effect of different dactylifera males and their whorl pollen grain on ...

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fruit set <strong>and</strong> yield (9). Economic yield depends on higher percentage <strong>of</strong>
normal fruit setting which further relies on pollination <strong>and</strong> its techniques
efficiency (time), time <strong>of</strong> flowering <strong>of</strong> male/female palms, <strong>pollen</strong> source <strong>and</strong>
quality, male-female compatibility, female flower receptivity <strong>and</strong>
environmental factors like temperature, rain <strong>and</strong> wind.
Many factors affect the pollination, one <strong>of</strong> them is <strong>pollen</strong> <strong>grain</strong> <strong>of</strong> <strong>different</strong>
male types which affect fruit set, yield <strong>and</strong> fruit characteristics. Different
researchers studied the <strong>effect</strong> <strong>of</strong> <strong>different</strong> male pollinizers on <strong>different</strong>
cultivars <strong>of</strong> female palm (4, 14, 19). Some other research workers
investigated that <strong>pollen</strong> source affect the productivity, maturity <strong>and</strong> fruit
quality <strong>of</strong> dates (8, 11, 12). Growers <strong>of</strong> D.I.Khan region generally use the
<strong>pollen</strong> <strong>grain</strong> <strong>of</strong> <strong>different</strong> male <strong>whorl</strong>s. Basically, <strong>whorl</strong> is an arrangement <strong>of</strong>
three or more leaves or other organs radiating from a single node <strong>of</strong> date
palm. The date palm has unique flowering behaviour in comparison with
other fruit plants. Twenty leaves emerged from four spiral nodes resulting five
leaves quarterly in a period <strong>of</strong> one year. The early spathes emerged top
spirally from axil <strong>of</strong> the leaves <strong>and</strong> three to four spathes emerged spirally in
nine months old leaves. The mid <strong>whorl</strong> spathes emerged in axil <strong>of</strong> one year
old leaves <strong>and</strong> later on lateral spathes emerged. The spathes in <strong>whorl</strong> vary
from 3 to 5 in male <strong>and</strong> female depending on the variety <strong>of</strong> date palm (16).
The present investigation was aimed to study the <strong>effect</strong> <strong>of</strong> <strong>different</strong> male
types <strong>and</strong> <strong>their</strong> <strong>pollen</strong> <strong>grain</strong>s <strong>whorl</strong> on fruit setting, fruit drop <strong>and</strong> fruit
characteristics <strong>of</strong> Dhakki dates under the agro-climatic conditions <strong>of</strong> Dera
Ismail Khan.
J. Agric. Res., 2011, 49(4)
MATERIALS AND METHODS
This study was conducted in the Faculty <strong>of</strong> Agriculture, Gomal University,
D.I.Khan, Pakistan during the year 2007 <strong>and</strong> 2008. Twenty seven Dhakki
palms <strong>of</strong> 28 years age <strong>and</strong> vigour were selected for this purpose. Nine <strong>males</strong>
symbolized as M 1 to M 9 were used as a <strong>pollen</strong> source for pollination. Male
<strong>whorl</strong>s were also positioned as upper, middle, lower, etc. Male spathes <strong>of</strong>
<strong>different</strong> <strong>whorl</strong> were cut as soon as sheath crack appeared at top <strong>of</strong> spath.
The protective spathes sheath was removed for <strong>pollen</strong> <strong>grain</strong> extraction <strong>and</strong>
flower spikes were placed on white paper sheet for one to two hours till the
completion <strong>of</strong> flowers opening. The <strong>pollen</strong> <strong>grain</strong>s were separated from the
flower parts by shaking, using mesh type cloth. Then the <strong>pollen</strong> <strong>grain</strong>s <strong>of</strong>
<strong>different</strong> <strong>whorl</strong>s were packed in air tight glass bottle <strong>and</strong> were stored in
refrigerator at 8°C. A small amount <strong>of</strong> <strong>pollen</strong> <strong>grain</strong> was taken <strong>and</strong> placed on
slide with one to two drops <strong>of</strong> 1% acetocarmine solution. The slides were
then heated for few minutes on a hot plate. Pollen viability was examined