Ramadhan Kilewa

Ecological organic agriculture (EOA) is a holistic production management system that can solve many problems in the vegetable crops’ value chain (VC). It is, however, unclear about the EOA technologies for the fruit vegetable VC that have already been validated or are in process of validation in Tanzania. A systematic literature search on EOA technologies relevant in Tanzania was conducted for research articles from 2010 until 2021. Most 10(30.4%) studies on fruit vegetables were equally distributed each 5(15.2%) in the years 2019 and 2020, respectively. A total of 33 records on fruit vegetables covered eight (8) regions of mainland Tanzania and one (1) region from the island of Zanzibar. Most 18(55%) studies were conducted in the Morogoro region. Based on the fruit vegetable VC, 26(68.4%) studies were for field establishment and management. Nine (9) key areas were identified, where most 9(27.3%) studies were on crop productivity and protection. Seventeen (17) EOA technologies were ...

Parthenium hysterophorus is an annual herbaceous plant native to tropical America; and an invasive plant in Africa causing distressing effects on natural flora. This study investigated the effects of P. hysterophorus on the composition and diversity of native herbaceous plant species in Simanjiro rangeland, Tanzania. Plant species count data were collected from 60 (1m2) quadrats. Using generalized linear models (GLM), the abundance of P. hysterophorus was regressed against the abundance and diversity of the native herbaceous plants. Also, Jaccard’s similarity index was used to compare species composition. Results showed that there were 14 herbaceous plant species belonging to 13 genera and 10 families in the study area. Parthenium hysterophorus was the most dominant species recorded. The abundance of P. hysterophorus has a substantial negative effect on the abundance and diversity of other herbaceous plant species. Moreover, Jaccard’s similarity index showed a slightly significant d...

The Maasai pastoralist community resides in Simanjiro District, Manyara Region, Tanzania. As a pastoralist community they are largely dependent on rangelands as a source of forage for their livestock. However, plant invasions are threatening rangeland productivity, displacing valuable forage species, leading to a reduction in livestock populations. The noxious weed Parthenium hysterophorus has recently been established in Simanjiro District and may pose a significant threat to livelihoods if effective control strategies are not put in place. This study was therefore conducted to determine pastoralists’ understanding of P. hysterophorus in Simanjiro District, Tanzania. Semi-structured and open-ended questionnaires were used to collect information on, among others, the date of introduction, means of spread, area coverage, effects of P. hysterophorus on livestock health and management control for P. hysterophorus.  Pastoralists were unaware of when P. hysterophorus was introduced altho...

ABSTRACT Parthenium hysterophorus is an invasive weed that poses significant threats to crop production, biodiversity, human and animal health. Few experiments have been carried out to test the effectiveness of biological control agents such as the beetle Zygogramma bicolorata against this invasive. We released Z. bicolorata beetles as bio-agent to control P. hysterophorus at the Tropical Pesticides Research Institute in Arusha, Tanzania, across two seasons, from February – July 2019 (wet) and August 2019 – January 2020 (dry). Feeding by Z. bicolorata reduced P. hysterophorus leaves, flowers, height as well as biomass, both in the dry and wet season. During the wet season, 100% of all P. hysterophorus leaves were eaten already 28 days after the onset of the experiment, particularly under the highest beetle population treatment (30 individuals). Parthenium hysterophorus flower numbers were greatly reduced under high beetle populations (30 individuals) compared to the control treatment (0 individuals) during both the wet and dry season. Parthenium hysterophorus height was reduced by 87% and 90% during the wet and dry season, respectively when 30 beetles were released. Similarly, biomass was reduced by 90% and 87% during the wet and dry season, respectively. Parthenium hysterophorus responses to beetle treatments did not differ significantly across seasons but the development of both the invasive and its control, Z. bicolorata, was slightly delayed in the dry season. We conclude that Z. bicolorata can be used as bio-agent to manage P. hysterophorus in Tanzania, particularly when released in large numbers.

The invasive weed Parthenium hysterophorus is aggressive and hazardous weed causing harms to biodiversity of natural plant communities, humans and animals in more than 20 countries worldwide. In Tanzania, Parthenium weed was first reported in Arusha region in 2010. Since 2010, areas invaded by parthenium weed in Arusha region has increased. However, detailed information on the distribution, density, frequency and abundance of P. hysterophorus weed in Tanzania are rare. Therefore, the present study was carried out to address two objectives: 1) to identify areas infested with parthenium weed in Arusha region in Tanzania 2) to determine density, frequency and abundance of parthenium weed. Field surveys were carried out at Njiro suburb, Arusha-Kilimanjaro border and Arusha Airport in Arusha region during January to February 2013. Parthenium weed was identified using visual method; and quadrates were used to determine number of parthenium weeds in the fields. The weed was found growing a...

Parthenium hysterophorus is an annual herbaceous plant native to tropical America; and an invasive plant in Africa causing distressing effects on natural flora. This study investigated the effects of P. hysterophorus on the composition and diversity of native herbaceous plant species in Simanjiro rangeland, Tanzania. Plant species count data were collected from 60 (1m2) quadrats. Using generalized linear models (GLM), the abundance of P. hysterophorus was regressed against the abundance and diversity of the native herbaceous plants. Also, Jaccard's similarity index was used to compare species composition. Results showed that there were 14 herbaceous plant species belonging to 13 genera and 10 families in the study area. Parthenium hysterophorus was the most dominant species recorded. The abundance of P. hysterophorus has a substantial negative effect on the abundance and diversity of other herbaceous plant species. Moreover, Jaccard's similarity index showed a slightly signi...