The overall objective of this project is to investigate crop-environmental interactions affecting head yields at a range of soil and grain moisture levels in a geographic frame of reference.

In 2002, 78 loads of rice were examined at the FRC receiving facility in West Sacramento, looking for relationships between moisture, combine damage and rice quality.

Head rice showed a typical significant relationship with moisture, quality decline — that is, quality drops significantly when rice is harvested below 21 percent moisture. Head rice quality did not improve at moistures above 21 percent.  Also, no apparent effect of harvest moisture on unfissured head rice was observed.  A possible reason for head rice loss is the moisture difference between wet and dry kernels.

In the second project objective, several geographic databases were acquired and the development of a geographic information system (GIS) describing production in the Sacramento Valley is being developed.  The purpose of this database will be to provide insight into the factors that influence the relationship between harvest moisture and grain quality.  This approach increases the probability of determining significant relationships between regional variables (for example, soil, dew point) and rice quality. These variables could then be assigned to individual fields.

 Finally, production and environmental factors that affect head yields during grain maturation are being studied at two levels — regionally with data provided by FRC and on-farm using grower provided information.  Timely acquisition of the needed information remains a challenge. Preliminary analysis points are needed to ascertain the relative importance of environmental variables, grain-wetting-cycles and duration of dew in the context of grain maturity.