MATERIALS AND METHODS
Meteorological condition during field experiments
Two rounds of field experiments from 2009 to 2011 were
conducted at Yichang Experimental Station (31°34´N,
112°04´E), Hubei Province, China. The monthly rainfall,
mean monthly temperature from September 2009 to May
2010 and September 2010 to May 2011 were listed in
Table 5. The mean temperature was low and the precipitation
was high in the round of 2009 to 2010. During the
harvesting period, it was rainy on May 12-15, followed
by sunny days on May 18-28 in 2010. Fortunately, it was
sunny and dry during the overall harvesting period in
2011.