MSc

Hybrid Napier grass, an interspecific cross between Napier grass
(Pennisetum purpureum Schum.) and bajra (Pennisetum glaucum L.) is a popular
fodder grass grown in many parts of Kerala. The present investigation was
undertaken to have an understanding on the growth characteristics, fodder
production potential and nutritive value of some popular cultivars of hybrid
Napier grass and also to find out the effect of plant population on their
performance. The experiment was conducted at the Agronomy research farm of
College of Horticulture, Kerala Agricultural University, Vellanikkara during
2009-2010.
Eight popular cultivars, namely, CO2, CO3, CO(CN)4, KKM-1, Suguna,
Supriya, IGFRI-3 and DHN-6 were planted under three different spacing of 60cm
x 60cm, 90cm x 60cm, and 90cm x 90cm. Observations were taken during the
period of one year on growth and fodder production potential. The nutrient
composition of different cultivars of hybrid Napier grass was also analysed.
Among the cultivars evaluated, the growth was comparatively fast in
KKM-1 followed by CO(CN)4 with respect to plant height, number of tillers, leaf
length, leaf area index, relative growth rate and net assimilation rate. The fodder
production potential of the cultivars was assessed by harvesting the herbage at 50-
55 days interval. The green and dry matter yields indicated a clear yield advantage
for KKM-1 and CO(CN)4, which were on par and hence can be ranked first. The
cultivars CO2 and DHN-6 can be ranked second based on yield. Suguna, CO3 and
Supriya came third in fodder production and IGFRI-3, fourth with the lowest
yield.
Regarding spacing, number of tillers per plant was comparatively higher at
wider spacing of 90cm x 90cm. Leaf area ratio and relative growth rate were also
higher under lower plant densities. At the same time, leaf area index was found to
be higher at closer spacing of 60cm x 60cm. Other parameters such as plant
height, number of leaves, leaf: stem ratio etc. were found to be non significant
with respect to spacing. Considering annual fodder production, herbage and dry
matter yields were higher at closer spacing of 60cm x 60cm.
Nutritional attributes like crude protein, crude fibre, ether extract, nitrogen
free extract, total ash, phosphorus, potassium, calcium, magnesium, and oxalate
content of all the cultivars were assessed. Nutritionally, the cultivars differed with
respect to crude protein and oxalate content. All the cultivars except CO2 had
higher crude protein content. Oxalate content which is an anti nutritional factor,
was higher in CO2 and IGFRI-3 while, the least oxalate content was recorded in
DHN-6. From nutrient point of view, the cultivar DHN-6 was found to be
superior.
Regarding the nutrient uptake from soil, KKM-1, CO(CN)4 and CO2 had
higher rate of removal. Among the three spacings, nutrient uptake by plants was
higher under closer spacing of 60cm x 60cm compared to wider spacings. Among
the cultivars, B:C ratio was maximum for KKM-1 and among the spacings, closer
spacing of 60cm x 60cm was found to be more profitable.
Among the cultivars evaluated, KKM-1 and CO(CN)4 ranked first with
respect to high fresh and dry fodder yield. Although the cultivars DHN-6 and CO2
were comparable in yield and ranked second, quality wise DHN-6 was better with
the least oxalate content, better leaf: stem ratio and crude protein content.
Therefore, along with KKM-1 and CO(CN)4, DHN-6 can also be recommended
for Kerala under irrigated conditions. The spacing of 60cm x 60cm was the ideal
spacing for hybrid Napier cultivation in Kerala condition for maximum yield