the unit value of rice is based primarily on its head
rice yield (HRY, the proportion of kernels greater
than 75%
of intact length; USDA-FGIS, 1994). Im-
proving HRY is an ongoing goal for rice growers.
The average moisture content of the paddy rice at harvest
(HMC,
expressed on a wet weight basis) influences HRY. For
medium-grain rice grown in Italy, dry conditions allowed
HMC to drop below about 15%, and a subsequent rain caused
a significant drop in HRY (Finassi et al., 2002). However,
when repeated rain events kept HMC above 20%, HRY was
not influenced by HMC. In Louisiana, where rain events are
common during rice maturation, long and medium grain rice
experienced a significant reduction in HRY when rice
dropped below 15.0% to 19.8% HMC depending on variety
and year of harvest (Jodari and Lindscombe, 1996). A warm-
er and drier harvest season caused fissuring to begin at higher
HMC than a cooler and more humid season. In two harvest
seasons
in Arkansas with numerous rain events, HRY
was not
affected by harvest moistures between 15% and 22% (Sie-
benmorgen et al., 1992).