The neem tree is famous for its drought resistance. Normally it grows well in areas with sub-arid to sub-humid conditions, with an annual rainfall between ca 400 and 1,200 mm. It can also grow in regions with an annual rainfall below 40mm, but in such cases it depends largely on the ground water. Under such conditions very low annual rainfall is sufficient for its survival. During severe, long-lasting droughts the leaves are shed, sometimes completely. Neem tree exist also in regions with up to ca 2,500 mm annual rainfall, provided the soil on which they grow is well drained, for instance on hills. The yield of fruits is normally low under such conditions, owing to flower- and fruit-shelding during the rainy seasons. Some attempts some years ago to grow neem in areas with high rainfall of ca. 3,000 - 4,000 mm/a, as in eastern Ecuador in the Amazonian basin and on Tonga Island, failed completely.
Neem can grow in many different type of soil, but it seems to develop best on well drained, deep sandy soils. In the Sudan and in India, it thrives on black cotton soils. In Nigeria A. indica develops well on other soils with high clay content but not with a high proportion of sand. In other parts of Africa(Benin) neem trees are found on red ferrolas and in the Caribean on calcareous soils. In soils with a high content of fine sand or silt, nutrient defeciences, lead to an obvious chlorosis of the leaves. Chlorosis is common for instance in parts of Haiti, in Westeren Senegal and West of Thies and in south western Madagascar south and north of Toliara. A indica exists on stony shallow soil, on soil with waterless subsoil and also on solis with a hard calcareous or clay pan near the surface. On very poor stands it does not grow well in groups or plantations owing to high intraspecific competiotion for water and soil nutrients. Under conditions neem plantation in Africa, have often died out after some years. FISHWICK emphasizes that soil water availability appears to the most critical factor, and this factor is combination of soil texture and local ground water supplies. On the other hand neem can also grow on alkaline or saline soil. In the Dominican republic, for instance, it grows well on former sugar cane fields which were abndoned owing to high salinity of the soil.
Neem as a typical stropical/substorpical plant, exists at annual mean temperatures between 21 and 32'c. It can tolerate high to very high temperatures, for instance northest ans central Africa where temperatures in the shade can reach ca. 50'C during the summer months. Temperatures below 4'c, and frost, are unfavourable and may result in shedding of leaves and occasionally even death of young plants. In the sub-Himalayan zone, where temperatures may fall below 0'c in winter, neem seems to be better adpted to cold conditions but young plants have to be protected by screens.
The neem tree is usually found on plains and low-lying hilly country. It thrives at altritudes upto 700-800 m and ocassionaly 1000m above the sea level. Higher altitudes are, as a rule, much less favourable.
Neem can grow in many different type of soil, but it seems to develop best on well drained, deep sandy soils. In the Sudan and in India, it thrives on black cotton soils. In Nigeria A. indica develops well on other soils with high clay content but not with a high proportion of sand. In other parts of Africa(Benin) neem trees are found on red ferrolas and in the Caribean on calcareous soils. In soils with a high content of fine sand or silt, nutrient defeciences, lead to an obvious chlorosis of the leaves. Chlorosis is common for instance in parts of Haiti, in Westeren Senegal and West of Thies and in south western Madagascar south and north of Toliara. A indica exists on stony shallow soil, on soil with waterless subsoil and also on solis with a hard calcareous or clay pan near the surface. On very poor stands it does not grow well in groups or plantations owing to high intraspecific competiotion for water and soil nutrients. Under conditions neem plantation in Africa, have often died out after some years. FISHWICK emphasizes that soil water availability appears to the most critical factor, and this factor is combination of soil texture and local ground water supplies. On the other hand neem can also grow on alkaline or saline soil. In the Dominican republic, for instance, it grows well on former sugar cane fields which were abndoned owing to high salinity of the soil.
Neem as a typical stropical/substorpical plant, exists at annual mean temperatures between 21 and 32'c. It can tolerate high to very high temperatures, for instance northest ans central Africa where temperatures in the shade can reach ca. 50'C during the summer months. Temperatures below 4'c, and frost, are unfavourable and may result in shedding of leaves and occasionally even death of young plants. In the sub-Himalayan zone, where temperatures may fall below 0'c in winter, neem seems to be better adpted to cold conditions but young plants have to be protected by screens.
The neem tree is usually found on plains and low-lying hilly country. It thrives at altritudes upto 700-800 m and ocassionaly 1000m above the sea level. Higher altitudes are, as a rule, much less favourable.
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