Controlling Gorse Seed Banks

“Gorse (Ulex europaeus L.) is a major agricultural and environmental weed in many parts of the world and has a persistent seed bank. Several techniques were investigated to either kill the seed or encourage it to germinate. Scarification of the seed coat resulted in almost complete germination of seeds. Smoked water had little effect on intact seed and high concentrations killed scarified seed. Gorse seed tolerated soaking in many organic compounds, however two bipyridyl herbicides at approximately 100-125 kg a.i ha-1 killed seed. Low levels of microwave radiation tended to increase germination and at high levels killed seed. Solarization did not give adequate control of seed banks. Gorse seed germinated over a range of temperatures from 14-24°C and appeared to have a bimodal optimum. Nearly all the seed is in the top 20 cm of soil and occurs within a few metres of the parent plant and seed will not establish from depths of more than 10 cm, so burial of isolated patches is a possible control technique. Potential seed bank control techniques and further research are discussed.”