Japanese knotweed, Sakhalin knotweed, and their hybrid, Bohemian knotweed, are invasive across much of the United States. Monocultures formed by these species threaten natural riparian areas, and effective methods of control are being sought. Injection of herbicide is a relatively new control technique with no known published results. Bohemian knotweed was injected with four treatment dosages: 1 ml (0.03 oz) (0.48 g ae) (0.017 oz ae), 3 ml (0.10 oz) (1.44 g ae) (0.05 oz ae), or 5 ml (0.17 oz) (2.4 g ae) (0.08 oz ae) of undiluted glyphosate (suggested application), and 5 ml (0.17 oz) of a glyphosate : water mix (1 : 1, by vol) (1.2 g ae) (0.04 oz ae). Injections were tested at two heights on the plants: low node, 0.2 m (0.66 ft) (L) or chest height node, 1.0 to 1.3 m (3.3 to 4.3 ft) (M). After 1 mo, average percent injury was greater than 90%, and analysis showed no effect of injection location on the stem and no difference between the suggested 5-ml (0.17 oz) glyphosate application and 3-ml (0.10 oz) application. Nine months after treatment there was a reduction in knotweed height and density, though vigorous regrowth was evident within plots. Although the injection method results in the short-term dieback of injected stems, drawbacks to its use in certain scenarios should be considered when developing an integrated management plan for knotweed control.

This study assessed the effects of oocyte age, cumulus cells and injection methods on in vitro development of intracytoplasmic sperm injection (ICSI) rabbit embryos. Oocytes were recovered from female rabbits superovulated with PMSG and hCG, and epididymal sperm were collected from a fertile male rabbit. The oocyte was positioned with the first polar body at 12 o'clock position, and a microinjection needle containing a sperm was inserted into the oocyte at 3 o'clock. Oolemma breakage was achieved by aspirating ooplasm, and the aspirated ooplasm and sperm were re-injected into the oocyte. The injected oocytes were cultured in M199 medium containing 10% fetal calf serum at 38 °C with 5% CO2 in air. The results showed that oocytes injected at 1 h post-collection produced a higher (p<0.05) fertilization rate than those injected at 4 or 7 h post-collection. Blastocyst rate in the 1 h group was higher (p<0.05) than in the 7 h group. Denuded oocytes (group A) and oocytes with cumulus cells (group B) were injected, respectively. Rates of fertilization and development of ICSI embryos were not significantly different (p<0.05) between the two groups. Four ICSI methods were applied in this experiment. In methods 1 and 2, the needle tip was pushed across half the diameter of the oocyte, and oolemma breakage was achieved by either a single aspiration (method 1) or repeated aspiration and expulsion (method 2) of ooplasm. In methods 3 and 4, the needle tip was pushed to the oocyte periphery opposite the puncture site, and oolemma breakage was achieved by either a single aspiration (method 3) or repeated aspiration and expulsion (method 4) of ooplasm. Fertilization rate in method 2 was significantly higher (p<0.05) than in methods 1 and 3. Blastocyst rates were not significantly different (p<0.05) among methods 1, 3 and 4, but method 2 produced a higher (p<0.05) blastocyst rate than method 3.