Canola (Brassica napus �Hyola 357 Magnum�)���� �������������� ����������������������������������������������� S. Halley

White Mold; Sclerotinia sclerotiorum����������������������������������� ��������������� ��������������� ��������������� Langdon Research/Extension Center

North Dakota State University

Langdon, ND 48249

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Adjuvants to Enhance the Efficacy of BASF 510 (Endura) Fungicide for Control of Sclerotinia sclerotiorum, 2003.

 

����� Adjuvants often are recommended added to fungicides for improved consistency under different environmental conditions. The objective of this study was to determine if efficacy of fungicide, BAS 510 (boscalid), can be enhanced by addition of different adjuvants (Preference, Activate Plus, Rivet, and Placement and experimental adjuvants AG 01023, AG 02059, AG 02013, AG01005, and AG 02013 + Preference). �Hyola 357 Magnum� canola, a roundup ready cultivar, was planted for evaluation of BAS 510 with different adjuvants 5 May with a double disk drill, disks, plot area spaced 6-inches apart, with 12 inch space followed by additional rows to reduce potential spray drift to adjoining plots. The field, soil type Cresbard-Svea complex, was located at the Langdon Research Extension Center. The selected trial area was previously cropped sunflower that had Sclerotinia sclerotiorum (Lib.) de Bary infection. The area was planted to plots 7 rows wide 16 ft. long in a RCB design with six replicates. Recommended production practices for Northeast North Dakota, NDSU Extension, were followed. Conditioned sclerotia were hand broadcast at about 100 grams / plot on 23 May. On 29 May an application of Roundup Ultra at 1 qt/acre was sprayed in 10.1 gpa at 25 psi for weed control. A second application of Roundup Ultra was applied on 14 June at a rate of 1.5 pts/acre in 17 gpa at 30 psi. Fungicides were applied on 10 July with CO₂ backpack sprayer with XR8002 nozzles orientated vertically in 18.4 gpa solution at 40 psi at 3:00 p.m. Canola was at growth stage 20 to 30% bloom. BAS 510 with �Placement�, and both �AG 02013� alone, and in combination with �Preference� were premixed and added to warm water for mixing. No compatibility problems were apparent. Low wind (4.7 mph, direction west) was present at spraying. A small rain shower (0.1 inches) occurred < 2 hours after spraying. Air temperature was 66� F with a relative humidity of 75 %. On 11 July an application of ascospores (approximately 5000/ml) were sprayed in 9 gpa water at 11:00 a.m. to increase chances of sclerotinia infection. The trial was swathed on 15 August and combined with a Hege plot combine on 2 September and the grain sample cleaned and processed for yield, and test weight measurement and % oil determination. Data was analyzed with the general linear model (GLM) in SAS. Least significant differences (LSD) were used to compare means at the 5% probability level.

 

����� All the adjuvants mixed well with the fungicide. No visible phytotoxicity was evident throughout the summer. Neither Sclerotinia nor Leptosphaeria maculans (blackleg) developed at this site but were present on the same cultivar at other station locations where supplemental water was added. A lack of precipitation during flowering, low relative humidity, and low soil moisture likely caused this difference between locations. No differences in test weight and oil were measured. A significant difference in yield was measured between BAS 510 with Preference, BAS 510 with AG 02059, BAS 510, BAS 510 with Rivet, and BAS 510 with AG 02013 and the untreated.� Some apparent yield enhancement was provided by fungicide application but the response could not be attributed to visible white mold or blackleg disease reduction. A further yield enhancement occurred with the addition of adjuvant AG02059 and Preference compared to fungicide alone. Yield enhancements with adjuvants do not occur often and warrant further investigation. Financial support for this research was received from Agriliance LLC.

 

Fungicide	Adjuvant		Yield	Test	Oil
		Rate		Weight
			lbs	lb/bu	%
untreated			1693	52.0	45.4
BAS 510	None		1979	51.9	45.2
BAS 510	Preference	0.25% v/v	2116	51.8	45.6
BAS 510	Activate Plus	0.25% v/v	1753	51.8	45.8
BAS 510	Rivet	0.5% v/v	2041	51.9	45.8
BAS 510	AG 01023	0.5% v/v	1868	51.8	45.6
BAS 510	AG 02059	0.25% v/v	2117	51.8	45.2
BAS 510	Placement	2 oz/a	1874	51.7	45.4
BAS 510	AG 02013	2 oz/a	1982	51.8	45.2
BAS 510	AG 02013 + Preference	2 oz/a + 0.25% v/v	1805	51.7	45.2
BAS 510	AG 01005	1% v/v	1911	51.8	46.0
LSD Z			264 Y	NS	NS
% C.V.			12	1	2

^Z Tested at 0.05 probability level for mean comparisons.

^Y Significant at 0.028 probability level for mean comparisons