International Journal of Agricultural Policy and Research
Vol.6 (7), pp. 90-97, July 2018
Available online at https://www.journalissues.org/IJAPR/
Author(s) retain the copyright of this article. Author(s) agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License.
Original Research Article
Evaluation of selected sweet potato landraces for high harvest index and high root yield indices for parental selection
1*Nwankwo, I.I.M., 1Akinbo, O.K., 1Ikoro, A.I., 1Orji, N.A.C and 2Njoku, T.C
1National Root Crops Research Institute, Umudike, Umuahia. Abia state, Nigeria.
2Department of Crop Science and Biotechnology, Faculty of Agriculture and Veterinary Medicine, Imo State University-Owerri, Nigeria.
Corresponding Author E-mail: nwankwomaxwell(at)yahoo.com.
The experiment was conducted at the National Root Crops Research Institute, Umudike in South eastern Nigeria with the aim to evaluate and select landraces of sweetpotato with high harvest index and high root yield and to conserve them as parents for future usage in crop improvement programme. Each accession was planted in a 3 × 3m plot in a Plot size of 9m2 and at a planting distance of 1.0m ×0.3m. The Experimental Design was randomized Complete Block Design. Each block contained 10 plots and replicated 3 times. The planting material was 30cm long. Vine cuttings from symptomless mother vines were planted on ridges when the rains have stabilized and the soil moisture was at field capacity. The experimental field was kept weed-free until harvested 120 days after planting. Fertilizer was NPK 15:15:15 using side application. Data were collected on: Total number of roots, Number of large roots and Number of small roots, total storage root weight, large storage root weight and above ground biomass. Data collected were subjected to Analysis of variance and Means separation was done using standard Error of means. Results obtained indicated that Kwara had 0.51 harvest index, Agege and Buttermilk 0.49 harvest index each, ABOM had 0.48 harvest index and ABCHI and Ex- Igbariam had 0.47 harvest index respectively. Their harvest indices although was lower than the Check variety (TIS87/0087) which had 0.53 harvest index, however, it was higher than the grand mean harvest index of 0.46. Accessions with high harvest index are high root yielding varieties. Therefore accessions with harvest index higher than the grand mean harvest index were recommended for inclusion into the sweet potato breeding programme as parents and should be documented, registered and release as variety. This will enable farmers to carry out commercialization and export of the sweetpotato crop and their products.
Key words: Landraces, harvest index, root yield, parents, breeding programme