Experiments were conducted to compare rates and formulations of quinclorac for postemergent control of slender speedwell in cool-season turf. A 50% ae wettable powder formulation (50WP) was compared with two granular formulations, a 1% clay granule (1G) and a 0.4% corn cob granule (0.4G). Each formulation was applied at 0.3, 0.6, 0.8, and 1.1 kg ha−1. Additionally, 2,4-D at 1.1 kg ha−1 was applied alone and in combination with quinclorac 50WP at 0.8 kg ha−1. Slender speedwell control with the 50WP or 0.4G formulations was superior to that obtained with the 1G. At lower rates, slender speedwell control with the 50WP was greater than with the 0.4G; however, the rates required to obtain 95% control were not significantly different. Tank mixing quinclorac 50WP at 0.8 kg ha−1 with 2,4-D at 1.1 kg ha−1 did not improve slender speedwell control but increased roughstalk bluegrass injury. Kentucky bluegrass, perennial ryegrass, and tall fescue were not injured by quinclorac. Roughstalk bluegrass and chewings fescue were temporarily discolored. Turf injury was rate-related and more severe with the 50WP than the 1G formulation.

Seed dormancy is the temporary inability of an imbibed seed to germinate under otherwise favourable conditions. It is an important trait for seed persistence in many higher plants. Dormant dehulled red rice caryopses can have a strong dormancy: the studied population shows an almost complete dormancy; that is, these caryopses do not germinate (usually germination is <1–2%) when incubated in water for the time usually adopted for germination tests (i.e. 2 weeks). However, after several months of incubation in water, dormant red rice caryopses start germinating in an anomalous manner. Most notably, the piercing of the caryopsis coat is very slow, sometimes arrested, until the coat completely breaks down and embryo growth is resumed. There is, therefore, a time lag between the initial rupture of the caryopsis coat and the start of seedling growth. It is argued that embryo growth can be triggered by the failure of the caryopsis coat even if seed dormancy has not been previously relieved, and thus germination is started and dormancy is forcefully interrupted. Accordingly, the time course of the anomalous germination shows a Gompertz distribution of times to failure. It is concluded that: (1) if the seed rests with the coat ruptured without further growth, it is still dormant; if so, therefore, (2) the breaking of the coat is not necessarily a marker of germination in this context.