Antifungal effect of a local Bacillus subtilis, isolate TM07, on Fusarium oxysporum f.sp. Lycopersici in Morogoro, Tanzania

Fusarium oxyporum f.sp. lycopersici causes tomato wilt, a severe disease that leads to extensive yield and quality loss of tomatoes in Tanzania. Management of Fusarium infection is particularly challenging given the health and environmental concerns over continued use of chemical pesticides on horticultural food crops. However, there is an increasing focus towards the use of biocontrol agents to combat phytopathogens worldwide. In this study, bacterial isolates from tomato rhizosphere were screened for their antagonistic activity in vitro on F. oxysporum. Based on its superior effectiveness, one isolate, designated TM07, was selected and characterized as Bacillus subtilis by morphological, biochemical and molecular procedures. On potato dextrose agar (PDA) the isolate showed an appreciable degree of radial growth inhibition (RGI) of 40.5% of the Fusarium, compared to control (55.9%). Further investigations are recommended to elucidate on the mechanism behind the inhibitory effect of isolate TM07. In vivo studies are also recommended to assess the possibility of applying the B. subtilis, isolate TM07, as a local biocontrol agent of Fusarium wilt of tomato and other susceptible crops

Effect of mulch and different fungicide spray regimes on yield of tomato (Solanum lycopersicum L.) in Tanzania

In many areas in Tanzania, pests management for tomato involves weekly pesticide sprays. The practice poses a threat to the environment and health of consumers. In this study the effect of pesticide spray regimes and use of mulch were evaluated on ‘Tanya VF’ and ‘Tengeru 97’ tomato varieties. Field experiment consisting of a 2×2×4 factorial arrangement in a split-split plot design with three replications was conducted at Sokoine University of Agriculture, Morogoro (6o05’S, 35o37’E and 525m above sea level). Treatment factors comprised two varieties (main plot factor), mulching/number of mulching (subplot factor) and three fungicide spray regimes (sub subplot factor). Results showed that the spray regimes: farmers’ practice (FP), Integrated Pests Management (IPM) based on pests scouting, sprays based on manufacturers’ recommendation (MR); produced significantly more fruits per plant and higher fruit weight compared to the control. There was no significant difference (p < 0.05) between FP, IPM and MR on fruit yield parameters. The results further revealed that use of mulch significantly led to higher fruit number per plant (p = 0.020). Although average fruit weight was similar (p < 0.05), other marketable fruit yield parameters were statistically different between mulched and non-mulched plots (p = 0.007). ‘Tanya VF’ had consistently higher yields compared to ‘Tengeru 97’. Fungicide sprays were statistically different to the control with respect to blossom end rot (p = 0.002), fruit rot (p < 0.001) and percentage of non-marketable yield (p = 0.001). Mulching significantly reduced American bollworm and blossom end rot (p = 0.012, p = 0.003, respectively). The major contributor to tomato fruit loss was Blossom End Rot (BER) and Fruit Rot for ‘Tengeru 97’ and ‘Tanya VF’, respectively. It is evident, therefore, that: a proper combination of tomato cultural management practices can significantly reduce the use of pesticides, and improve tomato fruit quality and marketable yield which would increase profit margin accrued by farmers.Key words: IPM, marketable yield, mulch, tomato

Participatory involvement of farming communities and public sectors in determining malaria control strategies in Mvomero District, Tanzania

No Abstract

EFFECT OF MULCH AND DIFFERENT FUNGICIDE SPRAY REGIMES ON YIELD OF TOMATO (SOLANUM LYCOPERSICUM L.) IN TANZANIA

ABSTRACT In many areas in Tanzania, pests management for tomato involves weekly pesticide sprays. The practice poses a threat to the environment and health of consumers. In this study the effect of pesticide spray regimes and use of mulch were evaluated on 'Tanya VF' and 'Tengeru 97' tomato varieties. Field experiment consisting of a 2×2×4 factorial arrangement in a split-split plot design with three replications was conducted at Sokoine University of Agriculture, Morogoro (6 o 05'S, 35 o 37'E and 525m above sea level). Treatment factors comprised two varieties (main plot factor), mulching/number of mulching (subplot factor) and three fungicide spray regimes (sub subplot factor). Results showed that the spray regimes: farmers' practice (FP), Integrated Pests Management (IPM) based on pests scouting, sprays based on manufacturers' recommendation (MR); produced significantly more fruits per plant and higher fruit weight compared to the control. There was no significant difference (p < 0.05) between FP, IPM and MR on fruit yield parameters. The results further revealed that use of mulch significantly led to higher fruit number per plant (p = 0.020). Although average fruit weight was similar (p < 0.05), other marketable fruit yield parameters were statistically different between mulched and non-mulched plots (p = 0.007). 'Tanya VF' had consistently higher yields compared to 'Tengeru 97'. Fungicide sprays were statistically different to the control with respect to blossom end rot (p = 0.002), fruit rot (p < 0.001) and percentage of non-marketable yield (p = 0.001). Mulching significantly reduced American bollworm and blossom end rot (p = 0.012, p = 0.003, respectively). The major contributor to tomato fruit loss was Blossom End Rot (BER) and Fruit Rot for 'Tengeru 97' and 'Tanya VF', respectively. It is evident, therefore, that: a proper combination of tomato cultural management practices can significantly reduce the use of pesticides, and improve tomato fruit quality and marketable yield which would increase profit margin accrued by farmers

Characterisation of botanical starches as potential substitutes of agar in tissue culture media

Seven botanical starches; cassava, sweet potato, Irish potato, maize, rice, wheat and sorghum were characterized to determine physicochemical properties influencing gel formation for preparation of tissue culture media. Total starch, protein, fat, amylose content, swelling power and pH were determined using acid hydrolysis, enzymic and spectrophotmetric methods. Each type of starch was tested for ability to support in vitro plant growth and 0.8% agar (w/v) was used as standard. Nodal explants cultures were initiated in Murashige and Skoog medium supplemented with 3% sucrose and 0.5 mg/l benzylaminopurine (BAP). After 21 days, number of leaves and nodes, plant height and fresh weight were determined for each  treatment. Significant (0.05) differences were observed between starch types in total starch, protein content and fats. Cassava had the highest starch content (81.5%) and irish potato had the lowest (29.3%). Highest protein content (12%) was observed in maize starch and the lowest (3.4%) in cassava. Fat content was highest (6.2%) in wheat and lowest in cassava (0.2%). Starch extract from rice had the highest amylose content (31.12%) while the cassava starch extracts had the lowest (20.75%). The starch extracted from wheat had the highest swelling power (105.1%) while irish potato starch had the lowest (52.1%). Sorghum starch had the lowest pH of 4.57 while the highest (6.92) was recorded in Irish potato starch. The growth of shoots in vitro on agar gelled media outperformed those of starch gelled media except for the number of leaves per shoot which cassava starch media recorded significantly the highest response (P = 0.05). Of all the starch gelled media, the best growth response was observed with cassava. Good performance was observed in starches with high starch content, low amylose content and high swelling powers. Key words: Starch, agar, gelling agent, in vitro plant growth

Supressing populations of tomato leaf miner (tuta absoluta) in the agro-ecological zones of Morogoro

Masters ThesisTomato leaf miner Tuta absoluta is a destructive and highly invasive insect pest of tomato and other solanaceous plants including plants in the family Fabaceae like beans. The range of host for the moth is extensive requiring in-depth surveys on both solanaceous and Fabaceae crops along with weeds to fully understand it. This study was aimed at understanding the spatiotemporal distribution of the moth along the Uluguru Mountains in Morogoro. The moth preference to alternative hosts and also efficacy of selected bio and synthetic insecticides in the management of the moth was also evaluated. From the results it was revealed that T. absoluta was present in all locations of the study in varying numbers. Weather factors such as rainfall and temperature had influence in the population of the moth. Population of the moth was determined by using delta traps loaded with para-pheromones on a sticky card that captured male moths. Trapping of the moth was conducted for 12 weeks for two growing seasons, 21 traps were used to trap the male moth for each season. Some weeks during trapping a high average population of 300 male moths were trapped while the lowest average population was 20 moths per week. Population fluctuation was observed to be influenced by the altitude of the location of trapping. Host preference was determined by sampling of plant leaves with visible damage of Tuta absoluta larva; The sampled leaves were placed in a plastic box with sand. Tomato (Solanum lycopersicum L), Eggplant (Solanum melongena), African eggplant (Solanum aethiopicum) and Amaranthus (Amaranthus retroflexus) were sampled in Morogoro Municipality and Mvomero district. Amaranthus was the least preferred of the host plants sampled compared to Tomato and Egg plant. Efficacy of synthetic and bio synthetic insecticides was determined in three locations using a synthetic insecticide Wiltigo and a combination of bio-insecticide Antario and recharge, Biotrine and recharge. The applied insecticides proved to be equally capable of controlling the moth in the field.East African Vegetable Crops Integrated Pest Management Innovations Lab (EAVCIPM – IL)

Supressing populations of tomato leaf miner (tuta absoluta) in the agro-ecological zones of Morogoro

Masters ThesisTomato leaf miner Tuta absoluta is a destructive and highly invasive insect pest of tomato and other solanaceous plants including plants in the family Fabaceae like beans. The range of host for the moth is extensive requiring in-depth surveys on both solanaceous and Fabaceae crops along with weeds to fully understand it. This study was aimed at understanding the spatiotemporal distribution of the moth along the Uluguru Mountains in Morogoro. The moth preference to alternative hosts and also efficacy of selected bio and synthetic insecticides in the management of the moth was also evaluated. From the results it was revealed that T. absoluta was present in all locations of the study in varying numbers. Weather factors such as rainfall and temperature had influence in the population of the moth. Population of the moth was determined by using delta traps loaded with para-pheromones on a sticky card that captured male moths. Trapping of the moth was conducted for 12 weeks for two growing seasons, 21 traps were used to trap the male moth for each season. Some weeks during trapping a high average population of 300 male moths were trapped while the lowest average population was 20 moths per week. Population fluctuation was observed to be influenced by the altitude of the location of trapping. Host preference was determined by sampling of plant leaves with visible damage of Tuta absoluta larva; The sampled leaves were placed in a plastic box with sand. Tomato (Solanum lycopersicum L), Eggplant (Solanum melongena), African eggplant (Solanum aethiopicum) and Amaranthus (Amaranthus retroflexus) were sampled in Morogoro Municipality and Mvomero district. Amaranthus was the least preferred of the host plants sampled compared to Tomato and Egg plant. Efficacy of synthetic and bio synthetic insecticides was determined in three locations using a synthetic insecticide Wiltigo and a combination of bio-insecticide Antario and recharge, Biotrine and recharge. The applied insecticides proved to be equally capable of controlling the moth in the field.East African Vegetable Crops Integrated Pest Management Innovations Lab (EAVCIPM – IL)

The flower industry in Tanzania: production performance and costs

Journal of Agronomy, 2006; 5 (3): 478-481A survey was conducted to assess production levels, costs, marketing and policy regulations affecting the flower industry in Tanzania. Results indicated that rose and chrysanthemum were the main ornamental crops produced for export with yield of 908 and 145.6 million flower stems and shoot cuttings per year in 2003, respectively. The surface areas under rose and chrysanthemum cultivation increased by 328.9 and 658.3% and the corresponding production by 316.84 and 666.33% between 1997 and 2003, respectively. Greenhouse construction accounted for 50% while purchase of land and rose planting materials represented 17.7 and 12.3% of the total investment cost, respectively. Interest on loans and freight charges accounted for 19 and 16.0% of the total operational cost, respectively. All chrysanthemum shoot cuttings were directly exported to The Netherlands whereas 90% of total rose flowers were exported to Europe through European middlemen with a marketing commission of 18-30% of sales and 52% of total operational cost. The average selling prices of rose and chrysanthemum were 0.23 and 0.11 US$ per flower stem and shoot tip cutting, respectively. Foreign growers appreciated the provision of tax exemption of five years but considered the National Agricultural Policy of 1997 being too general and not favourable to the flower industry

The flower industry in Tanzania: production performance and costs

Journal of Agronomy, 2006; 5 (3): 478-481A survey was conducted to assess production levels, costs, marketing and policy regulations affecting the flower industry in Tanzania. Results indicated that rose and chrysanthemum were the main ornamental crops produced for export with yield of 908 and 145.6 million flower stems and shoot cuttings per year in 2003, respectively. The surface areas under rose and chrysanthemum cultivation increased by 328.9 and 658.3% and the corresponding production by 316.84 and 666.33% between 1997 and 2003, respectively. Greenhouse construction accounted for 50% while purchase of land and rose planting materials represented 17.7 and 12.3% of the total investment cost, respectively. Interest on loans and freight charges accounted for 19 and 16.0% of the total operational cost, respectively. All chrysanthemum shoot cuttings were directly exported to The Netherlands whereas 90% of total rose flowers were exported to Europe through European middlemen with a marketing commission of 18-30% of sales and 52% of total operational cost. The average selling prices of rose and chrysanthemum were 0.23 and 0.11 US$ per flower stem and shoot tip cutting, respectively. Foreign growers appreciated the provision of tax exemption of five years but considered the National Agricultural Policy of 1997 being too general and not favourable to the flower industry