Invasives Blog

Cuscuta reflexa (Credit: CABI).

Travelling towards Western Kenya, you may have noticed some trees and bushes with yellowish creepy plant canopy covering them. Very few are aware that this is a parasitic invasive weed known as Cuscuta which is potentially threatening the survival of crops and biodiversity in the country. Also known as dodder, the weed is now found on a wide variety of hosts in Kenya namely crops in farms, bushy and waste places and forests virtually decimating them. It’s not uncommon to find it ravaging people’s live fences.

In their paper, recently published, Masanga et al. have identified Cuscuta reflexa, a south Asian dodder, for the first in Kenya. The other dodder species present in Kenya are cuscuta campestris which is naturalised and Cuscuta kilimanjari endemic to Eastern Africa. To compliment the research, Cabi scientists carried out a survey in Western Kenya and established the dodder species prevalent there to be Cuscuta reflexa, after samples were sent to the UK for bar coding. With this information and working with other stakeholders who have done similar work previously, we can develop relevant insights into this little understood threat to biodiversity and agricultural production, to guide the development of effective management strategies.

The dodder builds a canopy on the host plant and casts thousands of tendrils to form a dense spectacle before it strangles it, eventually killing it. If not checked, the weed has the potential of causing serious ramifications on the food security in the country in the near future. It is already affecting crops such tomatoes, sweet potatoes, tea, coffee and potatoes. The water towers and forest cover in western Kenya and Eastern Uganda are also threatened, if the weed spreads into Kakamega forest as has been reported, putting the region at risk.

Curiously, from a survey carried out in Western Kenya and Nyanza, very few farmers, in fact 0.86 percent of those interviewed found Cuscuta to be problematic in their lands when asked which weeds affected them most. Yet, what the farmers may not know is the crop is now encroaching to the economically valuable crops and the farmers have no clue what to do about it.

But on the flipside, when the respondents were asked whether Cuscuta is present on their farms, 97% of them said the weed is present whereas 3% of the respondents said they had not seen Cuscuta on their lands. But even those who have seen the weed have taken little notice of it assuming it is just a flower.

Some of the crops that are already under attack include mangoes, avocadoes, coffee, maize, beans, cassava, pawpaw, sweet potatoes and pumpkin. Others are Napier grass, guava, bananas. Most of these crops are very important to the livelihoods of farmers.

The fear is, if Cuscuta is not controlled, the country may see a 30 percent decline in food production within the next decade. The challenge is now on the government to come in and act before the country is chocked by the parasitic weed that is fast spreading. Over US$1.1 billion will be needed to research on how to manage the weed, sensitise farmers on how to deal with the ravaging weed.

It is vital that the government mobilises policymakers, particularly parliamentarians and donors, to increase funding for agriculture and research on how to manage the weed among others. But as it stands, government agencies are yet to commit to help in managing the spread of Cuscuta.

Agricultural officers are not yet well equipped to train farmers on how to deal with the menace that the weed is causing while the media too, has not done enough to sensitise households on the dangers posed by the dodder weed because of lack of information about it.

This has left the farmers literally on the own.

So far, farmers are using manual methods of control which include uprooting infested plants and burning them. However, in other areas people who are yet to understand the weed, they confuse for an ornamental plant and end up preserving it particularly on their fences!

In the survey done in Western Kenya and Nyanza, the respondents were asked if they have any management to control Cuscuta and 84% of them said they manage whereas 16% of the respondents said they do not. On methods of management; 61% of the respondents manage manually, 22% use mechanical method, 17% do not use any method of management and just 1% use chemicals.

But are the control methods effective? NO.

From the findings, it was also clear that there has been very little or no awareness created on Cuscuta management in their areas.  3% said awareness had been created by the local chief, 9% said that farmers control the weed individually, and 2% of the respondents said that there is no specific strategy stated.

But just how much do the chiefs know about Cuscuta control?

Farmers and residents suggest that Agricultural extension officers should lead in creating awareness through campaigns and meetings and demonstrate to them the suitable control measures. They also suggested that they should be sensitized on the importance of proper disposal of the removed weed and at the same time researchers, extension officers and the community need to work together to find a solution.       

According to the farmers, sensitization on the control and management of the weed should be taken down to the school level and the national and county governments should take the lead and work with the local opinion leaders and non-governmental organizations in the sensitization through media campaign and public ‘barazas’.

Through this sensitization, the farmers say, the popular myth that the weed comes with evil spirits will be debunked. The general consensus is the spread of Cuscuta must be fought from all fronts.

2 Comments

  1. Chris Parker, Bristol, UK on 9th February 2021 at 2:22 pm

    I have no reason to doubt the conclusion that Cuscuta reflexa is the predominant problem in Kenya, but the illustration, attributed to Dinesh Valke, identical to one labelled ‘Cuscuta reflexa’ on Wikipedia is, like a number of others on Wikipedia, almost certainly Cassytha filiformis, which is commonly conspicuous on trees in Kenya, especially near the coast. It is unrelated, generally much greener than Cuscuta, and has totally different flower and fruit.

    • Wayne Coles on 18th February 2021 at 1:52 pm

      Hi Chris, thanks for pointing out. This has now been corrected. Best wishes, Wayne.

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