BY

SIBONGILE ZIMBA

(Lecturer in Vegetable crops)

Bunda College (LUANAR)- Malawi

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SUBSTRATE AND GENOTYPE EFFECTS ON GROWTH

AND MINI TUBER YIELD FOR SEED POTATO

PRODUCTION IN MALAWI

OUTLINE OF THE PRESENTATIONIntroduction

Background

Problem statement

Study justification

Materials and methods

Results and discussion

Conclusion

Recommendation

Acknowledgement

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BACKGROUND

Importance of potato Food and nutritionIncome generatingIndustrial use

Production status World: 325 million tonnes/year Africa: 16.7 million tonnes/year Malawi: 2.2 million tonnes/yearyield of 11.9 tonnes/ha (FAO, 2009)

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PROBLEM STATEMENT AND JUSTIFICATION

Substrate and genotype

are important factors for minituber

production

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Due to limited multiplication programme

Potato farmers Lack healthy and quality seed potato

There is a need to

develop a system

Micropropagation offers a feasible

propagation technique

There are many factors that affect the

production in greenhouse

MAIN OBJECTIVE

To evaluate the effect of substrate (potting media) and genotype

on growth and seed yield performance of potato in order to

optimize clean seed potato production.

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MATERIALS AND METHODS

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Treatments

1. Genotype• Lady Rosetta• Van der plank• Up to date• Buffelspoort• Bp 1. 2007• Rosita• Magalabada

2. SubstrateVermiculite Saw dust River sand

Experimental site• Green house at Bunda

Experimental Duration• April – October 2011

Vermiculite

Saw dust

River sand

PLANTING

Volume of the tray was 0.028m3

Volume of the media in a tray was 0.015m3

Plantlets were planted at 10cm apart.

The tray contained 40 plants

Irrigation and fertiliser (Alsadon and Knutson, 1994)

Data collected:

Survival percent Plant height and vigourMini tuber yield

Data analysis in Genstat version 13

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TABLE 1. PLANT VIGOUR PER SUBSTRATE TYPE & GENOTYPE 7 WEEKS AFTERTRANSPLANTING

Genotypes Substrate

Sand Vermiculite Sawdust Mean

Magalabada 1.00±0.01h 2.00±0.00f 1.00±0.00i 1.33f

Rosita 1.00±0.33h 3.00±1.60d 1.07±1.67i 1.72e

Lady Rosetta 2.83±0.17f 4.83±0.13b 1.17±1.17i 2.94b

Bp 1. 2007 2.00±0.00g 4.67±0.33b 1.00±0.00i 2.55c

Up to date 1.80±0.17g 3.33±1.60c 1.00±0.00i 2.04d

Van der plank 2.67±0.33de 4.67±0.33a 2.00±0.00i 3.11a

Buffelspoort 1.00±0.00h 2.33±0.67ef 2.00±0.00i 1.78ef

Mean 1.76b 3.55a 1.33c

CV% 3.7%P-value S=0.001 G=0.001 S*G=0.001LSD0.05 S*G=0.319 Genotype=0.18 Substrate=0.13

8Values in the table are presented as mean ± standard errorMeans in the main effects have been compared separately

9Vermiculite River sand Saw dust

Figure 1: Bp 1 2007 plants at 5 weeks after transplanting in green house

TABLE 2. NUMBER OF TUBERS PER PLANT PER SUBSTRATE TYPE AND GENOTYPE AT HARVEST

Genotypes SubstrateSand Vermiculite Sawdust Mean

Magalabada 5±0.33fgh 8±0.00cd 2±0.00j 5.02c

Rosita 5±0.78fgh 9±0.08bc 2±0.33j 5.32bc

Lady Rosetta 6±0.17e 10±0.79b 3±0.44ij 6.13b

Bp1. 2007 4±0.22gh 6±0.29ef 3±1.33hi 4.59c

Up to date 7±0.29de 12±0.77a 3±0.68ij 6.99a

Van der plank 3±0.22ij 4±0.11hi 2±0.15j 2.76d

Buffelspoort 5±0.21efg 7±0.17de 2±0.47j 4.60c

Mean 4.94b 7.81a 2.39c

CV% 17.1%P-value S=0.001 G=0.001 S*G=0.001

LSD0.05

Substrate=0.564 Genotype=0.86 S*G=1.492 10

Values in the table are presented as mean ± standard errorMeans in the main effects have been compared separately

TABLE 3. YIELD (G/M2) PER SUBSTRATE TYPE AND GENOTYPE AT HARVEST

Genotype Substrate

Sand Vermiculite Sawdust Mean

Magalabada 954f 1059d 259i 757d

Rosita 962f 1490b 262i 904c

Lady Rosetta 640g 2146a 244i 1010b

Bp 1 2007 1136e 2140a 431h 1238a

Up to date 643g 2012a 291hi 982bc

Van der plank 708g 1263c 318hi 779d

Buffelspoort 700g 1364bc 240i 770d

Mean 820b 1740a 292c

CV% 9.1%P-value S=0.001 G=0.001 S*G=0.001LSD 0.05 S=54.4 G=83.1 S*G=143.9

11Means in the main effects have been compared separately

CONCLUSION

Vermiculite remained superior to other substrate types followed by river sand.

This was demonstrated by having good plant stand in trays with vermiculite than other media which subsequently influenced yields.

Introduced genotypes grew vigorously and yielded more per unit area than the local genotypes.

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RECOMMENDATION

Lady Rosetta, Bp 1. 2007, Up to date can be

recommended for optimal minituber production.

Future study to look into different greenhouse substrate

combinations and locally available material for optimising

minituber production.

Future study to look into Cost benefit analysis of different

substrates.

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STUDY LIMITATION

Knowledge on nutrition management for optimal minituber production in green house

Acknowledgement

Supervisory teamARDEPARC-South AfricaAPA

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THANK YOU(zikomo kwambiri)