Germination ecology and management of Portulaca oleracea L. - a weed of summer vegetable crops in Punjab Kaur Harnoor1, Kaur Navjyot2,*, Bhullar Makhan S3 1Department of Botany, Punjab Agricultural University, Ludhiana-141004, Punjab 2Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana-141004, Punjab 3Department of Agronomy, Punjab Agricultural University, Ludhiana-141004, Punjab *Corresponding author: navjyot_grewal@yahoo.com
Online published on 12 April, 2021. Abstract Portulaca oleracea L. is a major weed infesting many summer vegetable crops in Punjab. The present study was conducted to evaluate the effect of different environmental factors viz., temperature, light, salinity, pH, moisture stress and seed burial depth on germination and early seedling growth of this weed. The effect of different pre-emergence herbicides on emergence of P. oleracea was also studied. Untreated control seeds of this weed were dormant and exhibited 27% germination. Soaking of seeds in 1000 ppm GA for 24 hrs was most effective in overcoming seed dormancy. Optimum temperature required for germination of P. oleracea was 30°C. Germination of this weed was found to be independent of light, thus it can emerge under tree and crop canopies in both non-cropped and cropped areas. Germination decreased with increase in NaCl concentration from 0 to 250 mM and was inhibited by 50% at 163.56 mM NaCl. Germination also decreased with decrease in osmotic potential from 0 to -0.8 MPa and 50% inhibition of germination was recorded at -0.51 MPa. P. oleracea was able to germinate over a pH range of 6.5 to 8.5. Seedling emergence decreased with increase in seed burial depth and no emergence was observed when seeds were buried at soil depth greater than 2 cm. Emergence of P. oleracea seeds was found to be inhibited by all the tested herbicides viz., oxyfluorfen, pendimethalin, sulfentrazone, oxadiargyl and clomazone. Top Keywords Burial depth, Light, Moisture stress, Salinity, Temperature. Top |