Towards best-practice management of mistletoes in horticulture

Abstract

<jats:p> Mistletoe is increasingly being reported as a horticultural pest, infecting many species grown commercially for fruit, nuts, and other food products. Unlike mistletoe impacts on forestry, the published research on mistletoe in horticulture is scant, with management guidelines reliant on anecdotes, un-replicated trials on unrelated species, and often in different countries and growing systems. We have integrated the existing work to summarize information on the most effective control strategies for mistletoe in horticulture, and call attention to the paucity of empirical research. Despite grower interest in growth regulators and herbicides, limited trials suggest chemical treatment of mistletoe is ineffective, consistent with findings from forestry and ornamental trees. Although labour-intensive, ongoing mechanical removal is the most effective strategy to minimize mistletoe impacts but, without information available on effects of mistletoe infection on yield or tree mortality, cost-effectiveness calculations are not possible. Given the range of herbivores that consume mistletoe tissues, biological control may be useful, both to prevent initial infection and also reduce impacts on infected hosts in commercial plantations. To catalyse more research on mistletoes in horticulture, we articulate six priorities for further work, emphasizing the utility of tree crops as model systems to address questions regarding mistletoe ecology and host-parasite dynamics more broadly. </jats:p>

Mitigating the Mistletoe Menace: Biotechnological and Smart Management Approaches

“…Mistletoes have undoubtedly acquired pest status in many countries [ 26 ]. By drawing resources from other plants in communities with higher trophic levels, they parallel herbivores [ 108 ].…”

“…There is a great deal of liability associated with mistletoe in recreational settings, as well as commercial losses [ 26 , 28 , 31 , 90 ]. However, only a few surveys have been conducted at global scales to obtain data depicting the extent of damages caused by individual family members [ 87 , 91 ].…”

“…It is still necessary to ensure the prompt delivery and adequate coverage of chemical agents, even if they appear potent enough [ 26 , 34 , 181 ]. Ground applications can be effective but may not reach the hemiparasites in the tree overstory higher up in the canopies [ 34 ].…”

“…Alongside the world’s major plant pests, Striga , Orobanche , Cuscuta , and mistletoes are more pronounced [ 16 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. Striga , Orobanche, and Cuscuta have been reviewed extensively [ 19 , 20 , 21 , 22 , 23 , 24 ], but we would like to call attention to mistletoe, which has emerged as a growing global problem and requires better management and control [ 26 ].…”

Consuming and consumed: Biotic interactions of African mistletoes across different trophic levels

“…Boussim et al (1993) reported a small creamy‐white butterfly foraging the flower tufts of Tapinanthus in Burkina Faso. The two above‐mentioned lepidopteran families, both of which have a cosmopolitan distribution, are known to contain many species whose larvae feed exclusively on mistletoes (Watson et al, 2020).…”