TITLE:
Productivity and the Survival Rate after Winter Management of Seven Tropical Forage Accessions in Subtropical Region of China
AUTHORS:
Chengxin He, Ling Mo, Yuqing Huang, Zhongfeng Zhang, Michael Hare, Danjuan Zen, Gaozhong Pu
KEYWORDS:
Cold Tolerance, Production, Photosynthesis, Tropical Grasses, Winter
JOURNAL NAME:
Agricultural Sciences,
Vol.8 No.5,
May
27,
2017
ABSTRACT: Forage production and quality of five tropical grass
accessions (Guimu-1 hybrid elephant
grass (PG1), Mulato II
(M II), Ubon paspalum (PU), hybrid elephant grass (PH) and Reyan 11
paspalum (PR11)) and two tropical legume accessions (Reyan 5 stylo (SR5) and
Ubon stylo (SU)) were evaluated in a field experiment in a
subtropical area with hot summers and cold winters in Guangxi, China. Three
forage stubble cover managements: no cover (CK), dry mass cover (MC) and plastic
cover (PC) were applied at the end of the summer period to evaluate cold
tolerance and accession survival over the winter. Photosynthesis measurements
were taken from the forages in mid-summer. The results showed that PG1
accession produced significantly higher dry matter yields (67.0 t·ha-1) than the other grass and legume accessions. Legume
accessions SU and SR5 produced much less dry matter (6.4 - 7.2 t·ha-1) compared to the grasses. M II, PU and PR11 contained the largest proportion of leaf. PG1
and PH showed good cold tolerance (survival rate >85%) under -1°C
conditions without any cover management. PR11 had better cold tolerance than PU. M II exhibited very poor winter
survival under no cover and with massive cover,
and only survived well under plastic cover. The two stylo accessions died
completely under all winter cover management treatments. In the growing season,
under a given photosynthesis photon flux density (PPFD) =
1500 μmol m-2 s-1, the net photosynthesis rate Pn of all the seven
accessions was above
28 μmol m-2 s-1, of which hybrid
elephant grass and M II were above 42 μmol m-2 s-1.
Though these 7 tropical accessions yielded high production in the grow season, stylo and M II are sensitive to cold in subtropical region of Guangxi. The
result suggests that
PG1 and PU are good accessions and can be used as productive perennial pasture,
while stylo and M II are simply
considered as annual one. Additionally, if paspalum was trained in cool region
before being introduced to subtropical region, it may present
both productivity and enhancive cold tolerance.