Bacterial wilt of tomato, caused by Ralstonia solanacearum (Rs), is endemic in most tomato-growing areas of Nigeria, causing 60 to 100% loss in yield. Control measure requires definite information on race and biovar characteristics of the pathogen in those endemic areas. Soil samples were collected from seven states in Nigeria known for high incidence of tomato bacterial wilt. Isolations were performed on triphenyl tetrazolium chloride (TZC) and casamino peptone glucose (CPG) media. Morphological characterization of the pathogen was through simple staining, streaming and KOH solubility test.Molecular confirmation of pathogen's identity was through PCR amplification of genomic DNA using Rs-specific 759/760 primers (f:5'-GTCGCCGTCAACTCACTTTCC-3'; r:5'-GTCGCCGTAGCAATGCGGAATCG-3').Race was determined through hypersensitive reaction on tobacco leaves and biovar characterization was through carbohydrate utilization test. Thirty-four bacterial isolates showed the characteristic creamy white colour on TZC + CPG medium. . The isolates also amplified at 280 bp, confirming the pathogen as Rs. Thirty isolates belonged to Race 1 Biovar III while four belonged to Race 3 Biovar II. The findings are relevant while devising a more targeted management approach to bacterial wilt of tomato in Nigeria.

Higher exposure rate to certain chemicals found in processed foods that reduce iodine absorption and a depletion in the amount of iodine found in soil have been reported to be detrimental to health. This study seeks to examine the consumers' acceptability and willingness to pay a price premium for iodine-enriched tomatoes in Abeokuta, southwest, Nigeria. Primary data were used to collect a sample of 300 respondents. The data were analyzed by descriptive statistics and Contingent Valuation Method (CVM) under double bounded dichotomous choice approach. The use of dichotomous choice (DC) method in explaining the willingness to pay (WTP) in contingent valuation studies is a common method in Economics. Research has shown that double-bounded Dichotomous Choice methods provide statistically superior outcomes than single bounded methods, given appropriate sampling design. Results from the socioeconomic characteristics of the respondents revealed a mean age of 42 years and are mainly (83%) in their economic active age (<50 years), 69% male respondents, 63% were married and 53% of the respondents had prior knowledge of iodine-biofortified tomato. It was also revealed that 58% of the respondent are willing to accept and pay a premium for iodine-biofortified tomato. Although, the proportion of the respondents who were willing to pay generally decreases with increases in price. It is concluded that age, level of education, income, prior knowledge and bid price were the significant factors influencing respondents' willingness to pay a price premium for iodine-biofortified tomato in the study area.

Tomato is often attacked by wilt caused by Fusarium oxysporium. Iodine is known to have fungistatic effect in pathogen control. The present experiment was aimed at determining the effect of iodine compounds (potassium iodide, KI and potassium iodate, KIO) on 3 incidence and severity of Fusarium wilt and yield of two tomato accessions, FUNAABTO/106 and FUNAABTO/123. The experiment was conducted in the screenhouse and on the field. KI was applied at concentrations of 1, 2, 3, 5 mM while KIO was applied 3 at concentrations of 0.5, 1, 2, 3 mM. The untreated plots served as control. Results showed that FUNAABTO/106 treated with 0.5 mM KIO in the screenhouse and on the 3 field had the least (0.00%) disease incidence. Disease severity was significantly (p ≤0.05) lower (1.00) in the screenhouse in pots containing FUNAABTO/106 treated with 1 mM KIO On the field, FUNAABTO/106 treated with 0.5 mM KIO had the least (1.17) disease 3. 3 severity. FUNAABTO/106 treated with 0.5 mM KIO in the screenhouse and on the field 3 were significantly higher (1.65t/ha and 18.54t/ha respectively) in yield. The study concluded that application of iodine compounds at lower concentrations reduced the incidence and severity of Fusarium wilt and increased the yield of tomato.

Nutrient leaching causes agronomic and environmental problems in intensively cultivated soils. In this study, the effect of biochar on retension of nutrient in sandy loam soil was evaluated. Upland rice was amended with 3 different sources of biochar in randomized complete design with 4 replications. The treatment included a control (no input), fertilizer, and upland rice either applied alone or in combination with the three different sources of biochar (poultry manure, corn cobs and groundnut shell). Biochar levels were 5 t ha -1 each and were incorporated into the soil at the same time. Inorganic fertilizer was applied at a rate of 90, 60, 60 and 45, 30, 30 kg ha -1 NPK, as straight fertilizer and then top-dress with nitrogen levels in the form of urea 30 kg ha -1 N eight (8) weeks after transplanting. Upland rice was planted in each lysimeter. Leachate from each lysimeter was collected at 3 weeks intervals for 24 months. For the 24 months running biochar significantly decreased the volume of water leached. Control and 90N60P60K treatments showed higher concentrations of NO3-N and K in the leachate. At a depth of 70 cm leaching significantly reduced with all the three different sources of biochar combined with 45N30P30K and 90N60P60K. The application of three different biochar sources to tropical sandy loam soil may give environmental benefits such as carbon sequestration and reduced nitrate and potassium leaching. Our results indicated that biochar and 45N30P30K combination could be appropriate as a sustainable agronomical approach.

A trial was conducted to evaluate the competitive indices of upland rice-cowpea intercrop. Sole cropping of the two crops was also done. The experiment was a randomized complete block with 4 replications. The treatment included a control (no input), fertilizer, rice and cowpea intercrop either applied alone or in combination with three different sources of biochar (poultry manure, corn cobs and groundnut shell). At the same time 5 t ha -1 of biochar level each were incorporated into the soil. Inorganic fertilizer was applied at the rate of 90, 60, 60, and 45 kg ha -1 NPK, as straight fertilizer, and then top-dressed with nitrogen levels in the form of urea at 30 kg ha -1 N eight (8) weeks after transplanting. The crops were arranged in a 3:1 rice-cowpea ratio. In this study, intercropping system gave higher land equivalent ratio (LER). Biochar of poultry manure+45N30P30K exhibited higher rice aggressivity (2.43), relative crowding coefficient (1.74) and competitive ratio (4.11). Rice performed better in terms of competitive ratio when grown in combination with cowpea. In terms of nutrient use efficiency nitrogen was high with intercrops, but was very low in sole crop. Intercropping of rice with cowpea gave higher economic advantage (9544.5), income equivalent ratio (403.1), production and cost benefit ratio for biochar poultry manure+45N30P30K (2.68) than 90N60P60K (2.52) respectively. For economic crop yield in upland rice-based ecosystems, small-holder farmers, therefore, should intercrop rice and cowpea and apply biochar +45N30P30K and nitrogen (30 kg N ha -1 ).