| 1 | Plant large cacti at the back of the garden. | |
| 2 | Similar levels of such particles were found in the discharge from nearby sewage treatment plants. | |
| 3 | Brown streak also spreads if farmers sell or give away cuttings of infected plants. | |
| 4 | In many wind-pollinated species, plants flower all together, and for a brief time. | |
| 5 | Some farmers fear, however, that cross-pollination could create lower-quality hybrid plants and lead to economic losses. |