Vol. 12, Issue 12 (2023)

Author(s):
Kanhaiya Lal, Mukesh Kumar, Vikram Bharati, Jyostnarani Pradhan and SS Prasad

Abstract:
Managing weeds involves understanding the distribution of weed seeds and how they emerge. Many agronomic practices, such as tillage, influence these factors, thus playing a critical role in weed management strategies. A study during the rainy (kharif) season of 2021 to understand the impact of different crop establishment methods- W1:Puddled transplanted rice (PUTTR); W2:Direct seeded rice on permanent beds (PBDSR)(+R)-with residue; W3:ZTR -Zero till direct seeded rice-R (without residue); W4:ZTR -Zero till direct seeded rice +R (Residue); W5: UPTR-Unpuddled transplanted rice; on the vertical spatial distribution of weed seeds within the soil and the emergence dynamics of distinct weed species was systematically assessed. Based on the results, PBDSR+R and ZTR +R/-R possessed 83% and 17% beads, respectively, in the 0-3 cm and 3-6 cm. There were no beads found in the lesser disturbed soil at the lower depth. Contrary to conventional tillage (PUTTR and UPTR), which resulted in higher soil disturbance, conventional tillage (PUTTR and UPTR) produced only 11% and 21% beads on top layer (preliminary 3 cm) and 21% and 34% on 3-6 cm, 38% and 28% on 6-9 cm and 26% and 13% on 9-12 cm, respectively. A high proportion of weed seeds are buried below 3 cm under PuTTR and UPTR systems, reducing weed incidence. Furthermore, the study revealed that regardless of test weight, the maximum seedling emergence occurred in ZT without residue, followed by ZT+R. However, higher emergence occur in relatively higher test weight. Weeds germinated the least in PuTTR and UPTR. Using tillage methodologies in conjunction with complementary weed control measures, the present study provides valuable insights that can influence judicious decision-making in the field of weed management.