[ti:Ideas for Getting a Firm Grip on Weed Control ] [ar:Jim Tedder] [al:Agriculture Report] [by:www.51voa.com] [00:00.00]This is the VOA Special English [00:02.89]Agriculture Report. [00:04.82]When is a plant [00:06.63]considered a weed? [00:08.55]Experts at Penn State University [00:11.85]have a simple answer: [00:13.53]When the undesirable qualities [00:16.58]outweigh the good qualities. [00:19.44]Consider that crops generally [00:22.24] produce several hundred seeds [00:24.34]from each plant. [00:25.71]By comparison, each weed plant [00:29.13]can produce tens or even [00:31.37]hundreds of thousands of seeds. [00:33.92]And some buried seeds [00:36.53]can survive up to forty years [00:39.58]-- or even longer. [00:41.63]Eradicating weeds means [00:44.76] that you have to remove [00:46.00]all the seeds and roots [00:48.49]so the plants will not grow back. [00:50.93]But birds or the wind can [00:54.85]reintroduce them to the land. [00:56.78]A more common way [00:59.26]to deal with weeds [01:00.57]is to control them enough [01:03.00]so that the land can be used [01:05.55]for planting. [01:06.79]Experts advise using two [01:09.65]or more control methods [01:11.58]to deal with weeds. [01:13.45]Chemical weed killers [01:16.49]or natural treatments [01:18.11]like corn gluten [01:20.04]can suppress weed growth. [01:22.09]Dense planting of a crop [01:24.83]can also act as a natural control. [01:28.00]Bill Curran at Penn State [01:31.42] in University Park, Pennsylvania, [01:33.48]is a professor of weed science. [01:36.53]He says one of the most common [01:39.45]methods for suppressing weeds [01:41.56]is dense planting. [01:43.55]He says a dense, competitive crop [01:46.98]that quickly shades the soil [01:49.53]will help suppress many weeds. [01:52.01]The seeds need light to grow, [01:55.56]so blocking the sun [01:57.49]will reduce weed growth. [01:59.42]Other controls include [02:01.97]turning over the soil, [02:03.52]pulling the weeds or covering them [02:06.57]with mulch made of wood, [02:09.00]garden waste or other material. [02:12.04]But even mulch has its limits. [02:15.90]Natural resource specialists [02:18.82]point out that weeds can be [02:21.07]transported in mulch. [02:23.06]This is also true of soil, [02:25.73]grain, hay and animals. [02:28.72]Yet animals like sheep [02:31.58]or goats eat weeds, [02:33.57]so they can provide [02:35.31]a biological control. [02:37.36]Insects and other organisms [02:40.60]can also act as biological controls. [02:43.52]Preventing the spread of weeds [02:46.94]is an important part [02:49.06]of weed management. [02:50.86]Farm vehicles should be kept [02:54.65]out of areas with weeds. [02:57.02]If that is not possible, [02:59.69]then clean off the equipment [03:02.56]and your shoes when leaving. [03:05.79]Some people burn weeds [03:08.96]or bury them deeply [03:10.83]or make them into mulch. [03:13.69]Professor Curran says [03:16.49]another way to make use [03:18.35]of weeds is to compost them. [03:21.09]The process of making [03:23.46]organically rich compost [03:25.63]produces heat. [03:27.38]The heat will kill many, [03:29.86]though not all, weed seeds. [03:32.72]The same is true of seeds [03:35.34]that pass through animals [03:37.02]that graze on weeds. [03:39.38]And that's the VOA Special English [03:42.68]Agriculture Report, [03:44.04]written by Jerilyn Watson. [03:46.35]Tell us about your own struggle [03:49.02]against weeds. [03:50.14]You can post comments [03:52.19]at 51voa.com. [03:56.80]I'm Jim Tedder.