Disease Problems

1996 Dry Bean Grower Survey of Pest Problems and Pesticide Use in Minnesota and North Dakota
ER 44
1998

Disease Problems

White mold was the worst disease problem for 76% of survey respondents on 70% of their acres, followed by rust for 11% of respondents on 9% of their acres. White mold was the worst disease problem on 76% of Minnesota and 68% of North Dakota respondents' acres. This value is slightly less than reported for white mold in 1995 by North Dakota respondents, but is an increase from the 61% reported by Minnesota respondents in 1995. Rust was the worst disease problem on 4% of Minnesota and 11% of North Dakota respondents' acres. Root rot, bacterial blight and Alternaria were the worst disease problems on only a small percentage of respondents’ acres (Table 15).

White mold was ranked as one of the three worst disease problems by Northarvest survey respondents on 78% of dry bean acres reported, the same as in 1995. Rust was ranked as one of the three worst diseases on 50% of respondents' acres, slightly higher than in 1995. Bacterial blight was reported as one of the three worst disease problems on 19% of dry bean acres reported, similar to 1995. Root rot was reported as one of the three worst disease problems on 10% of Northarvest respondents' acres (Table 16).

White mold was cited as one of the three worst disease problems slightly more frequently in Minnesota than in North Dakota (81% of respondents' acres compared to 77% in North Dakota). Rust was cited more frequently in North Dakota than in Minnesota (55% of respondents' acres compared to 34% in Minnesota). Root rot was cited as one of the three worst disease problems twice as frequently in Minnesota as in North Dakota (17% of respondents' acres compared to 8% in North Dakota) (Table 16).

White mold was ranked as the worst disease problem in all Minnesota and North Dakota districts. Rust was the second worst disease problem in MN3, ND1, ND3 and ND5. Root rot was ranked as the second worst disease problem in MN4 and MN5. Neither rust nor root rot were ranked very highly when compared to white mold (Table 17).

White mold also ranked as one of the three worst diseases in all Minnesota and North Dakota districts. Root rot was reported as one of the three worst diseases, second only to white mold, in MN2, MN4 and MN5, a problem on 39%, 19% and 17% of respondents' acres, respectively. Rust was reported as one of the three worst diseases, second only to white mold in MN1 and all North Dakota districts, a problem on 60%, 68%, 51%, 56%, 58% and 41% of respondents acres, respectively (Table 18).

The data indicate that white mold was a serious problem throughout the Northarvest growing area. Rust was more frequently cited as a problem in those districts where pinto beans were the dominant planted class. Root rot was more frequently cited as a problem in those districts where kidney beans were an important or dominant class.

Table 15. Worst disease problem^{^a} in 1996 for respondents in
Minnesota and North Dakota.

Worst Disease Problem	Respondents^{^b}		Acres reported^{^c}
Worst Disease Problem	Number	%	Number	%
Minnesota
White Mold	152	75.2	41,460	76.3
Rust	10	5.0	2,210	4.1
Root Rot	9	4.5	1,453	2.7
Bacterial Blight	2	1.0	310	0.6
Alternaria	1	0.5	77	0.1
None	28	13.9	2,561	4.7
North Dakota
White Mold	309	76.7	115,383	67.6
Rust	54	13.4	18,536	10.9
Bacterial Blight	10	2.5	3,243	1.9
Root Rot	3	0.7	1,188	0.7
Alternaria	1	0.2	163	0.1
None	26	6.5	5,720	3.4
Northarvest Total
White Mold	461	76.2	156,843	69.7
Rust	64	10.6	20,746	9.2
Bacterial Blight	12	2.0	3,553	1.6
Root Rot	12	2.0	2,641	1.2
Alternaria	2	0.3	240	0.1
None	54	8.9	8,281	3.7

^aRanked as No. 1 disease problem by respondents.
^bBased on 202 responding in Minnesota and 403 responding in North Dakota.
^cRespondents’ acres only.

Table 16. Diseases ranked as one of the three worst^{^a} in 1996 by
respondents in Minnesota and North Dakota.

No. 1, 2 or 3 Disease Problem	Respondents		Acres Reported^{^b}
	Number	%	Number	%
Minnesota
White Mold	165	72.1	44,168	81.2
Rust	56	24.5	18,209	33.5
Root Rot	38	16.6	9,234	17.0
Bacterial Blight	32	14.0	8,860	16.3
Alternaria	2	0.9	332	0.6
None	28	12.2	2,561	4.7
North Dakota
White Mold	357	77.1	131,309	76.9
Rust	241	52.1	94,126	55.1
Bacterial Blight	72	15.6	33,089	19.4
Root Rot	36	7.8	12,823	7.5
Alternaria	13	2.8	6,702	3.9
None	26	5.6	5,720	3.4
Northarvest Total
White Mold	522	75.4	175,477	78.0
Rust	297	42.9	112,335	49.9
Bacterial Blight	104	15.0	41,949	18.6
Root Rot	74	10.7	22,057	9.8
Alternaria	15	2.2	7,034	3.1
None	54	7.8	8,281	3.7

^{aRanked as No. 1, 2 or 3 disease problem by respondents.

^bRespondents’ acres only.}

Table 17. Worst disease problem^{^a} in 1996 in each Northarvest district
for respondents in Minnesota and North Dakota.

Northarvest District	Worst Disease Problem	Respondents		Acres Reported^{^b}
Northarvest District	Worst Disease Problem	Number	%	Number	%
Minnesota
MN1	White Mold	60	92.3	20,694	81.2
MN2	White Mold	12	80.0	5,418	87.0
MN3	White Mold	22	61.1	3,611	66.9
	Rust	3	8.3	350	6.5
MN4	White Mold	35	79.5	4,900	79.9
	Root Rot	4	9.1	475	7.8
MN5	White Mold	23	54.8	6,837	61.5
	Root Rot	3	7.1	678	6.1
North Dakota
ND1	White Mold	81	78.6	27,370	72.8
	Rust	16	15.5	4,181	11.1
ND2	White Mold	66	94.3	31,072	85.5
ND3	White Mold	65	63.1	24,221	55.6
	Rust	20	19.4	8,051	18.5
ND4	White Mold	56	94.9	21,716	91.4
ND5	White Mold	41	60.3	11,004	37.4
	Rust	14	20.6	5,514	18.7

^{aDiseases reported as No. 1 problem on more than 5% of respondents’ acres.

^bDistrict reponsdents’ acres only.}

Table 18. Diseases ranked as one of three^{^a} worst in 1996 in each
Northarvest district in Minnesota and North Dakota.

Northarvest District	No. 1, 2, or 3 Disease Problem	Respondents		Acres Reported^{^b}
Northarvest District	No. 1, 2, or 3 Disease Problem	Number	%	Number	%
Minnesota
MN1	White Mold	64	92.8	22,442	88.0
	Rust	39	56.5	15,250	59.8
	Bacterial Blight	15	21.7	6,212	24.4
	Root Rot	8	11.6	3,016	11.8
MN2	White Mold	12	70.6	5,418	87.0
	Root Rot	5	29.4	2,427	39.0
MN3	White Mold	25	61.0	3,961	73.4
	Bacterial Blight	5	12.2	729	13.5
	Root Rot	7	17.1	698	12.9
	Rust	6	14.6	562	10.4
MN4	White Mold	38	73.1	5,115	83.5
	Root Rot	10	19.2	1,180	19.3
	Bacterial Blight	6	11.5	1,064	17.4
MN5	White Mold	26	52.0	7,232	65.0
	Root Rot	8	16.0	1,913	17.2
	Rust	7	14.0	1,453	13.1
North Dakota
ND1	White Mold	95	77.2	31,118	82.8
	Rust	75	61.0	25,490	67.8
	Bacterial Blight	22	17.9	10,325	27.5
ND2	White Mold	69	84.1	31,786	87.4
	Rust	36	43.9	18,439	50.7
	Bacterial Blight	21	25.6	10,672	29.4
	Root Rot	7	8.5	4,189	11.5
ND3	White Mold	83	75.5	31,936	73.3
	Rust	62	56.4	24,570	56.4
	Bacterial Blight	15	13.6	5,727	13.1
ND4	White Mold	57	86.4	21,792	91.7
	Rust	33	50.0	13,659	57.5
	Bacterial Blight	5	7.6	2,596	10.9
ND5	White Mold	53	64.6	14,667	49.8
	Rust	35	42.7	11,968	40.6
	Bacterial Blight	9	11.0	3,769	12.8

aDiseases reported as No. 1, 2, or 3 problem on more than 10% of respondents’ acres;
respondents reporting no problem not included.
^bDistrict respondents’ acres.

This site was last updated on November 14, 2002

202 Hultz Hall
Department of Entomology
College of Agriculture
Fargo, North Dakota 58105-5346
Phone: (701) 231-7581
FAX: (701) 231-8557

For more information, please contact:

Extension Entomologist: Phillip Glogoza pglogoza@ndsuext.nodak.edu