Premium
Defoliation Effects on Agronomic Performance of Seeded Pennisetum Hexaploid Hybrids
Author(s) -
Spitaleri R. F.,
Sollenberger L. E.,
Schank S. C.,
Staples C. R.
Publication year - 1994
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1994.00021962008600040020x
Subject(s) - hybrid , pennisetum , biology , dry matter , clipping (morphology) , pennisetum purpureum , agronomy , field experiment , imperata , mulch , philosophy , linguistics
Interspecific Pennisetum hybrids between pearl millet [ P. glaucum (L.) R.Br.] and elephantgrass ( P. purpureum Schum.) have been developed that are seed propagated, productive, and high in nutritive value, but defoliation effects on hybrid agronomic performance have not been assessed. A field experiment was conducted on an Adamsville soil (hyperthermic, uncoated Aquic Quartzipsamment) in 1991 and 1992 to determine the effect of three clipping treatments (every 6 or 12 wk to 15 cm and every 6 wk to 30 cm) on dry matter (DM) yield, nutritive value, and persistence of 10 seeded hybrids and ‘Mott’ elephantgrass. In the first year of defoliation, Mott and the hybrids had similar yields when harvested at 6‐wk intervals (9.7 vs. 9.2 Mg ha −1 yr −1 ), but hybrids had greater yields than Mott when harvested at 12‐wk intervals (17.9 vs. 13.0 Mg ha −1 yr −1 ). Yields were greater for Mott than hybrids in the second year, regardless of clipping treatment. In 1991, crude protein (CP) concentration was not different when cut every 6 wk (139 g kg −1 DM), but Mott had higher CP than the hybrids when clipped every 12 wk (112 vs. 95 g kg −1 ). Across clipping treatments, in vitro digestible organic matter (IVDOM) was greater for Mott than for the hybrids (638 vs. 602 g kg −1 OM) in 1991. In 1992 there were no differences in CP or IVDOM between Mott and hybrids. After 1 yr of defoliation, winter survival of hybrid plants was 18%, while Mott survival was 100%. Comparison of reserve status of hybrids and Mott showed that hybrids had lower rhizome mass (0.46 vs. 1.1 kg m −2 ), total nonstructural carbohydrate (TNC) concentration (115 vs. 276 g kg −1 DM), and TNC pool (56 vs. 304 g m −2 ). These data indicate that seeded hybrids are productive and high in nutritive value. Their potential for use in the U.S. Gulf Coast, however, depends on development of lines that are more persistent under defoliation.