Miriam Wanjiku Mbiyu1,2*, William Maina Muiru1, John Wangai Kimenju1, Moses Wabomba Nyongesa2, Solveig Haukeland3,4

1Department of Plant Science and Crop Protection, University of Nairobi, P.O Box 30197-00100, G.P.O, Nairobi, Kenya
2Kenya Agricultural Livestock Research Organization (KALRO – Tigoni), P.O Box 338, Limuru 00217, Kenya
3International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
4The Norwegian Institute of Bioeconomy Research (NIBIO), P.O. Box 115, 1431 Ås, Norway

(Manuscript received 25 March 2021; accepted for publication 28 January 2022)

Abstract. In-vitro assays to determine the effect of plant extracts on egg viability and mortality of J2s of potato cyst nematode were evaluated. Methanol, ethyl acetate, hexane and water were used as solvents. Eggs and J2s were exposed to plant extracts for 24, 48 and 72 hrs. Treatments were arranged in a completely randomized design with three replications. Loss of egg viability and mortality of J2s significantly increased with an increase in the time of exposure to the extracts. Hexane extracts had a significantly higher loss of egg viability. Mexican sunflower extracts had a significantly higher loss of egg viability, having 93 and 89.2% non-viable eggs/cyst in experiments 1 and 2, respectively, compared to other plant extracts. This was followed by garlic, which had 89.5 % and 86.3%, and then ginger, 86.8% and 85.9% non-viable eggs/cyst in experiments 1 and 2, respectively. Garlic, Mexican sunflower and ginger after 72 hrs of treatment exposure had significantly (P<0.05) high juvenile mortalities of 64.5%, 64.9% and 70.2%. Mexican sunflower, ginger and garlic extracts were effective in inducing loss of egg viability and mortality of J2s of PCN.