Effectiveness of Zygogramma bicolorata as a biocontrol agent against Parthenium hysterophorus in Arusha, Tanzania

This research article published by Taylor & Francis Online, 2020Parthenium 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

Advances and trends in ecological organic agriculture (EOA) technologies and research on fruit vegetables produced in Tanzania

This research article was published by CABI Reviews 2022Ecological 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 applied in fruit vegetables, mostly biocontrol 7(21%) in tomatoes. Overall, 27(81.8%) studies only researched the EOA technologies, while 3(9.1%) studies validated the EOA technologies, 2(6.1%) researches were in progress, and 1(3.0%) was progressing validation. Few 3(9.1%) studies portrayed the involvement of youth and women using the principles of participatory action research (PAR) during the validation. Generally, the EOA technologies are readily available, require minimal skills and labour, are cost-effective, sustainable, easily implementable in the fruit vegetable VC and can be simply accessed and utilized in cultivating organic fruit vegetables