EFFECT OF DIFFERENT SUBSTRATES ON SURVIVAL OF TRANSPLANTED BANANA 'GRAND NAINE' CULTIVAR INTO GREENHOUSE

‘Dwarf Cavendish’ is the most common banana cultivar in Pakistan, but plans are under way to introduce internationally available cultivars such as ‘Grand Naine’ into Pakistan. The use of different substrates for acclimatization of in vitro plantlets was studied. In vitro plantlets with good shoot-root system were transferred to the greenhouse onto seven different soil types and their combinations as substrates. These were river silt, black sand (commonly used in nurseries in Pakistan), clay, desert sand, hill sand, sugar cane compost, and sugar mill soil residues. Obtained results indicated that river silt and its combinations with desert sand (1:1 and 2:1, respectively) are better substrates. The survival percentage on inorganic substrates after one month of culture was 100%. In addition, acclimatized bananas were growing much better on the soil mixture of river silt and desert sand at a ratio of 2:1. The recorded vegetative data of plants grown on these two substrates were: plant length above soil surface 8, 12 cm; number of leaves 4, 4; second leaf length 10, 13 cm; leaf width 5, 7 cm; stem thickness 0.9, 1.2 cm; number of roots 20, 15; and roots length 18, 29 cm, respectively. Most likely, the addition of desert sand resulted in better aeration to allow more vigorous growth of the root system compared to pure silt. Other substrates such as sugar mill soil residues and sugar cane compost had 0% survival. The addition of sand did not increase the survival percentage except in the mixture of sugar mill residue and desert sand at ratio 1:1, where the survival percentage was 80%. Eventually, using local nutrient-rich soil substrates like river Indus silt could be of additional benefit on the acclimatization of in vitro cultivated bananas. Acclimatized plants of ‘Grand Naine’ cultivar were successfully transferred to open field and produced an average of 38 kg/bunch as compared to 12 kg obtained from common ‘Dwarf Cavendish’ (Basrai). The results of this study will help to reduce costs for in vitro banana production in Pakistan.