Abstract:
Sorghum and Napier hybrid cultivars exhibit better adaptation to tropical climates, offering
a sustainable solution to fodder shortages during dry periods. This study investigated the
growth and nutrient assimilation of Sugargraze (Sorghum bicolor), Red-Napier (Pennisetum
purpureum cross), and CO5 (P. purpureum x Pennisetum americanum) grown at Diyagama
Farm located in the mid country wet zone of Sri Lanka. Fodder cultivars were randomly
assigned to plots (25m²) according to Randomized Complete Block Design. Sugargraze
seeds and Napier stem cuttings were planted with a recommended spacing of 15 x 45 cm
and 1 x 1 m within and between rows, respectively. After 12 days, Sugargraze and Napier
cultivars received a recommended mixture of Urea-TSP-MOP at the rate of 125-125-100
kg/ha and 100-200-150 kg/ha, respectively. Shoot or plant density, clump or plant height,
and leaf density were weekly recorded. Forages were harvested at nine weeks, and their dry
mater (DM), organic matter (OM) and ash contents were determined. Subsequently, fresh
matter (FM) and DM yields were estimated. At two weeks, Red-Napier and CO5 initiated
shooting and reached the peak (p<0.05) shoot density at six (4.11 shoots/m2
) and seven (5.90
shoots/m2
) weeks, respectively. They achieved the peak (p<0.05) leaf density at eight weeks
(48.15 and 76.80 leaves/m2
, respectively). At harvest, Sugargraze recorded the highest
(p<0.05) plant height, plant density, and leaf density (113.74 cm, 33.00 plants/m2
, and
251.25 leaves/m2
, respectively), followed by CO5 and Red-Napier. Proximate composition
of fodder was different (p<0.05) among the cultivars. Sugargraze exhibited higher (p<0.05)
DM and OM contents (15.44% and 90.32%, respectively) than Red-Napier (12.08% and
83.48%, respectively) and CO5 (10.55% and 82.46%, respectively). Moreover, Sugargraze
recorded greater (p<0.05) FM and DM yields (22.08 and 3.43 MT/ha, respectively) than
Red-Napier (10.92 and 1.32 MT/ha, respectively) and CO5 (15.10 and 1.60 MT/ha,
respectively). Sugargraze demonstrated superior nutrient assimilation, outperforming RedNapier and CO5 at Diyagama in the in mid country wet zone of Sri Lanka.
