Previous Page Table of Contents Next Page


Poster 7.5: Evaluation of different harvest times of four genotypes of sunflower (Helianthus Annuus L.) for ensiling - L.C. Gonçalves, N.M. Rodriguez, L.G.R. Pereira, J.A.S. Rodrigues, I. Borges, A.L.C.C. Borges and E.O.S. Saliba


L.C. Gonçalves, N.M. Rodriguez, I. Borges,
A.L.C.C. Borges and E.O.S. Saliba

J.A.S. Rodrigues


Departamento de Zootecnia
Escola de Veterinaria-UFMG, Brazil.
E-mail: [email protected]

EMBRAPA-Centro Nacional de Milho e Sorgo
Brazil


L.G.R. Pereira
Graduate student

INTRODUCTION

In recent years, the sowing of fodder crops during the rainy season (January to March) has become very popular. Generally, corn [maize] and sorghum are used, because they produce a well-preserved silage of good nutritive value. However, their DM yields and quality are uncertain from year to year, because of frequent drought stress.

Sunflower stands out as an alternative for forage production and conservation as silage because of its drought tolerance, its high DM yields, its resistance to cold and heat, its adaptability to different edaphoclimatic conditions and its relative independence of latitude, altitude and photoperiod (Cotte, 1959; Tomich, 1999).

To obtain silage of good quality and of high nutritive value, the material should be cut at the appropriate stage of maturity. Tan and Tumer (1996) ensiled sunflower at several stages of maturity and concluded that the final flowering stage was the best for silage making.

The present study was carried out at the EMBRAPA National Centre of Research in Corn and Sorghum. The objectives were to evaluate sunflower cultivars ‘V2000’, ‘DK180’, ‘M734’ and ‘Rumbossol-91’ grown in a completely randomized block with 3 replications and cut and ensiled 30, 37, 44 and 51 days after flowering.

RESULTS

Table 1 shows that many of the plots had inferior stands compared to those recommended by Castro et al. (1996) of 40 to 50 thousand plants per hectare. Rumbosol-91 was significantly taller than the other cultivars, but had the lowest percentage heads and the highest percentage stem. DM yield of V2000 was inferior to the others, except at the first harvest date (Table 2). The DM concentration of the material is the most important factor for the quality of the ensiling process (McDonald et al., 1991) and it is recommended that it be between 30 and 35%.

Laboratory silos of PVC, 40 cm long by 10 cm in diameter, were used, and the silos were opened after 56 days.

Table 1. Stand density, height, head diameter and percentages of heads, stems and leaves at four maturities

Days after flowering

Stand density
(plants/ha)

Height
(cm)

Diameter
(cm)

Head
(%)

Stem
(%)

Leaf
(%)


V2000

30

39.59ABa

195.00Ba

16.84Aa

46.34Aa

35.56Ba

18.12Aab

37

26.74Ba

190.00Ba

20.44Aa

42.17Aa

37.34Aba

20.49Aa

44

33.34Aa

178.33Ba

17.56Aa

47.22Aa

37.16Aba

15.61Bab

51

19.44Aa

176.67Ba

15.55Aa

51.85Aa

37.68Ba

10.47Ab


DK180

30

31.60Ba

205.00Ba

17.56Aa

44.38Aa

35.46Ba

20.16Aa

37

39.58Aba

190.00Ba

15.56Aba

52.00Aa

35.03Ba

12.97Ba

44

25.35Aa

200.00Ba

17.67Aa

45.63Aa

38.32Ba

16.05Ba

51

38.19Aa

203.33Ba

12.22Aa

41.16Ba

42.41Ba

16.43Aa


M734

30

30.56Ba

193.33Ba

19.67Aa

48.83Aa

32.68Ba

18.49Aa

37

42.71ABa

181.78Ba

14.78ABa

48.99Aa

33.30Ba

17.71ABa

44

46.53Aa

198.33Ba

15.11Aa

50.67Aa

31.25Ba

18.08ABa

51

39.58Aa

191.67Ba

13.22Aa

48.58ABa

35.62Ba

15.79Aa


RUMBOSOL 91

30

58.33Aa

235.00Aa

16.67Aa

26.52Ba

50.27Aab

23.21Aa

37

57.64Aa

226.67Aa

13.68Ba

33.38Ba

44.20Ab

22.43Aa

44

25.35Ab

228.33Aa

17.78Aa

29.95Ba

46.05Ab

24.01Aa

51

42.36Aab

228.33Aa

15.00Aa

24.78Ca

57.20Aa

18.01Aa

Coefficient of variation

32.80

6.616

18.42

11.90

11.23

20.01

Notes: Capital letters compare harvest times among cultivars. Small letters compare harvest times within each cultivar

The largest silage densities were observed for V2000, which may be explained by its having the lowest DM concentration. Within each cultivar, the densities decreased with time, due to the higher DM concentrations as plants matured, with the exception of V2000. These results are superior to those reported by Tomich (1999), who studied 13 genotypes with an average density of 677.4 kg/m3, and they are also above those found for farm silos, with values of around 600 to 800 kg/m3 for a good compression (Nussio, 1992). The quality of the preservation decreased with age of the plants, as shown by increasing pH, particularly for V2000, which also had high ammonia-nitrogen (NH3-N) levels. In another experiment done at our laboratory with 13 genotypes (Tomich, 1999), the mean values of ether extract and in vitro DM digestibility of the silages were 13.7% and 50%, respectively, and showed normal profiles of lactic acid and AGV production.

Table 2. Production of fresh matter, DM, and DM of plants, heads, leaves and stems at four maturities

Days after flowering

Fresh matter
(t/ha)

DM
(t/ha)

DM as percentage of

Plants

Heads

Leaves

Stems


V2000

30

30.94Aa

5.63Aa

17.85Aa

23.45Aa

20.35Ab

22.45Aa

37

16.31Ab

3.05Bb

19.13Ba

6.23Aa

29.27Bb

16.17Ba

44

10.28Ab

3.27Bb

32.80Ba

26.77Aa

48.43Aab

21.37Ba

51

7.57Ab

2.73Bb

35.17Ba

30.30Ba

58.13Aa

22.73Ba


DK180

30

24.58Aa

6.03Aa

24.53Ab

24.20Ab

31.77Ab

21.00Aa

37

21.49Aa

6.22Aa

29.30ABb

27.43Ab

46.30Bab

26.47Aba

44

12.85Ab

5.50Aa

42.57ABa

32.10Ab

60.70Aa

24.80ABa

51

11.39Ab

6.40Aa

59.60Aa

51.30ABa

71.97Aa

31.00Ba


M734

30

29.93Aa

6.53Aa

22.10Ab

21.70Ab

22.27Ab

19.20Aa

37

20.21Ab

6.24Aa

32.27ABb

25.73Ab

31.30Bb

20.80ABa

44

13.51Abc

7.49Aa

55.43Aa

37.30Aab

68.43Aa

25.70Ba

51

10.35Ac

6.57Aa

67.33Aa

49.73ABa

78.10Aa

32.30Ba


RUMBOSOL-91

30

24.38Aa

6.15Aa

25.70Ac

24.77Ab

38.43Ab

31.60Ab

37

12.57Ab

5.32Aa

43.20Ab

39.83Ab

70.10Aa

37.90Aab

44

15.77Ab

6.95Aa

49.23ABb

42.40Ab

76.43Aa

41.80Aab

51

7.43Ab

4.79Aa

68.57Aa

68.97Aa

84.50Aa

55.13Aa

Coefficient of variation

26.50

19.97

26.60

32.62

24.59

31.88

Notes: Capital letters compare cutting times among genotypes. Small letters compare cutting times within each genotype.

Table 3. Density, DM, CP of the silages cut and ensiled at four maturities

Days after flowering

Density (kg/m3)

DM (%)

CP (%)

pH

NH3-N


V2000

30

2092.50Aa

18.60Aa

13.09Aa

4.43

14.76

37

1821.33Aa

22.28Aa

13.37Aa

5.26

24.27

44

1559.00Aa

31.10Ba

13.18Aa

5.28

12.52

51

1494.33Aa

32.79Ba

12.66Aa

5.24

21.59


DK180

30

1673.67Aa

23.06Ab

11.17Aba

4.42

11.00

37

1570.67Abab

28.70Ab

10.31Ba

4.18

9.72

44

1261.00Aab

39.40Abb

11.40Ba

5.14

9.51

51

1050.33Bb

56.56Aa

10.69Ba

*

*


M734

30

1921.00Aa

21.06Ab

11.25Ba

4.42

8.46

37

1575.00Aba

31.83Ab

10.62Ba

4.17

14.38

44

1240.33Ab

52.05Aa

11.25Ba

5.14

7.75

51

914.67Bb

61.30Aa

12.06Aba

*

*


RUMBOSOL-91

30

1615.67Aa

25.70Ac

9.18Ca

4.07

8.64

37

1189.33Ba

41.24Ab

9.94Ba

4.84

7.48

44

1084.00Aa

44.90Abb

9.44Ca

5.25

9.35

51

666.00Bb

64.57Aa

7.00Cb

*

*

Coefficient of variation

18.87

24.49

8.45



Notes: Capital letters compare harvest times among genotypes. Small letters compare harvest time within each genotype. * = Not determined.

CONCLUSIONS

1. The best harvest time for ensiling varied according to genotype, and was 37 days after flowering for DK180 and M734, more than 51 days for V2000, and about 30 days for Rambosol-91.

2. V2000 had the highest CP concentrations, but even with 35% DM at ensiling it provided silages with undesirable pH and NH3-N. Within each genotype there were no differences between harvest times in the CP concentration, with the exception of Rumbosol-91, which had lower values at 51 days.

REFERENCES

Castro, C., Castiglioni, V.B.R., & Balla, A. 1996. A cultura do girassol: Tecnologia de Producao. Documentos EMBRAPA-CNPSo, n.67. 20 p.

Cotte, A. 1959. Le tournesol-fourrage. Sunflower for fodder. Herb. Abstr., 29: 92.

Nussio, L.G. 1992. Producao de silagem de alta qualidade. p. 155-175, in: Congresso Nacional de Milho e Sorgo 19, 1992, Porto Alegre, Conferencias. Porto Alegre: SSA/SCT/ABMS/EMATER-RS, EMBRAPA/CNPMS, 1992.

McDonald, P., Henderson, A.R., & Heron, S. 1991. The Biochemistry of Silage. 2nd edition. Marlow, UK: Chalcombe Publications.

Tan, A.S., & Tumer, S. 1996. Research on the evaluation of silage quality of sunflowers. Anadolu 6: 45-57 (Abstract)

Tomich, T.R. 1999. Avaliacao das silagens de treze cultivares de girassol (Helianthus annuus L.) participantes do ensaio nacional. Belo Horizonte, UFMG, Escola de Veterinaria. Dissertacao. (Mestrado em Zootecnia).


Previous Page Top of Page Next Page