Description and Management Guidelines



Home.gif (3162 bytes)

Next.gif (3180 bytes)

Back.gif (3162 bytes)

Agronomy Fact Sheet Series 2001-3


F. Jodari, plant breeder, Rice Experiment Station, Biggs, CA

C.W. Johnson, plant breeder, Rice Experiment Station, Biggs, CA

J.J. Oster, plant pathologist, Rice Experiment Station, Biggs, CA

K.S. McKenzie, plant breeder and director, Rice Experiment Station, Biggs, CA

W.M. Canevari, M.W. Hair, R.G. Mutters and J.F. Williams are Farm Advisors, UC Cooperative Extension, San Joaquin, Colusa/Yolo, Butte/Glenn and Sacramento/ Sutter/Yuba counties respectively

R.L. Wennig, staff research associate, Dept. of Agronomy & Range Science, UC Davis


M-104 is a very early, semidwarf, glabrous, Calrose quality medium grain. It was developed by CCRRF at the Rice Experiment Station (RES) and released to growers in March 2000. Its pedigree consists of all Calrose medium-grain varieties developed at RES.


M-104 is compared to very early maturing M-103 and early maturing M202. Compared to M-103 in statewide tests, it heads at the same time, has improved lodging resistance, yields 8% higher, and has similar whole whole grain and total milled rice yields. Compared to M-202, M104 heads 8 days earlier, has similar resistance to blanking caused by cool temperatures 10 to 14 days before heading during microsporogensis, and has similar yield, seed size and kernel weight. M-104 is susceptible to blast race IG-1 found in California.


M-104 compared to M-103 at the coldest San Joaquin location has consistently exhibited improved seedling vigor, improved lodging resistance and has averaged 3.5% higher yield than M-103. It headed 2 days later than M-103 and 9 days earlier than M-202. Milling sample means taken at 5 different harvest dates from a strip trial of M-104 and M-103 in 1999 at San Joaquin indicate that whole grain and total milled rice yields are similar. Laboratory analysis for physiochemical characteristics (apparent amylose content, protein and gelatinization temperature) by the USDA Rice Quality Laboratory indicate that it fits medium-grain standards. Milled rice samples of M-104, M-103 and M-202 were distributed to various rice marketing organizations and individual rice quality evaluators in 1997 to 1999. Responses from evaluations indicate M-104 is similar to M-202 and M-103 for various cooking and taste characteristics. M-104 can be commingled with other Calrose medium grains.

Summary of Agronomic Characteristics for
M-103, M-104, and M-202
1995 to 1999

Character M-103 M-104 M-202
Seedling vigor (score) 4.3 4.4 4.5
Days to 50% heading 80 80 88
Plant height (cm) 92 91 98
Lodging (%) 49 37 43
Blanking - Davis 7 16 12
Blanking - San Joaquin 8 13 18
Blanking - Greenhouse 22 21 24
Harvest moisture (%) 18.8 18.2 21.4
Yield (lb/acre @ 14%) 8087 8801* 8790
Stem rot score 5.4 5.4 5.2
Milling (%) total 68.1 67.8 67.2
Milling (%) whole grain 63.4 63.1 61.0
Brown rice 1000 grain wt (gms) 22.1 24.4 24.0
Brown rice length (cm) 5.8 6.4 6.2
Brown rice width (cm) 2.7 2.9 3.0
Ratio (L/W) 2.15 2.21 2.06

* - M-104 yielded significantly higher than other entries (LSD( 0.05)

Summary of Agronomic Characteristics for
M-103, M-104, and M-202
1996 to 1999 at San Joaquin

Character M-103 M-104 M-202
Seedling vigor (score) 4.0 4.5 4.1
Days to 50% heading 90 92 101
Plant height (cm) 82 84 86
Lodging (%) 21 9 12
Harvest moisture (%) 20.5 21.6 23.9
Yield (lb/acre @ 14%) 8800 9107 8550
Milling (%) total 73.2 73.1 ---
Milling (%) whole grain 66.1 67.9 ---

Area of Adaptation

M-104 is being released as a Calrose medium grain. It is a viable, very early, medium-grain replacement for M-103 in the coldest rice production areas (San Joaquin) with improved seedling vigor, lodging resistance and kernel size. It also has a small yield improvement over M-103 with similar milling yield potential. M-104 also has potential as an alternative to, and/or may be used in conjunction with, M-202 in the cooler rice production areas because of its yield potential and milling qualities. Geographic lines for production may be areas east of Highway 70 and south of Highway 20. It could also be used for late plantings or for early plantings for duck clubs in the warmer production areas. M-104 can be best described as a very early maturing Calrose medium grain with M-202 kernel size that has better seedling vigor, lodging resistance and higher yield potential than M-103.

Management Guidelines

The following guidelines are based on research, observation and experience gained in developing M-104. These suggested cultural practices are intended to assist in the production of optimum yields and quality of M-104.

  • Uniform water depth, fertility, seed distribution and weed control are important because they affect heading, harvest moisture and in turn head rice milling yield.
  • Fertilizer rates and management should be similar to those for M-103 and M-202 in your production area.
  • Preferred seeding dates are the same as for M-103 and M-202. Be aware that planting early in warmer production areas can limit yields and head rice potential. M-104 should be seeded at the rate of 130 to 150 lbs/acre or similar to the rate utilized for M-204 in you area. Excessive seeding rates reduce yield potential and increase susceptibility to disease.
  • Water depth should be increased to about 8 inches before panicle initiation (55 to 60 days after planting) to heading to protect panicles from low temperature exposure during occasional cool nights.

Home.gif (3162 bytes)Next.gif (3180 bytes)Back.gif (3162 bytes)