The Rate of Decline of Sugarbeet Cyst Nematode in Central California Under Nonhost Crops May Impact Biofuel Production

Cropping history, field size, and nematodes present other than sugarbeet cyst nematode for the 10 San Joaquin Valley fields (A to J) sampled in the study_

Years	Field Location
	A	B	C	D	E	F	G	H	I	J
−1a	Cabbage	Bok choy	Wheat	Sugarbeet	Sugarbeet	Sugarbeet	Sugarbeet	Sugarbeet		Sugarbeet
0	Cabbage	Bok choy	Sugarbeet	Bean	Bean	Tomato	Tomato	Bean	Sugarbeet	Tomato
1	Tomato	Beans	Beans	Wheat	Wheat	Wheat	Wheat	Wheat	Corn	Corn
2	Cabbage	Cabbage	Tomato	Fallow	Tomato	Tomato	Tomato	Tomato	Fallow	Corn
3	Wheat	Wheat	Wheat	Bean	Tomato	Tomato	Tomato	Tomato	Sugarbeet	Corn
4	Tomato	Tomato	Tomato	Wheat	Wheat	Wheat	Wheat	Wheat	Fallow
5	Wheat	Tomato	Tomato	Corn	Tomato	Tomato	Tomato	Tomato	Fallow
6	Tomato	Beans	Wheat	Bean	Wheat	Wheat	Wheat	Wheat
Size of field (ha)	32	3	32	32	8	8	8	8	32	32
Years out of sugarbeet prior to −1	Unknown	8	7	Unknown	4	4	8	8	4	20
Other plant-parasitic nematodes	none detected	none detected	Pratylenchus sp.	Tylenchorhynchus sp.	Meloidogyne sp., Pratylenchus sp., Xiphinema sp.	Meloidogyne sp., Pratylenchus sp., Xiphinema sp.	none detected	none detected	none detected	Helicotylenchus sp.

Physical characteristics of soils in fields sampled in the study_

		Percent
Field location	Soil type	Sand	Silt	Clay	OMa	SP	pH	EC millimhos/cm	Ca milliequivalents/l	Mg milliequivalents/l	Na milliequivalents/l	SAR
A	silty clay loam	15	48	37	2.0	46	7.0	0.81	3.1	2.9	2.1	1
B	silty clay	11	44	45	2.1	53	7.2	0.62	2.5	1.9	1.8	1
C	silty clay	12	47	41	2.4	55	7.3	0.61	2.4	2.1	1.6	1
D	silty clay	14	45	41	1.8	50	6.9	0.80	3.4	2.3	2.3	1
E	silty clay	12	44	44	1.8	48	7.0	0.67	3.0	1.8	1.9	1
F	silty clay	15	44	41	1.5	46	7.1	0.69	3.1	2.3	1.5	1
G	silty clay loam	14	47	39	1.5	45	6.2	0.59	2.0	1.8	2.1	2
H	silty clay	13	42	45	1.4	44	6.1	0.65	2.3	2.1	2.1	11
I	loam	35	44	21	6.2	47	7.4	0.73	3.7	2.3	1.3	1
J	loam	37	37	25	5.2	44	7.3	0.58	2.9	1.7	1.2	1

Recovery of Heterodera schachtii eggs and cysts from 10 San Joaquin Valley fields for multiple years after initiation of sampling_

Field Location		Number/gram
	Years	Eggs		Cysts		Eggs/cyst
A	0.0	4.35	ba	0.267	c	10.9	c
	0.3	1.88	a	0.114	abc	7.6	bc
	1.8	2.07	a	0.134	abc	8.7	bc
	2.8	0.74	a	0.034	a	5.3	ab
	3.8	1.80	a	0.223	bc	3.5	ab
	6.3	0.41	a	0.067	ab	2.1	a
B	0.0	0.17	a	0.011	a	1.2	a
	0.5	0.02	a	0.001	a	0.2	a
	1.8	0.01	a	0.001	a	0.1	a
	2.8	0.03	a	0.002	a	0.3	a
	3.8	2.94	b	0.187	b	5.4	b
	5.1	0.21	a	0.038	a	1.4	a
C	0.0	0.21	a	0.029	a	1.4	a
	1.8	1.78	b	0.150	bc	7.0	b
	2.8	0.65	a	0.052	a	4.2	a
	3.8	1.27	ab	0.168	c	3.4	a
	5.1	0.47	a	0.072	ab	2.0	a
	6.3	0.51	a	0.097	abc	2.4	a
D	0.0	1.28	ab	0.036	a	6.3	bc
	0.3	0.59	ab	0.066	a	2.2	ab
	1.8	1.44	b	0.072	a	7.0	bc
	2.8	1.03	ab	0.038	a	7.9	c
	4.4	0.31	ab	0.019	a	2.5	ab
	6.3	0.13	a	0.026	a	0.9	a
E	0.0	1.08	c	0.066	c	6.1	d
	0.3	0.84	bc	0.044	bc	5.2	bcd
	1.8	0.72	abc	0.025	ab	5.7	cd
	2.8	0.23	ab	0.019	ab	2.0	abc
	4.4	0.12	a	0.003	a	1.1	a
	5.1	0.31	ab	0.013	ab	2.7	abcd
	6.3	0.21	ab	0.032	ab	1.3	ab
F	0.0	1.60	b	0.089	ab	6.1	b
	0.3	0.90	ab	0.127	b	3.9	ab
	1.8	1.14	ab	0.059	ab	5.6	ab
	2.8	0.32	ab	0.049	ab	1.9	ab
	4.4	0.10	a	0.018	a	0.7	a
	5.1	0.35	ab	0.061	ab	2.0	ab
	6.3	0.06	a	0.019	a	0.4	a
G	0.0	0.04	a	0.002	ab	0.3	a
	0.3	0.15	a	0.009	bc	1.2	a
	1.8	0.00	a	0.001	a	0.0	a
	2.8	0.13	a	0.005	abc	1.0	a
	4.4	0.03	a	0.001	ab	0.3	a
	5.1	0.09	a	0.013	c	0.8	a
	6.3	0.00	a	0.000	a	0.0	a
H	0.0	0.00	a	0.006	bc	0.0	a
	0.3	0.67	b	0.006	bc	6.4	b
	2.0	0.18	a	0.001	a	1.8	a
	2.8	0.01	a	0.010	c	0.1	a
	4.4	0.00	a	0.001	ab	0.0	a
	5.1	0.12	a	0.003	ab	1.2	a
	6.3	0.00	a	0.001	ab	0.0	a
I	0.0	9.59	c	0.204	a	25.0	b
	1.8	7.00	bc	0.230	a	20.8	b
	2.3	3.99	ab	0.121	a	16.5	b
	3.3	1.72	a	0.155	a	4.0	a
	4.6	1.17	a	0.151	a	4.7	a
J	0.0	1.51	b	0.188	b	5.1	a
	0.3	1.38	b	0.172	b	5.2	a
	2.8	0.40	a	0.042	a	3.0	a
	3.8	0.32	a	0.074	a	1.9	a