Disease Control Practices

Disease Control Practices

Fungicides were used on 28% of Northarvest survey respondents' acres, down from 43% in 1997 and
61% in 1996. Fungicides were used on 28% of Minnesota and 27% of North Dakota respondents' acres,
down from 59% and 37%, respectively, in 1997 and from 68% and 59% in 1996. Benlate was the most
widely used fungicide in Minnesota, applied to 19% of respondents acres, followed by Topsin M, applied
to 8% of their acres, and Tilt, applied to 0.4% of their acres. Benlate was the most widely used fungicide
in North Dakota, applied to 13% of respondents' acres, followed by Topsin M applied to 9% of their
acres, Tilt applied to 2%, Bravo applied to 2%, and maneb applied to less than 1% (Tables 10 and 11).

The percentage of acres treated by ground was nearly 9 times that treated by air for all Northarvest
respondents. It was 9 times as great for Minnesota respondents and 8 times as great for North Dakota
respondents (Table 10).

Minnesota respondents sprayed 27% of their acres with the benzimidazole fungicides Benlate and Topsin
M for white mold control, compared with 52% in 1997, 44% in 1996 and 21% in 1995. North Dakota
respondents sprayed 22% of their acres with the benzimidazole fungicides, compared to 28% in 1997,
22% in 1996 and 18% in 1995. In Minnesota 9% of respondents' acres were band sprayed (directed
spray with drop nozzles between the rows) with benzimidazole fungicides and 19% were broadcast
sprayed, a slightly higher percentage of band spraying than in previous years. In North Dakota, 12% of
respondents' acres were band sprayed with benzimidazole fungicides and 10% were broadcast sprayed,
an increase in band spraying from 1996 and 1997. Wet conditions in 1996 and 1997 may have reduced
the ability of respondents to band spray in a timely manner. Use of Benlate in Minnesota was about twice
that of Topsin M and in North Dakota it was about 50% higher (Table 11).

Table 10: Fungicides applied to dry beans in 1998 by respondents in Minnesota and
North Dakota

		Total Acres Treated^c		Acres Treated by Air^c		Acres Treated by Ground
Fungicide^a	Method of Appl.^b	Number	%	Number	%	Number	%
Minnesota
Benlate	Banded	1,880	7.5	0	0	1,880	7.5
Benlate	Broadcast	2,904	11.7	378	1.5	2,526	10.1
Tilt	-	208	0.8	108	0.4	100	0.4
Topsin M	Banded	230	0.9	0	0	230	0.9
Topsin M	Broadcast	1,812	7.3	190	0.8	1,622	6.5
Total Fungicide		7,034	28.2	676	2.7	6,358	25.5
North Dakota
Benlate	Banded	7,117	9.9	0	0	7,117
	Broadcast	<2,040	2.8	570	0.8	1,470	2.0
Bravo	-	1,600	2.2	0	0	1,600	2.2
Maneb	-	850	1.2	200	0.3	650	0.9
	-	1,645	2.3	135	0.2	1,510	2.1
Topsin M	Banded	<1,395	1.9	0	0	1,395	1.9
Topsin M	Broadcast	4,915	6.8	1,205	1.7	3,710	5.2
Total Fungicide		19,562	27.2	2,110	2.9	17,452	24.3
Northarvest
Benlate	Banded	8,997	9.3	0	0	8,997	9.3
Benlate	Broadcast	4,944	5.1	948	1.0	3,996	4.1
Bravo	-	1,600	1.7	0	0	1,600	1.7
Maneb	-	850	0.9	200	0.2	650	0.7
Tilt	-	1,853	1.9	243	0.3	1,610	1.7
Topsin M	Banded	1,625	1.7	0	0	1,625	1.7
Topsin M	Broadcast	6,727	7.0	1,395	1.4	5,332	5.5
Total Fungicide		26,596	27.5	2,786	2.9	23,810	24.6

^{aMention of a trade name does not constitute an endorsement, recommendation nor
preference over other similar

fungicides.

^bRespondents were not asked method of application for Bravo, Maneb or Tilt.

^cRespondents’ acres only.}

Table 11: Fungicides and application methods for white mold control in 1998 in
Minnesota and North Dakota.

Fungicide	Band Applied		Broadcast		Total
Fungicide	Acres	%^a	Acres	%^a	Acres	%^a
Minnesota
Benlate	1,880	7.5	2,904	11.7	4,784	19.2
Topin M	230	0.9	1,812	7.3	2,042	8.2
Total^b	2,110	8.5	4,716	18.9	6,826	27.4
North Dakota
Benlate	7,117	9.9	2,040	2.8	9,157	12.8
Topin M	1,395	1.9	4,915	6.8	6,310	8.8
Total^b	8,512	11.9	6,955	9.7	15,467	21.5
Northarvest
Benlate	8,997	9.3	4,994	5.1	13,991	14.5
Topin M	1,625	1.7	6,727	7.0	8,352	8.6
Total^b	10,622	11.0	11,721	12.1	22,343	23.1

^{aPercent of respondents’ acres

^bTotal of Benlate and Topin M}

Rust fungicides were used on 4% of Northarvest respondents' acres, compared to 9% in 1997 and 34%
in 1996. Tilt, available in both states under a specific exemption (section 18), was used on 2% of
Northarvest respondents' acres, followed by Bravo on less than 2% and maneb on less than 1%. In
Minnesota, Tilt was used on less than 1% of respondents' acres. In North Dakota, Tilt was used on 2%
of respondents' acres, followed by Bravo on 2% and maneb on 1% (Table 12). This dramatic reduction
in use of rust fungicides since 1996 is at least partly due to increased use of pinto varieties that have
resistance to the current rust races, as indicated in the section on varieties grown.

Table 12: Fungicides used for rust control in 1998 in Minnesota and North Dakota

State	Bravo		Maneb		Tilt		Total
State	Acres	%^a	Acres	%^a	Acres	%^a	Acres	%
Minnesota	0	0	0	0	208	0.8	208	0.8
North Dakota	1,600	2.2	850	1.2	1,645	2.3	4,095	5.7
Northarvest Total	1,600	1.7	850	0.9	1,853	1.9	4,303	4.4

^{aPercent of respondents’ acres

^bTotal of Bravo, Maneb and Tilt}