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.
The male anthers of the flower are removed by vacuum suction
leaving only the female stigma.
Plants without their anthers removed are used as a male pollen
Paired male and female panicles are isolated under small bags to
allow for cross pollination to occur.
After a few days the F1hybrid seed can be observed to be
Female panicles producing hybrid seed are labeled with a unique
cross number. One hundred to two hundred crosses are
made each year.
The hybrid seed are germinated and seedlings are produced
in the greenhouse.
Hybrid seedlings are transplanted to the field and are protected
from birds by netting.
Laser leveling equipment is used to produce a uniform slope
across the field to facilitate watering and draining the fields
Levees are prepared to separate each experimental field trial.
Experimental yield plots are planted using the most promising breeding lines.
After planting, fertilizer is applied using specialized equipment.
Gates and tiles are placed in levees to facilitate irrigating and
draining of individual fields.
Laterals between levees are filled with water using an
underground water system.
The filled lateral is used to push water into experimental blocks.
Flexible tiles are lifted out of the water when the field is flooded.
About 10 days after planting seedlings emerge through the soil
and differences in vigor can be observed.
Breeding lines with poor seedling vigor are eliminated from
Field plots are trimmed to a uniform length using a herbicide
Additional fertilizer is applied to the plots prior to flowering.
As plots begin to flower, maturity notes are recorded.
After plots have flowered, plant height is recorded.
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 agricultural chemicals is sometimes
As the plots ripen, samples are harvested at a grain moisture
level that will produce the best milling yield.
Some plots are hand harvested to maintain seed purity.
Each hand harvested plot is bundled and tagged with a bar
coded number that uniquely identifies it.
Hand harvested bundles are hauled out of the flooded field and
are transported to a thresher
Tagged bundles are hung separately in a screened area
protected from birds.
Grain is stripped off of each bundle with a thresher.
Straw and chaff is removed from each threshed sample.
Bar codes on tags are used to track yield data for each sample.
Some plots are harvested using a small plot combine.
Grain from each plot is captured in a separate sack and tagged.
Straw from the main crop harvest is removed from experiments
where a ratoon (second) crop will be harvested.
Stubble from the main crop is flooded and fertilized, and soon
the ratoon crop is observed to be developing.
Flowering of the ratoon crop occurs in the fall.
Data are summarized and scientists share research results
with farmers at Field days.
Breeding nursery facilities are used during the winter months
in Puerto Rico.