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Effect of cutting height of the parent pseudostem on yield and time of production of the following sucker in banana
Scientia Horticulturae, 31 (1987) 89-94
89
Elsevier Science Publishers B.V., Amsterdam - - Printed in The Netherlands
Effect C u t t i n g H e i g h t of the P a r e n t P s e u d o s t e m on Yield and T i m e of P r o d u c t i o n of the F o l l o w i n g S u c k e r in B a n a n a J.W. DANIELLS and P.J. O'FARRELL
Department of Primary Industries, South Johnstone Research Station, South Johnstone, Qld. (Australia) (Accepted for publication 28 August 1986)
ABSTRACT DanieUs, J.W. and O'Farrell, P.J., 1987. Effect of cutting height of the parent pseudostem on yield and time of production of the following sucker in banana. Scientia Hortic., 31: 89-94. Parent pseudostems of bananas were cut at three different heights at harvest. Growth and yield of the following sucker were examined. Cutting high (200 cm) increased bunch weight by 4.6 kg (12%) and decreased the time to harvest by 18 days (5%) compared to cutting low (10 cm). Cutting at medium height (100 cm) resulted in an intermediate bunch weight, but there was no difference in time to harvest compared to cutting high. The increase in bunch weight resulted from an increase in the number of fingers per bunch, with no change in finger size. The pseudostem height of the follower at the commencement of the experiment was used as a covariate in the analysis of results. There was a 16.5-kg increase in bunch weight with increase in follower height across the range 115-217 cm. The crop cycle of the follower was decreased by 113 days across the same range. Keywords: bananas; management; timing; yield.
INTRODUCTION
When a banana bunch is harvested, the pseudostem supporting the bunch may be either entirely or partially removed in the harvesting operation. The usual practice in north Queensland is to leave 100-200 cm of pseudostem standing. This is thought to contribute to the growth of the following sucker (Walmsley and Twyford, 1968; Turner and Barkus, 1973 ). Nayar et al. (1956) reported a significant decrease in yield by cutting the parent pseudostem at ground level compared to the normal practice of cutting high. Crop management practices which influence the time of maturity are important as tools in maintaining evenness in a plantation, and also as means to 0304-4238/87/$03.50
© 1987 Elsevier Science Publishers B.V.
90 control the overall timing of production. Nayar et al. (1956) made no mention of any effects on the time to bunch harvest. However, the local observation in north Queensland is one of delayed development of the follower when the parent is cut low, or when the parent is broken at ground level due to strong winds. This is particularly evident if the follower is small. The work reported here examines the effect of the cutting height of the parent pseudostem on the yield and time of harvest of the follower. MATERIALSAND METHODS The experiment was carried out at South Johnstone, north Queensland (latitude 17 ° 38' S), on a deep alluvial clay loam during 1981-82. The planting selected was a first ratoon crop of bananas, Musa (AAA group, Cavendish subgroup) 'Williams', grown in a double-row arrangement at a density of 2222 plants h a - 1. Plants with bunches considered to be within 1 month of the normal time of commercial harvest were selected as datum plants. The pseudostem heights of their following suckers ( Ratoon 2 ) were measured just prior to the commencement of the experiment, and ranged from 115 to 217 cm. The experiment was laid out as a completely randomized design. Treatments consisted of cutting the parent pseudostem, irrespective of bunch maturity, at the commencement of the experiment at the heights 200, 100 or 10 cm above ground level, and are referred to as high, medium and low, respectively. Each treatment was represented by 60 single-plant replications. The experiment commenced on 11 August 1981. During the course of the experiment, side dressings of dolomitic limestone at 1 t ha -1, P at 36 kg ha -1 as superphosphate, N at 51 kg ha -1 as ammonium nitrate and K at 100 kg h a - 1 as potassium chloride were broadcast on the rows with a Vicon R mechanical fertilizer spreader. Dolomitic limestone and superphosphate were applied 6-monthly and ammonium nitrate and potassium chloride monthly. Paraquat was sprayed as required to control weeds. Trickle irrigation ensured that water was freely available to plants throughout their growth. Leaf spot fungus was controlled by the application of mancozeb and miscible oil at fortnightly intervals. Four representative parent pseudostems from the trial were sampled for dry weight analysis to provide some information on the amount of material potentially available to the following sucker from the 10-100 cm and the 100-200 cm pseudostem portions. As an indication of growth, the pseudostem height of the follower was recorded monthly until bunch emergence. Plants were harvested when the average diameter of the middle 3 fingers of the outer whorl of the third hand from the proximal end reached 3.7 cm. Data recorded at bunch harvest included
91 bunch weight, finger number and hand number per bunch, and average finger length of the 3rd and 9th hands. In the statistical analysis of data, the follower height at the commencement of the experiment was used as a covariate. RESULTS The length of the crop cycle of the follower was increased by 18 days by cutting the parent pseudostem low compared to high (Table I). This was a function of both increased duration to bunch emergence and from bunch emergence to harvest, but these increases just failed to be significant at the 5% level (Table I). Cutting at medium height was not significantly different to cutting high. Bunch weight increased with an increase in the amount of parent pseudostem that was retained (Table I). Cutting high increased bunch weight by 4.6 kg (12%) compared to cutting low. Greater bunch weight was a function of a greater number of fingers per bunch (Table I). There was no difference in average finger weight between treatments (data not shown ). Followers from parents cut high were taller when harvested than the other treatments, but the differences were small. Most of this difference seems to have occurred during the first m o n t h of growth at the commencement o f the experiment (Table I). There was no significant difference after this. Covariance analysis was applied to the results because follower height at harvest of the parent influenced yields of the follower. Follower height at the commencement of the experiment had larger effects on yield and time of harvest than did the cutting height of the parent (Table I ). The crop cycle of the follower was decreased by 113 days with increase in follower height across the range 115-217 cm. For the medium cutting height treatment, this meant a reduction from 382 to 269 days. Across the same range of follower heights, bunch weight increased by 16.5 kg. For the medium cutting height treatment, this meant an increase from 35.3 to 51.8 kg in bunch weight. Dry weight analysis of the four representative parent pseudostems is shown in Table II. Approximate nutrient concentrations were taken from Turner and Barkus (1983) to calculate the quantity of N, P and K present in the pseudostem sections. DISCUSSION Retaining 200 cm of parent pseudostem has enabled following plants to cycle faster and yield higher. While the exact reason for this improved growth of plants is not known, the importance of transfer of mineral elements from the parent to the follower has been identified by Walmsley and Twyford (1968) and Turner and Barkus (1973). Table II from the present experiment shows
-1.107"* 0.101
Slope ( B ) SEB ÷ ÷
NS --
172 a 171 a 178 a
Days to bunch emergence from 11/8/81
-1.184 0.109
143 a 146 a 153 a
Days to bunch emergence to b u n c h harvest
0.162 0.015
44.1 c 42.4 b 39.5 a
Bunch weight (kg)
0.993 0.071
255 b 247 b 230 a
Number of fingers per b u n c h
0.264 0.048
350 b 344 a 340 a
Pseudostem height ( c m ) of follower at b u n c h harvest
-0.225 0.025
30.1 c 26.8 b 23.3 a
Change in follower height ( cm ) 11/8-9/9/81
NS ÷ --
49.1 a 47.1 a 48.8 a
Change in follower height ( cm ) 9/9-12/10/81
*Values in columns not followed by a c o m m o n letter differ significantly ( P < 0.05 ). **For every 1 cm increase in follower height at the c o m m e n c e m e n t of t h e experiment, t h e r e was reduction of 1.107 days to b u n c h harvest. Similar regressions were done for each parameter. + Regression n o t significant. ÷ +SEB = S t a n d a r d error of slope.
314 a* 317 a 332 b
Days to bunch harvest from 11/8/81
High Medium Low
Cutting height
The effect of cutting height of t h e p a r e n t pseudostem on growth a n d b u n c h characteristics of the following plant. Results shown are adjusted means using follower height at h a r v e s t of t h e p a r e n t as a covariate. Regressions indicate t h e relationship
TABLE I
93 TABLE II Fresh weight, dry weightand mineralcontent of the parent pseudostemsremovedin the treatments (means_ S.E. of 4 pseudostems) Pseudostem section
Total fresh weight ( k g )
Total dry weight( k g )
N (g) (0.97%)*
P (g) (0.21%)*
K (g) (2.12%)*
10-100 cm** 100-200 cm Total, 10-200 cm
28.4_ 1.1 18.1_+0.8 46.5 _+1.8
1.84___0.06 1.30___0.05 3.14 _+0.11
18+ 12 30
4 3 7
39 28 67
*Taken fromTurner and Barkus (1983). **Abovegroundlevel. +1.84kgX0.97%. how substantial is the potential reserve of nutrients in the parent pseudostem. For example, about 30 g N is located in the 10-200-cm section of pseudostem, which compares with a weekly sucker gain of 1.9 g N demonstrated by Montagut and Martin-Prevel (1965). As well as movement of mineral elements, there may also be transfer of carbohydrates and water to the developing follower. The most significant contribution by the parent pseudostem to the follower was probably during the first month, as indicated by the changes in plant height (Table I). Turner and Barkus (1973) and Shanmugavelu and Balakrishnan (1980) demonstrated nutrient movement to be prominent during the first 2 months following pseudostem cutting in their experiments. Parent pseudostems were thoroughly rotted by the time of bunch emergence (4-5 months after harvest of the parent in the present experiment). Cutting height as a method of controlling crop timing and maintaining uniformity would have limited application as the change in time to harvest is relatively small. The loss in yield that occurs by cutting low plus the greater labour requirements to chop up the pseudostems and problems of vehicle access to interrows also makes it unattractive. The effects of follower height at harvest of the parent on subsequent growth of the follower are quite large. This provides a useable method of crop control. In many parts of the world, and in Israel in particular (Ticho, 1971 ), follower selection is used to great advantage in timing production. In this experiment, the larger the follower was within the range 115-217 cm at the time of harvest of the parent, the higher was the yield of the follower. The large treatment effect on time of harvest of the follower (May-September) may have contributed in part to bunch weight differences due to seasonal factors. We could expect a decline in bunch weight of 10-15% in north Queensland from May to September harvests (unpublished data, 1984). However, the decline in bunch weight was 32% (medium cutting height), with a decrease in follower height across the range 217-115 cm. This suggests that larger followers probably do produce larger bunches, but further research is required to confirm this.
94 R e a c h i n g a selection decision b e t w e e n f o r w a r d v i g o r o u s followers w h i c h p r o duce larger b u n c h e s in a s h o r t e r t i m e or s m a l l e r followers w h i c h will p r o d u c e s m a l l e r b u n c h e s a n d t a k e longer to do so will b e i n f l u e n c e d b y p r o b a b l e m a r k e t prices a n d i n d i v i d u a l p r e f e r e n c e s . ACKNOWLEDGEMENTS T h a n k s are due to t h e s t a f f of t h e D P I S o u t h J o h n s t o n e R e s e a r c h S t a t i o n for a s s i s t a n c e in t h e c o n d u c t of t h e trial a n d to R. S h e p h e r d for a s s i s t a n c e in t h e a n a l y s i s of results.
REFERENCES Montagut, G. and Martin-Prevel, P., 1965. Besoins en engrais des bananeraies antillaises. Fruits, 20: 265-273. Nayar, T.G., Seshadri, V.S. and Bakthavathsalu, C.M., 1956. A note on mattocking practices in banana culture. Indian J. Hortic., 13:210-211. Shanmugavelu, K.G. and Balakrishnan, R., 1980. Growth and development of banana. National Seminar on Banana Production Technology, Tamil Nadu Agricultural University, India, pp. 67-72. Ticho, R.J., 1971. The banana industry in Israel. Trop. Sci., 13: 289-301. Turner, D.W. and Barkus, B., 1973. Loss of mineral nutrients from banana pseudostems after harvest. Trop. Agric. (Trinidad), 50: 229-233. Turner, D.W. and Barkus, B., 1983. The uptake and distribution of mineral nutrients in the banana in response to supply of K, Mg and Mn. Fertii. Res., 4: 89-99. Walmsley, D. and Twyford, I.T., 1968. The translocation of phosphorus within a stool of Robusta bananas. Trop. Agric. (Trinidad), 45: 229-233.
89
Elsevier Science Publishers B.V., Amsterdam - - Printed in The Netherlands
Effect C u t t i n g H e i g h t of the P a r e n t P s e u d o s t e m on Yield and T i m e of P r o d u c t i o n of the F o l l o w i n g S u c k e r in B a n a n a J.W. DANIELLS and P.J. O'FARRELL
Department of Primary Industries, South Johnstone Research Station, South Johnstone, Qld. (Australia) (Accepted for publication 28 August 1986)
ABSTRACT DanieUs, J.W. and O'Farrell, P.J., 1987. Effect of cutting height of the parent pseudostem on yield and time of production of the following sucker in banana. Scientia Hortic., 31: 89-94. Parent pseudostems of bananas were cut at three different heights at harvest. Growth and yield of the following sucker were examined. Cutting high (200 cm) increased bunch weight by 4.6 kg (12%) and decreased the time to harvest by 18 days (5%) compared to cutting low (10 cm). Cutting at medium height (100 cm) resulted in an intermediate bunch weight, but there was no difference in time to harvest compared to cutting high. The increase in bunch weight resulted from an increase in the number of fingers per bunch, with no change in finger size. The pseudostem height of the follower at the commencement of the experiment was used as a covariate in the analysis of results. There was a 16.5-kg increase in bunch weight with increase in follower height across the range 115-217 cm. The crop cycle of the follower was decreased by 113 days across the same range. Keywords: bananas; management; timing; yield.
INTRODUCTION
When a banana bunch is harvested, the pseudostem supporting the bunch may be either entirely or partially removed in the harvesting operation. The usual practice in north Queensland is to leave 100-200 cm of pseudostem standing. This is thought to contribute to the growth of the following sucker (Walmsley and Twyford, 1968; Turner and Barkus, 1973 ). Nayar et al. (1956) reported a significant decrease in yield by cutting the parent pseudostem at ground level compared to the normal practice of cutting high. Crop management practices which influence the time of maturity are important as tools in maintaining evenness in a plantation, and also as means to 0304-4238/87/$03.50
© 1987 Elsevier Science Publishers B.V.
90 control the overall timing of production. Nayar et al. (1956) made no mention of any effects on the time to bunch harvest. However, the local observation in north Queensland is one of delayed development of the follower when the parent is cut low, or when the parent is broken at ground level due to strong winds. This is particularly evident if the follower is small. The work reported here examines the effect of the cutting height of the parent pseudostem on the yield and time of harvest of the follower. MATERIALSAND METHODS The experiment was carried out at South Johnstone, north Queensland (latitude 17 ° 38' S), on a deep alluvial clay loam during 1981-82. The planting selected was a first ratoon crop of bananas, Musa (AAA group, Cavendish subgroup) 'Williams', grown in a double-row arrangement at a density of 2222 plants h a - 1. Plants with bunches considered to be within 1 month of the normal time of commercial harvest were selected as datum plants. The pseudostem heights of their following suckers ( Ratoon 2 ) were measured just prior to the commencement of the experiment, and ranged from 115 to 217 cm. The experiment was laid out as a completely randomized design. Treatments consisted of cutting the parent pseudostem, irrespective of bunch maturity, at the commencement of the experiment at the heights 200, 100 or 10 cm above ground level, and are referred to as high, medium and low, respectively. Each treatment was represented by 60 single-plant replications. The experiment commenced on 11 August 1981. During the course of the experiment, side dressings of dolomitic limestone at 1 t ha -1, P at 36 kg ha -1 as superphosphate, N at 51 kg ha -1 as ammonium nitrate and K at 100 kg h a - 1 as potassium chloride were broadcast on the rows with a Vicon R mechanical fertilizer spreader. Dolomitic limestone and superphosphate were applied 6-monthly and ammonium nitrate and potassium chloride monthly. Paraquat was sprayed as required to control weeds. Trickle irrigation ensured that water was freely available to plants throughout their growth. Leaf spot fungus was controlled by the application of mancozeb and miscible oil at fortnightly intervals. Four representative parent pseudostems from the trial were sampled for dry weight analysis to provide some information on the amount of material potentially available to the following sucker from the 10-100 cm and the 100-200 cm pseudostem portions. As an indication of growth, the pseudostem height of the follower was recorded monthly until bunch emergence. Plants were harvested when the average diameter of the middle 3 fingers of the outer whorl of the third hand from the proximal end reached 3.7 cm. Data recorded at bunch harvest included
91 bunch weight, finger number and hand number per bunch, and average finger length of the 3rd and 9th hands. In the statistical analysis of data, the follower height at the commencement of the experiment was used as a covariate. RESULTS The length of the crop cycle of the follower was increased by 18 days by cutting the parent pseudostem low compared to high (Table I). This was a function of both increased duration to bunch emergence and from bunch emergence to harvest, but these increases just failed to be significant at the 5% level (Table I). Cutting at medium height was not significantly different to cutting high. Bunch weight increased with an increase in the amount of parent pseudostem that was retained (Table I). Cutting high increased bunch weight by 4.6 kg (12%) compared to cutting low. Greater bunch weight was a function of a greater number of fingers per bunch (Table I). There was no difference in average finger weight between treatments (data not shown ). Followers from parents cut high were taller when harvested than the other treatments, but the differences were small. Most of this difference seems to have occurred during the first m o n t h of growth at the commencement o f the experiment (Table I). There was no significant difference after this. Covariance analysis was applied to the results because follower height at harvest of the parent influenced yields of the follower. Follower height at the commencement of the experiment had larger effects on yield and time of harvest than did the cutting height of the parent (Table I ). The crop cycle of the follower was decreased by 113 days with increase in follower height across the range 115-217 cm. For the medium cutting height treatment, this meant a reduction from 382 to 269 days. Across the same range of follower heights, bunch weight increased by 16.5 kg. For the medium cutting height treatment, this meant an increase from 35.3 to 51.8 kg in bunch weight. Dry weight analysis of the four representative parent pseudostems is shown in Table II. Approximate nutrient concentrations were taken from Turner and Barkus (1983) to calculate the quantity of N, P and K present in the pseudostem sections. DISCUSSION Retaining 200 cm of parent pseudostem has enabled following plants to cycle faster and yield higher. While the exact reason for this improved growth of plants is not known, the importance of transfer of mineral elements from the parent to the follower has been identified by Walmsley and Twyford (1968) and Turner and Barkus (1973). Table II from the present experiment shows
-1.107"* 0.101
Slope ( B ) SEB ÷ ÷
NS --
172 a 171 a 178 a
Days to bunch emergence from 11/8/81
-1.184 0.109
143 a 146 a 153 a
Days to bunch emergence to b u n c h harvest
0.162 0.015
44.1 c 42.4 b 39.5 a
Bunch weight (kg)
0.993 0.071
255 b 247 b 230 a
Number of fingers per b u n c h
0.264 0.048
350 b 344 a 340 a
Pseudostem height ( c m ) of follower at b u n c h harvest
-0.225 0.025
30.1 c 26.8 b 23.3 a
Change in follower height ( cm ) 11/8-9/9/81
NS ÷ --
49.1 a 47.1 a 48.8 a
Change in follower height ( cm ) 9/9-12/10/81
*Values in columns not followed by a c o m m o n letter differ significantly ( P < 0.05 ). **For every 1 cm increase in follower height at the c o m m e n c e m e n t of t h e experiment, t h e r e was reduction of 1.107 days to b u n c h harvest. Similar regressions were done for each parameter. + Regression n o t significant. ÷ +SEB = S t a n d a r d error of slope.
314 a* 317 a 332 b
Days to bunch harvest from 11/8/81
High Medium Low
Cutting height
The effect of cutting height of t h e p a r e n t pseudostem on growth a n d b u n c h characteristics of the following plant. Results shown are adjusted means using follower height at h a r v e s t of t h e p a r e n t as a covariate. Regressions indicate t h e relationship
TABLE I
93 TABLE II Fresh weight, dry weightand mineralcontent of the parent pseudostemsremovedin the treatments (means_ S.E. of 4 pseudostems) Pseudostem section
Total fresh weight ( k g )
Total dry weight( k g )
N (g) (0.97%)*
P (g) (0.21%)*
K (g) (2.12%)*
10-100 cm** 100-200 cm Total, 10-200 cm
28.4_ 1.1 18.1_+0.8 46.5 _+1.8
1.84___0.06 1.30___0.05 3.14 _+0.11
18+ 12 30
4 3 7
39 28 67
*Taken fromTurner and Barkus (1983). **Abovegroundlevel. +1.84kgX0.97%. how substantial is the potential reserve of nutrients in the parent pseudostem. For example, about 30 g N is located in the 10-200-cm section of pseudostem, which compares with a weekly sucker gain of 1.9 g N demonstrated by Montagut and Martin-Prevel (1965). As well as movement of mineral elements, there may also be transfer of carbohydrates and water to the developing follower. The most significant contribution by the parent pseudostem to the follower was probably during the first month, as indicated by the changes in plant height (Table I). Turner and Barkus (1973) and Shanmugavelu and Balakrishnan (1980) demonstrated nutrient movement to be prominent during the first 2 months following pseudostem cutting in their experiments. Parent pseudostems were thoroughly rotted by the time of bunch emergence (4-5 months after harvest of the parent in the present experiment). Cutting height as a method of controlling crop timing and maintaining uniformity would have limited application as the change in time to harvest is relatively small. The loss in yield that occurs by cutting low plus the greater labour requirements to chop up the pseudostems and problems of vehicle access to interrows also makes it unattractive. The effects of follower height at harvest of the parent on subsequent growth of the follower are quite large. This provides a useable method of crop control. In many parts of the world, and in Israel in particular (Ticho, 1971 ), follower selection is used to great advantage in timing production. In this experiment, the larger the follower was within the range 115-217 cm at the time of harvest of the parent, the higher was the yield of the follower. The large treatment effect on time of harvest of the follower (May-September) may have contributed in part to bunch weight differences due to seasonal factors. We could expect a decline in bunch weight of 10-15% in north Queensland from May to September harvests (unpublished data, 1984). However, the decline in bunch weight was 32% (medium cutting height), with a decrease in follower height across the range 217-115 cm. This suggests that larger followers probably do produce larger bunches, but further research is required to confirm this.
94 R e a c h i n g a selection decision b e t w e e n f o r w a r d v i g o r o u s followers w h i c h p r o duce larger b u n c h e s in a s h o r t e r t i m e or s m a l l e r followers w h i c h will p r o d u c e s m a l l e r b u n c h e s a n d t a k e longer to do so will b e i n f l u e n c e d b y p r o b a b l e m a r k e t prices a n d i n d i v i d u a l p r e f e r e n c e s . ACKNOWLEDGEMENTS T h a n k s are due to t h e s t a f f of t h e D P I S o u t h J o h n s t o n e R e s e a r c h S t a t i o n for a s s i s t a n c e in t h e c o n d u c t of t h e trial a n d to R. S h e p h e r d for a s s i s t a n c e in t h e a n a l y s i s of results.
REFERENCES Montagut, G. and Martin-Prevel, P., 1965. Besoins en engrais des bananeraies antillaises. Fruits, 20: 265-273. Nayar, T.G., Seshadri, V.S. and Bakthavathsalu, C.M., 1956. A note on mattocking practices in banana culture. Indian J. Hortic., 13:210-211. Shanmugavelu, K.G. and Balakrishnan, R., 1980. Growth and development of banana. National Seminar on Banana Production Technology, Tamil Nadu Agricultural University, India, pp. 67-72. Ticho, R.J., 1971. The banana industry in Israel. Trop. Sci., 13: 289-301. Turner, D.W. and Barkus, B., 1973. Loss of mineral nutrients from banana pseudostems after harvest. Trop. Agric. (Trinidad), 50: 229-233. Turner, D.W. and Barkus, B., 1983. The uptake and distribution of mineral nutrients in the banana in response to supply of K, Mg and Mn. Fertii. Res., 4: 89-99. Walmsley, D. and Twyford, I.T., 1968. The translocation of phosphorus within a stool of Robusta bananas. Trop. Agric. (Trinidad), 45: 229-233.