Impact of crop establishment on major weeds and their vertical distribution in rice Lal Kanhaiya1, Bharati Vikram, Kumar Mukesh*, Pramanick Biswajit, Jat Raj Kumar, Prasad S.S., Pradhan Jyostnarani Department of Agronomy, Dr Rajendra Prasad Central Agricultural UniversityPUSA, Samastipur, Bihar, 848125, India 1Krishi Vigyan Kendra, Kishanganj, BAU, Sabour, Bhagalpur, Bihar, 813210, India *Corresponding author email: mukesh.agro@gmail.com
Online Published on 24 April, 2024. Abstract Weed management strategies across diverse cropping systems must address weed seed distribution and emergence behaviour. Various agronomic practices, including tillage, have been documented to influence these factors, thus assuming a critical role in the formulation of weed management strategies. In a study during the rainy (Kharif) seasons of 2021 and 2022, the impact of different crop establishment methods: puddled transplanted rice (PuTTR); direct-seeded rice on permanent beds (PBDSR)-with residue (+R); zero till direct-seeded rice (ZTDSR)+R/-R; ZTDSR with inversion (+I)+R/-R; unpuddled transplanted rice (UPTR); (+R); ( R) on the vertical spatial distribution of weed seeds within the soil and the emergence dynamics of distinct weed species was systematically assessed. The results unveiled that vertical distribution in PBDSR+R and ZTR +R/-R had 84% of beads (simulated weed seeds) in 0-3 cm and 16% in 3-6 cm. None of the beads were found in the lower depth of lesser disturbed soil. In contrast, conventional tillage (PuTTR and UPTR) had higher soil disturbance resulting in only 12.75% and 22.5% beads on top layer (0-3 cm) and 19.4 % and 34.5 % in 3-6 cm, 36.16 % and 24.8 % in 6-9 cm, 28 % and 14.3% in 9-12 cm, respectively. PuTTR and UPTR systems reduce the weed incidence by bury the high proportion of weed seeds below 3 cm. Furthermore, the study delineated that the maximal seedling emergence of Leptochloa cheninsis, Ammannia baccifera, Echinochloa crus-galli and Caesulia axillaris in ZT without residue followed by ZT+R. R egardless of weed species, the average emergence was 14%. The minimal germination of weeds was in PuTTR and UPTR. This investigation furnishes invaluable insights that may inform judicious decision-making in the realm of weed management, with an emphasis on the judicious integration of tillage methodologies and complementary weed control measures. Top Keywords Ammannia baccifera, Crop establishment, Echinochloa crus-galli, Leptochloa chinensis, Vertical distribution, Weed emergence pattern. Top |