IeCAB2010 June 1-15 Timing of Bunch Pruning Management Enhances Bunch and Fruit Qualities of ‘PITA 24’ Plantain (Musa AAB) Hybrid 1 Baiyeri, K. P.; 1 Aba, S. C. and 2 Tenkouano, A. 1 Baiyeri, K. P.; 1 Aba, S. C. and 2 Tenkouano, A. 1 Dept. of Crop Science, University of Nigeria, Nsukka, Nigeria. 2 International Institute of Tropical Agriculture, P.M.B 5320, Ibadan, Oyo state, Nigeria. PITA 24

IeCAB2010 June 1-15INTRODUCTION Many pests and diseases, especially black leaf Sigatoka disease (Mycosphaerella fijiensis), have significantly affected Musa cultivation over the years and have spurred genetic improvement programs. Many pests and diseases, especially black leaf Sigatoka disease (Mycosphaerella fijiensis), have significantly affected Musa cultivation over the years and have spurred genetic improvement programs. The use of resistant cultivars is considered the most appropriate component in efforts to control the diseases. Improved genotypes could be readily adopted by farmers. The use of resistant cultivars is considered the most appropriate component in efforts to control the diseases. Improved genotypes could be readily adopted by farmers. ‘PITA 24’, a secondary triploid plantain-derived hybrid is among the Musa genotypes recently selected by the International Institute of Tropical Agriculture (IITA) for biotic stress tolerance and improved yield. ‘PITA 24’, a secondary triploid plantain-derived hybrid is among the Musa genotypes recently selected by the International Institute of Tropical Agriculture (IITA) for biotic stress tolerance and improved yield.

IeCAB2010 June 1-15 Introduction …  This genotype produces a very large bunch of about 9-12 hands (nodal clusters), but only the first four to five proximal hands are properly filled to marketable fingers. Therefore, the poor fruit-filling feature of ‘PITA 24’could have a negative impact on its adoption potential. Fruit size is an important commercial characteristic for markets specializing in plantains. Therefore, the poor fruit-filling feature of ‘PITA 24’could have a negative impact on its adoption potential. Recent studies on ‘PITA 24’ (Aba et al., 2009 & Baiyeri et al., 2009) proved that the selective removal of male bud and few distal hands from a developing bunch has the potential to increase the size and grade of harvested fruits. Recent studies on ‘PITA 24’ (Aba et al., 2009 & Baiyeri et al., 2009) proved that the selective removal of male bud and few distal hands from a developing bunch has the potential to increase the size and grade of harvested fruits.

IeCAB2010 June 1-15 Introduction … However, reports on sink-source modifications in banana fruit growth differ between studies; and may be related to differences in fruit age at the time bunch pruning was performed. However, reports on sink-source modifications in banana fruit growth differ between studies; and may be related to differences in fruit age at the time bunch pruning was performed.  Westwood (1978) noted that the earlier and heavier ‘thinning’ or ‘pruning’ is done, the larger the final fruit size.  In many fruit trees, pruning when applied at the appropriate time improves fruit size, colour and organoleptic qualities, reduces limb breakage, hence producing fruits of more alluring appearance at harvest.  Pruning, assures that assimilates are not wasted on the non- essential portions of the bunch, but channelled for the optimum growth of the remaining fruits.

IeCAB2010 June 1-15 This study investigated the post-anthesis period at which bunch pruning would be most effective in enhancing the bunch and fruit qualities of ‘PITA 24’ plantain. This study investigated the post-anthesis period at which bunch pruning would be most effective in enhancing the bunch and fruit qualities of ‘PITA 24’ plantain. Objective

IeCAB2010 June 1-15 Materials and Methods: Experimental Site: The experiment was conducted at the High Rainfall Station of the International Institute of Tropical Agriculture, Onne ( ' N, ' E, 10 m a.s.l.), Rivers state Nigeria. Design of Experiment: Bunch pruning (i.e., removal of two distal hands and the male bud) was applied at full anthesis (at the opening of the last female hand) or at weekly intervals of 1, 2, 3 or 4 weeks thereafter. These were compared with a no- prune control in a randomized complete block design of four replications.

IeCAB2010 June 1-15 Data Collection Data were collected at harvest on the following Data were collected at harvest on the following Bunch weight Bunch weight Number of hands & fingers per bunch Number of hands & fingers per bunch Number of properly filled fruits Number of properly filled fruits Bunch fill index Bunch fill index Weights of hands 1- 6 (proximal hands) Weights of hands 1- 6 (proximal hands) Mean fruit weight, length & girth of 4 middle fingers per hand Mean fruit weight, length & girth of 4 middle fingers per hand Pulp fresh weight Pulp fresh weight Fruit edible proportion Fruit edible proportion Pulp dry matter content Pulp dry matter content Days to fruit-filling (i.e., time lapse between flowering and harvest) Days to fruit-filling (i.e., time lapse between flowering and harvest) Harvest index Harvest index Fruit yield (tonnes) per hectare Fruit yield (tonnes) per hectare

IeCAB2010 June 1-15 Data Analysis The data collected were subjected to Analysis of Variance (ANOVA) following RCBD model using GENSTAT Release 7.2 DE (GENSTAT, 2007). The data collected were subjected to Analysis of Variance (ANOVA) following RCBD model using GENSTAT Release 7.2 DE (GENSTAT, 2007). The separation of treatment means for significant effects was by least significant difference (LSD) at 5 percent probability level as described in Steel and Torrie (1980). The separation of treatment means for significant effects was by least significant difference (LSD) at 5 percent probability level as described in Steel and Torrie (1980).

IeCAB2010 June 1-15 Results Bunch and fruit quality traits generally improved with bunch pruning until 3 weeks after bunch anthesis (see Table below). Bunch and fruit quality traits generally improved with bunch pruning until 3 weeks after bunch anthesis (see Table below). There was a drop in bunch-fill index, number of properly filled fruits, harvest index, fruit yield and individual fruit size when pruning was delayed for 4 weeks after full bunch anthesis. There was a drop in bunch-fill index, number of properly filled fruits, harvest index, fruit yield and individual fruit size when pruning was delayed for 4 weeks after full bunch anthesis. The best quality fruits were obtained when pruning was applied immediately after the opening of the last female hand (i.e., at full bunch anthesis). Fruit traits on Figure 1 showed clearly that quality of fruits improved with pruning up till 3 weeks after bunch anthesis. The best quality fruits were obtained when pruning was applied immediately after the opening of the last female hand (i.e., at full bunch anthesis). Fruit traits on Figure 1 showed clearly that quality of fruits improved with pruning up till 3 weeks after bunch anthesis.

Table 1: Bunch and fruit traits as influenced by time of pruning application

IeCAB2010 June 1-15 Figure 1: Bar charts showing the fruit quality traits as influenced by time of bunch pruning

IeCAB2010 June 1-15 Conclusion and application of findings  Our results confirmed that bunch and fruit qualities of plantain could be improved through a judicious and timely application of bunch pruning.  For optimum result, bunch pruning management should not be delayed beyond 3 weeks after the opening of the last female hand.