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Raymer, P.L., D.G. Bullock, and D.L. Thomas. 1990. Potential of winter and spring rapeseed cultivars for oilseed production in the southeastern United States. p. 223-225. In: J. Janick and J.E. Simon (eds.), Advances in new crops. Timber Press, Portland, OR.

Potential of Winter and Spring Rapeseed Cultivars for Oilseed Production in the Southeastern United States

P.L. Raymer, D.G. Bullock, and D.L. Thomas

  1. INTRODUCTION
  2. METHODS
  3. RESULTS
  4. CONCLUSIONS
  5. REFERENCES
  6. Table 1
  7. Table 2
  8. Fig. 1

INTRODUCTION

Rapeseed (Brassica napus L.) has been successfully grown in Europe as an oilseed crop for over 300 years (Ohlson 1972), but only in recent years has production occurred in the United States. Currently, oilseed rape ranks third worldwide as a source of vegetable oil (Haumann 1988). The development of low erucic acid and low glucosinolate cultivars and in combination with changes in U.S. Food and Drug Administration regulations that allow the use of low erucic acid rapeseed oil as an edible oil have substantially improved the status of winter rape as an oilseed crop in the United States.

Double cropping is a viable production system in the southeastern United States. Soft red winter wheat is currently the only winter cash crop under large scale production in this region. The development of additional winter crops is therefore necessary for implementing economical and productive double-cropping systems. Rapeseed has potential to develop as a major winter cash crop in this area, although current production is estimated at less than 2,000 hectares. Historically, only winter cultivars, most developed for northern Europe, have been evaluated in this area (Hoveland et al. 1981, Duncan and Hoveland 1986). Mild winters and rapidly rising spring temperatures typical to this region often cause inadequate vernalization and heat stress during bloom and seed fill of winter cultivars. More recently, cultivars developed for spring planting in more northern latitudes have been successfully grown as a winter crop in this region.

This study was conducted to compare the potential of spring and winter rapeseed cultivars when grown as a winter crop in the Coastal Plain and Piedmont regions of the southeastern U.S.

METHODS

Three winter cultivars, 'Cascade', 'Crystal', and 'Glacier', and three spring cultivars, 'Global', 'Hanna', and 'Westar' were seeded in replicated yield trials at two Georgia locations (Tifton and Griffin) during the fall of 1987. The Tifton and Griffin locations are typical of the Coastal Plain and Southern Piedmont regions, respectively Tifton has an elevation of 110 m and is located at 31.28 N latitude. Griffin has an elevation of 270 m and is located at 33.10 N latitude. Plots consisted of seven rows 3 m in length and spaced 18 cm apart. Plots were arranged in a randomized complete block design with four replications.

'Westar', 'Cascade', and 'Glacier' were also evaluated in a planting date study at Tifton during the fall of 1987. The treatments were arranged in a split-plot design with four replications. Planting dates formed the main plots and cultivars the subplots. The plot size and row pattern were as described above. Planting dates were at approximately two week intervals from 18 September to 24 December.

RESULTS

No differences in survival among cultivars were observed at either location during the relatively mild winter of 1987-88. Spring cultivars produced 9% more seed yield and matured 13 days earlier than the winter types at Griffin (Table 1). Spring cultivars produced 125% more seed yield and matured an average of 17 days earlier than winter types at Tifton (Table 2).

The bloom date of 'Westar', a spring type, was affected by planting date, in contrast to bloom dates of 'Cascade' and 'Glacier', winter types, which were relatively unaffected (Fig. 1). Planting 'Westar' earlier than November induced precocious flowering during the fall or winter months (Fig. 1). This could predispose this cultivar to injury in more severe winters.

CONCLUSIONS

Although spring and winter cultivars had similar yields at the Griffin location, winter cultivars which were developed to withstand winter temperatures, frequently experience considerable winter kill when grown in the Southern Piedmont. Since incorporation of winter hardiness is normally not a breeding objective when developing spring cultivar, it is unlikely that spring cultivar would be able to consistently survive winters typical of the Southern Piedmont.

Relatively mild winters are typical in the Coastal Plain region (approximately 5°F warmer than the Southern Piedmont). Spring cultivars may offer better yield potential here than winter types. Using spring cultivars for winter production in this area eliminates vernalization problems frequently experienced with traditional winter cultivars. Earlier bloom and maturity of spring type cultivars may reduce heat stress during seed fill and improve the potential for double crop production of soybean, sorghum (Duncan and Hoveland 1986), and peanut after rapeseed harvest. However, the identification and/or development of winter-hardy spring type cultivars will be necessary to insure survival during occasional severe winters.

REFERENCES

Table 1. Performance of spring and winter rapeseed cultivar at Griffin, Georgia, 1987-88.

Type cultivarYieldz
(kg/ha)		Test weight
(kg/m3)		Date of
50% bloom		Maturity
date		Plant height
(cm)
Spring
'Global'2743627Mar 20May 3097
'Hanna'2552625Mar 20May 3094
'Westar'1586624Mar 22May 3084
Mean2294625Mar 21May 3091
Winter
'Cascade'1907502Mar 24June 5102
'Crystal'2434631Apr 2June 16119
'Glacier'2168642Apr 3June 14132
Mean2169592Mar 30June 12117
Spring vs. Wintern.s.n.s.******
Planted October 9, 1987.
zLSD (.05) = 456 kg/ha.

Table 2. Performance of spring and winter rapeseed cultivar at Tifton, Georgia, 1987-88.

Type cultivarYieldz
(kg/ha)		Test weight
(kg/m3)		Date of
50% bloom		Maturity
date		Plant height
(cm)
Spring
'Global'2641722Feb 28May 7147
'Hanna'2577705Mar 21May 17135
'Westar'2376722Mar 20May 18127
Mean2531717Mar 13May 14137
Winter
'Cascade'1290641Mar 28May 24142
'Crystal'1120581Apr 5June 6147
'Glacier'936575Apr 16June 5152
Mean1126600Apr 6June 1147
Spring vs. Winter********n.s.
Planted November 2.
zLSD (.05) = 411 kg/ha.

Fig. 1. Effect of planting date on bloom date of three rapeseed cultivars at Tifton, Georgia, 1987-88.

Last update August 27, 1997 by aw