SAHEL WEATHER AND CROP SITUATION 1999 Global Information and Early Warning System on food and agriculture
	Report No 2- 12 July 1999

WIDESPREAD AND ABOVE NORMAL RAINS IN LATE JUNE AND EARLY JULY COMPENSATED FOR REDUCED PRECIPITATION IN EARLY AND MID-JUNE

SUMMARY

Rising concerns over reduced precipitation in early or mid-June, particularly in Burkina Faso and Niger have eased with abundant rains over most producing areas of the Sahel since late June. Rains have now started in western Gambia, northern Senegal, southern Mauritania, central and northern Mali, eastern Niger and the Sahelian zone of Chad where plantings have started. Further south, above normal rains benefitted recently planted crops and compensated for the below average rains of early to mid-June. In Guinea Bissau, they helped desalination of swamp rice fields where rice seedlings, now in seedbeds, will be transplanted. In Cape Verde, first rains have been registered in early July. Satellite imagery indicates that during the first dekad of July, precitation remained normal to above normal throughout the Sahel except in the south of Chad.

The dry spell of early to mid-June in Burkina Faso and Niger delayed plantings and necessitated replantings in some areas. This might reduce production if rains do not continue late in the season.

Grasshoppers are reported in Chad, the Gambia and Niger. Grain-eating birds are reported in Mali and Niger. Control measures are underway. Rodent attacks to crops are also reported in Niger. The Desert Locust situation remained calm during June. Low numbers of adults are expected to appear in the summer breeding areas of the Sahel but no significant developments are expected.
 

SITUATION BY COUNTRY

SOME DEFINITIONS

In these reports, reference will be made to four different eco-climatic zones based on the average annual precipitation and agricultural features, i.e. Sahelian zone, Sudano-Sahelian zone, Sudanian zone and Guinean zone. They are shown in the map and described below:

Sahelian zone: Where average annual precipitation ranges between 250 and 500 mm. This zone is at the limit of perennial vegetation. In parts where precipitation is less than 350 mm, only pastures and occasional short-cycle drought-resistant cereal crops are grown; all cropping in this zone is subject to high risk.

Sudano-Sahelian zone: Where average annual precipitation ranges from 500 to 900 mm. In those parts of this zone where precipitation is less than 700 mm, mostly crops with a short growing cycle of 90 days are generally cultivated predominantly sorghum and millet.

Sudanian zone: Where average annual precipitation ranges from 900 to 1 100 mm. In this zone, most cereal crops have a growing cycle of 120 days or more. Most cereals, notably maize, root and cash crops are grown in this zone.

Guinean zone: Where average annual precipitation exceeds 1 100 mm. Guinea-Bissau and a small area of southern Burkina Faso belong to this zone, more suited to root crop cultivation.

Reference will also be made to the Intertropical Convergence Zone (ITCZ), also known by its trace on the earth's surface, called the Intertropical Front. The ITCZ is a quasi-permanent zone between two air masses separating the northern and southern hemisphere trade winds. The ITCZ moves north and south of the equator and usually reaches its most northerly position in July. Its position defines the northern limits of possible precipitation in the Sahel; rain-bearing clouds are generally situated 150-200 km south of the Intertropical Front.