Mulching for weed control: influence of type, depth, herbicide formulation and activation irrigation level on germination and growth of three container nursery weed species^©

This research was conducted to assess the impact of herbicide formulation, mulch type and depth, and activation moisture on germination and growth of crabgrass (Digitaria sanguinalis), garden spurge (Chamaesyce hirta), and eclipta (Eclipta prostrata). Granular or liquid formulations of indaziflam, prodiamine, and dimethanamid-P + pendimethalin were evaluated for control of these weed species by in combination with either pinestraw, pinebark, or hardwood mulch at depths of 0, 2.5, or 5.1 cm (0, 1 or 2 in.) followed by herbicide activation irrigation levels (one-time irrigation level following treatment) of either 1.3, 2.5, or 5.1 cm (0.5, 1, or 2 in.). Weed seed placement (below or above the mulch layer) and light penetration through different types and depths of 0, 1.3, 2.5, 5.1, and 10.2 cm (or 0, 0.5, 1, 2, and 4 in., respectively) of mulches were also analyzed.
Results showed when using herbicides, mulch depth and herbicide formulation had a greater effect on weed control compared with mulch type or herbicide activation irrigation level.
Mulch depths of 5.1 cm (2 in.) and liquid formulations generally provided the highest degree of weed control.
There were no differences in light penetration or weed counts when mulch was applied at levels of at least 2.5 cm (1 in.).

Proceedings of the 2017 Annual Meeting of the International Plant Propagators’ Society

D. Saha, C. Marble, B.J. Pearson, H.E. Perez, G.E. Macdonald, D. Odero, A. Chandler

https://doi.org/10.17660/ActaHortic.2018.1212.69