identify other sources of resistance to anthracnose present in the country that can be exploited to control effectively and sustainably the disease.

Using composting technology, the biodegradable fraction of solid wastes collected from Agbalepedogan district in Lomé (Togo) was transformed into composts with no phytotoxicity suitable for use in agriculture. The household urban solid wastes were mixed with poultry manure and Mucuna pruriens leaves in appropriate percentages and transformed into composts. The composting process was monitored by temperature, pH and C/N ratio controlling. The composts quality was appreciated by phytotoxicity test, particle size distribution, contents of nitrogen, phosphorus, potassium, organic matter and trace elements. The results showed that composts particle size distribution presented four fractions (>10 mm, 5-10 mm, 2-5 mm and ≤2 mm) whose average percentages are respectively 9.04±0.2%; 10.71±0.2%; 12.68±0.4% and 67.53±0.6%, respectively. Composts produced contained 1.02±0.1% - 2.72±0.2% of nitrogen, 1.35±0.3% - 2.70±0.4% of phosphorus, 1.31±0.2% - 1.72±0.3% of potassium and 23.50±0.4% - 37.75±0.5% of organic matter. The pH in final composts were between 8.50±0.2 and 9.00±0.3 while C/N ratio varying from 8.06±0.2 to 13.13±0.2. The concentrations of some heavy metals in final products were 79.8±1.7 - 140.2±1.6 mg/kg.dm of zinc, 27.1±1.01 - 76.6±1.03 mg/kg.dm of copper, 2.07±0.33 - 9.19±0.22 mg/kg.dm of lead, 4.13±0.16 - 11.05±0.36 mg/kg.dm of nickel and 0.79±0.02 - 2.15±0.03 mg/kg.dm of cadmium. These concentrations were lower than the limited value for heavy metals prescribed by French and US EPA regulation for organic and organic-mineral fertilizers. Int. J. Agril. Res. Innov. Tech. 9(2): 1-8, December 2019

In Togo, cultivated yams are severely infected by Yam Mosaic Virus (YMV). In order to find an efficient method for researching genotypes resistant to the virus, this study aims to screen plants obtained from yam seeds. As such, 640 yam seedlings were produced from seeds collected on 20 plants (accessions) of wild yams, D. praehensilis (10) and D. abyssinica (10) and on 12 plants of the complex D. cayenensis-rotundata. The yam seeds were collected during prospections carried out in october 2018, covering 14 districts in Central and Plateaux regions of Togo. Then, 20 yam seedlings (ten plants in two replicates) per accession, were inoculated with YMV isolate M9-30 using mechanical inoculation. Leaf samples taken from the inoculated seedlings, were analyzed by RT-PCR to detect the YMV, using QiAgen one step RT-PCR Kit and a pair of primers YMV1 & YMV2 (196 pb) . Data was analyzed using GenStat 12.1 and SPSS 20.  Following the observations and molecular analyzes, it appears that 46.5% of the seedlings inoculated in D. praehensilis, were resistant, while 27.08% of resistant plants and 0.47% of tolerant plants were obtained in  D. cayenensis-rotundata  complex and 17% resistant plants obtained in D. abyssinica. Statistical analysis showed a significant difference between among accessions of D. praehensilis and those of D. abyssinica at P≤0.05. The high rate of 30% of resistant plants provided in total, and specifically, the results obtained in D. cayenensis-rotundata compared to those provided in 2012 using clonal selection, i.e. 8.33%, suggest that, screening of seedlings from yam seeds, is efficient and could be used for researching yam genotypes resistant to YMV. Results of D. abyssinica and of some accessions of D. cayenensis-rotundata, would be influenced by the proximity of other yam species. The yam seeds production environment would, therefore, be an important factor to take into account.

No abstract