4. Results

4.1. GDD at germination, silking and harvest periods in 2002 – 2004

▼ 35 (continued)

Figure 2:Temperature sums (GDD) during the four successive years 2002 - 2004 growing seasons of forage maize at location Berge

Figure 2 shows ranges of temperature sums (according to AGPM, L’Association Générale des Producteurs de Maïs) at three points of the vegetation period (germination, silking and harvest) over a period of three successive years, 2002-2004. According to AGPM developed in France, the base minimum temperature is considered to be 6°C.

4.2. Leaf area and leaf area index (Manual measurement)

▼ 36 

The results of leaf area index and leaf area development in early and mid-early maturity groups during the vegetation periods are shown in figures 3 and 4. Only core varieties of the maturity groups are represented in the figures. Year 2004 results were incorporated here for the purpose of comparing the results for the three successive years, though it was not originally part of this experiment.

Figure 3:Whole plant green leaf area and leaf area index (average of core varieties Baxxos, Nescio, Tassilo, Arsenal and Symphony)

Figure 4:Whole plant green leaf area and leaf area index (average of core varieties: Lacta, LG3226, Pontos, PR39B50, Rivaldo and Topper)

▼ 37 

Figures 5 and 6 show the overall view of maximum leaf area index of each variety within the maturity groups in year 2002. Not included here, were the selected and recommended silage maize varieties for Brandenburg region in year 2002, which included early, mid-early, mid-late varieties and variety FAO 750. Leaf area index for both maturity group fall between 3-4, with mid-early maturity group tending to higher LAI than early group.

Figure 5:Leaf area index (max.) of early maturity varieties by manual measurement in 2002

Figure 6:Leaf area index (max.) of mid-early maturity varieties by manual measurement in 2002

▼ 38 

Table 5: Leaf parameters of reference plants of silage maize, early and mid-early maturity groups in regional variety trial of Brandenburg in the year 2002 at location Berge (Harvest: 03.09. and 09.09.2002 respectively)

Variety

Maturity number

Maximum leaf area [cm²]

Maximum

LAI

Green leaf area at harvest [cm2]

LAI at harvest

SLA of all leaves at harvest [cm2g-1 DM]

Early

X Tassilo

S 200

3630

2.90

3307

2.65

151

X Symphony

S 220

3504

2.80

3232

2.59

149

X Diplomat

S 210

4034

3.23

3796

3.04

154

X Sagitta

S 210

3902

3.12

3574

2.86

150

X Average (n=4)

3767

3.01

3477

2.78

151

LSD (α=5 %)

 

665

0.53

679

0.54

16

Mid-early

X Probat

S 230

3928

3.14

3618

2.89

131

X Fjord

S 240

3847

3.08

3115

2.49

164

X Romario

ca. S 240

4422

3.54

4009

3.21

154

X Eurostar

ca. S 240

5730

4.58

5180

4.14

159

X Effekt

S 240

4685

3.75

4327

3.46

153

X Rivaldo

S 240

4280

3.42

3697

2.96

154

X Average (n=6)

4482

3.59

3991

3.19

152

LSD (α=5 %)

 

552

0.44

666

0.53

19

X Check variety

Leaf parameters were obtained from reference plants during the 2002 and 2003 vegetation periods (table 5 and 6). Intermediate harvest was done at the period of silking to determine maximum leaf area and leaf area index. The difference between maximum leaf area at flowering and green leaf area at harvest indicates the amount of green leaf area lost to senescence, which also expresses the intensity of the same. Specific leaf area was also calculated from all leaves measured at harvest, but the first five lower leaf generations that dried and withered out were not included in the measurements for SLA. Only check varieties of the maturity groups in years 2002 and 2003 are included in the tables.

4.3. Leaf area index measurement using LAI 2000 plant canopy analyser

Leaf area measurements in 2002 using LAI 2000 plant canopy analyser were started in the third week of July (table 7) earlier developments in leaf area index could therefore not be presented by this method. Only check varieties of the maturity groups are presented in the tables. This was also the period when most varieties were approaching the phase of maximum leaf area. Results of LAI by LAI 2000 for all the varieties, tested in each maturity group in both years, are shown in Appendix 10, 11, 12, 13 and 14.

▼ 39 

Table 6:Leaf parameters of reference plants of silage maize, early and mid-early maturity groups in regional variety trial of Brandenburg at location Berge (Harvest: 15.08. and 23.08.2003 respectively)

Variety

Maturity number

Maximum leaf area

[cm²]

MaximumLAI

Green leaf area at harvest [cm²]

LAI

at harvest

SLA of all

leaves

at harvest

[cm2g-1 DM]

Early

X Pernel

S 190

4341

3.47

1460

1.17

208

X Tassilo

S 200

4086

3.27

2129

1.70

182

X Symphony

S 220

4408

3.53

1320

1.06

195

X Ravenna

S 210

4191

3.35

1320

1.06

181

X Talman

S 210

4411

3.53

1030

0.82

185

X Early Star

S 220

4665

3.73

1444

1.16

199

X Ambros

S 220

4550

3.64

1389

1.11

195

X PR39G12

ca.S 220

5012

4.01

2297

1.84

197

X PR39P49

S 220

4242

3.39

1427

1.14

175

X average

(n = 9)

4434

3.55

1535

1.23

191

LSD (α=5 %)

 

411

0.33

680

0.54

18

Mid-early

X LG 3226

S 240

4483

3.59

1523

1.22

182

X Rivaldo

S 240

4795

3.84

1286

1.03

183

X Sandrina

S 250

4989

3.99

804

0.64

176

X Acapulco

S 230

4299

3.44

867

0.69

187

X Topper

S 230

4862

3.89

1187

0.95

186

X Flavi

S 250

4439

3.55

1301

1.04

163

X Average

(n = 6)

4644

3.72

1161

0.93

179

LSD (α = 0.05)

790

0.63

1065

0.85

23

X Check variety

In 2003 measurements with LAI 2000 were taken at an earlier stage of leaf development than in 2002 (table 8). The last measurement for mid-early maturity group was done when early varieties were already harvested.

From table 9 for mid-early check varieties it is observed that the leaf area index of all the varieties had already considerably expanded by the first measurement (18th June), using LAI 2000 plant canopy analyser. Proceeding measurements showed increase in leaf area index, up to a peak level between 15th July and 24th July. Later measurements indicated a decline in leaf area index up to the time of harvest. A sharp LAI decline corresponded to the period of water deficit between 08th August up to the time of harvest and high temperature, which caused leaf wilting at the beginning and drying of leaves with time. The average maximum leaf area index was 3.57 on the 24th July LAI measurements, although some individual varieties had already attained maximum LAI before this time. Comparison between such varieties that attained maximum LAI earlier than the others and dry matter yield, dry matter content and starch yield, to check if there could be any additional advantage over other varieties with slower rate of LAI attainment could be appropriate.

▼ 40 

Table 7:Leaf area index of early and mid-early check varieties of forage maize using LAI 2000 in year 2002 at location Berge

Variety

Date

 

22.07.

31.07.

07.08.

15.08.

Early

X Tassilo

2.82

2.90

3.16

3.10

X Symphony

3.53

3.73

3.91

3.95

X Diplomat

3.13

3.22

3.40

3.51

X Sagitta

2.54

3.53

3.67

3.70

X Average

3.26

3.35

3.53

3.57

LSD (α =5 %)

0.28

0.27

0.30

0.32

Mid-early

X Probat

3.03

3.19

3.12

3.17

X Fjord

3.32

3.41

3.46

3.57

X Romario

3.12

3.32

3.31

3.49

X Eurostar

3.37

3.54

3.39

3.67

X Effekt

3.39

3.62

3.51

3.59

X Rivaldo

3.15

3.32

3.22

3.34

X Average

3.23

3.40

3.33

3.47

LSD (α = 5 %)

0.232

0.250

0.271

0.390

Table 8:Leaf area index of early check varieties of forage maize using LAI 2000 in year 2003 at location Berge

Variety

Date

       
 

18.06.

25.06.

03.07.

08.07.

15.07.

24.07.

29.07.

8.08.

12.08.

X Pernel

1.82

2.22

2.74

3.06

3.18

2.28

2.32

1.32

0.81

X Tassilo

1.55

2.03

2.56

2.90

2.67

2.13

2.18

1.28

0.71

X Symphony

1.92

2.48

2.92

3.05

3.11

2.53

2.41

1.49

0.89

X Ravenna

1.96

2.22

2.74

2.89

2.80

2.46

2.31

1.39

0.80

X Talman

1.67

2.16

2.83

2.75

2.88

2.54

2.31

1.24

0.62

X Early Star

1.68

2.07

2.52

2.99

2.96

2.35

2.21

1.33

0.90

X Ambros

1.66

2.13

2.47

2.88

2.82

2.57

2.54

1.40

0.78

X PR39G12

1.95

2.4

2.74

2.85

3.04

2.40

2.00

1.28

0.80

X PR39P49

1.99

2.34

2.69

2.93

3.11

2.56

2.34

1.28

0.91

X Average

1.80

2.23

2.69

2.92

2.95

2.42

2.29

1.33

0.80

LSD (α = 0.05)

0.21

0.17

0.22

0.24

0.45

0.43

0.24

0.16

0.31

Early maturity varieties indicated LAI approaching a value of 2 at the first measurement of 18.06.2003 (table 8). The average values of LAI in early maturity varieties were on the lower than those of mid-early maturity varieties for every date of measurement. However, unlike mid-early maturity varieties, whereby maximum LAI were attained at later dates, between 15th and 24th July, early maturity varieties attained maximum LAI at earlier dates, between 3rd and 15th July. The average maximum LAI for early maturity varieties was 2.95 recorded on the 15th July measurement (compared to 3.57 for mid-early maturity varieties).

▼ 41 

Table 9:Leaf area index of mid-early check varieties of forage maize in 2003 using LAI 2000 plant canopy analyser in year 2003, Berge

Variety

Date

        
 

18.06

25.06

03.07.

08.07.

15.07.

24.07.

29.07.

08.08.

12.08.

18.08.

X LG 3226

1.76

2.40

2.86

3.17

3.35

3.67

2.83

1.91

0.95

0.87

X Rivaldo

1.80

2.39

3.01

3.14

3.39

3.52

2.85

2.23

1.48

1.27

X Sandrina

2.04

2.29

2.85

3.28

3.43

3.57

3.16

1.94

1.31

1.06

X Acapulco

1.83

2.38

2.83

2.92

3.26

3.59

2.77

2.03

1.25

1.02

X Topper

2.07

2.57

3.06

3.34

3.71

3.68

3.42

2.33

1.20

1.06

X Flavi

2.01

2.43

2.91

3.03

3.28

3.38

2.95

1.83

1.32

1.18

X Average

1.92

2.41

2.92

3.15

3.40

3.57

3.00

2.05

1.25

1.08

LSD (α = 0.05)

0.18

0.30

0.28

0.30

0.29

0.31

0.47

0.44

0.22

0.16

A short characteristic of averages of check varieties (X), averages of all varieties in each maturity group (Average), coefficient of variation (CV %), least significant differences (LSD) and standard deviation (SD) from the results obtained through LAI 2000 plant canopy analyser (Table 10 and 11).

Table 10:LAI measurement with LAI 2000 plant canopy analyser of early and mid-early maturity group of forage maize in year 2002, Berge

Variety

Specifications

23.07.02

31.07.02

07.08.02

15.08.02

Early

X average (n = 4)

3.258

3.345

3.534

3.566

 

Average (n = 20)

3.205

3.272

3.476

3.530

 

CV (%)

6.076

5.896

6.109

6.383

 

LSD(α =0.05)

0.276

0.273

0.301

0.319

 

SD

0.097

0.096

0.106

0.113

Mid-early

X average (n = 6)

3.229

3.997

3.333

3.472

 

Average (n = 22)

3.201

3.351

3.310

3.420

 

CV (%)

5.137

5.280

5.796

8.071

 

LSD (α = 0.05)

0.232

0.250

0.271

0.390

 

SD

0.082

0.088

0.096

0.138

▼ 42 

Figure 7 indicates the results of the two methods used to determine leaf area index in early maturity group. Manual method was deployed from early stage of crop development, 14 days after sowing, while LAI 2000 was used at a later date (18.06) during the vegetation period. As the figure indicates, LAI by manual method had higher values than those of the counterpart LAI 2000.

Table 11:LAI measurements with LAI 2000 plant canopy analyser of early and mid-early maturity group of forage maize in year 2003, Berge

Variety

Specifi-cations

Date

         
  

18.06.

25.06.

03.07.

08.07.

15.07.

24.07.

29.07.

08.08.

12.08.

18.08.

Early

n = 9(X)

1.80

2.23

2.69

2.92

2.95

2.42

2.29

1.33

0.80

 
 

n = 18

1.82

2.28

2.70

2.89

2.97

2.43

2.29

1.38

0.83

 
 

CV (%)

8.23

5.214

3.92

5.78

10.56

8.38

7.42

8.31

17.72

 

LSD (α = 0.05)

0.21

0.17

0.22

0.24

0.44

0.43

0.24

0.16

0.31

 

Mid-

n = 6(X)

1.92

2.41

2.92

3.15

3.40

3.57

3.00

2.05

1.25

1.08

early

n = 25

1.90

2.37

2.89

3.15

3.40

3.53

3.08

2.16

1.29

1.05

 

CV (%)

6.53

9.10

6.90

6.77

5.97

6.23

10.74

14.27

12.24

11.10

LSD (α = 0.05)

0.18

0.30

0.28

0.30

0.29

0.31

0.47

0.44

0.22

0.16

Figure 7:Leaf area index by manual and LAI 2000 plant canopy analyser measurements of early maturity check varieties in 2003, Berge

▼ 43 

The results of LAI by manual and LAI 2000 methods are indicated in figure 7. Measurement of LAI by LAI 2000 was started at a later date (18.06) A drop in LAI curve of LAI 2000 measurements in 23.07 was a result of incomplete measurements of the replications due to bad weather (rain).

4.4. Light interception and leaf angle

The results of the experiment indicated close relationship between leaf area index, leaf angle and light interception. For the early maturity varieties leaf area index ranged between 2.0 and 2.4 (figure 9, year 2003), leaf angles were between 51° and 59° (average) and light interception between 70 and 83 %. Most of the intercepted light was however between 77 and 79 %, which corresponded to varieties with mean leaf angles lying between 55 and 57°.

The results also showed that certain varieties within this group with leaf angles between 51° and 55° attained maximum leaf area index above 2.3, while a majority of the varieties within this group had leaf angles ranging from 55 to 57°, but had lower leaf area index than the former between 2.1 and 2.3.

▼ 44 

At a lower leaf area index was less light intercepted by the plants. This was manifested on both ends of the vegetation period. Firstly, at the beginning of the vegetation period leaf numbers were low consequently for some varieties, which also had lower leaf expansion rates than others their leaf areas were relatively small. An example of such varieties was Arsenal in early maturity group whose leaf area index increased slower than the rest of the check varieties within that group, which had also the lowest value of maximum leaf area index. However it maintained a longer period of maximum leaf area index than the rest of the check varieties except for variety Pedro. This characteristic could compensate for the low LAI by exposing the photosynthetic apparatus to a longer period for light interception and photosynthesis. A combination of these factors including a more horizontal leaf angles at this period of growth affected leaf area index and light interception. Most varieties of the early maturity group intercepted maximum light between 77 and 79 % and this was between the range of 2.1 and 2.3 of leaf area index. However, fewer varieties (4) attained higher LAI above 2.3 and maximum light interception above 80 %.

A reduction in leaf number and leaf area had occurred when leaf senescence set in. Photosynthetic active areas of the leaves were reduced during leaf senescence as the lower (older) leaves paled and dried off. Senescence started from topmost leaves proceeding downwards during the later stage of maturity. Senescence was less pronounced in 2002 than in 2003 among the groups due to a more favourable weather condition during the vegetation period. In 2003 water deficit in August quickened the leaf dry out. However, the phenomenon of drought could help to trace some important factors among the varieties like drought tolerance and the effects of water deficit on the so called stay-green varieties. Figure 8 shows the relationship between leaf area index and light interception by early maturity varieties of maize in 2002.

As the figure 8 indicates a majority of the varieties within this group intercepted maximum light between 90 – 95 % at corresponding LAI of 3.0 – 3.8. These values were higher than those of year 2003 in comparison, which were 75 – 83 % intercepted light at average LAI between 2.0 and 2.4 (figure 9).

▼ 45 

Figure 8:Leaf area index and light interception by early maturity varieties of forage maize in year 2002, Berge

Figure 9:Leaf area index and light interception by early maturity varieties of forage maize in year 2003, Berge

Light interception within early maturity varieties was linear in relationship to leaf area index. Most of the light intercepted (between 75 and 83 %) fell within the leaf area index of 2.0 and 2.4. Compared to mid-early maturity group early maturity group had lower mean leaf area indices consequently much less light was intercepted by early maturity varieties than mid-early group. This affected the results of dry matter yield and energy yield, which were lower in early maturity group than in mid-early maturity group. However, similar trends in these parameters were also seen in year 2002 in that the values of the said parameters were lower in early than in mid-early maturity groups.

▼ 46 

Figure 10:Leaf area index and light interception by mid-early maturity varieties of forage maize in year 2002, Berge

Figure 11:Leaf area index and light interception by mid-early maturity varieties of forage maize in year 2003, Berge

The figure 10 shows the relationship between LAI (mean) and intercepted light in by mid-early maturity varieties of forage maize in the year 2002. It indicates that maximum light of between 90 and 95 % was intercepted by most of the varieties within this group, this fell between LAI of 3.0 – 3.7.

▼ 47 

The figure 11 of mid-early maturity varieties shows a close link between leaf area index and intercepted light. Greater light was intercepted by varieties with larger leaf area indices. Comparing with early maturity varieties (figure 10) there was more compactness (closeness) to one another among the mid-early varieties than early varieties. The early varieties were dispersed in location between one another. This also explains the significant difference in leaf area indices within the early maturity varieties and the insignificant difference within the mid-early varieties in year 2003. Most varieties within mid-early maturity group intercepted most of the light LAI of 2.2 and 2.8. This corresponded to light interception between the ranges of 77 – 85 %. These values are lower than those of year 2002, which were 90 – 95 % of intercepted light and average LAI between 3.0 – 3.8. These, in addition to favourable weather condition accounted for the greater yield in dry matter in 2002 than in the following year.

4.5. Individual leaf areas and leaf generation (numbers) of the varieties

Maximum leaf area (size) in both maturity groups lie between leaf generation 9, 10 and 11, which were also locations of cob leaf of the varieties. Leaf number for the varieties was between 14 and 16 (tables 12 and 13).

Table 12:Leaf area of individual leaves [cm²] of check and core varieties for early maturity group (2002)

Variety

Leaf generation (number)

              
 

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

X Tassilo

5

10

20

45

90

153

242

349

455

495

496

442

395

270

143

44

X Symphony

6

13

30

59

112

217

339

474

497

531

474

404

235

147

  

X Diplomat

7

15

30

57

109

199

296

438

535

551

503

459

359

260

169

95

X Sagitta

6

13

25

45

107

191

300

427

545

589

563

494

352

270

117

 

CV Baxxos

6

14

30

57

123

195

338

501

537

573

495

438

331

174

27

 

CV Nescio

6

12

27

54

111

204

401

576

627

627

590

510

360

152

9

 

X average

6

13

26

52

105

190

294

422

508

542

509

450

335

237

143

70

CV average

6

13

29

56

117

200

370

539

582

600

543

474

346

163

18

 

Xcheck variety
CVcore variety

▼ 48 

Individual leaf area (leaf generation) of check and core varieties of early and mid-early maturity groups in year 2003 are indicated in tables 14 and 15. The highest leaf areas were between 9, 10, 11 and 12 in both groups. Total leaf numbers were between 14 and 18 in early and 15 and 16 in mid-early groups.

Table 13:Leaf area [cm²] of individual leaves of check and core varieties of mid-early maturity group (2002)

Variety

Leaf generation (number)

              
 

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

X Probat

4

11

19

46

94

188

292

446

568

613

572

474

362

191

  

X Fjord

6

12

32

66

123

204

294

428

489

539

504

446

350

204

301

123

X Romario

7

14

32

56

119

227

291

462

575

605

619

525

438

299

153

 

X Eurostar

7

15

30

58

126

234

341

538

688

743

721

653

565

478

336

152

X Effekt

5

14

30

73

169

302

428

591

653

667

600

512

374

214

150

 

CV Lacta

7

16

37

79

156

302

389

508

546

563

505

450

318

157

  

CV Pontos

6

16

29

71

143

226

366

477

567

610

596

527

470

327

170

79

CV PR39B50

6

13

30

58

112

221

333

498

592

616

580

508

357

160

190

187

CV Rivaldo

7

14

35

69

132

232

353

470

565

573

575

477

385

217

123

 

CV Topper

6

15

32

60

127

238

333

439

558

561

488

428

266

157

  

X average

6

13

30

61

127

231

333

489

590

623

599

515

412

267

213

138

CV average

6

15

32

66

132

237

355

487

574

601

563

495

355

217

182

129

Xcheck variety
CVcore variety

Table 14:Leaf area [cm²] of individual leaves of check and core varieties for early maturity group (2003)

Variety

Leaf generation (number)

                
 

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

X Pernel

6

12

21

44

78

152

232

325

455

544

571

533

463

353

284

174

105

63

X Tassilo

6

10

18

40

62

95

137

217

330

466

537

555

495

418

319

231

152

76

XSymphony

7

14

32

66

124

201

334

471

593

628

591

523

420

286

117

   

X Ravenna

7

13

27

67

127

211

346

471

612

626

589

509

383

198

24

   

X Talman

8

18

39

81

160

279

455

587

653

642

561

439

318

171

    

X Early Star

7

14

27

48

87

134

235

373

509

621

655

612

522

426

292

140

  

X Ambros

8

13

20

43

84

131

223

364

500

578

588

561

493

413

303

184

91

 

X PR39G12

7

15

32

60

102

179

298

438

576

718

690

632

554

423

253

139

  

X PR39P49

7

12

26

61

122

224

390

539

663

686

635

518

302

79

    

CV Baxxos

8

15

27

54

99

200

288

420

553

656

661

598

500

351

148

   

CV Nescio

6

14

30

65

124

222

368

564

676

688

659

591

488

316

154

   

X average

7

13

27

57

105

178

294

420

543

612

602

542

439

307

227

174

116

70

CV average

7

15

29

60

112

211

328

492

615

672

660

595

494

334

151

   

▼ 49 

As the name early and mid-early suggests there were differences in rates of leaf development between early and mid-early maturity varieties in 2002 as shown in the figure 12. Leaf area development in early and mid-early maturity varieties in year 2002 indicated slow initial growth during the first 28 days after germination both maturity groups had similar slow rate of leaf expansion followed by rapid expansion rate in both groups. There was a sharper rise in rate of leaf expansion by the early maturity group than in the mid-early attaining maximum leaf area earlier than mid-early, however levelled off at a plateau lower than the mid-early maturity group.

Table 15:Leaf area [cm²] of individual check and core varieties of mid-early maturity varieties of forage maize in 2003

Variety

Leaf generation (number)

              
 

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

X LG 3226

6

13

27

56

102

171

262

370

519

637

650

570

505

438

351

254

X Rivaldo

6

13

35

69

147

225

356

498

590

622

612

546

463

325

222

109

X Sandrina

5

13

27

53

101

171

261

433

559

657

648

623

529

412

266

80

X Acapulco

6

12

27

66

120

187

350

489

575

627

580

491

403

323

214

102

X Topper

6

15

34

77

146

216

372

507

598

670

585

579

454

351

175

 

X Flavi

6

12

24

51

100

166

273

445

590

659

646

631

573

494

365

188

CV Lacta

6

13

27

71

131

219

372

527

647

675

658

559

473

309

110

 

CV Pontos

7

14

35

74

113

185

316

456

591

692

641

594

524

495

345

190

CV PR39B50

7

12

30

58

108

165

288

409

536

597

631

556

483

369

226

87

X average

6

13

29

62

119

189

312

457

572

645

620

573

488

391

266

147

CV average

6

13

31

68

117

190

325

464

591

655

643

570

493

391

227

139

Leaf area of mid-early maturity varieties however expanded slower overtaking and attaining a much higher peak (maximum leaf area) than the counterpart. A faster rise in leaf area expansion in the early maturity group enabled them to intercept maximum light necessary for photosynthesis, thereby affording earlier dry matter accumulation. This however was not an indication for attaining higher yields or forage quality than the counterpart due to other factors like leaf senescence rates, leaf duration, total leaf numbers and leaf sizes at the time of harvest.

▼ 50 

Figure 12:Average leaf area development rates of early and mid-early maturity groups of forage maize in 2002, Berge

4.6. Maximum leaf area

Maximum leaf area at silking of varieties tested in both years of maturity groups and their averages are presented in table 16 and 17. Most of the varieties in both groups attained higher leaf area in 2003 than 2002.

Table 16:Maximum leaf area at silking of early maturity varieties in 2002 and 2003 at location Berge

Early maturity varieties

Leaf area

[cm2]

Leaf area

[cm2]

Average

 

2002

2003

 

Pernel

3655

4341

3998

Tassilo

3630

4086

3858

Symphony

3504

4408

3956

Ravenna

3488

4191

3839

Talman

3878

4411

4144

Early Star

4307

4665

4486

Baxxos

3777

4578

4177

Cascadas

4500

5137

4818

Nescio

4269

4890

4579

PR39H32

5138

5128

5133

Ambros

3995

4550

4272

PR39G12

4815

5012

4913

PR39P49

4463

4242

4353

n = 13

4109

4588

 

Average (2002, 2003)

  

4348

LSD α = 5 %

665

411

498

▼ 51 

In year 2003 as indicated in table 16 and 17 most of the varieties within both maturity groups showed increase in leaf area as compared to results of year 2002 Although adverse weather conditions could not allow normal leaf senescence to take place, most varieties in early and mid-early maturity groups had already attained maximum leaf area expansion before water deficit and high temperature set in. Here was a significant difference in leaf area within early maturity group and the interaction between the varieties and years was significant in early and mid-early group.

Leaf area and leaf number of a plant affect light interception and photosynthesis hence dry matter production. In several studies differences in total leaf area were associated with changes in leaf size rather than differences in total leaf number (El-Sharkawy et al. 1965, Ibrahim & Buxton 1981). Total sum of green leaf area was probably more influenced by the size of individual green leaf area of the plant than by the leaf number. In tables 18-21 green leaf area and leaf number of check and core varieties of early and mid-early maturity groups are presented for 2002 and 2003 at harvest time. There are cases in these tables of some varieties with fewer leaf numbers, but having higher total leaf areas, due to larger individual leaf sizes than the counterparts. The tables also show the effect of water deficit in 2003 in shifting leaf zones with largest leaf areas from cob leaf zone, upwards. However leaf number and green leaf area of all the varieties within each maturity group were greatly reduced at the time of harvest due to drought.

Table 17:Maximum leaf area at silking of mid-early maturity varieties in 2002 and 2003 at location Berge

mid-early maturity varieties

Leaf area

[cm2]

2002

Leaf area

[cm2]

2003

Average

LG3226

4686

4483

4585

Rivaldo

4280

4795

4538

Sandrina

4903

4989

4946

Acapulco

4291

4299

4295

Topper

3811

4862

4336

Joxxal

4331

4807

4569

Lacta

4056

5062

4559

Milagro

4324

5009

4667

Montello

4370

4698

4534

Energystar

4017

4657

4337

PR39B50

4272

5225

4748

Pontos

4672

4806

4739

Andino

4766

5260

5013

Flavi

4502

4439

4471

n = 14

4377

4813

 

Average (2002, 2003)

  

4595

LSD α = 5 %

552

790

621

▼ 52 

Table 18:Average of green leaf area [cm²] and leaf number from cob leaf position of early check and core varieties of forage maize at harvest time in 2002 at location Berge (03.09.02)

Variety

Leaf location in relation to cob position

Sum LA

Leaf number

          
 

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

  

X Tassilo

 

158

318

426

503

490

455

408

319

179

69

 

3325

10

X Symphony

 

24

149

339

461

497

531

480

404

235

147

 

3267

10

X Diplomat

 

98

276

401

527

574

502

476

398

286

193

87

3818

11

X Sagitta

  

270

402

539

588

581

524

393

247

117

 

3661

9

CV Nescio

 

33

109

401

567

641

618

607

510

257

152

 

3895

10

CV Baxxos

  

46

306

439

514

563

509

453

361

139

13

3343

10

X Average

 

94

253

392

508

537

517

472

378

237

132

87

3518

10

CV Average

 

33

77

353

503

577

591

558

481

309

146

13

3619

10

Cob leaf (0) was used as a reference position of the leaf generation, negative numbers (-) indicate leaf generation below cob leaf, positive numbers (+) are leaf generation above cob leaf. Leaves that were fully senesced were not included in table 20.

Table 19:Average of green leaf area [cm²] and leaf number from cob leaf position of mid-early check and core varieties of forage maize at harvest time in 2002 at location Berge (09.09.02)

Variety

Leaf location in relation to cob position

Sum LA

Leaf number

          
 

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

  

X Probat

 

53

165

362

530

580

594

531

439

297

133

 

3684

10

X Fjord

 

0

97

161

340

508

533

510

422

322

187

143

3223

11

X Romario

 

59

208

439

539

590

632

550

468

360

164

 

4009

10

X Eurostar

 

70

330

593

691

740

710

634

565

435

297

154

5219

11

X Effekt

39

137

406

535

662

662

616

541

442

249

150

 

4439

11

X Rivaldo

 

35

223

295

548

581

592

526

446

312

138

 

3696

10

CV Topper

  

183

373

459

559

568

503

436

299

181

 

3561

9

CV Lacta

29

54

68

320

380

572

535

485

411

217

126

 

3197

11

CV PR39B50

 

107

263

249

446

622

581

513

369

160

190

187

3687

11

CV Pontos

  

269

515

580

607

584

488

404

245

129

 

3821

9

X Average

39

59

238

397

552

610

613

549

464

329

178

148

4045

11

CV Average

29

80

196

364

466

590

567

497

405

230

157

187

3567

10

▼ 53 

Table 20:Average of green leaf area [cm²] and leaf number from cob leaf position of early check and core varieties of forage maize at harvest time in 2003 at location Berge (12.08.2003)

Variety

Leaf location in relation to cob position

Sum LA

Leaf

number

      
 

-1

0

1

2

3

4

5

6

  

X Pernel

  

240

396

301

275

173

75

1460

6

X Tassilo

202

249

444

430

338

263

164

76

2166

8

X Symphony

 

118

408

360

210

165

60

 

1321

6

X Ravenna

 

114

269

353

307

178

187

24

1432

7

X Talman

  

400

235

194

152

50

 

1031

5

X Early Star

  

329

329

247

267

203

93

1468

6

X Ambros

 

214

310

309

242

177

116

83

1451

7

X PR39G12

 

400

632

554

423

253

139

 

2401

6

X PR39P49

  

403

406

418

166

67

 

1460

5

CV Baxxos

  

133

370

237

221

69

 

1030

5

CV Nescio

  

119

551

453

249

77

 

1449

5

X Average

202

219

382

375

298

211

129

70

1577

6

CV Average

  

126

461

345

235

73

 

1240

5

(0) Cob leaf position as a reference point, (-) Leaf generation below cob leaf, (+) Leaf generation above cob leaf

Table 21:Average of green leaf area [cm²] and leaf number from cob leaf position of mid-early check and core varieties of forage maize at harvest time in 2003 at location Berge (18.08.03)

Variety

Leaf location in relation to cob position

Sum LA

Leaf

number

      
 

-1

0

1

2

3

4

5

6

  

X LG3226

63

119

252

280

302

263

123

55

1457

8

X Rivaldo

 

72

200

357

410

323

193

109

1664

7

X Sandrina

 

85

524

411

367

217

73

 

1677

6

X Acapulco

  

178

222

319

174

109

 

1002

5

X Topper

  

326

313

199

147

144

65

1194

6

X Flavi

280

251

421

466

494

301

167

 

2380

7

CV Lacta

90

97

263

388

415

235

64

 

1552

7

CV Pontos

89

322

263

319

409

307

190

 

1899

7

CV PR39B50

 

75

166

200

312

188

71

 

1012

6

X Average

171

132

317

341

348

238

135

76

1562

7

CV Average

90

165

230

302

378

244

108

 

1488

7

(0) Cob leaf position as a reference point
(-) Leaf generation below cob leaf
(+) Leaf generation above cob leaf

Green leaf area of surviving leaves of mid-early maturity varieties at harvest total sum of green leaf area of individual variety and corresponding green leaf numbers (Table 21). Cob leaf (0) was used as a reference position of the leaf generation, negative numbers (-) indicate leaf generation below cob leaf, positive numbers (+) are leaf generation above cob leaf. Leaves that were fully senesced were not included in table 15, whose number can be deduced from whole plant total leaf number.

▼ 54 

Figure 13:Percent green leaf area at harvest of early check maturity varieties of forage maize in 2002 and 2003, location Berge

The figure 13 shows the percentage of green leaf area of early check maturity varieties of forage maize at the time of harvest in 2003. As the figure indicates, only about 20 – 50 % of the leaves remained vital in most of the varieties within this group. Except for variety Tassilo, which indicated higher percentage of green leaves, all other check varieties fell between 20 and 33 % of green leaves. There were greater fluctuations among the varieties within this group in retaining green leaves than seen in mid-early maturity varieties. The differences in leaf areas within this group were found to be statistically significant. Nearly all the early maturity varieties retained above 90 % of green leaves up to the time of harvest comparing with the results of 2002. This sharp contrast in leaf senescence between these two years was mainly due to varying weather conditions in both years water limitation being the major factor. Water deficit from mid August up to harvest time hastened the rate of leaf senescence in 2003. This caused much reduction in both average total leaf area leaf size and leaf number at the time of harvest compared to the results of 2002. Check and non-check varieties seemed to be equally affected by water deficit although some non-check varieties slightly superseded the check varieties in percentage green leaf area at harvest time.

Figure 14:Percent green leaf area at harvest of mid-early check maturity varieties of forage Maize in 2002 and 2003, location Berge

▼ 55 

The figure 14 shows the percentage of green leaf at the time of harvest in mid-early maturity varieties of forage maize. As was the case with early maturity group percentage green leaf area in mid-early maturity group was greatly reduced below 50 %. Most varieties within this group had between 20 and 35 % of green leaf area at harvest time. Check varieties showed no advantage over non-check varieties.

Figure 15:Leaf area of all leaves per plant (max.) and leaf number (total.), green leaf area and green leaf number at harvest of early maturity check varieties of forage Maize in 2002 and 2003, Berge

▼ 56 

The figure 15 shows leaf area of all leaves (maximum) that was attained for each early maturity check varieties and the corresponding total leaf number (leaf generation). The period of maximum leaf area and total leaf number also corresponded to the period of flowering. Green leaf area and green leaf number at harvest time showed the extent at which reduction in area and number of the leaves took place within the group in each year as affected by varying environmental conditions. The maximum sum of green leaf area was reduced to between 1500 and 2500 cm², total leaf number was between 5 and 8 and between 9 and 12 leaves dried per plant.

Figure 16:Leaf area of all leaves per plant (max.) and leaf number (total), green leaf area and green leaf number at harvest of mid-early maturity check varieties of forage maize in 2002 and 2003, location Berge

▼ 57 

Represented in figure 16 are leaf area of all leaves per plant (maximum) and corresponding total leaf number of mid-early check varieties (2003). Stay green character could also be expressed through the maintenance of green leaf area up to harvest time by a variety. Maximum leaf area ranged between 4000 and 5000 cm², while the total leaf number was between 16 and 18. At harvest the maximum sum of leaf area was reduced to between 1000 and 2500 cm² and the total leaf number to between 6 and 8. Leaf senescence left 9 until 11 dried leaves per plant. The number of senesced leaves was higher in varieties with higher total leaf numbers than in varieties with lower total leaf numbers. For instance check varieties Sandrina and Acapulco both had total leaf numbers of 17, lost 11 to senescence and had 6 vital and green leaves each at harvest, while check variety Rivaldo and Flavi, both had total leaf numbers of 16 each, lost 9 and had 7 green and vital leaves at harvest.

Table 22:Leaf area, dry mass and specific leaf area of check variety Symphony of early maturity group

Cob position

Leaf generation

Leaf area

[cm²]

Dry weight

[g]

SLA

[cm2 g-1 DM]

-5

5

127.5

0.28

455

-4

6

220.2

0.99

222

-3

7

347.2

1.59

218

-2

8

502.5

2.50

201

-1

9

651.8

3.22

202

0

10

621.5

3.39

183

1

11

611.7

3.49

175

2

12

513.3

2.66

193

3

13

372.3

2.05

182

4

14

277.1

1.47

189

5

15

107.1

0.54

198

Cob position: (o) is cob-leaf, (-) leaf below the cob-leaf, (+) leaf above cob-leaf, x leaf generation that dried off, not weighed

▼ 58 

Table 22 shows in connection with figures 17, 18, 19 and 20, specific leaf area (SLA cm² g-1) at individual plant level, in relation to leaf area (cm²), dry matter weight (g) and leaf generation. Cob leaf (0) was taken as reference position on plant leaf generation.

Figure 17:Specific leaf area (SLA) of early maturity varieties (n=21) in 2002, Berge

Figure 18:Specific leaf area (SLA) of early maturity varieties (n=18) in 2003, Berge

▼ 59 

Figure 19: Specific leaf area (SLA) of mid-early maturity varieties (n=22) in 2002, Berge

Figure 20:Specific leaf area (SLA) of mid-early maturity varieties (n=25) in 2003, Berge

Figures 17 - 20 indicate specific leaf area (SLA) of early and mid-early maturity groups of forage maize tested in years 2002 and 2003. Senesced leaves that fell off the plants and missing were not included in the measurements.

▼ 60 

Figures 21 and 22 compare dry weight of plant components (leaf, stem, cob leaf and cob dry weight expressed as percent of whole plant dry weight) of early and mid-early check varieties of forage maize for 2002 and 2003. There was a reduction in cob and cob leaf dry weight an increase in leaf and stem dry weight in 2003 in both maturity groups.

Figure 21:Plant dry weight [%] of check varieties (early maturity group)

▼ 61 

Figure 22:Plant dry weight [%] of check varieties (mid-early maturity group)

Figure 22:Plant dry weight [%] of check varieties (mid-early maturity group)

4.6.1. Statistical analysis

Statistical analysis showed significant differences in dry matter yield, dry matter content, energy yield and leaf area. All the pooled values showed significant differences within the group. The effect of variation in year on the given parameters was significant except in crude protein, which was insignificant even in the pooled values. Like in mid-early maturity varieties, there were significant differences in all pooled values as well as in year * treatment interactions among varieties. Therefore unless otherwise stated only the means (average values) of the parameters tested will be discussed, significant differences of the parameters will be discussed in detail.

Table 23:Variation analysis for early maturity varieties of forage maize tested in year 2002 and 2003

Early maturity

group (n=13)

 

F-value

Parameters

Unit

Within varieties

Between years

Pooled error within varieties

Pooled error between years

Dry matter yield

[dt ha -1 ]

4.043*

1904.256*

5.523*

2601.047*

Dry matter content

[%]

3.365*

66.871*

14.276*

283.720*

CV Starch yield

[dt ha -1 ]

1.045 ns

16.907*

9.663

156.400*

Starch content

[%]

0.962 ns

19.873*

7.258*

149.915*

Energy yield

[NEL MJ ha -1 ]

3.581*

1789.161*

6.095*

3045.222*

Crude fibre

[%]

1.657 ns

61.049*

6.853*

252.520*

Crude protein

[%]

0.841 ns

1.533 ns

2.009*

3.661 ns

Leaf area

(BBCH 55/65)

[cm²]

6.636*

28.473*

9.127*

39.159*

* Significant difference: 5 %

▼ 62 

Table 24:Variation analysis (NIRS) for mid-early maturity varieties of forage maize tested in year 2002 and 2003

Mid-early maturity group (n = 14)

 

F-value

Parameters

Unit

Within varieties

Between years

Pooled error within varieties

Pooled error

between years

Dry matter yield

[dt ha -1 ]

1.720 ns

711.551*

3.899*

1613.380*

Dry matter content

[%]

2.339 ns

50.995*

17.898*

390.151*

Starch yield

[dt ha -1 ]

1.460 ns

373.448*

5.177*

1324.096*

Starch content

[%]

2.073 ns

94.408*

6.956*

316.765*

Energy yield

[NEL MJ ha -1 ]

1.544 ns

652.555*

4.948*

2090.839*

Energy content

[NEL MJ kg -1 ]

1.986 ns

237.300*

5.400*

645.314*

Crude fibre

[%]

1.772 ns

155.727*

4.535*

398.623*

Crude protein

[%]

1.586 ns

10.251*

3.408*

22.023*

Leaf area

(BBCH 55/65)

[cm²]

1.107 ns

16.113*

1.569 ns

22.830*

*Significant difference: 5 %

According to analysis of variance mid-early maturity varieties there were insignificant differences in all parameters tested within the group (table 24).The results of the analysis showed significant differences in all the parameters tested between the two years. Pooled values indicated significant differences within the group and between the years, in all the parameters tested, except for leaf area within the group, which was insignificant. The effect of variation in varieties within this group was insignificant. This showed that changes in environmental (weather) conditions from year to year played a significant role in shaping yield and forage quality of maize varieties.

▼ 63 

In the early maturity varieties (table 23) unlike the mid-early varieties, whereby there were no effects of variety within the group on all the parameters given here. However significant differences were seen in dry matter yield, dry matter content, energy content and leaf area. All the pooled values showed significant differences within the group. The effect of variation in year on the given parameters was significant except in crude protein, which was insignificant even in the pooled values.

4.7. Dry matter yield and dry mass content

Table 25 shows dry matter yield and dry matter content of early maturity group of silage maize in years 2002 and 2003.

Table 25:Dry matter yield and dry matter content of 13 early maturity varieties of silage maize tested in 2002 and 2003 and 3 core varieties tested in the 3 years 2002-2004, location Berge

Variety

Dry matter yield [dt ha-1]

Dry matter content [%]

 

2002

2003

2004

2002

2003

2004

Pernel

177.2

111.5

 

36.18

38.95

 

Tassilo

167.9

105.7

154.0

36.60

43.45

30.28

Symphony

175.0

100.1

 

32.85

38.58

 

Ravenna

168.1

99.7

 

37.35

40.95

 

Talman

180.9

103.9

 

35.43

43.13

 

Early Star

171.3

100.3

 

33.93

38.60

 

Baxxos

184.4

101.3

159.5

36.67

37.85

29.95

Cascadas

183.0

107.0

 

33.45

35.92

 

Nescio

186.0

113.1

160.4

33.33

41.70

27.67

PR39H32

175.2

99.1

 

30.33

34.60

 

Ambros

186.7

117.7

 

34.87

39.12

 

PR39G12

185.3

104.7

 

31.70

38.82

 

PR39P49

166.7

98.7

 

33.48

40.45

 

n = 13

177.5

104.8

 

34.32

39.39

 

n = 3

  

158.0

  

29.30

LSD (α = 0.05)

10.6

10.0

12.9

1.52

2.68

1.41

▼ 64 

Of all the varieties tested in the two experiments 13 varieties were tested in both years, from which analysis of variance was made. Varieties that were tried in the three years 2002, 2003 and 2004 (core varieties) are included in table 25 for comparison of the changes in dry matter yield and dry matter content over the three years.

Table 26:Dry matter yield and dry matter content of 14 mid-early maturity varieties of silage maize tested in 2002 and 2003 and 5 core varieties tested in the 3 years 2002, 2003 and 2004, location Berge

Variety

Dry matter yield [dt ha-1]

Dry matter content [%]

 

2002

2003

2004

2002

2003

2004

LG3226

192.2

135.5

 

39.00

47.80

 

Rivaldo

180.0

122.0

175.2

37.63

39.80

31.53

Sandrina

186.2

123.2

 

35.13

42.85

 

Acapulco

188.1

132.3

 

36.50

41.85

 

Topper

180.8

117.1

176.6

39.23

46.20

32.15

Joxxal

175.9

115.8

 

37.95

48.40

 

Lacta

176.2

134.4

185.1

40.25

44.50

34.15

Milagro

189.8

129.9

 

40.63

43.45

 

Montello

175.4

124.4

 

38.60

45.63

 

Energystar

179.4

127.0

 

38.53

43.15

 

PR39B50

184.2

118.0

175.8

37.53

47.20

31.40

Pontos

172.3

131.9

189.5

37.90

42.35

32.13

Andino

182.0

122.1

 

41.07

42.63

 

Flavi

193.5

128.4

 

34.35

36.48

 

n = 14

182.6

125.9

 

38.16

43.74

 

n = 5

  

180.4

  

32.27

LSD α=5 %

10.9

10.2

15.0

2.16

2.05

1.44

Dry matter yield and dry matter content of 14 mid-early maturity varieties of silage maize tried in years 2002 and 2003 and 5 varieties tried for the three years (2002-2004) are shown in table 26. The complete table for all the varieties tested in each year is in Appendix 1

▼ 65 

However, there was no significant difference within the varieties, only between the two years was a significant difference found between the varieties. Similarly, higher average dry matter content between the maturity groups was found in mid-early maturity group than in early maturity group. Although weather conditions at the research station for both years sharply contrasted, namely one being more favourable than the other, yet the relation of average dry matter yield and dry matter content between the maturity groups did not alter. As it was the case in year 2002, the average dry matter yield and content in year 2003 for mid-early maturity varieties were higher than those of early maturity varieties. However the average dry matter yield for year 2003 of early maturity varieties (105.0 dt ha-1) and mid-early maturity varieties (125.4 dt ha-1) were much lower than for year 2002: early 176.5 dt ha-1 and mid-early 181.5 dt ha-1. The average dry matter content for year 2003 for both early (39.29 %) and mid-early (43.61 %) maturity varieties were higher than the values of year 2002 of 34.4 % and 38.2 % respectively.

Dry matter yield (dt ha-1): The average dry matter yield for early maturity varieties in year 2002 was 176.5 dt ha-1 and 105 dt ha-1 in 2003. However, the average dry matter yield for year 2002 was much higher than that of 2003, due to more favourable weather conditions for growth in 2002. There was a significant difference in dry matter yield within this group for each year. The interaction between the varieties and the years was significant. Differences in dry matter yield within the group are a result of genotypic differences in yield potentials of individual varieties within the group.

Dry matter content (%): The average dry matter content for early maturity varieties was 34.4 % in 2002 and 39.29 % in 2003. There was a significant difference in dry matter content within this group and between the years. Genotypic and environmental variations affected both dry matter yield and dry matter content in both years.

▼ 66 

Figure 23:Dry matter yield and green leaf area of early maturity varieties of forage maize at harvest in 2002 and 2003, Berge

Figure 24:Dry matter yield and green leaf area of mid-early maturity varieties of forage maize at harvest in 2002 and 2003, Berge

Dry matter yield and green leaf area at harvest of early and mid-early maturity check varieties in 2002 and 2003 are presented in figures 23 and 24. Whether maintaining high green leaf area at harvest contributed to improved dry matter yield, especially under unfavourable environmental conditions (water deficit), was a question the figures were seeking to answer.

4.8. Forage quality

▼ 67 

Forage quality of maturity groups tested in years 2002 and 2003 differed between the years. Early maturity varieties showed significant differences not only in dry matter yield, dry matter content and leaf area, but also in energy yield. The rest of the parameters tested like crude fibre, crude protein, starch content and starch yield showed insignificant difference within the group. In both groups however, all tested parameters indicated significant differences in year * variety interaction except in the early group, which showed insignificant difference in crude protein content. Pooled values for both years showed significant differences for all the parameters tested except for the crude protein content in the early group, which was insignificant.

Forage value of silage maize depends on the increase in dry matter content. Concentration of organic substances in the cob and of importance also is the digestibility so that the intake of nutrients may increase in ruminants (Gross 1986, Hepting 1992, Eder 1993).

Of great importance in evaluating silage maize for forage is the energy production or energy yield (GJ NEL ha-1), dry matter content of whole plant and starch content in the dry matter Hepting 1994).

▼ 68 

Increase in starch yield increases the relative energy yield, which in turn gives high forage value. Starch content in the whole plant is determined by its content in the cob. It increases with development of cob

Quality parameters of silage maize of maturity group early and mid-early varieties in regional variety trial of Brandenburg in 2002, 2003 and 2004 (core varieties) at location Berge.

Table 27:Starch yield and starch content of early maturity varieties of maize in 2002, 2003 and 2004, location Berge

Early maturity varieties

Starch yield

[dt ha-1]

Starch content

[%]

 

2002

2003

2004

2002

2003

2004

Pernel

61.0

28.5

 

34.44

25.52

 

Tassilo

59.0

36.8

47.6

35.23

34.71

30.90

Symphony

57.8

28.5

 

33.24

28.61

 

Ravenna

65.9

34.8

 

39.24

34.91

 

Talman

62.7

35.8

 

34.68

34.32

 

Early Star

64.5

27.2

 

37.57

27.08

 

Baxxos

70.1

22.0

48.5

37.93

21.69

30.40

Cascadas

71.3

26.2

 

38.95

24.50

 

Nescio

68.7

40.8

53.5

36.93

36.08

33.32

PR39H32

61.8

21.2

 

35.38

21.27

 

Ambros

62.4

32.2

 

33.45

27.34

 

PR39G12

57.6

31.4

 

31.12

29.77

 

PR39P49

62.5

29.3

 

37.45

29.70

 

n = 13

63.5

30.4

 

35.82

28.88

 

n = 3

  

49.9

  

31.54

LSD α = 0.05

6.4

6.3

6.7

3.40

4.69

2.86

▼ 69 

Table 27 shows starch yield and starch content for the silage maize varieties of early maturity group, which were tested in both years 2002 and 2003. The results of year 2004 show varieties that were tested in the three years (core varieties) and are used for the purpose of comparing the results of three years test of these varieties. Starch yield and starch content for mid-early maturity varieties tested in 2002 and 2003 and core varieties (2004) are indicated in table 28. Significant differences were found in starch yield and starch content between the years in both maturity groups (table 23 and 24). Core varieties also showed significant differences in the three years analysis.

Table 28:Starch yield and starch content of mid-early maturity varieties of forage maize in 2002, 2003 and 2004, location Berge

Varieties

Starch yield

[dt ha-1]

Starch content

[%]

 

2002

2003

2004

2002

2003

2004

LG3226

77.1

42.4

 

40.09

31.26

 

Rivaldo

67.8

35.6

55.6

37.76

29.15

31.71

Sandrina

62.5

37.8

 

33.62

30.72

 

Acapulco

73.1

47.2

 

38.89

35.58

 

Topper

75.5

38.4

61.4

41.81

32.65

34.79

Joxxal

63.4

31.9

 

36.05

27.55

 

Lacta

70.1

46.7

61.7

39.85

34.71

33.20

Milagro

74.6

34.8

 

39.30

26.89

 

Montello

67.0

37.8

 

38.30

30.37

 

Energystar

68.3

40.6

 

38.13

31.82

 

PR39B50

74.8

39.2

62.2

40.60

33.25

35.41

Pontos

64.7

43.6

57.6

37.60

33.07

30.43

Andino

68.9

36.7

 

37.85

30.07

 

Flavi

72.6

32.5

 

37.55

25.27

 

n = 14

70.0

38.9

 

38.39

30.88

 

n = 5

  

59.7

  

33.11

LSD α=5 %

6.8

5.9

7.8

2.87

3.40

3.25

Energy yield and energy content are important parameters in evaluating the quality of forage maize. In table 29 early maturity varieties tested in 2002 and 2003 and core varieties (2004) are shown. The average energy yield for year 2002 was 115.1 GJ NEL ha-1 and 61.7 GJ NEL ha–1 in 2003, for the early varieties tested in both years (13 varieties). The average energy content was 6.52 MJ NEL kg-1 (2002) and 5.87 MJ NEL kg-1 (2003). Significant differences existed between the years in energy yield and energy content (table 23 and 24).

▼ 70 

In table 30 is energy yield and energy content of mid-early maturity varieties tested in the years 2002 and 2003 and core varieties (2004). The average energy yield for 2002 was 121.2 GJ NEL ha-1 and 74.5 GJ NEL ha-1 in 2003. The average energy content was 6.64 MJ NEL kg-1 (2002) and 5.92 MJ NEL kg-1 (2003). Significant differences were found between the years in energy yield and energy content.

Correlation coefficients between maize forage parameters in early and mid-early maturity groups in 2002 and 2003 trials at location Berge (tables 31, 32, 33 and 34).

Table 29:Energy yield and energy content of early maturity varieties of forage maize in 2002, 2003 and 2004, location Berge

Early maturity varieties

Energy yield

[GJ NEL ha-1]

Energy content

[MJ NEL kg-1]

 

2002

2003

2004

2002

2003

2004

Pernel

117.7

63.9

 

6.64

5.72

 

Tassilo

112.9

66.2

98.6

6.73

6.26

6.40

Symphony

113.6

58.2

 

6.50

5.82

 

Ravenna

112.2

62.0

 

6.68

6.22

 

Talman

117.9

64.2

 

6.52

6.18

 

Early Star

112.3

58.4

 

6.55

5.82

 

Baxxos

122.9

57.6

101.0

6.66

5.68

6.33

Cascadas

118.6

58.5

 

6.48

5.46

 

Nescio

123.5

72.4

103.6

6.64

6.41

6.46

PR39H32

110.1

55.0

 

6.31

5.57

 

Ambros

124.4

70.0

 

6.67

5.94

 

PR39G12

119.4

61.8

 

6.44

5.89

 

PR39P49

111.9

60.0

 

6.71

6.07

 

n= 13

115.1

61.7

 

6.52

5.87

 

n = 5

  

101.0

  

6.40

LSD α =5 %

7.6

6.7

9.2

0.20

0.28

0.19

▼ 71 

Table 30:Energy yield and energy content of mid-early maturity varieties of forage maize in 2002, 2003 and 2004, location Berge

Mid-early maturity varieties

Energy yield

[GJ NEL ha-1]

Energy content

[MJ NEL kg-1]

 

2002

2003

2004

2002

2003

2004

LG3226

129.7

81.1

 

6.75

5.99

 

Rivaldo

119.9

71.5

112.1

6.66

5.86

6.40

Sandrina

118.8

72.2

 

6.38

5.86

 

Acapulco

124.9

82.0

 

6.65

6.19

 

Topper

123.7

70.4

112.3

6.85

6.01

6.37

Joxxal

113.2

65.0

 

6.44

5.61

 

Lacta

117.0

82.0

114.3

6.64

6.10

6.17

Milagro

128.0

73.1

 

6.75

5.63

 

Montello

115.4

73.3

 

6.58

5.90

 

Energystar

118.6

76.0

 

6.62

5.97

 

PR39B50

125.5

71.1

112.4

6.81

6.03

6.40

Pontos

113.3

80.0

119.2

6.59

6.07

6.29

Andino

119.1

70.4

 

6.54

5.77

 

Flavi

130.1

75.8

 

6.73

5.90

 

n= 14

121.2

74.5

 

6.64

5.92

 

n = 5

  

114.1

  

6.33

LSD α=5 %

7.9

7.3

109.4

0.19

0.23

0.23

Table 31:Correlation matrix for maize forage parameters of early maturity group in 2002 (significant at 0.2199)

 

DM content

Elos

XF

XP

Starch content

VIVO

DOM

DM yield

Starch yield

NEL

DM content

         

Enzy.s.s

0.5366

        

XF

-0.4477

-0.9482

       

XP

-0.2608

0.1785

-0.3391

      

Starch content

0.3405

0.7704

-0.8527

0.2015

     

VIVO DOM

0.5361

0.9999

-0.9486

0.1787

0.7708

    

DM yield

0.0966

0.0097

-0.0061

0.1126

-0.1280

0.0081

   

Starch yield

0.2642

0.6970

-0.7725

0.2314

0.0432

0.6965

0.4195

  

NEL

0.5211

0.9990

-0.9541

0.2190

0.7709

0.9989

0.0098

0.6973

 

Energy yield

0.1716

0.4871

-0.4613

0.1989

0.2549

0.4856

0.8771

0.6998

0.4876

Table 32:Correlation matrix for maize forage parameters of early maturity group in 2003 (significant at 0.2319)

 

DM content

Elos

XF

XP

Starch content

VIVODOM

DM yield

Starch yield

NEL

DM content

         

Enzy.s.s

0.7353

        

XF

-0.7273

-0.9817

       

XP

0.1600

0.4570

-0.5265

      

Starch content

0.7779

0.9380

-0.9341

0.2925

     

VIVO DOM

0.7360

-

-0.9818

0.4552

0.9386

    

DM yield

0.2729

0.0869

-0.0253

-0.6347

0.1964

0.0884

   

Starch yield

0.7688

0.8609

-0.8383

0.0686

0.9422

0.8619

0.5053

  

NEL

0.7293

0.9996

-0.9835

0.4787

0.9341

0.9995

0.0700

0.8525

 

Energy yield

0.6148

0.6169

-0.5602

-0.2390

0.6662

0.6180

0.8366

0.8707

0.6038

▼ 72 

Table 33:Correlation matrix for maize forage parameters of mid-early maturity group in 2002 (significant at 0.2096)

 

DM content

Elos

XF

XP

Starch content

VIVODOM

DM yield

Starch yield

NEL

DM content

         

Enzy.s.s

0.2178

        

XF

-0.2578

-0.9716

       

XP

-0.1236

0.1628

-0.3161

      

Starch content

0.3257

0.8798

-0.8709

0.0771

     

VIVO DOM

0.2161

0.9999

-0.9713

0.1616

0.8807

    

DM yield

0.0977

0.2561

-0.1884

-0.3447

0.2236

0.2562

   

Starch yield

0.2792

0.7401

-0.6930

-0.1543

0.8072

0.7409

0.7500

  

NEL

0.2094

0.9990

-0.9773

0.2046

0.8764

0.9988

0.2356

0.7263

 

Energy yield

0.1518

0.5586

-0.4927

-0.2238

0.4859

0.5586

0.9435

0.8942

0.5418

Table 34:Correlation matrix for maize forage parameters of mid-early maturity group in 2003 (significant at 0.1966)

 

DM content

Elos

XF

XP

Starch content

VIVODOM

DM yield

Starch yield

NEL

DM content

         

Enzy.s.s

-0.0603

        

XF

0.0172

-0.9464

       

XP

0.0507

0.1894

-0.3652

      

Starch content

0.1728

0.8791

-0.9225

0.2484

     

VIVO DOM

-0.0602

0.9999

-0.9458

0.1893

0.8782

    

DM yield

-0.1352

0.4108

-0.2677

-0.3358

0.2685

0.4117

   

Starch yield

0.0560

0.8427

-0.7997

0.0021

0.8594

0.8425

0.7210

  

NEL

-0.0578

0.9994

-0.9524

0.2214

0.8813

0.9992

0.3957

0.8364

 

Energy yield)

-0.1262

0.6977

-0.5678

-0.1823

0.5448

0.6983

0.9392

0.8865

0.6860


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