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United States Department of Agriculture

Agricultural Research Service

A Year in the Life of the Breeding Program - A Pictorial Review
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Choice of parents to use in a cross


 Fundamental to the breeding program is the choice of parents
 to be used in a cross to develop a new cultivar. Here the flowering  part
 of the  rice plant is being cut open to expose the sexual parts.

Removal of male anthers


 The male anthers of the flower are removed by vacuum suction
 leaving only the female stigma.

male pollen source 

 Plants without their anthers removed are used as a male pollen

Paired male and female panicles 

 Paired male and female panicles are isolated under small bags to
 allow for cross pollination to occur.

First generation Hybrid seed 

 After a few days the F1hybrid seed can be observed to be

Female panicles producing hybrid seed 

 Female panicles producing hybrid seed are labeled with a unique
 cross number. One hundred to two hundred crosses are
 made each year.

Germinated hybrid seed 

 The hybrid seed are germinated and seedlings are produced
 in the greenhouse.

Transplanted hybrid seedlings 

 Hybrid seedlings are transplanted to the field and are protected
 from birds by netting.

Laser leveling of field 

 Laser leveling equipment is used to produce a uniform slope
 across the field to facilitate watering and draining the fields
 after planting.

Levee preparation 

 Levees are prepared to separate each experimental field trial.

Experimental yield plots planted 

 Experimental yield plots are planted using the most promising breeding lines.

Application of fertilizer 

 After planting, fertilizer is applied using specialized equipment.

Gates and tiles used in irrigation 

 Gates and tiles are placed in levees to facilitate irrigating and
 draining of individual fields.

Lateral watering 

 Laterals between levees are filled with water using an
 underground water system.

Full Lateral 

 The filled lateral is used to push water into experimental blocks.

Flexible tiles 

 Flexible tiles are lifted out of the water when the field is flooded.

Observation of seedling vigor 

 About 10 days after planting seedlings emerge through the soil
 and differences in vigor can be observed.

Elimination of lines with poor seedling vigor 

 Breeding lines with poor seedling vigor are eliminated from
 the program.

Trimming of field plots


 Field plots are trimmed to a uniform length using a herbicide
 spray rig.

Additional fertilizer application


 Additional fertilizer is applied to the plots prior to flowering.

Maturity notes taken


 As plots begin to flower, maturity notes are recorded.

Plant height recorded


 After plots have flowered, plant height is recorded.

Disease resistance evaluation


 Breeding lines are also evaluated for resistance to diseases
 like rice blast in inoculated nurseries.



 As the weight of the developing grain increases, some breeding
 lines will lodge.

Aerial application of chemicals


 Aerial application of agricultural chemicals is sometimes

Harvesting of plots


 As the plots ripen, samples are harvested at a grain moisture
 level that will produce the best milling yield.

Hand harvesting of plots


 Some plots are hand harvested to maintain seed purity.

Hand harvested bundle


 Each hand harvested plot is bundled and tagged with a bar
 coded number that uniquely identifies it.

Transporting bundles


 Hand harvested bundles are hauled out of the flooded field and
 are transported to a thresher

Bundle shed


 Tagged bundles are hung separately in a screened area
 protected from birds.



 Grain is stripped off of each bundle with a thresher.

Straw removal


 Straw and chaff is removed from each threshed sample.

Bar coded tags


 Bar codes on tags are used to track yield data for each sample.

Small combine


 Some plots are harvested using a small plot combine.

Combine harvesting


 Grain from each plot is captured in a separate sack and tagged.

Straw disposal


 Straw from the main crop harvest is removed from experiments
 where a ratoon (second) crop will be harvested.

Ratoon crop


 Stubble from the main crop is flooded and fertilized, and soon
 the ratoon crop is observed to be developing.

Flowering of ratoon crop


 Flowering of the ratoon crop occurs in the fall.

Field Day


 Data are summarized and scientists share research results
 with farmers at Field days.

Puerto Rico nursery


 Breeding nursery facilities are used during the winter months
 in Puerto Rico.

Last Modified: 2/23/2005
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