Effects Of Combined Foliar Application Of Gibberellic Acid And Benzylaminopurine On Potato Tuber Sprouting And Subsequent Yields
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Date
2011Author
Muchiri, Daniel P. M.
Nyankanga, R.O.
Hutchinson, M.J.
Ambuko, J.
Type
PresentationLanguage
enMetadata
Show full item recordAbstract
Timely availability of well-sprouted seed potato tubers at the on-set of rains is critical for
attaining high yields. In the major potato regions in Kenya with a bimodal rainfall, the window
of planting is two weeks. However, most potato varieties are dormant for longer than three
weeks. Consequently, seed tubers planted too soon after their harvest exhibit delayed plant
emergence, poor establishment and produce low yields. Therefore, rapid tuber dormancy
breakage is desirable for tubers meant for seed. Gibberellic acid (GA) and benzylaminopurine
(BA) are known to cause dormancy breakage but little information is available on their combined
application. A field experiment was undertaken to determine the effects of combined application
of GA and BA on tuber sprouting and subsequent yields of Asante, Dutch Robyjn and Kenya
Sifa potato varieties. Foliar application of GA and BA was done alone or in combination at four
levels; 0, 50,100 and 300ppm for GA and 0, 50, 75 and100 ppm for BA. There was no
significant difference between GA when applied singly or in combination with BA on dormancy
breakage but there was significant effects of combined application of GA and BA on tuber sprout
length, number of sprouts per tuber and sprouts vigour in a dose dependent manner. In the field,
tubers from GA and GA+BA treated plants gave plants with more stems per plant, leaflets per
plant, number of tubers per plant and total yields at harvest with increased rate of application.
BA alone was not effective on breaking dormancy. The results from this study show that GA and
BA work synergistically to initiate dormancy breakage and sprouts growth. Therefore, foliar
application of GA alone or in combination with BA can be used to break dormancy in tuber
potatoes and improve the subsequent sprout growth and tuber yields.