- Author: Luis Espino
Last year we had a bad blast year - several fields that had never experienced blast got the disease and some reported yield losses. This year growers and PCAs are paying more attention to try to prevent the disease from causing damage.
Leaf blast symptoms of the disease begin as small grayish, whitish or bluish spots that enlarge to form diamond shaped lesions.
Lesions can coalesce and cover most of the leaf blades, causing "holes" of dead plants. This holes are usually observed at the edge of the field, in areas where nitrogen was overapplied because of overlap during aqua application. Excess nitrogen make plants more susceptible to infection.
Neck and panicle blast are of economic importance. Infection of the panicles directly reduce yield by causing empty heads that produce little or no grain.
Environmental conditions that favor the disease are extended periods of free moisture on the surface of the plant, night time temperatures between 63-73 F, no wind and high relative humidity.
When treating for blast, time your applications so that the young panicles are protected as they emerge from the boot. The fungicide azoxystrobin inhibits spore germination, and therefore is more effective when applied as a protectant. When using a fungicide, follow label directions and rates.
- Author: Luis Espino
Released June 30, 2011, by the National Agricultural Statistics Service (NASS), Agricultural Statistics Board, United States Department of Agriculture (USDA).
Rice: Area planted to rice in 2011 is estimated at 2.68 million acres, down 26 percent from 2010 and the lowest planted acreage since 1987. Area for harvest is forecasted at 2.65 million acres, down 27 percent from last year.
In all States except California, severe drought conditions, excessive flooding, and higher prices for competing commodities contributed to the decline in rice acres compared to last year. Area planted to rice in Arkansas, the largest rice-producing State, is at the lowest level since 1989. In California, water was in good supply, which allowed growers to plant 3 percent more rice than in 2010.
As of June 19, ninety-seven percent of the rice crop had emerged, on par with the previous year and the 5-year average. Growers in Louisiana and Texas were dealing with salt water intrusion due to the dry conditions. By month's end, 61 percent of the crop was rated in good to excellent condition, compared with 74 percent the same time last year.
Rice Area Planted and Harvested by Class - States and United States:
2010 and 2011
--------------------------------------------------------------------------------
Class and State: Area planted : Area harvested
:---------------------------------------------------------------
: 2010 : 2011 : 2010 : 2011 1/
--------------------------------------------------------------------------------
: 1,000 acres
:
Long grain :
Arkansas .......: 1,595 970 1,590 960
California .....: 6 5 6 5
Louisiana ......: 500 390 495 385
Mississippi ....: 305 185 303 184
Missouri .......: 250 140 248 136
Texas ..........: 185 175 184 173
:
United States ..: 2,841 1,865 2,826 1,843
:
Medium grain :
Arkansas .......: 195 200 194 199
California .....: 510 530 505 527
Louisiana ......: 40 30 40 30
Missouri .......: 3 5 3 4
Texas ..........: 4 5 4 5
:
United States ..: 752 770 746 765
:
Short grain 2/ :
Arkansas .......: 1 1 1 1
California .....: 42 40 42 40
:
United States ..: 43 41 43 41
:
All :
Arkansas .......: 1,791 1,171 1,785 1,160
California .....: 558 575 553 572
Louisiana ......: 540 420 535 415
Mississippi ....: 305 185 303 184
Missouri .......: 253 145 251 140
Texas ..........: 189 180 188 178
:
United States ..: 3,636 2,676 3,615 2,649
--------------------------------------------------------------------------------
1/ Forecasted.
2/ Includes sweet rice.
- Author: Luis Espino
Here's the beginning of the 2011 rice season in three graphs*:
Degree day (DD) accumulation over the developmental threshold of 55 oF (starting May 1st) during early May in 2011 was similar to 2008 and 2009. By mid May, temperatures dropped drastically and DD accumulation for 2011 now resembles more 2010, a cool year. Rice planted early to mid May is behind.
During 2011, there were not enough heat units during mid May and early June (no DD). In comparison, during 2008, heat unit accumulation was high during mid May and increased gradually from the end of May to early June.
Average daily temperatures during early May 2011 were higher than during 2010. However, the trend didn't last long and temperatures dropped in mid May. During late May and early June 2011 temperatures were substantially lower than during the same period in 2010.
What's coming next? Hard to say, but we seem to be facing another unusual year that looks much like 2010.
*All temperatures used are from the CIMIS station #32 at Colusa.
- Author: Luis Espino
The last couple of weeks we had some unusually cold weather. Some days, daytime temperature was 20 degrees below the average for this time of the year. The graph below compares average maximum daily temperatures with actual 2011 maximum daily temperatures during April and May in Colusa County.
Because of the cold weather, rice seedlings aren't growing much. Growth is very slow, and plants seem to lag behind. However, don't think that just because the rice is not growing, other organisms are also slowed down. I've been hearing of shrimp in several fields, and saw some in a field that was planted two weeks ago. Look at the size of the shrimp and the size of the seedlings in the pictures below.
Tadpole shrimp can grow very fast. A few days with water temperatures between 60 and 84 can promote egg germination and shrimp development. Since the rice is growing slower than normal because of the cold weather, it is under more risk of being injured by shrimp. Monitor your field closely during seedling development, and worry about shrimp only until the rice breaks the water surface. Once the rice is out of the water, shrimp will not cause damage. A lengthy discussion of the biology of the tadpole shrimp was included in the May issue of the Rice Briefs newsletter, available at the Colusa County Rice Program website: http://ucanr.org/sites/colusa/rice/Newsletter/
For monitoring and treatment recommendations, go to the UC IPM website: http://www.ipm.ucdavis.edu/PMG/selectnewpest.rice.html
/span>
- Author: Luis Espino
Released May 23, 2011, by the National Agricultural Statistics Service, Agricultural Statistics Board, United States Department of Agriculture