Studies on the sensitivity of Azolla species to rice herbicides

摘要

Laboratory and green house experiments were conducted during 2002 to find out the sensitivity of different Azolla species to rice herbicides. From the screening experiment in the laboratory, three herbicides viz. anilofos 0.4 kg ha~(-1), butachlor 1.25 kg ha~(-1) and clomazone 0.3 kg ha~(-1) and four species of Azolla viz., A. microphylla, A. filiculoides, TNAU hybrid and Rong Ping hybrid at 500 kg ha~(-1) were chosen and compared independently and in different combinations in the pot culture experiment. Rice var. CO 47 was raised under green house conditions and the experiment was carried out under FRBD with 3 replications. The growth, yield and yield parameters were recorded after imposing the treatments. The results revealed that combination of clomazone 0.3 kg ha~(-1) and A. microphylla performed significantly superior with respect to plant growth, yield attributes and yield. Among the herbicides tried, clomazone application at 03 kg ha~(-1) showed an increase in plant growth characters, yieldattributes and yield. Between the individual Azolla species, A. microphylla recorded the highest grain yield and was on par with A. filiculoides.