Jump to first page IeCAB2010 held 1-15 June 2010 Region of Bunch Pruning Influences the Bunch and Fruit Physical Traits of ‘PITA 24’ Plantain (Musa AAB) Hybrid 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.

Jump to first page IeCAB2010 held 1-15 June 2010 Introduction n Fruit position on a developing bunch is an important source of variability in fruit size at harvest. n In bananas, distal fruits which often do not reach commercial size constitute a loss in respiration and redistribution of dry matter with no commercial value. n Recent studies on ‘PITA 24’ plantain (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 the remaining fruits at harvest.

Jump to first page IeCAB2010 held 1-15 June 2010 n Achieving uniformity of fruit size within a bunch is very important commercially. n For example, for a fruit to qualify for export from French West Indies to continental France, it must be at least 30 mm in diameter and 170 mm long. n Uniformity in size and quality of fruits makes grading easier in grocery stores; facilitates handling and minimizes uneven ripening (Marchal, 1998). Introduction…

Jump to first page IeCAB2010 held 1-15 June 2010 Objectives of the Study This study aimed at enhancing fruit size at harvest and promoting uniformity of fruits within a bunch through pruning at opposite ends of a developing infrutescence.

Jump to first page Materials and Methods Experimental Site: The experiment was conducted at the High Rainfall Station of the International Institute of Tropical Agriculture(IITA), Onne ( ' N, ' E, 10 m a.s.l.), Rivers state Nigeria. Design of Experiment: The experimental treatments comprised of three alternative pruning arrangements; proximal pruning (PP), distal pruning (DP) and pruning at both ends (BE) of a developing fruit bunch. These were evaluated alongside a no-prune control in a randomized complete block design (RCBD) of four replications. Illustration is shown in the next slide. Treatment application: Two hands of fruits (nodal clusters) were severed from the designated region as soon as the last female hand was exposed following the lifting of the bract. Male bud was removed in all the pruned bunches, while the control plants were left intact. One hand of fruits was severed from both ends of the bunch in those bunches pruned at both ends (BE).

Jump to first page Pruning arrangements: Proximal [PP] Distal [DP] Both Ends [BE] Control

Jump to first page Data Collection Data were collected at harvest on the following: n Bunch weight n Number of hands & fingers per bunch n Number of properly filled fruits n Bunch fill index n Weights of hands 1- 6 (proximal hands) n Mean fruit weight, length & girth of 4 middle fingers per hand n Pulp fresh weight n Fruit edible proportion n Pulp dry matter content n Harvest index n Fruit yield (tonnes) per hectare

Jump to first page IeCAB2010 held 1-15 June 2010 Data Analysis n The data collected were subjected to Analysis of Variance (ANOVA) following RCBD model using GENSTAT Release 7.2 DE (GENSTAT, 2007). n 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).

Jump to first page IeCAB2010 held 1-15 June 2010 Results n Results showed a non-significant difference in bunch weight between the treatments, but fruit and bunch yield drastically reduced in the proximally pruned bunches (see table below). n Bunch and fruit metric traits were similar and superior in bunches pruned at the distal (DP) and both ends (BE) of the bunch. The poorest fruits came from the no-prune bunches. n In addition to improved fruit size (weight, length and girth), bunches pruned at both ends also produced fairly uniform fruits (Figure 1). This pruning regime produced curves of more uniform gradients, representing bunches with more uniform fruits at harvest.

Jump to first page IeCAB2010 held 1-15 June 2010 Table 1: Yield components of ‘PITA 24’ plantain as influenced by region of bunch pruning application

Jump to first page IeCAB2010 held 1-15 June 2010 Charts showing the fruit metric traits of ‘PITA 24’ as influenced by region of bunch pruning. Hd 1 -Hd 6 represents the first six proximal fruits.

Jump to first page IeCAB2010 held 1-15 June 2010 Conclusion and application of findings n A lack of difference in bunch weights between the treatments suggests that the reduction in sink volume improved the growth of the remaining fruits and ensured a greater efficiency in dry matter partitioning to the bunch. n The poor quality fruits observed in the proximally pruned bunches suggests that it is a wasteful practice to remove the first two proximal hands which are the first to be initiated on the bunch meristem, and the most matured and the largest at any point of harvest. n Our results revealed that an improvement in fruit yield and quality could be achieved through a selective removal of some distal fruits with the terminal bud, but a complementary excision of some proximal fruits is necessary when uniformity of fruits is desired.