The assay was conducted

between June 2000 and January 2001 at the Fabio Baudrit

Experiment Station of the University of Costa Rica, located

in the San Jose district, in Alajuela, Costa Rica. The objective

of the trial was to assess the influence of 0; 1.85; 3.70; 5.60;

7.40 and 11 metric tons/ha (mt/ha) of dry matter of rice

stubble (Var. CR-5272) as dead mulch on the ground surface,

on the weeds and on the yield of the Huasteco bean variety,

planted with least tilling. It was found that the rice stubble, in

amounts over 3.7 mt/ha on the ground, drastically diminished

the number of weeds, due mainly to the reduction of the

temperature fluctuations and the percentage of

photosynthetic active and total light that reached the soil

surface. Besides, it improved the moisture holding capacity

of the soil. The favorable effects of these factors were

reflected in a greater production of bean grains.