MSIRI Crop Report - End April 2008

> MSIRI Crop Report - End April 2008

(posted on 7/5/08)

MAURITIUS SUGAR INDUSTRY RESEARCH INSTITUTE

                                                                                                                                  7 May 2008

  

SUGAR CANE CROP 2008

 

Status:  End April 2008

1.       Climate

1.1     Rainfall

The island’s average rainfall for the month of April 2008 was 57 mm over the sugar cane areas and represented only 24% of a long-term mean of 233 mm.  Below normal rainfall was in fact recorded in all sectors with 24 mm, 77 mm, 65 mm, 12 mm and 88 mm in the North, East, South, West and Centre respectively.  These amounts represented 15% of the long-term mean in the North, 31% in the East, 23% in the South, 12% in the West and 30% in the Centre.

Cumulative rainfall for the period October 2007 to April 2008 was 952 mm in the North, 1672 mm in the East, 1450 mm in the South, 659 mm in the West and 1681 mm in the Centre.  The average for the island was 1353 mm.  The cumulative rainfall represented 97%, 115%, 84%, 87%, 88% and 94% of the respective long-term mean of the respective sectors and of the island.

Rainfall, during April 2008, has therefore been deficient in all sectors and did not meet the water requirements of the crop.

1.2     Temperature

Maximum and minimum temperatures recorded during the month of April 2008 at the MSIRI agro-meteorological stations are given below.  The mean maximum temperature exceeded the respective normal by 1.0 oC at Réduit, 0.7 oC at Pamplemousses, 1.3 oC at Union Park and 1.8 oC at Belle Rive.  The mean minimum temperature was similar to the normal at Union Park but was below normal at the other stations.  Thus the resulting mean amplitude was above normal by 2.6 oC at Réduit, 1.3 oC at Union Park, 1.0 oC at Pamplemousses and 2.3 oC at Belle Rive.  Above normal maximum temperatures enhance sucrose production through photosynthesis while below normal minimum temperature and higher temperature amplitude promote sucrose accumulation at the expense of growth.

Station

Maximum (oC)

Minimum (oC)

Amplitude (oC)

Réduit

27.7 (26.7)*

18.6 (20.2)

9.1 (6.5)

Union Park

27.0 (25.7)

19.5 (19.5)

7.5 (6.2)

Pamplemousses

30.4 (29.7)

20.4 (20.7)

10.0 (9.0)

Belle Rive

27.8 (26.0)

18.2 (18.7)

9.6 (7.3)

* Figures in bracket represent the normal (1971-2000)

1.3     Sunshine

Data from the MSIRI agro-meteorological stations showed that sunshine hours during April 2008 were above normal at all sites.  Recorded bright sunshine as a percentage of the normal amounted to 126 at Réduit, 163 at Union Park, 118 at Pamplemousses and 133 at Belle Rive.  Above normal radiation conditions favour photosynthesis and biomass production resulting in rapid growth or sucrose accumulation depending on the availability of soil moisture and the temperature regime.


Station

April 2008

Normal

% of Normal

Réduit

253

200

126

Union Park

240

147

163

Pamplemousses

263

222

118

Belle Rive

245

184

133

2.       Stalk height (Table 2a and 2b)

Cane growth was assessed during the last week of April at the 48 sites representative of the five sugar cane sectors of the island.  These sites cover the various agro-climatic zones, varieties under cultivation and stages of development of the crop.  Data collected are compared with the mean of the five best cane yielding years of the last ten years (referred to as normal) for each sector and for the island, and with that of the corresponding period in 2007.

2.1     Stalk elongation

Stalk elongation during the month of April 2008 was lower than for the corresponding period in 2007 in all sectors except in the North and West where it was higher by 2.3 cm and 1.3 cm, respectively.  Growth during the month of April amounted to 27.1 cm in the North, 28.4 cm in the East, 30.1 cm in the South, 41.3 cm in the West and 26.8 cm in the Centre.  Compared to the normal, growth during April was inferior in the North, East, South and Centre by 7.7 cm, 4.2 cm, 2.1 cm and 5.0 cm respectively whereas in the West it was higher than the normal by 5.5 cm.  Island-wise, the stalk growth of 29.6 cm, recorded for the month of April, was lower than that of 2007 and the normal by 2.1 cm (6.6%) and 6.7 cm (18.5%).

2.2     Cumulative Elongation (Table 2b)

Cumulative growth from end-December 2007 to end-April 2008 amounted to 146.1 cm in the North, 159.8 cm in the East, 162.8 cm in the South, 162.0 cm in the West and 140.1 cm in the Centre.  These cumulative growths were higher than those of 2007 by 13.0 cm (9.8%) in the North, 7.4 cm (4.9%) in the East and 5.5 cm (3.5%) in the South whereas in the West and Centre it was slightly below that of 2007 by 0.5 cm (0.3%) and 0.9 cm (0.6%).  For the same period, growth was below normal in all sectors, namely by 21.1 cm in the North, 11.8 cm in the East, 20.5 cm in the South, 10.8 cm in the West and 9.7 cm in the Centre.  Island-wise the cumulative elongation of 155.8 cm was higher than the 149.2 cm of the 2007 crop by 4.4% (6.6 cm) but lagged behind the normal (174.0 cm) by 10.5% (18.2 cm).

2.3     Total cane height (Table 2c)

Total stalk height as at end-April 2008 was 168.0 cm in the North, 206.1 cm in the East, 204.1 cm in the South, 195.5 cm in the West and 183.2 cm in the Centre.  These figures, when compared to the corresponding period in 2007, were higher in the North, East and Centre by 10.5 cm, 9.7 cm and 1.5 cm respectively whereas in the South and West sectors they were comparable.  Total cane height at end-April 2008 was below normal in all sectors.  It lagged by 29.2 cm (14.8%) in the North, 7.9 cm (3.7%) in the East, 31.0 cm (13.2%) in the South, 4.7 cm (2.4%) in the West and 14.3 cm (7.2%) in the Centre.

Island-wise the total cane height of 193.5 cm at end-April 2008 crop was superior to that of end-April 2007 by 5.0 cm (2.6%) but below the normal by 20.5 cm (9.6%).

3.       Sucrose Accumulation (Tables 3A and 3b)

Cane samples from miller-planters’ land in all factory areas and covering the main cultivated varieties were analyzed for sucrose content.  The average pol % cane (richesse) was calculated on the basis of area under cultivation of each variety in the different factory areas of each sector.  The results are compared to those of last year and the reference year 2001. The data clearly show the higher sucrose content of the early varieties M 52/78, M 703/89 and R 573 in comparison with the mid-season ones M 1176/77 and M 1400/86, and the late season ones R 570 and M 3035/66.

The richesse derived from this sampling was 7.3% in the North, 9.2% in the East, 7.9% in the South, 7.4% in the West and 8.4% in the Centre.  Compared to the corresponding period in 2007, sucrose content at end-April 2008 was comparable in the South, higher in sectors East and Centre by 0.6o and 1.2o, but lagged by 1.1o in the North and 0.3o in the West.  Compared to the corresponding period in 2001, the reference crop, richesse at the end of April for the present crop was higher in all sectors, namely by 2.3o in the North and East, 0.9o in the South, 1.4o in the West and 1.3o in the Centre.

Island-wise, richesse of the 2008 crop at end-April is similar to that of the corresponding period for the 2007 crop but higher than that of 2001 by 1.6o.

4.       CROP 2008

Weather during April 2008, in terms of the combination of deficient rainfall with higher maximum temperatures, below normal minimum temperatures and the favourable solar radiation regime, has promoted sucrose accumulation to the detriment of growth.  This is reflected in the generally lower elongation rates recorded during the past month and relatively elevated sucrose contents of the cane analysed at end-April.  It should be pointed out that this relatively high sucrose content will not necessarily mean a higher than normal extraction rate in 2008 as sucrose content at harvest will still be tributary to the forthcoming weather.  Based on the stalk height data recorded to date, island cane productivity is expected to be at least comparable to that of 2007 but below the normal.  The 2007 crop will be heavily dependent on extraction rates, which will be determined by weather conditions experienced during the ripening phase.