Abstract:
Aeschynomene indica (Fabaceae) (Singhala: Diyasiyambala) is a nitrogen-fixing weed
commonly found in rice fields. This study was undertaken to determine the effect of A.
indica on growth and yield of rice variety LD 365 in comparison with two non-nitrogen
fixing weeds Fimbristylis miliacea (Singhala:Kudamatta) and Cyperusiria (Singhala:
Thunassa).
Observations were made on the growth and yield of the potted rice variety LD 365
grown with no weeds and with A. indica, F. miliacea and C. iria separately. Shoot length,
number of panicles per plant, number of seeds per panicle, weight hundred seeds were
measured. The experiment was conducted in a Complete Randomized design (CRD) with
3 replicates. Statistical analysis was carried out using the Student Newman-Kuells Means
Separation Test of SAS program (9.1.3).
LD 365 plants grown with A. indica (1:1) had 25.8% higher shoot length, 29% more
number of tillers per plant/ number of panicles per plant, 61% more number of seeds per
panicle and 13% higher seed weight than those grown with no weeds. Furthermore, LD
365 grown with other weed plants showed negative effect of weeds on rice plant growth
and yield. Rice is a N demanding crop Tor better growth and higher yield, therefore Nfixing
weeds could be integrated into rice ecosystem for better productivity with less fertilizer
inputs.
