Germination, growth pattern and competitive ability of erect spiderling (Boerhavia erecta L.)

Results showed that increasing light intensity from 13.46 to 2,800 fc significantly increased the germination percentage of Boerhavia erecta L. seeds in the soil. In the filter paper, direct sunlight reduced germination percentage. Shoots were shorter under high light intensity than in the dark. Root lengths were longer under high light intensity than in the dark. Higher germination percentage was observed from 0-1.0 cm than 2.0-4.0 cm sowing depth. No germination was obtained at a depth of 8-16 cm. Higher germination was observed in 30 to 50% soil moisture than at 20% and 60%. Seeds failed to germinate at 10%, 80%, and 100% soil moisture or saturation. Seeds of B. erecta germinated at pH5 to 7. No germination was observed at pH 4 and 9. Seedlings that germinated at pH6 and 7 had longer shoots and roots than at pH 5 and 8. In two weeks, B. erecta had already formed well developed branches, flowers started to set into fruits and matured in 14 to 16 days after fruit setting. The plant produced as much as 543 to 729 panicles, with 38 to 47 seeds per panicle and at an average range of 20,765 to 29,655 seeds per plant per growing season. The field experiment showed that grain yield obtained at a weed population of 10 to 20 plants/sq m were comparable to plots handweeded three times equivalent to weed-free. Further, increase in weed population from 40 to 150 plants/sq m caused a significant yield reduction ranging from 12.5 to 51.38%. The unweeded plots got the lowest grain yield equivalent to 75% reduction. High population of B. erecta resulted to stunted crop growth with less number of leaves, lighter ear and seed weight, and shorter ear length, consequently, reduction in the total grain yield of corn. Meanwhile, increase in weed population resulted to stunted growth of B. erecta with less number of leaves and branches. Consequently, reduction in the number of panicle per plant and seeds per panicle resulted to a significant reduction in the total number of seeds per plant from 19,987 to 1,982. Weed population from 10 to 20 plants/sq m the number of seeds reduced by 14.0%, 40, 60 and 80 plants/sq m by 21.33 to 48.03%, 100 plants/sq m by 74.0%, 150 plants/sq m by 81.27% and the unweeded plots by 90.06%