Relation between seeding times and stem yield of sorghum in cold region in Japan

Figures & data

Table 1. Seeding date.

Year	I	II	III
2009	May 20	June 3	June 18
2010	May 19	June 3	June 18
2011	May 20	June 3	June 17
2012	May 21	June 4	June 18

Figure 1. Changes of air temperature during the growing season. Note. F: First ten days of the month; M: Middle ten days of the month; L: Last ten days of the month; L*: Last eleven days of the month.

Table 2. Heading rate of Kazetachi.

Year	I	II	III
	%
2009	27.8	5.6	0
2010	45.0	11.1	0
2011	0	0	0
2012	16.7	0	0

Note. Heading rate at November 5.

Table 3. Heading date of Wray.

Year	I	II	III
2009	August 26	August 31	September 6
2010	August 10	August 11	August 26
2011	August 14	August 16	August 29
2012	August 22	August 27	August 29

Table 4. Days to heading after seeding in Wray.

Year	I		II		III
2009	98.5 ± .5	A a	89.6 ± .5	A a	80.1 ± 1	C a
2010	82.7 ± .4	A c	69.8 ± .1	B d	69.7 ± 0	B c
2011	86.6 ± .3	A c	74.5 ± .2	B c	73.4 ± 1	B b
2012	93.0 ± .2	A b	84.9 ± .4	B b	72.2 ± 0	C b
4 years	90.9 ± .8	A –	79.7 ± 1.0	B –	73.9 ± 1	C –

Note. Uppercase letters of the same letter denote no significant difference at the 5% level in the same year. Lowercase letters of the same letter denote no significant difference at the 5% level in the same seeding period. Each value represents the mean ± standard error.

Table 5. Total leaf number of main stem.

Year	I		II		III
(a) Kazetachi
2009	30.7 ± .2	A c	29.8 ± .2	B d	29.2 ± 0	B c
2010	36.4 ± .3	A a	35.3 ± .2	B a	33.9 ± 0	C a
2011	34.1 ± .3	A b	34.0 ± .4	A b	31.3 ± 0	B b
2012	33.4 ± .1	A b	32.2 ± .2	B c	31.9 ± 0	B b
4 years	33.7 ± .3	A –	32.9 ± .3	AB –	31.5 ± 0	B –
(b) Wray
2009	20.4 ± .2	A b	20.4 ± .2	A a	19.6 ± 0	B c
2010	20.9 ± .1	A ab	20.3 ± .1	B a	21.2 ± 0	A a
2011	20.8 ± .1	A ab	20.5 ± .2	A a	20.3 ± 0	A b
2012	21.2 ± .1	A a	19.5 ± .1	B b	17.9 ± 0	C d
4 years	20.8 ± .1	A –	20.2 ± .1	A –	19.7 ± 0	A –

Note. Uppercase letters of the same letter denote no significant difference at the 5% level in the same year. Lowercase letters of the same letter denote no significant difference at the 5% level in the same seeding period. Each value represents the mean ± standard error.

Table 6. Total dry weight per plant.

Year	I		II		III
	g
(a) Kazetachi
2009	278 ± 12	A a	231 ± 11	B b	218 ± 8	B c
2010	301 ± 12	A a	281 ± 13	A a	259 ± 11	A ab
2011	305 ± 19	A a	291 ± 17	AB a	244 ± 16	B bc
2012	303 ± 11	A a	313 ± 13	A a	302 ± 10	A a
4 years	297 ± 7	A –	279 ± 8	AB –	256 ± 7	B –
(b) Wray
2009	258 ± 13	A a	246 ± 9	A b	243 ± 9	A ab
2010	236 ± 13	A a	251 ± 8	A b	234 ± 5	A ab
2011	259 ± 9	AB a	282 ± 11	A a	228 ± 8	B b
2012	233 ± 6	B a	254 ± 7	A b	254 ± 6	A a
4 years	247 ± 5	A –	257 ± 5	A –	240 ± 4	A –

Note. Uppercase letters of the same letter denote no significant difference at the 5% level in the same year. Lowercase letters of the same letter denote no significant difference at the 5% level in the same seeding period. Each value represents the mean ± standard error.

Table 7. Stem dry weight per plant.

Year	I		II		III
	g
(a) Kazetachi
2009	142 ± 8	A b	119 ± 7	B b	106 ± 5	B c
2010	168 ± 9	A a	158 ± 9	A a	141 ± 7	A ab
2011	166 ± 13	A a	159 ± 11	A a	129 ± 11	A bc
2012	167 ± 7	A a	174 ± 9	A a	169 ± 6	A a
4 years	161 ± 5	A –	152 ± 5	A –	136 ± 5	B –
(b) Wray
2009	169 ± 11	A a	162 ± 7	A b	164 ± 6	A b
2010	181 ± 11	A a	193 ± 6	A a	168 ± 4	A b
2011	184 ± 6	AB a	208 ± 10	A a	165 ± 6	B b
2012	166 ± 5	A a	193 ± 7	A a	194 ± 5	A a
4 years	174 ± 4	A –	188 ± 4	A –	173 ± 3	A –

Note. Uppercase letters of the same letter denote no significant difference at the 5% level in the same year. Lowercase letters of the same letter denote no significant difference at the 5% level in the same seeding period. Each value represents the mean ± standard error.

Table 8. Stem volume per plant.

Year	I		II		III
	cm^3
(a) Kazetachi
2009	511 ± 19	A b	481 ± 23	A b	454 ± 18	A c
2010	738 ± 28	A a	721 ± 27	A a	666 ± 29	A ab
2011	726 ± 37	A a	707 ± 39	A a	597 ± 37	B b
2012	660 ± 21	B a	726 ± 34	AB a	757 ± 20	A a
4 years	661 ± 17	A –	659 ± 20	A -	617 ± 19	A -
(b) Wray
2009	484 ± 21	A b	526 ± 19	A b	519 ± 18	A b
2010	618 ± 36	A a	639 ± 21	A a	626 ± 17	A a
2011	583 ± 19	A a	638 ± 27	A a	572 ± 23	A ab
2012	499 ± 14	B b	548 ± 22	AB b	587 ± 17	A ab
4 years	538 ± 13	B –	587 ± 12	A –	575 ± 10	AB –

Note. Uppercase letters of the same letter denote no significant difference at the 5% level in the same year. Lowercase letters of the same letter denote no significant difference at the 5% level in the same seeding period. Each value represents the mean ± standard error.

Table 9. Unit weight of dry main stem.

Year	I		II		III
	mg cm^−3
(a) Kazetachi
2009	276	A a	246	B a	233	B a
2010	227	A c	218	A b	211	A b
2011	225	A c	223	A b	213	A b
2012	252	A b	240	AB ab	222	B ab
4 years	244	A –	231	AB –	220	B –
(b) Wray
2009	347	A a	308	B c	315	B a
2010	293	AB c	303	A c	271	B b
2011	316	A bc	326	A b	290	B b
2012	333	B ab	354	A a	333	B a
4 years	325	A –	322	A –	303	B –

Note. Uppercase letters of the same letter denote no significant difference at the 5% level in the same year. Lowercase letters of the same letter denote no significant difference at the 5% level in the same seeding period.

Figure 2. Stem shape of Kazetachi based on internode characteristics.

Note. These stem shapes are drawn by the average of length and cross-sectional area of each elongated internode, excluding the internode position including the neck internode. Black points represent the average of stem length in each plot. Uppercase letters of the same letter indicate no significant difference at the 5% level in the same year. The internode positions enclosed within a black line were elongating rapidly during August 1–20 in 2009.

Figure 3. Stem shape of Wray based on internode characteristics.

Note. These stem shapes are drawn by the average of length and cross-sectional area of each elongated internode, excluding the internode position including the neck internode. Black points represent the average of stem length in each plot. Uppercase letters of the same letter indicate no significant difference at the 5% level in the same year.

Table 10. Cumulative air temperature during rapid thickening period of IN8-IN10 in Wray.

Year	I	II	III
	℃・d
2009	462	479	487
2010	498	504	541
2012	415	456	493

Note. Periods associated with plots I, II, and III are, respectively, June 20–July 10, June 30–July 20, and July 10–July 30.