Integrated Management of Fusarium Wilt-Root Knot Nematode Complex on Tomato in Central Highlands of Kenya

Abstract

Tomato plays a critical role in meeting nutritional food requirements, generating income and creating employment for both the rural and urban populations in Kenya. However, its production is threatened by the Fusarium wilt caused by Fusarium oxysporum f.sp. lycopersici, root knot nematodes (Meloidogyne spp), Fusarium wilt-root-knot nematode complex and Tomato leaf miner (Tuta absoluta) among others. Yield losses of 80-100% in some instances, have been reported due to the Fusarium wilt -root knot nematode complex. Field experiments were set up in two sites (Kagio and Mwea) in Kirinyaga County in Central highlands of Kenya to evaluate the effectiveness of various Integrated Pest Management (IPM) packages for the management of fusarium wilt-root knot nematode disease complex in tomatoes. The trials were established in two seasons, the long rains (March -July 2016) and the short rains (September 2016-January 2017). The IPM packages tested were NatuGro system (a combination of soil improvers, plant biostimulants and Trichoderma harzianum T22), a fungicide (carbendazim), Nemix (Bacillus sp. based biocontrol agent) and bionematicide (Paecilomyces lilacinus T251) applied either singly or in combination. Root knot nematode (RKN) gall index, as a measure of nematode disease severity was assessed twice during the experimental period; at flowering and mid fruit stage, while severity of fusarium wilt was assessed using the vascular wilt rating scale of 0-5. Fusarium wilt incidence was evaluated biweekly from 2 weeks after transplanting by visual assessment of wilt symptoms and expressing them as a percentage of total number of plants per plot. Both total and marketable tomato yields were determined at the end of the experimental period (4 months after transplanting). Integrating NatuGro system, Carbendazim and P. lilacinus was most effective in reducing RKN disease severity and damage and improving tomato growth followed by NatuGro system applied singly. Fusarium wilt severity and incidence were low throughout the experimental period and in all the treatments in both experimental sites.

Status of Root-Knot Nematode (<i>Meloidogyne</i> Species) and Fusarium Wilt (<i>Fusarium oxysporum</i>) Disease Complex on Tomato (<i>Solanum lycopersicum</i> L.) in the Central Rift Valley, Ethiopia

“…However, greenhouse experiments elsewhere in the world reported the synergistic effects of different soil-born pathogens and Meloidogyne species on a range of host plants, Al-Hazmi and Al-Nadary [32]; Ansari et al [33]; Golden and van Gundy [34]; Kumar [35]; Kumar [36]; Lobna et al [21] and Onkendi [37]. Fusarium wilt-RKN disease complex is one of the most widely recognized and economically important diseases in the world, Wanjohi et al [38]) as they both affect the function of the root system. The two often infect tomato simultaneously, forming a complex that increases the incidence and severity of Fusarium wilt, Onkendi et al [37].…”

“…Among the Meloidogyne species, M. incognita is the most common in tomato production worldwide, Gautam et al [39]. The presence of fungal survival structures (chlamydospores) that enhance its ability to persist in the soil for a long time and its wide host range makes its (F. oxysporum) management fairly challenging, Wanjohi et al [38].…”

Use of bacterial biocontrol agents for the control of Fusarium oxysporum f.sp. Lycopersici, tomato wilt in Kenya

“…In Kenya, the main tomatoes-producing counties are Kirinyaga (14%), Kajiado (9%), and Taita Taveta (7%) where farming is predominantly done using the open eld (95%) and greenhouse systems (5%) respectively (Mwangi et al 2020). Tomato production is hampered by a variety of soil-borne pathogens predominated by Fusarium oxysporum that causes Fusarium wilt of tomatoes leading to yield losses of > 80% (Wanjohi et al 2018). Fusarium wilt management has yielded few results over the years, with the most popular method being the application of fungicides, which has also been deemed unworkable due to F. oxysporum's soil-borne nature (Collins, 2016).…”

Prevalence of Bacterial Wilt Disease Caused by Ralstonia solanacearum in Tomatoes within Meru South Sub-County

“…In Africa, Egypt leads in tomato production followed by Nigeria (FAOSTAT, 2021). In Kenya, tomato production accounts for 14% of the total vegetable produce and about 7% of the total horticultural crops [2]. Despite tomato being a major vegetable, its production in Kenya (average of 20.4 tonnes/ha) has remained below the global average (59.4 tonnes/ha) and the production by other African countries like South Africa (67.1 tonnes/ha) (FAOSTAT, 2021).Tomato farming is a popular economic activity among farmers in Kenya.…”