Comportamento del riso crodo nell'emergenza

The results are summarized of field trials conducted at Olcenengo in 1994-96 to study the effects on the emergence of crodo rice (Oryza sativa var. sylvatica) of environmental conditions and agronomic practices. In untilled soil irrigated at the end of March, emergence began in mid-April, reached a maximum at the beginning of May and was completed by the end of May. There was a correlation between the method of soil cultivation (no-tillage, disc or rotary harrowing and ploughing) and crodo rice emergence in land under either rice cultivation or set-aside; in general lowest emergence rates were obtained by ploughing to a depth of 10-20 cm in March. Emergence rates also fell with depth of ploughing, and this effect was more pronounced at high humidity. A study of seed longevity indicated that percentage germination fell from some 90% for freshly interred seeds to 20% after 2 years.