California experiment bins Left: August 16 – 1 st bin. 46 cm depth on right.
1
California experiment bins Left: August 16 – 1 st bin. 46 cm depth on right. Right: September 10 harvest date – 61 cm depth on left. Introduction: Some commercial wildrice (Zizania palustris) producers have observed that plants growing in deeper water develop larger seeds. Experiments were conducted in California and Minnesota to examine the influence of water depth upon wild rice plant development. Materials and Methods: California - Wildrice was grown in 11L pails containing of 12 kg of Dudgen-graven pale brown loam suspended in 120 cm lined steel tanks. The soil was amended with 15-15-15, zinc chelate, iron chelate, flooded on June 20, 2005. On June 24, 2005 Franklin wildrice seedlings at Wild Rice Growth Stage Scale (WRGSS) 03 were seeded at 283 seed/m 2 at 15, 30, 46, 61 and 76 cm depths in four replicate tanks. On September 10, 2005 before any shattering occurred, all heads with dark seed were harvested. Head length was recorded and seed larger than 1mm diameter was counted and measured for length. Plant height was measured at the harvest date. Minnesota - Franklin (same seed source as California) and Itasca at WRGSS 03 were transplanted on May 9, 2005 into preflooded soils in 11L pots (10-15 seedlings per pot) containing 9.3 kg of dry sandy loam topsoil previously amended with two 6-g planting tablets (14-4-6). Four replicates of pots were suspended in a single tank at 15, 30, 46, 61, and 76 cm depths. Pots were top dressed with urea at heading, equivalent to 55 kg/ha. At harvest, pedicels per panicle were counted, plant height measured from soil level to bottom of panicle, and seeds counted and weighed. Hulled seed length was estimated using WinSeedle Software (Regent Instruments, Quebec, Canada). Influence of Water Depth upon Plant Development, Yield and Seed Size of Modern Wildrice Cultivars D.B. Marcum and R.A. Porter University of California, Davis and University of Minnesota Results: California - The late plant date caused accelerated maturity resulting in mature grain 78 days from seeding. Seed on all primary and some secondary panicles was mature; we counted and measured only plump, dark seed >1mm in diameter. Although plant height above water declined with increased water depth, total plant height above the soil level increased with depth (Fig 1). No seedlings reached the surface from 76 cm, and only two of the four replicates at the 61 cm depth had plants. Panicle length was similar at 15, 30 and 46 cm depth, with smaller panicles at the 61 cm depth (Fig 2). The number of mature seed per panicle and total seed yield was reduced as depths increased from 15-30 cm to 46-61 cm. Minnesota - Midge damage during emergence affected plants in deeper pots, allowing only a few of the 46 cm depths and none of the deeper ones to survive. Pedicel number was not significantly different between depths, but was higher for Itasca than for Franklin (Fig 3). Plant height from soil level decreased significantly from 30 to 46 cm depth for Franklin, and increased from 15 to 30 cm depth for Itasca. Seed weight increased significantly from 15 to 30 cm depth for Itasca only. However, seed length increased significantly; for Franklin as depth increased from 30 to 46 cm and for Itasca as depth increased from 15 to 30 cm depth. Minnesota experiment bin a)Seeded 6/24/05 atW RG SS 03.H eightabove soil surface m easured 9/9/05. Vertical bars are standard errorofm ean. Sim ilarletters indicate no difference P<0.05. Figure 1.Influence ofw aterdepth upon heightofFranklin w ildrice, C alifornia,2005(a). Waterdepth,cm 15 30 46 61 P lantheight above soil surface,cm 150 175 200 225 250 a ab bc bc 100-seed w eigtt,g 2.0 2.5 3.0 3.5 4.0 Waterdepth,cm 15 30 46 61 Length ofseed,m m 7 8 9 10 11 12 13 14 15 Pedicels perpanicle 0 50 100 150 200 250 a)Vertical bars are standard errorofm ean, Sim ilarletters fordata points indicate no significance P<0.05. Figure 3.Influence ofw aterdepth upon plantheight,pedicels per panicle,100-seed w eight,and seed length ofFranklin and Itasca w ildrice,M innesota,2005(a). PlantH eight,cm 80 90 100 110 120 130 140 150 160 Franklin Itasca a a b PlantH eight N um berof Pedicels per Panicel Length ofseed a a b a b 100-seed w eight a b a b b a a a a a a b a a b Discussion: Seed length in both experiments increased with depth. Seed weight of Itasca, but not Franklin in Minnesota increased with depth. Fewer number of mature seed per panicle with Franklin in California suggests increased seed length and weight could be due to allocation of resources to fewer seed per panicle as depth increases. Although wildrice is known to easily emerge from depths greater than 46 cm, midge affected emergence in Minnesota in this experiment and we have no good explanation for poor emergence from 61 cm and no emergence from 76 cm depths in the California experiment. Total num berof m ature seed 0 250 500 750 1000 1250 1500 Waterdepth,cm 15 30 46 61 Length ofseed,m m 10 12 14 16 18 20 22 Num berofm ature seed perpanicle 0 10 20 30 40 50 60 a)W RG SS 03 Franklin w as planted 6/24/05 and harvested 9/10/05 (78 D ays)prior to evidence ofshattering. O nly m ature,dark seed w ith diam eters >1m m w ere m easured. Vertical bars are standard errorofm ean, Sim ilarletters fordata points indicate no significance P<0.05. Figure 2.Influence ofw aterdepth upon Franklin w ildrice panicle length,m ature seed perpanicle,total num ber ofm ature seed,and seed length,C alifornia,2005(a). Panicle length,m m 140 160 180 200 220 240 260 c bc ab a Panicle length Num berofm ature seed perpanicle Length ofseed b a b a b c ab a Total num berof m ature seed a bc c ab
description
Influence of Water Depth upon Plant Development, Yield and Seed Size of Modern Wildrice Cultivars D.B. Marcum and R.A. Porter University of California, Davis and University of Minnesota. - PowerPoint PPT Presentation
Transcript of California experiment bins Left: August 16 – 1 st bin. 46 cm depth on right.
California experiment binsLeft: August 16 – 1st bin. 46 cm depth on right. Right: September 10 harvest date – 61 cm depth on left.
Introduction: Some commercial wildrice (Zizania palustris) producers have observed that plants growing in deeper water develop larger seeds. Experiments were conducted in California and Minnesota to examine the influence of water depth upon wild rice plant development.
Materials and Methods:
California - Wildrice was grown in 11L pails containing of 12 kg of Dudgen-graven pale brown loam suspended in 120 cm lined steel tanks. The soil was amended with 15-15-15, zinc chelate, iron chelate, flooded on June 20, 2005. On June 24, 2005 Franklin wildrice seedlings at Wild Rice Growth Stage Scale (WRGSS) 03 were seeded at 283 seed/m2 at 15, 30, 46, 61 and 76 cm depths in four replicate tanks. On September 10, 2005 before any shattering occurred, all heads with dark seed were harvested. Head length was recorded and seed larger than 1mm diameter was counted and measured for length. Plant height was measured at the harvest date.
Minnesota - Franklin (same seed source as California) and Itasca at WRGSS 03 were transplanted on May 9, 2005 into preflooded soils in 11L pots (10-15 seedlings per pot) containing 9.3 kg of dry sandy loam topsoil previously amended with two 6-g planting tablets (14-4-6). Four replicates of pots were suspended in a single tank at 15, 30, 46, 61, and 76 cm depths. Pots were top dressed with urea at heading, equivalent to 55 kg/ha. At harvest, pedicels per panicle were counted, plant height measured from soil level to bottom of panicle, and seeds counted and weighed. Hulled seed length was estimated using WinSeedle Software (Regent Instruments, Quebec, Canada).
Influence of Water Depth upon Plant Development, Yield and Seed Size of Modern Wildrice CultivarsD.B. Marcum and R.A. Porter University of California, Davis and University of Minnesota
Results:
California - The late plant date caused accelerated maturity resulting in mature grain 78 days from seeding. Seed on all primary and some secondary panicles was mature; we counted and measured only plump, dark seed >1mm in diameter. Although plant height above water declined with increased water depth, total plant height above the soil level increased with depth (Fig 1). No seedlings reached the surface from 76 cm, and only two of the four replicates at the 61 cm depth had plants. Panicle length was similar at 15, 30 and 46 cm depth, with smaller panicles at the 61 cm depth (Fig 2). The number of mature seed per panicle and total seed yield was reduced as depths increased from 15-30 cm to 46-61 cm.
Minnesota - Midge damage during emergence affected plants in deeper pots, allowing only a few of the 46 cm depths and none of the deeper ones to survive. Pedicel number was not significantly different between depths, but was higher for Itasca than for Franklin (Fig 3). Plant height from soil level decreased significantly from 30 to 46 cm depth for Franklin, and increased from 15 to 30 cm depth for Itasca. Seed weight increased significantly from 15 to 30 cm depth for Itasca only. However, seed length increased significantly; for Franklin as depth increased from 30 to 46 cm and for Itasca as depth increased from 15 to 30 cm depth.
Minnesota experiment bin
a) Seeded 6/24/05 at WRGSS 03. Height above soil surface measured 9/9/05.Vertical bars are standard error of mean. Similar letters indicate no difference P<0.05.
Figure 1. Influence of water depth upon height of Franklin wildrice,California, 2005(a).
Water depth, cm
15 30 46 61
Pla
nt h
eigh
t ab
ove
so
il su
rfac
e, c
m
150
175
200
225
250
a
ab
bc
bc
100-
seed
wei
gtt,
g
2.0
2.5
3.0
3.5
4.0
Water depth, cm15 30 46 61
Leng
th o
f se
ed,
mm
7
8
9
10
11
12
13
14
15
Ped
icel
s pe
r pa
nicl
e
0
50
100
150
200
250
a) Vertical bars are standard error of mean, Similar letters for data points indicate no significance P<0.05.
Figure 3. Influence of water depth upon plant height, pedicels per panicle, 100-seed weight, and seed length of Franklin and Itasca wildrice, Minnesota, 2005(a).
Pla
nt H
eigh
t, c
m
80
90
100
110
120
130
140
150
160
FranklinItasca
aa
b
Plant Height
Number of Pedicels perPanicel
Length of seed
a
a
b
a
b
100-seed weight
a
b
a
bb
a
a
a
a
a a
b
a
a
b
Discussion: Seed length in both experiments increased with depth. Seed weight of Itasca, but not Franklin in Minnesota increased with depth. Fewer number of mature seed per panicle with Franklin in California suggests increased seed length and weight could be due to allocation of resources to fewer seed per panicle as depth increases. Although wildrice is known to easily emerge from depths greater than 46 cm, midge affected emergence in Minnesota in this experiment and we have no good explanation for poor emergence from 61 cm and no emergence from 76 cm depths in the California experiment.
Tot
al n
um
ber
of
mat
ure
se
ed
0
250
500
750
1000
1250
1500
Water depth, cm15 30 46 61
Leng
th o
f se
ed,
mm
10
12
14
16
18
20
22
Nu
mb
er o
f m
atur
e s
eed
per
pan
icle
0
10
20
30
40
50
60
a) WRGSS 03 Franklin was planted 6/24/05 and harvested 9/10/05 (78 Days) priorto evidence of shattering. Only mature, dark seed with diameters >1mm were measured. Vertical bars are standard error of mean, Similar letters for data points indicate no significance P<0.05.
Figure 2. Influence of water depth upon Franklin wildrice panicle length, mature seed per panicle, total number of mature seed, and seed length, California, 2005(a).
Pan
icle
len
gth
, m
m
140
160
180
200
220
240
260
c
bc
aba Panicle length
Number of mature seed per panicle
Length of seed
b
a
b
a
b
c
ab
a
Total number of mature seed
a
bc
c
ab
