OPERATIONAL SUCESS OF DIRECT SURFACE SEEDING STRATEGIES FOR VERATRUM CALIFORNICUM

Malheur Experiment Station

Information for Sustainable Agriculture

OPERATIONAL SUCCESS OF DIRECT SURFACE SEEDING STRATEGIES FOR

CORN LILY (VERATRUM CALIFORNICUM)

Clint Shock, Erik Feibert, Cheryl Parris, and Lamont Saunders, Malheur Experiment Station, Oregon State University, Ontario, OR

Introduction

Corn lily (Veratrum californicum) is native to higher elevations of the intermountain West. Corn lily is of interest because it has the potential to provide pharmaceutical precursors for use against cancer. Fall planting of seed could be important, because the seed requires a period of cold to break dormancy (vernalization). Fall planting of seed of other native perennials has resulted in poor stands in some years at the Malheur Experiment Station. Loss of soil moisture, soil crusting, bird and rodent damage, seed decomposition, and seedling damping off are some detrimental factors hindering emergence of fall planted seed. Previous trials with native perennial seed at the Malheur Experiment Station have examined seed pelleting, planting depth, and soil anti-crustants (Shock et al. 2010). Planting at depth with soil anti-crustant improved emergence compared to surface planting. Seed pelleting did not improve emergence. Despite these results, emergence of native seed was extremely poor for all treatments due to soil crusting, bird damage, and other factors.

In established native perennial fields at the Malheur Experiment Station and in rangelands we have observed prolific natural emergence from seed that falls on the soil surface and is covered by thin layers of organic debris. This trial tested the effect of four factors on surface planted seed (Table 1). Row cover can be a protective barrier against soil desiccation and bird damage. Sawdust can mimic the protective effect of organic debris. Sand can help hold the seed in place. Seed treatment can protect the emerging seed from fungal pathogens that might cause seed decomposition or seedling damping off. The treatments did not test all possible combinations of factors, but tested the combinations that would theoretically be most likely to result in the best stand establishment. The trials tested five combinations of seed cover, row cover, and seed treatment for emergence of three sources of V. californicum seed at two sites; Ontario, Oregon and McCall, Idaho.

Materials and Methods

Seed weights for three seed sources (Table 2) of corn lily were determined. A portion of the seed was treated with a liquid mix of the fungicides Ridomil MZ58 and Captan (100g Ridomil, 100g Captan in 1 liter of water). Seed weights of the treated seeds were determined after treatment. The seed weights were used to make seed packets containing approximately 600 seeds each. The seed packets were assigned to one of five treatments (Table 1). One trial was planted manually on November 5, 2009 at McCall, Idaho. Another trial was planted manually on November 12, 2009 at Ontario, Oregon. Planting simulated mechanical planting.

Additional sources of loss of stand could be rodent damage, insect damage, or early drying of the soil. Mouse bait packs were scattered over the trial area. Plants were regularly observed and protected from insect damage, if it occurred. The seed beds and seedlings were supplied drip irrigation if the soil dried.

The experimental designs were randomized complete blocks with six replicates. Plots were 1 30-inch bed by 5 ft long. Two 5-ft-long rows were planted on each bed.

Table 1. Treatments evaluated for emergence of corn lily (Veratrum californicum).

	row cover	sawdust	seed treatment*	sand
Treatment	row cover	sawdust	seed treatment*	sand
1	yes	yes	yes	yes
2	yes	yes	yes	no
3	yes	yes	no	no
4	yes	no	yes	no
5	no	yes	yes	no

*mixture of Captan and Ridomil fungicides for prevention of seed decomposition and seedling damping off.

Table 2. Seed sources of corn lily (Veratrum californicum) submitted to emergence treatments.

Source	Origin	Untreated seed weight	Tetrazolium test
		Seeds/g	%
1	Manti-La Sal National Forest, Utah	202.2	71
2	Sawtooth Mountains, Idaho	226.9	98
3	Central Mountains, Idaho	219.3	69

A tetrazolium test was run to determine corn lily seed viability from the three sources (Table 2). The tetrazolium results were used to correct the raw emergence data to be the emergence of viable seed.

After planting, sawdust was applied in a narrow band over the seed row at 0.26 oz/ft of row (558 lb/acre). For the treatments receiving both sawdust and sand, the sand was applied at 0.65 oz/ft of row (1,404 lb/acre) as a narrow band over the sawdust. Following planting and sawdust and sand applications, some of the beds were covered with row cover. The row cover (N-sulate, DeWitt Co., Inc., Sikeston, MO) covered four rows (two beds) and was applied with a mechanical plastic mulch layer.

At Ontario, the field was drip-irrigated for 24 hours on November 20 to ensure adequate moisture for germination. On March 13, 2011, the row cover was removed and emergence counts were made in each plot. Emergence counts were again taken on March 23, and April 13.

At McCall, the row cover was removed and corn lily emergence counts were made in each plot on May 13, 2010.

Data were analyzed using analysis of variance (General Linear Models Procedure, NCSS, Kaysville, UT). Means separation was determined using Fisher’s least significant difference test at the 5 percent probability level, LSD (0.05).

Results and Discussion

There was no significant difference between seed sources in the response to the planting treatments (Tables 3 and 4). Averaged over seed sources, row cover with sawdust and seed treatment (treatment 2) significantly improved emergence over bare soil with sawdust and seed treatment (treatment 5) at both Ontario and McCall. Sand with row cover, sawdust, and seed treatment (treatment 1) did not improve emergence over no sand with row cover, sawdust, and seed treatment (treatment 2) at either site.

In comparing treatment 2 (row cover with sawdust and seed treatment) with treatment 3 where the seed treatment was omitted, the seed treatment was detrimental to corn lily emergence and stands at both Ontario and McCall.

In comparing treatment 2 (row cover with sawdust and seed treatment) with treatment 4 where the sawdust was omitted, the effect of sawdust was detrimental to corn lily emergence at Ontario and beneficial to corn lily emergence at McCall.

In conclusion, at Ontario, row cover was the important factor in improving emergence. At McCall, row cover and sawdust were the important factors in improving emergence.

References

Shock, C.C., E.B.G. Feibert, L.D. Saunders, and N. Shaw. 2010. Emergence of native plant seeds in response to seed pelleting, planting depth, scarification, and soil anti-crusting treatment. Oregon State University Agricultural Experiment Station, 2009 Annual Report:218-222.

Table 3. Emergence of corn lily (Veratrum californicum) from three seed sources in response to 5 treatments applied at planting in the fall of 2009 in Ontario, OR. Corn lily emergence for each source was corrected to the percent emergence of viable seed. Means within columns followed by the same letter are not significantly different at P = 0.05 according to Fisher’s protected LSD. Malheur Experiment Station, Oregon State University, Ontario, OR.

					Source 1	Source 2	Source 3	Average over sources
Trt.	row cover	sawdust	seed treatment	sand	Apr 13	Apr 13	Apr 13	Average over dates	Mar 13	Mar 23	Apr 13
					---------------------------------------------- % ---------------------------------------------------------
1	yes	yes	yes	yes	27.9	27.7	27.7	18.7b	11.72	16.6	27.8b
2	yes	yes	yes	no	30.0	23.1	25.5	17.2b	10.2	15.1	26.2b
3	yes	yes	no	no	36.8	32.7	34.5	24.3a	15.2	23.0	34.7a
4	yes	no	yes	no	42.2	31.3	33.7	23.8a	14.6	21.1	35.7a
5	no	yes	yes	no	0.0	0.4	0.4	0.2	0.1	0.1	0.2c
LSD (0.05)		Treatment						4.1
		Seed source						NS
		Trt X Date						5.4

Table 4. Emergence of corn lily (Veratrum californicum) from three seed sources in response to 5 treatments applied at planting in the fall of 2009 in McCall, ID. Emergence for each source was corrected to the percent emergence of viable seed. Means within columns followed by the same letter are not significantly different at P = 0.05 according to Fisher’s protected LSD. Malheur Experiment Station, Oregon State University, Ontario, OR.

	row cover	sawdust	seed treatment	sand	Source 1	Source 2	Source 3
Trt.	row cover	sawdust	seed treatment	sand	May 13	May 13	May 13	Average

1	yes	yes	yes	yes	52.2	36.5	39.6	42.8b
2	yes	yes	yes	no	44.3	43.4	40.4	42.7b
3	yes	yes	no	no	58.7	44.5	48.3	50.5a
4	yes	no	yes	no	32.3	32.7	42.5	35.8c
5	no	yes	yes	no	2.4	2.6	4.5	3.2d
LSD (0.05)		Treatment			6.2
		Seed source			NS
		Trt X Sel			NS

Cite as:

Shock, C.C., E.B.G. Feibert, C.A. Parris, and L.D. Saunders. 2011. Operational Success of Direct Surface Seeding Strategies for Corn Lily (Veratrum californicum). p 204-207. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2010, Department of Crop and Soil Science Ext/CrS 132.