What is claimed is

1.

A method for selecting plants tolerant to a PPO herbicide comprising: a) applying to a population of seeds a seed treatment comprising an amount of a PPO herbicide effective to inhibit the early growth of a seed sensitive to said PPO herbicide, b) placing said population of seeds under conditions sufficient for germination, and c) selecting plants that grow.

2.	A method according to claim 1, wherein said population of seeds is obtained from a cross, wherein one of the parents in the cross is a PPO herbicide tolerant plant.

3.	A method according to claim 1, wherein said population of seeds is obtained from the selfpollination of a PPO herbicide tolerant plant.

4.	A method according to claim 1, wherein said seed tolerant to a PPO herbicide comprises a heterologous polynucleotide encoding a PPO.

5.	A method according to claim 4, wherein said heterologous polynucleotide is under the control of a promoter capable of directing the expression of said heterologous polynucleotide in said seed tolerant to a PPO herbicide or in emerging seedlings derived from said seed tolerant to a PPO herbicide.

6.	A method according to claim 5, wherein said heterologous polynucleotide encodes an PPO herbicide tolerant PPO.

7.	A method according to claim 6, wherein said heterologous polynucleotide is derived from a bacterium.

8.	A method according to claim 6, wherein said heterologous polynucleotide encodes a modified PPO.

9.	A method according to claim 8, wherein said heterologous polynucleotide that encodes a modified PPO is derived from a plant.

10.	A method according to claim 9, wherein said heterologous polynucleotide that encodes a modified PPO is derived from Arabidopsis.

11.	A method according to claim 1, wherein said population of seeds is derived from a monocotyledonous plant.

12.	A method according to claim 11, wherein said monocotyledonous plant is selected from the group consisting of maize, wheat, sorghum, rye, oats, turf grass, rice and barley.

13.	A method according to claim 1, wherein said population of seeds is derived from a dicotyledonous plant.

14.	A method according to claim 13, wherein said dicotyledonous plant is selected from the group consisting of soybean, cotton, tobacco, sugar beet and oilseed rape.

15.	A method according to claim 1, wherein said step of applying to said population of seeds a seed treatment comprises soaking said population of seeds in a composition comprising a PPO herbicide.

16.	A method according to claim 1, wherein said step of applying to said population of seeds a seed treatment comprises coating seeds of said population with a composition comprising a PPO herbicide.

17.

A method according to claim 1, wherein said PPO herbicide is selected from the group consisting of an aryluracil, a diphenylether, an oxadiazole, an imide, a phenyl pyrazole, a pyridyl pyrazole and an other heterocyclyl pyrazole derivative, a pyridyl amide derivative, a 3substituted2aryl4,5,6,7tetrahydroindazole, a phenopylate and Ophenylpyrrolidinoand Ophenylpiperidinocarbamate analogs of said phenopylate.

18.	A method according to claim 1, wherein said PPO herbicide is a NPhenyluracil.

19.	A method according to claim 18, wherein said NPhenyluracil is benzoic acid 2 chloro5 [3, 6dihydro3methyl2, 6dioxo4 (trifluoromethyl)1 (2H)pyrimidinyl] 1, 1dimethyl 2oxo2 (2propenyloxy) ethyl ester (9CI).

20.	A treated seed comprising an amount of a PPO herbicide effective to inhibit the early growth of a PPO herbicide sensitive seed.

21.	A treated seed according to claim 20, wherein said seed is derived from a monocotyledonous plant.

22.	A treated seed according to claim 21, wherein said monocotyledonous plant is selected from the group consisting of maize, wheat, sorghum, rye, oats, turf grass, rice and barley.

23.	A treated seed according to claim 20, wherein said seed is derived from a dicotyledonous plant.

24.	A treated seed according to claim 23, wherein said dicotyledonous plant is selected from the group consisting of soybean, cotton, tobacco, sugar beet and oilseed rape.

25.	A composition comprising an amount of a PPO herbicide effective to inhibit the early growth of a PPO herbicide sensitive seed, wherein said composition is applied to a seed as a seed treatment.

26.

A composition according to claim 25, wherein said PPO herbicide is selected from the group consisting of an aryluracil, a diphenylether, an oxadiazole, an imide, a phenyl pyrazole, a pyridyl pyrazole and an other heterocyclyl pyrazole derivative, a pyridyl amide derivative, a 3substituted2aryl4,5,6,7tetrahydroindazole, a phenopylate and O phenylpyrrolidinoand Ophenylpiperidinocarbamate analogs of said phenopylate.

27.	A composition according to claim 26, wherein said PPO herbicide is a NPhenyluracil.

28.	A composition according to claim 27, wherein said NPhenyluracil is benzoic acid 2 chloro5 [3, 6dihydro3methyl2, 6dioxo4 (trifluoromethyl)1 (2H)pyrimidinyl]1, 1dimethyl 2oxo2 (2propenyloxy) ethyl ester (9CI).

29.	A composition according to claim 25, wherein said amount of a PPO herbicide is between 1 and 160 g aV kg seed.

30.	A composition according to claim 29, wherein said amount of a PPO herbicide is between 2 and 40 g ai/kg seed.

31.	A composition according to claim 30, wherein said amount of a PPO herbicide is between 5 and 20 g ai/kg seed.

32.	A method comprising applying to a seed a composition according to claim 25.

33.

A method for producing PPO tolerant seeds comprising a) producing PPO tolerant plants by transforming plants with a heterologous polynucleotide encoding a PPO b) crossing two plants by pollinating a recipient plant with pollen from a donor plant, wherein at least one of the two plants is tolerant to PPO herbicide c) allowing the pollinated plant to set seeds d) harvesting said seeds; and, optionally e) testing for PPO tolerance by applying a seed treatment comprising a PPO herbicide to seeds resulting from each cross.

34.	The method according to claim 33, wherein the donor plant and the recipient plant are identical.

35.	The method according to claim 33, wherein the donor and/or the recipient plant are from an elite line or from a line for inbred or hybrid seed production.