Pests - 70
 

 

 

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A SINGLE BLACKBIRD CAN DESTROY AN OUNCE OF RICE A DAY

And sometimes 1 to 2 million blackbirds will occupy an area along a slough or wild area by a rice field. So there is good news in promising repellents (not poisonous) now being tested. Registration for this use must wait on wider tests in 1971, including any environmental problems.

CARBOFURAN AND BUX DID NOT FAZE TADPOLE SHRIMP BUT KILLED WATER WEEVIL

Hatched-out shrimp populations were suppressed only a little -- if at all -by 1/2 pound active chemicals per acre applied to the soil surface.

Rice water weevils are most troublesome in counties north of the Sutter Buttes, concentrating along margins of fields adjacent to levees. For more specifics, see "1971 U.C. Pest and Disease Control Program for Rice."

RESISTANCE TO WATER WEEVIL LOOKS POSSIBLE IN THREE RICE LINES

These lines were selected from 7,640 varieties examined. They are being intercrossed to intensify any resistance. Work continues on other control methods. Adult numbers were not reduced appreciably by fall burning of levees (where weevils overwinter at base of grasses).

SHORT VARIETIES, RESISTANT TO LODGING, ARE COMING CLOSER

Crosses between California and short varieties have produced thousands of lines 18 to 30 inches high.

CHEMICALS DID POORLY IN TESTS AGAINST LODGING

RH531 eliminated lodging and shortened plants but seriously reduced yields in both 1969 and 1970. Cycocel applied as a foliar spray at the jointing stage had no apparent effect. Other chemicals will be screened in 1971.

STRIPPER HARVESTER IS GETTING FIRST TESTS

The aim is no longer to take the entire plant into a machine to separate the grain. Results were very promising in 1970, and a prototype stripper harvester will be tested again in 1971. Success will require a short-statured stiff-strawed nonlodging variety. A successful stripper, likely lighter than present harvesters, could be less costly and maneuver better, covering more acreage in a day.

HARVEST LOSSES ARE EXAMINED IN COMBINE STUDY

To keep harvest losses at acceptable levels in 1971, check your straw rows periodically. Harvest rates above 160 sacks per hour can mean 10 percent losses or more in standing rice. In down rice the loss could reach 20 percent at 150 sacks per hour. Tests showed separation loss was generally much greater than cylinder loss. Modified straw walkers and/or shoes for improved performance will be studied. To estimate your losses in pounds/acre, count seeds on ground in a square foot area, and multiply by 2.9.

 

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