International Journal of Horticulture, 2016, Vol.6, No.22, 1-14
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respectively. In the late season, increases in total solids were obtained in Crimson sweet, Charleston Grey and
Anderson with manuring, where Kaolac and Sugarbaby shows no response to manure application. Unmanured
Sugarbaby had the highest vitamin C content (92.31 mg/100 g), followed by Crimson Sweet and Anderson. These
varieties show no or little response to manure application (Table 8). The highest increase in vitamin C was
observed in Kaolac with NPK application. The vitamin C content in Charleston Grey responded to both OMF
and NPK application. In late season crop, unmanured Anderson had the highest vitamin C while Crimson
sweet, Kaolac and Sugarbaby responded to manure treatment compared to control. Charleston Grey and Anderson
show no response to manurial treatments in terms of vitamin C content in fruits.
3 Discussion
The effects of variety and manure types were significant on growth, yield and nutritional qualities of watermelon
in both rainy and late season crops. In general, water melon varieties responded differently with respect to their
growth and yield characters to the application of manure compared to control. These varied responses can be
attributed to differences in the genetic makeup or potentials of the tested varieties.
In the late season, variety had no significant effects on the number of leaves per plant, vine length per plant and
number of vine branches per plant in watermelon. However, these parameters were outstanding for Crimson
Sweet during the late season, and this could be related to the ability of Crimson sweet to better adapt to the
environmental condition of the late season. It may also indicate the differing ability of the variety for water uptake
and use efficiency of nutrient and light (Wakindiki et al., 2011; Sensoy et al., 2012). In rainy season, Charleston
Grey covered the ground faster, while Crimson Sweet grew very rapidly in the late season compared with other
varieties. This could have increased their ability and competitive ability and tolerance of season weather
conditions (Chen et al., 2004; Agele et al., 2008).
The highest number of flowers was also obtained in Charleston Grey which was not significantly different from
Kaolac and Crimson Sweet, while Anderson still had the lowest number of flowers and was not significantly
different from those produced by Sugarbaby and Crimson Sweet. The numbers of flowers produced by the tested
varieties were not significantly different for rainy season crop. Crimson sweet produced the highest number of
flowers in the late season and this response further supported the better tolerance ability of adverse conditions of
the late season by this variety (Sensoy et al., 2012). Non consistent trend were found for fruit yield components
which include number of fruits, number of fruit rots and cracked fruits, fruit weight, fruit length and diameter
among the tested varieties. Kaolac and Anderson recorded the highest number of fruits while Crimson Sweet
produced significantly low fruits compared to other varieties in the rainy season. The number of fruits produced
in Anderson contrasted with its low prior vigour of growth. This trend shows that the fewer numbers of flowers
produced in Anderson were set to fruit. Other varieties had higher number of flowers but poor fruit setting which
may be due to high fruit abortion and other physiological dysfunction during rainy season. In both rainy and late
season, Kaolac produced the highest number of fruits, presumably due to better adaptation to season growing
environmental conditions. Charleston Grey which recorded highest number of flowers but low fruit setting had
high number of cracked and rotten fruits, Although Charleston Grey is more vigorous in growth, it produced poor
fruit yield in the rainy season. The fruit sizes are depicted by the fruit length and fruit diameter in all the tested
varieties. In the rainy season the fruits of Charleston Grey were the biggest in length, while Anderson has the
widest fruit diameters but not significantly different from Kaolac and Sugarbaby. Crimson Sweet produced highest
fruit diameter in the late season crop in contrast to its lowest number of fruits produced. Fruit weight was highest
in Anderson for rainy season crop, while Charleston Grey is highest in the late season crop. Hence, Anderson can
well tolerate the rainy season conditions of site of study which can be related to its ability to produce larger/heavy
