Effect Of Type Of Initiation And Growing Media On Growth And Nutrient Uptake Of Plantain (Musa Aab) At The Nursery Stage

ABSTRACT

Plantain (Musa spp) is one of the most important food crops. A limiting factor to large-scale production and or expansion of existing plantation is the difficulty in obtaining adequate planting materials. Although the tissue culture technique provides a higher multiplication rate, facilities are non-existent, and if available, the cost will be expensive and unavailable to most farmers in developing countries such as Ghana. The split-corm technique is a cheaper method for raising planting material from the parent sucker. However, the type of sucker (sword or maiden), initiation and growing media and nutrient requirements has not been adequately studied. In experiment 1, the study evaluated the split-corm materials derived from sword and maiden sucker on different initiation media; sawdust (SD) (100%), carbonated rice husk (CRH) (100%) and mixture of SD and CRH (50%:50% v/v). Data was collected on number of sprout, percentage sprout, number of shoot, shoot height, shoot diameter, number of root and root diameter at 3, 6 and 9 weeks after planting (WAP). Initiation media did not have any significant effect on the number of sprouted corm and percentage of sprouted corm. The CRH induced the greatest pseudostem height, pseudostem girth, number of roots/corm, and root diameter and was significantly different from that of the SD and SD:CRH. The percentage sprouted corms decreased with time after planting. No significant difference was observed between sword or maiden sucker in most of the parameters considered, although the sword sucker derived material induced thicker shoot, greater number of roots and bigger root diameter than maiden sucker derived material. Significant (p < 0.05) difference was observed between type of propagule and type of initiation media interaction for shoot height, shoot diameter and number roots/split-corm. In experiment 2, the performance of split-corm derived material was evaluated in three types of

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growing media; soil only (100%), mixture of soil and carbonated rice husk (CRH) (50%:50% v/v) and mixture of soil, carbonated rice husk and compost (25%:25%:50% v/v, SOIL/CRH/COMP) and four nitrogen fertilizer rates (0, 5, 10 and 20 gN) /plant on sucker growth, dry matter production and nutrient uptake were studied under pot conditions. Sprouted split-corm plantlets were transferred to the growing media at 3, 6 and 9 weeks after planting in the initiation media, and monitored for 17 weeks. Data was collected on total plant dry weight and partitioned to plant parts. Other vegetative parameters considered included root length, leaf area, plant height, pseudostem girth, corm circumference, corm height. Results showed that the SOIL/CRH/COMPOST growing media significantly induced the greatest total dry matter and was 73% higher than that of soil only and over 100% higher for 3 and 6 week transplants respectively. SOIL/CRH/COMPOST significantly induced the greatest leaf area, pseudostem girth and plant height. The partitioning of the total dry matter to plant parts ranged between 12.5 – 17.5% to the leaf, 22.6 – 30.4% to the pseudostem, 20.6 -28.4% to corm and 32.5 – 36.6% to roots for 3 week transplant, and 16.3 – 20.9% to the leaf, 27.2 – 35.5% to the pseudostem, 19.5% - 23.5% to corm and 24.1 – 34.1% to root for 6 weeks transplant. Nitrogen accumulation was highest in SOIL/CRH/COMPOST medium, and was four- fold higher for 3 weeks transplant, and 3-fold higher for 6 week transplant than SOIL ONLY. The total N accumulated by the plant and partitioned to the various plant parts was influenced by the type of growing media and the plant part. The highest N was partitioned to the leaf, followed by the pseudostem for 3 week transplant, while for 6 week transplant between 36.33% -51.43% of N accumulated was partitioned to the leaf, followed by 17.65%-25.01% to the corm, 14.48% - 17% to the pseudostem, and 13.83%-24.21% to the roots for 6 weeks transplants. The SOIL/CRH/COMPOST medium

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produced the highest dry matter of 289.6g at 5gN fertilization for 3 week old transplants, while the same medium SOIL/CRH/COMPOST produced the highest dry matter at 10gN for 6 week old transplants. A predictive equation of Y= 20.41x + 4022, was established between total plant dry weight and leaf area with R2 = 0.89 for 6 week old plantlets, while Y= 0.19x + 19.19 was established between pseudostem dry weight and total dry weight with R2 = 0.99 for 6 week old plantlets. The SOIL/CRH/COMPOST medium produced the highest dry matter for both 3 and 6 week old transplants but this was observed at different N rates for the different transplants. This result is due to the low bulk density, better aeration porosity, water holding capacity and better growing medium provided by the SOIL/CRH/COMPOST. The addition of the compost greatly promoted growth and reduced the use of external N source.