Country along the banks.From Khartoum to Sennar the country is uninteresting; banks flat, vegetation and population considerable, here and there cultivation by sagias, crops mostly dura.
South of Sennar the thorn jungle along the banks becomes very dense, and at high Nile dips into the water; often the only way to get through it is by hippopotamus paths, though the roads on both banks have been cleared and there are meshras at frequent intervals.
Speaking generally, the further south one goes the steeper and higher the banks become, the channel of the river being worn away by the rush of water. The country on the right bank is mostly jungle, with little cultivation and few villages.
Between Wad Medani and Sennar the jungle on the left bank runs in a strip of one or two miles in breadth; west of this strip are the cultivation and villages, which extend right across to the White Nile. Near Wad Medani the cultivation is continuous, and one marches for miles through dura fields.
As one proceeds south, the cultivation becomes less general, until south of Senga, where it is mostly confined to strips along the river bank, and a certain amount round villages a few miles inland. South of Senga the jungle is replaced by forest, large tamarind trees, etc., with thick undergrowth, and open marshes extend along the banks, which, in the dry season, afford excellent grazing. The grass, which grows to a height of 8 to 10 feet in the rains, dies rapidly as the rain ceases, and throughout November and December the natives burn enormous tracts of the dry grass. These grass fires, intended to improve the grazing as well as to enable people to get about the country, are, as may be imagined, exceedingly detrimental to the forest trees, which become distorted and stunted. The forest on both banks of the Blue Nile south of Senga is chiefly composed of acacias of several varieties, laot, tamarisk, kittr, hashab, talh, soffar, and sidr. A few kakamut, tebeldi, dom palms, and sycamores are also to be seen in these forests.
Climate.The months of December, January, and February are cool and healthy. March, April and May are hot. The rainy season begins in May and lasts till the end of October.[72] August, September, and October are very hot and damp. The drenching rains cool the air temporarily, but the subsequent heat is moist and enervating. On the upper reaches at Sennar, Karkoj, and further south, as the vegetation and foliage increase in density, so does malarial fever abound in proportion for at least a month after the rains have ceased. September and October are probably the worst months.
In October, frequent heavy thunderstorms occur with torrential rain; they are, however, very local. Heavy dew at night. The storms get less frequent as the month goes on, and are over before November, after which the climate gradually improves. The north wind blows fitfully during November and December, and the nights are cold, but the temperature by day is very high until late in December, particularly south of Karkoj. Serut fly.The “serut fly” practically appears and disappears with the rains, and is scarce in October, except in certain places. Its northern limit is Sennar. Mosquitoes are bad at all stations at night during August, September, and October.
Cotton.Cotton is cultivated by the natives on the Blue Nile either on the foreshore of the river or inland on ground found by experience to be suitable in a good rainy season.
On the Dinder the only crop raised is the rain crop. This is sown in July after the heavy rains have commenced at the same time as dura, etc. The foreshore sowing takes place simultaneously with that of other foreshore crops, i.e., about December, after the river has fallen, according to the state of the Nile and the height of the submerged banks thus cultivated.
Both rain and foreshore crops begin to be ready for picking 4 months after sowing. There are usually three pickings, the last being the worst, as by that time the plants, which during winter are neglected, are invariably suffering from drought.