Background Pepper (Piper nigrum L.) is among key spice crops grown in Morogoro district of Tanzania. Most of the pepper types grown in the district are only known by their local names as Babu kubwa, Babu ndogo, Babu kati and Ismailia. This may limit information on germplasm collection or genetic resource for plant improvement and trade in markets with variety specifications. The aim of this study was to generate preliminary information of the pepper types based on their morphological characteristics for easy comparison with other known pepper varieties in the spices industry. Methods The evaluation of pepper morphological characters was conducted following a randomized complete block design with three replications and four treatments (pepper types). Observations were recorded with respect to 28 characters (9 qualitative and 19 quantitative) which entail vegetative (8) and reproductive (20) traits. The quantitative data for vegetative, inflorescence and berry characters were subjected to analysis of variance. Mean separation test was conducted using Turkey’s Honest Significance Test at (α = 0.05). Correlation and regression analyses were performed to explore the relationship between yield and yield attributes of pepper. Results Babu kubwa and Babu ndogo pepper types were characterized by erect and horizontal branching habit, whereas the others showed hanging habit. Babu kubwa had longer spikes (12.4 cm), leaves blade (17.9 cm), leaf petiole (2.8 cm), wider leaves (12.9 cm) and larger berries (5.8 mm) than all other pepper types. Babu kubwa and Babu kati had cordate and acute leaf bases, respectively while other types had round leaf base shapes. The highest number of flowers was recorded on Babu kubwa (93.5) and Ismailia (90.7) with spikes weighing 7.6 g and 7.5 g, respectively compared to other types. Babu ndogo and Ismailia had compact spikes, while other types had medium loose spikes. Babu kati had the highest number of spikes kg−1 (282.6) due its lower spike weight compared to other types. The highest weight of 100 fresh spikes (704.3 g) and 1000 fresh berries (164.2 g) was recorded on Ismailia. Spike length was significantly positively correlated to yield (r = 0.23, R2 = 0.08, p < 0.001). However, yield had a significant negative correlation with the number of spikes kg−1 (r =  −0.85, R2 = 0.017, p = 0.001) and fresh weight of 1000 berries (r = −0.91, R2 = 0.003, p = 0.04). Conclusions The pepper types grown in Morogoro district differed significantly based on most of the evaluated traits. This information can be used to formulate methods and strategies for conservation and in turn genetic improvement of the crop. Despite that the pepper types literary matched with characters of some well-known commercial varieties, confirmation of genetic relatedness is yet needed. Further studies need to be conducted in consecutive years and involve assessment of internal quality attributes. Other studies should encompass wider range of pepper types from other producing areas in Tanzania in order to establish their morphological distinctness, genetic diversity and interrelationships in relation to the globally known commercial varieties.

Msogoya et al. J. Appl. Biosci. 2014. Effect of harvesting stages on yield and nutritional quality of African eggplant (Solanum aethiopicum) fruits. ABSTRACT Objective: Farmers often harvest African eggplant (Solanum Aethiopicum L.) fruits at different stages of fruit maturity. The influence of these harvesting practices on fruit productivity and nutritional quality is not known. This study was conducted to determine the effect of harvesting stages on yield and nutritional quality of African eggplant varieties. Methodology and results:The experiment was laid out in a split plot arrangement in a complete randomized block design with three replications. Three African eggplant varieties (Tengeru white, AB2 and Manyire green) and three harvesting stages (1, 2 and 3) were used as main plot factor and sub plot factor, respectively. Harvesting stage 1 (immature fruits) was characterized by fruits with non-shiny peel, harvesting stage 2 (mature fruits) was characterized by fruits with shinny peel and harvesting stage 3 (overmature fruits) was characterized by fruits with yellow coloration at the bottom. Fruit yield was assessed based on number and weight of fruits per plant while fruit nutritional quality was assessed in the laboratory based on carbohydrate, fibres, calcium, potassium, magnesium, phosphorus, iron, β-carotene and ascorbic acid contents. The collected data were subjected to analysis of variance using MSTATC statistical software. Treatments mean separation was conducted based on Student-Newman Keuls at P < 5 %. Results showed that yield in number of fruits per hectare decreased while yield in metric tons per hectare increased with fruit development stages. Varieties Tengeru white and AB2 had the highest yields based on metric tons at harvesting stage 2 while Manyire green had the highest yield at harvesting stage 3. Carbohydrate and fibre contents increased while ascorbic acid, β-carotene and most minerals decreased with fruit development stages. Conclusion and application of results:This study recommends harvesting immature fruits for high vitamin and mineral contents and delayed harvesting for the highest yield. As yield and nutritional quality trends vary with varieties, further studies are required to determine the effect of harvesting stages on yield and nutritional quality of different varieties of African eggplant.

Background: Pepper (Piper nigrum L.) is an important spice produced by small-scale farmers in Morogoro district of Tanzania for both local and export markets. Recently, farmers have reported a decline in crop productivity due to spike shedding and stem wilting of pepper plants. The study was conducted to obtain baseline information on the extent of the disorders. Methods: An altitudinal transect survey was conducted in Morogoro district from October to November 2018. Data were collected from 216 pepper farmers through a questionnaire, focus group discussions, and field observations. Chi square tests (α = 0.05) were used to compare differences between gender, pepper cultivars by wards and yield, spike shedding and stem wilting by pepper cultivars and plant species used to support pepper vines. Fisher's exact test at (α = 0.05) was used to compare the effects of production constraints and altitude. A regression analysis was performed to explore the relationship between altitude and the incidence of spike shedding and stem wilting. Results: The majority of interviewees (69%) had observed spike shedding and stem wilting of pepper on their farms for > 3 years. Spike shedding was more prominent at 300 meters above sea level (masl, 85.7%), while stem wilting was reported by most (66.7%) farmers at 457 masl. The most affected pepper cultivar was reported to be "Babu kati" in Mtombozi (19.2% of respondents) and "Ismailia" in Mkuyuni and Kibogwa (28.9% of respondents) wards, while in Kibungo ward cultivar "Babu ndogo" (85.7% of respondents) and in Konde ward cultivar "Babu kubwa" (53.8% of respondents) were most affected. Approximately 53% of respondents reporting the disorders used Jatropha to support the pepper vines, and 93% of the farmers reported the disorders to occur during the dry season. A greater proportion of the interviewed farmers (92.1%) reported applying no measures to control spike shedding and stem wilting of pepper. Conclusions: Incidence of spike shedding and stem wilting was higher at a low altitude compared to high altitude areas. The magnitude of the disorders differed among pepper cultivars regardless of support plants species used. Poor adoption of key agronomic practices and lack of any information on control measures may be contributing to the high incidence of the disorders in the study area. The study demonstrates the extent of the problem, and provides a baseline for identifying the causal agent(s) of spike shedding and stem wilting, which in turn will allow appropriate control measures to be selected.

The quality and safety of pepper (Piper nigrum L.) are a function of crop management practices, harvest maturity, harvesting methods and subsequent handling after harvest, including storage conditions and processing methods. The review shows that volatile oil decreases with shade intensity (15-30%). Essential oil, oleoresin, piperine and monoterpenes (thujene, α-pinene, sabinene, limonene, α-phellandrene and linalool) increase with altitude, while β-caryophyllene and total phenol decrease with increase in altitude. Fermentation of ripe pepper fruits forms odorants (butanoic acid, 3-methylindole, and 4-methylphenol) attributing intense faecal/shed-like off-flavour white pepper powder. Low-drying temperature (≤56°C) and duration (≤3 hrs) lead to low bulk density (0.17 g/ml) and low moisture loss (31%). Excessive soaking of black peppercorns prior to mechanical decortication reduces volatile oil and increases moisture content and broken berries. Availability of heavy metals in grinding machines increases the level of heavy metals; Fe (69.8-1147 mg/kg), Pb (21.3-947 μg/kg) and V (64.1-1072 μg/kg) in pepper powder. Storing peppercorns along with other materials enhances cross-contamination of heavy metals; Pb, Cd and Cr. High moisture content (> 13%) and farmers' unawareness resulted in high (2200 to > 30000 cfu/g) mycotoxins contamination. Environmental and industrial pollutants such as plasticizers, bisphenol A, polycyclic aromatic hydrocarbons and pesticides are also pepper contaminants of high merit. Radiofrequency pasteurization, vacuum-assisted steaming, ethylene oxide fumigation, atmospheric pressure plasma, dry heat sterilization, gamma-irradiation and ultraviolet-C light treatments are among strategies to enhance the quality and safety of pepper. More precautions also have to be taken to regulate the shade, drying temperature and duration, soaking duration, hygienic processing and storage in order to retain quality, minimize the risk of microbial or chemical contaminations and comply with standards.

Aflatoxins are toxins produced by certain strains of Aspergillus flavus that are found in several crops. This toxin is produced by Aspergillus flavus in food and feeds results in adverse health effects for humans and animals, as well as economic barriers to farmers and countries. This study aimed to assess the awareness of farmers in harvesting and postharvest handling practices for the management of Aflatoxin in maize. The assessment was conducted using questionnaire to capture data on bio-data information, farmer’s awareness on aflatoxin contamination, harvesting time, post-harvesting practices, and storage facilities. Statistical analyses were performed using Statistical Package for Social Science (SPSS) version 25. The result shows that 65.63% of farmers in Kilosa and 67.28% of farmers in Gairo districts were aware of aflatoxin contamination. The study revealed that, during harvesting time, 92% of farmers at Kilosa and 98% of farmers in Gairo district harvest maize when completely dry. In drying practice, the use of canvas had higher usage compared to other practices where 42.70% of farmers in Kilosa and 16.70% of farmers in the Gairo district were using canvas. Additionally, it was observed that the majority of farmers in both districts store their maize by using storage bags/sacks that favor the rise of insect/pest contamination. The study suggests that there is a need for establishing an educational campaign for maize farmers on the effect of aflatoxin contamination to improve their awareness. The knowledge should base on harvesting, drying practices, and modern storage facilities that can reduce aflatoxin contamination.