Evaluation of field performance and storage of some tropical short-day onion (Allium cepa L.) cultivars

The storage of bulbs of onion (Allium cepa L.) is very crucial to ensure its availability throughout the year. Experiments were conducted at Sokoine University of Agriculture to evaluate the growth and yield characteristics of some tropical short–day onion cultivars and the storability of their bulbs after harvest. The first experiment in 1994 involved 21 cultivars evaluated for their growth and yield variables. The second experiment, involving six cultivars, was carried out in 1996 and in addition to performance evaluation, the storability of bulbs was investigated. Results showed significant differences among the cultivars in yield, yield components and storability. Granex 429 had the highest yield among cultivars in both trials, but had very poor storability. Serrana and XPH 6074 had long storability and maintained more than 50% of their weight after 5 months of storage. These two cultivars are promising as good sources of genes to incorporate storage traits in other cultivars of onio

Effect of Grafting on Yield and Quality of Hybrid Tomato (Solanum lycopersicum Mill.) Cultivars

Tanzania Journal of Agricultural Sciences (2018) Vol. 17 No. 2, 39-45Grafting has proven to mitigate some soil-borne diseases and abiotic stresses as well as improve plant growth, yield and fruit quality. However, in Tanzania the effect of grafting on plant growth, yield and fruit quality of hybrid tomato cultivars is not yet fully explored. Therefore, the objective of this study was to evaluate the effect of grafting eggplant rootstocks on plant growth, yield and fruit quality of hybrid tomato cultivars grown in Tanzania. The study was conducted at Sokoine University of Agriculture in Morogoro, Tanzania, and the experiment was laid out in a Randomized Complete Block Design with eight treatments each replicated three times. Hybrid tomato cv. Assila and Monica were each cleft-grafted onto eggplant EG190, EG195 and EG203 rootstocks and transplanted in the open field. Ungrafted plants of the same tomato cultivars were used as controls. Data were subjected to Analysis of Variance using GenStat v.14 statistical package (VSN International, UK) and treatment means were separated based on Tukey’s Test at P≤0.05. Results reveal that grafting eggplant EG190, EG195 and EG203 rootstocks significantly reduced total fruit yield (p = 0.001) and marketable yield (p = 0.001) for all tomato cultivars but significantly (p = 0.001) increased total soluble solids contents for all tomato cultivars, and titratable acidity for Monica in comparison to ungrafted controls. Further studies are required to determine rootstocks that are vigorous enough to carry scions of these hybrid tomato cultivars for yield improvement

Effect of improved tomato cultivars on productivity and profitability in Morogoro region, Tanzania

Journal of Animal &Plant Sciences, 2016. Vol.30, Issue 3: 4774-4780The objective of this study was to assess yield, revenue and profit from F1 hybrid tomato cultivars compared to farmers' preferred open pollinated local tomato cultivars grown in Tanzania. Seeds of local and F1 hybrid tomato varieties were sourced from local agro-dealers. The experiment was laid out in a randomized complete block design with four treatments (cv. Assila, Eden, Shanty and Oxyl Premium) and four controls consisting of local tomato cultivars (cv. Tengeru 97, Tanya, Cal-J and Riogrande). A treatment was replicated three times each with 12 plants. The seedlings were planted at a spacing of 60 cm x 60 cm in an open field at Sokoine University of Agriculture during the rainy and dry seasons. Data on total and marketable fruit yields were analyzed using Genstat statistical software version 15 and treatment means were separated based on Fisher’s unprotected LSD test at p< 0.05. Seed and production costs were computed based on real cost while revenues and net profits were estimated based on fruit marketable yield and retail prices of TSh. 700 and 1000 per kilogram (One USD = TSh. 2000). Results indicated that cv. Assila significantly (p = 0.002) produced higher total and marketable fruit yields than all local tomato cultivars during both the dry and rainy seasons. Moreover, cv. Eden significantly (p = 0.002) produced higher total and marketable fruit yields than all local cultivars during the dry season only while cv. Shanty produced higher marketable yields than all local cultivars during the rainy season only. The production costs of F1 hybrid tomato cultivars were higher than those of local tomato cultivars during both seasons. Tomato cv. Assila produced higher revenue and net profit than all local cultivars during both seasons while cv. Shanty produced higher revenue and net profit than all local tomato cultivars during the rainy season only. It is therefore recommended that farmers in Morogoro region should grow cv. Assila during both the rainy and dry seasons, and cv. Shanty during the rainy season only

Grafting compatibility between selected rootstocks and Tanzanian local tomato cultivars

Journal of Applied Biosciences 106:10274 –10278Objective: The objective of this study was to evaluate the effect of different rootstocks on graft success of Tanzanian local tomato cultivars. Eggplant rootstocks (EG190, EG195, EG203 and EG219, and tomato rootstock (Hawaii 7996) were obtained from AVRDC in Taiwan while local tomato cultivars (Tengeru 97, Tanya, Cal-J and Riogrande) were sourced locally. Methodology and Results: Cleft graft method was carried out when seedlings of eggplant, Hawaii 7996 and local tomato cultivars were 30, 17 and 14 days old, respectively. The grafted seedlings with graft union tied using grafting clips were healed in a dark chamber for three days and then in a transparent chamber for three days. The average temperature and relative humidity in both chambers were maintained at 21-30°C and 85-95 %, respectively. The grafted seedlings were hardened for seven days in an open nursery with 30% overhead shade prior to transplanting. Data on graft success were subjected to analysis of variance using MSTATC statistical software and treatments mean separation was conducted based on Student-Newman Keuls at P < 5 %. Results show that graft success between eggplant rootstocks and local tomato cultivars was higher ranging from 86 to 100%. On the contrary, grafting rootstock Hawaii 7996 with local tomato cultivars significantly (PB 5%) resulted in a lower graft success ranging from 30 to 50% during the hardening stage in the open nursery. Conclusion and application of results: Tanzanian local tomato varieties can be grafted onto eggplant rootstocks EG190, EG195, EG203 and EG219 with high graft success. As these eggplant rootstocks are resistant to soil borne diseases, farmers should graft their varieties in order to increase tomato yield. Further studies are therefore required to optimize the grafting conditions to improve graft success between rootstock Hawaii 7996 and local tomato cultivars

Effect of thidiazuron on in vivo shoot proliferation of popular banana (Musa spp. L) cultivars in Tanzania

Journal of Applied Biosciences, 2018; 81:7214 – 7220Objective: Thidiazuron (TDZ) is a diphenyl urea-based cytokinin, which is non-degradable and persistent in plant tissues. The effect of these TDZ properties on in vivo banana proliferation when deshealthed corms are temporarily dipped in such growth regulator is unknown. The objective of this study was to evaluate the effect of temporary treatments with TDZ of deshealthed banana corms on in vivo sucker multiplication. Methodology and Results: The study was comprised of a split plot experiment in a randomized complete design with three replications each replication with 15 corms. The main plot factor was banana cultivars (Mtwike, Mzuzu and Bukoba) while the sub-plot factor was TDZ concentrations (0.5, 1.0, 2.0 and 3.0 mg/l). Moistened sawdust was steam-sterilized for 45 minutes and then filled for cooling in wooden propagators. Banana suckers were cleaned to remove roots and surface-sterilized for 15 seconds. The sterilized corms were deshealthed to expose axillary buds and decorticated to suppress the apical meristems. These corns were each dipped in TDZ at 0.5, 1.0, 2.0 and 3.0 mg/l for 12 hours and then planted into the sterilized sawdust media in the propagators. Results showed that the number of shoots per corm significantly (P < 0.05) increased as TDZ concentration increased from 0.0 to 2.0 mg/l but decreased as TDZ increased to 3.0 mg/l. The number of leaves per sucker significantly (P < 0.05) decreased as TDZ concentration increased from 0.0 to 3.0 mg/l. Conversely, corms treated with TDZ at 2.0 mg/l produced suckers with the largest number of leaves of 4.9 per sucker followed by corms treated with TDZ at 1.0, 3.0 and 0.5 mg/l with 4.5, 4.3 and 3.3 leaves per sucker, respectively. Banana cultivars had a significant (P < 0.05) effect on the number of shoots per corm where banana cv. Bukoba produced the largest number of shoots of 6.4 per corm while banana cv. Mtwike and Mzuzu produced 2.3 and 2.9 shoots per corm, respectively. Conclusion and Application: The findings from this study provide evidence that in vivo shoot multiplication rates and sucker growth of banana cv. Mzuzu, Bukoba and Mtwike can be increased by dipping for 12 hours deshealthed corms in TDZ solution at 2.0 mg/l. The low in vivo multiplication rates of banana cv. Mtwike and Mzuzu underscore the need for further studies to determine alternative best cytokine-based growth regulators

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

Assessment and management of post harvest losses of fresh mango under small-scale business in Morogoro, Tanzania

Journal of Animal & Plant Sciences, 2011. Vol. 11, Issue 1: 1358-1363This study was conducted to assess postharvest losses and the effect of shade during wholesale market and hot water treatments on storage of mango cv. ‘Dodo’. To assess postharvest losses, mature fruits were packed on semi-rigid bamboo cartons, loaded on a truck without separators in between cartons and transported from Mkuyuni ward to Morogoro urban, Tanzania. The effect of heat stress during the wholesale market was evaluated by storing mango fruits under the sun, woven polypropylene shade and black net shade at Sokoine University of Agriculture. Mango fruits dipped in hot water at 60° C for 10 minutes were compared with untreated ones as control. Results showed that the fruit total postharvest losses were 43.8 % with the wholesale market, transport and harvest stages accounting for 30.6 %, 10.6 and 2.6 % of the total losses, respectively. The main features of fruit deterioration during the wholesale market stage were softening and microbial decay each accounting for 50.7 and 39.6 % of the total losses within the stage, respectively. Microbial decays of 7.2 % and mechanical injuries of 2.0 % were the major features of mango fruit deterioration during the transport and harvest stages. Storing fruits for three days under the woven polypropylene and black net shades significantly reduced fruit postharvest losses by 52.7 and 38 %, respectively in comparison with fruit storage under the sun. Hot water treatment reduced the incidence of microbial decay by 85 % and improved fruit total soluble solids content by 15 % in comparison to untreated fruits. However, hot water treatment reduced fruit firmness and shelflife by 56.0 and 71.4 %, respectively. In the short term, wholesale traders are advised to store fruits under the polypropylene shade while in the long term, municipal and council authorities are argued to construct cold storage facilities for fresh fruits. Furthermore, farmers are advised to disinfect mangoes with hot water, especially those purported for immediate marketing

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

Effect of benzylaminopurine on in vivo multiplication of French plantain (Musa spp. AAB) cv. ‘Itoke sege’

Journal of Applied Biosciences, 2014; 74:6086– 6090Objective: In vivo macropropagation is an alternative simple and cheap technique for banana multiplication. However, the response of cv. “Itoke Sege” to in vivo macropropagation combined with different benzylaminopurine (BAP) concentrations is not known. This study was conducted to determine the appropriate concentration of BAP for enhancing in vivo macropropagation of French plantain cv. ‘Itoke Sege’. Methodology and results: Sword suckers of about 70 - 80 cm tall and 14 -16 cm collar diameter were obtained from farmers’ fields in Rungwe district in Mbeya, Tanzania. Moistened sawdust was steamsterilized for 45 minutes and then filled for cooling in wooden propagators of 1.5 m x 2.20 m x 0.3 m dimension. Suckers were partially peeled, washed to remove roots and surface-sterilized for 15 seconds by dipping them in hot boiling water. The sterilized corms were desheathed to expose axillary buds and decorticated to suppress the apical meristems. Fifteen corms in three replications were each dipped in BAP at 0.0, 1.5, 3.0 and 6.0 mg/l for 12 hours and then planted into sawdust media. Irrigation was done immediately but subsequent watering was carried out when necessary. In vivo multiplication response was evaluated based on number of days to first shoot emergence, number of shoots per corm, number of roots per shoot and shoot size. Results showed that BAP concentration at 1.5 mg L-1 significantly (P < 0.05) reduced the number of days to first shoot emergence of 15.78 days followed by BAP at 3.0, 6.0 and 0.0 mg L-1 with 25.18, 28.39 and 36.43 days, respectively. Similarly, BAP concentration at 1.5 mg L-1 significantly (P < 0.05) increased sucker productivity with 17.11 suckers per corm followed by BAP at 0.0, 3.0 and 6.0 mg L-1 with 15.23, 13.08 and 12.96 suckers per corm, respectively. Corms treated with BAP at 1.5, 3.0, 6.0 mg L-1 significantly (P > 0.05) produced taller shoots with length of 27.0, 27.3 and 26.7 cm followed by corms treated with BAP at 0.0 mg L-1 with shoot length of 22.7 cm. Conversely, corms treated with BAP at 0.0 and 6.0 mg L-1 produced suckers with larger collar diameter of 3.4 and 2.4 cm followed by suckers from corms treated with BAP at 3.0 and 1.5 mg L-1 with collar diameters of 2.2 and 2.0 cm, respectively. Suckers from corms treated with BAP at 0.0 and 3.0 mg L-1 had larger number of leaves of 4.8 and 4.6 per sucker followed by suckers from corms treated with BAP at 1.5 and 6.0 mg L-1 with 4.0 and 3.8 leaves per sucker, respectively. Conclusion and application: Based on these findings, it is concluded that in vivo macropropagation combined with BAP at 1.5 mg L-1 is a suitable technique for improving multiplication and sucker growth of French plantain cv. ‘Itoke Sege’. The findings of this study provide an opportunity for the use of in vivo macropropagation coupled with BAP at 1.5 mg L-1 as an alternative simple and cheap technology for rapid and mass production of planting materials for recalcitrant plantain varieties. Further study is recommended to evaluate the response of cv. “Itoke Sege” to in vivo macropropagation combined with other cytokinebased growth regulators. Research is also required to test the responses of other recalcitrant plantain cultivars to in vivo macropropagation in combination with different BAP concentrations