Integrated Management of Sweet Potato Weevil (Cylas spp.) Based on Planting Material Treatment and Spray Regime in Northern Ghana
Issah Sugri *
Council for Scientific and Industrial Research-Savanna Agricultural Research Institute, Box 52, Tamale, Ghana.
Francis Kusi
Council for Scientific and Industrial Research-Savanna Agricultural Research Institute, Box 52, Tamale, Ghana.
Eli Gaveh
Department of Horticulture, College of Agriculture and Natural Resources, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Matthew Akalagtota Anafo
West Africa Centre for Crop Improvement (WACCI), University of Ghana, Accra PMB 30, Ghana.
Kwabena Acheremu
Council for Scientific and Industrial Research-Savanna Agricultural Research Institute, Box 52, Tamale, Ghana.
George Yakubu Mahama
Council for Scientific and Industrial Research-Savanna Agricultural Research Institute, Box 52, Tamale, Ghana.
Bashiru Haruna
Council for Scientific and Industrial Research-Savanna Agricultural Research Institute, Box 52, Tamale, Ghana.
Iddrisu Yahaya
Council for Scientific and Industrial Research-Savanna Agricultural Research Institute, Box 52, Tamale, Ghana.
Yussif Baba Kassim
Council for Scientific and Industrial Research-Savanna Agricultural Research Institute, Box 52, Tamale, Ghana.
Fulera Tahiru
Council for Scientific and Industrial Research-Savanna Agricultural Research Institute, Box 52, Tamale, Ghana.
Peter Quandahoh
Council for Scientific and Industrial Research-Savanna Agricultural Research Institute, Box 52, Tamale, Ghana.
Rashidatu Abdulai
Council for Scientific and Industrial Research-Savanna Agricultural Research Institute, Box 52, Tamale, Ghana.
Ahmed Seidu
Council for Scientific and Industrial Research-Savanna Agricultural Research Institute, Box 52, Tamale, Ghana.
Jerry Asalma Nboyine
Council for Scientific and Industrial Research-Savanna Agricultural Research Institute, Box 52, Tamale, Ghana.
Julius Yirzagla
Council for Scientific and Industrial Research-Savanna Agricultural Research Institute, Box 52, Tamale, Ghana.
John Mbugri Azasiba
Council for Scientific and Industrial Research-Savanna Agricultural Research Institute, Box 52, Tamale, Ghana.
Mutari Abubakari
Council for Scientific and Industrial Research-Savanna Agricultural Research Institute, Box 52, Tamale, Ghana.
Issah Alidu Abukari
Council for Scientific and Industrial Research-Savanna Agricultural Research Institute, Box 52, Tamale, Ghana.
Deborah Aya Gumanga
Council for Scientific and Industrial Research-Savanna Agricultural Research Institute, Box 52, Tamale, Ghana.
Mohammed Mujitaba Dawuda
Department of Horticulture, Faculty of Agriculture, Food and Consumer Sciences University for Development Studies, Nyankpala, Box 1882, Tamale, Ghana.
*Author to whom correspondence should be addressed.
Abstract
Aims: The sweet potato weevil (Cylas spp.) exerts the most biotic threat in sweet potato production in most countries. A dual challenge exists regarding integrated management of the Cylas spp. in Ghana, namely, the wide use of farmer-saved planting material with higher infestation and the cryptic feeding habit.
Study Design: The experimental set-up was a split plot with the main plot as planting material treatment and sub-plot as spray regime.
Place and Duration of Study: The study was conducted at Voggu in the Kumbungu District, and Gani in the Kassena-Nankana East Municipal of Ghana from July to October in 2022 and 2023.
Methodology: The planting material treatment comprised an untreated control, shea (i.e., vine cuttings dipped in shea butter slurry), wood ash (i.e., vine cuttings dipped in wood ash solution), neem powder (i.e., vine cuttings dipped in aqueous neem seed powder at 75 g/l), insecticide + fungicide [i.e., vine cuttings dipped in cocktail of K-Optimal (Lambda-Cyhalothrin 15 g/l + acetamiprid 20g/l EC) at rate of 0.4ml/L + fungicide (Mancozeb 800 WP) mixture for 60 sec.], and Furadan (Carbo-furan placed in furrows at planting).
Results: The results are discussed in relation to plant establishment, leaf damage, stover yield, storage root yield, stem/root damage and yield losses. Leaf damage showed a sigmoid peak at 6 WAP probably, indicating the critical window to administer control measures to achieve matching results. Significant increase (p<0.01) in root yield occurred in insecticide (19.1t/ha) and neem seed extract (1.8t/ha) sprays compared to the control (11.0 t/ha). Yield losses hovered at 4.6% with insecticide spray, 6.2% with neem seed extract and 10.5% with control. Integration of planting material treatment with insecticide spray showed benefit cost ratios ranging from 2.5 to 40.2. A dual management strategy involving planting material treatment and preferably, insecticide spraying at 6 WAP could reduce infestation build-up.
Keywords: Spray regime, pest management, seed treatment, neem oil, productivity, economic benefit