SEED-GERMINATION OF TYPHA-SUBULATA IN RELATION TO WEED MANAGEMENT

The effects of light and temperature on germination of Typha subulata were examined under a combination of various temperature and light reg imes. The influence of different storage environments was studied by p lacing the seeds in the dark under air-dry conditions or immersed in w ater at 4 +/- 1 and 21 +/- 3C and tested for germination after 6 and 1 4 months. The significance of salinity was assayed by incubating the s eeds in sodium chloride solutions. The seeds of T. subulata exhibited a high potential for germination (88 to 98%) in a wide range (10 to 35 C) of continuous or alternate temperatures. After the 6-month-storage pretreatment, germination was close to 100% in all treatments. The 14- month-old samples showed a germination rate higher than 96% when they were maintained under dry conditions at both temperatures. However, ge rmination decreased to 64% at 4C and 0% at 21C under wet storage, The germination was affected by salinity only at high concentrations. Thes e results indicate that in the irrigation districts of southern Argent ina, the infesting potential of this weed could be minimized by disrup ting the sexual reproductive cycle and by maintaining wet channel beds during the period of irrigation recess.