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Healthy seed cane supply is the lifeline in the productivity and profitability of sugarcane and hence the sustainability of sugar industry, the Ethiopian sugar estates/projects have been using tissue cultured sugarcane planting materials since 2011/12. However, there is no study that shows the practical advantage of tissue culture over the conventional seed sources at Ethiopian situations. Thus, the current work was carried out to evaluate the two seed sources of two sugarcane genotypes. Accordingly, analysis of variance proved that the interaction effects of genotype by seed source is highly significant (p<0.001 at α=5%) in all the response variables tested. Similarly, the two seed sources showed statistically significant differences throughout all the responses. The two sugarcane genotypes also showed marked variation in all the responses except the number of live buds per stalk, stalk height (cm) and number of two bud setts produced per stalk. In sugarcane genotype B52-298, the rate of propagation for tissue culture seed source is 1:44.68 against 1:13.72 of its donor from conventional seed source. In NCo-334, tissue culture seed source produced a propagation rate of 1:40.11 against 1:13.98 of its donor conventional seed source. Regardless of the other benefits, planting a hectare B52-298 and NCo-334 provided a direct net benefit of US$ 5448 and US$ 3999, respectively. Thus, the current result revealed that tissue culture seed source is a realistic and better alternative over the conventional seed source in sugarcane as initial seed cane at Tendaho Sugar Development Project. Evaluation of the two seed sources for all genotypes at each sugar estates/projects in successive three tier system of seed cane production and commercial stages could be the future line of work.

In spite of the costly procurement and secondary acclimatization activities, the Ethiopia Sugar estates use huge quantity of micropropagated sugarcane plantlets to complement the conventional propagation method. The current study was aimed at finding rapid and cost effective propagation method for sugarcane planting materials multiplication to complement in vitro propagation method. In the study, acclimatized sugarcane plantlets were treated with Diammonium phosphate fertilizer (DAP), plant growth regulators and leaf trimming treatments. Plantlets lacking fertilizer, plant growth regulators and without trimming were used as free check. Data were collected on the number of tillers per shoot, average shoot length and number of leaves per shoot after 30 days. Analysis of variance revealed that the interaction effects of genotypes, trimming, DAP and plant growth regulators application was very highly significant (p<0.0001). Treatment combinations containing DAP at 0.16 gm L -1 m -2 with plant growth regulators GA3, BAP and kinetin each at 0.04 mg L -1 m -2 and trimming one-third of the leaves gave optimum in vivo shoot proliferation responses. On this treatment combination, B52-298 gave 6.45 ± 0.51 tillers per shoot with 4.39 ± 1.44 cm average shoot length and 5.12 ± 0.23 leaves per shoot while NCo-334 produced 5.77± 0.79 tillers per shoot with 7.21 ± 0.11 cm average shoot length and 5.51 ± 0.05 leaves per shoot. Similarly, N14 gave 5.36 ± 0.55 tillers per shoot with 5.71 ± 0.15 cm average shoot length and 5.41 ± 0.30 leaves per shoot on the same treatment combination. Thus, the current result can be used as rapid and cost effective sugarcane planting material multiplication system to complement the costly micropropagation technology and hence minimize the cost of sugar production.

No abstract

In Vitro rooting of micropropagated micro-shoots of two commercial sugarcane varieties was carried out with the aim of evaluating the root induction responses of the sugarcane varieties (B41-227 and N14) to alpha naphthalene acetic acid (NAA) and Indole -3-butyric acid (IBA). Accordingly, four levels of NAA (0, 1, 2, and 3 mg L -1 ) and IBA (0, 1, 2 and 3 mg L -1 ) in a completely randomized design with 4 × 4 × 2 factorial treatment combination arrangements were tested. Data on the number of roots per shoot and average root length (cm) were collected after 30 days of culture on ½ MS root induction medium. Analysis of variance revealed that the interaction effects of NAA, IBA and the sugarcane genotypes on number of roots per shoot and average root length of both sugarcane varieties was very highly significant (P<0.0001). Culture medium containing 2 mg L -1 NAA and 1 mg L -1 IBA for B41-227 and 1 mg L -1 NAA alone for N14 was found to be optimum. On these medium, B41-227 gave 33 ± 0.15 roots per shoot with 2.92 ± 0.18 cm root length and N14 produced 35± 0.20 roots per shoot with 3.2 ± 0.25 cm root length. The rooted plantlets were survived 100% after four weeks of acclimatization in greenhouse on Farmyard manure and soil at 2:8 ratios.The optimized protocol can be used to develop healthy and profuse root system in the sugarcane micro-shoots, an essential stage in sugarcane micropropagation.