The two major species of genus Madhuca found in India are Madhuca Indica (Latifolia) and Madhuca Longifolia (Longifolia). Mahua is widely accepted as local name, for both these species. This plant is common in deciduous forests. The seed potential of this tree in India is 500,000 tons and oil potential is 180,000 tons.
Madhuca Latifolia is a medium sized to large deciduous tree, distributed in Andhra, Gujarat, Madhya Pradesh, Orisssa, Bihar and Uttar Pradesh. Madhuca Longifoia, a large evergreen tree found in South India, and evergreen forests of the Western ghats from Konkan Southwards. The tree is planted in most part of India, propagating either by itself or sown seeds.
Botanical Features: M. Latijolia is a deciduous tree, while M. Congijolia is ever green or semi ever green tree. Mahua attains height up to 70 ft. The tree matures from 8 to 15 years, and fruits up to 60 years. The two species are not differentiated in Trade. The kernels are 70% of seed by weight. Seed contains two kernels, having 25 mm x 17.5 mm in size. Oil content in Latifolia is 46% and 52% in Longifolia. In seeds, oil content is 35% and protein in 16%.
Flowering: The flowering season extends from February to April. The copious fall of succulent, corollas weave a cream coloured carpet on the ground. Mahua flower is rich in sugar (73%) and next to cane molasses constitute the most important raw material for alcohol fermentation. The yield of 95% alcohol is 405 liters from one ton of dried flowers.
Fruiting: The matured fruits fall on the ground in May and July in the North India and August and September in the South India. The orange brown ripe fleshy berry is 25 to 50 mm long and contains one to four shining seeds. The seeds can be separated from the fruit wall by pressing. Drying and decortications yield 70% kernels on the weight of seeds.
Kernel: Each seed contains two kernels. As other forest crop, seed collection of mahua is difficult. Birds and animals eat the fleshy fruits. Collection of seeds and kernel separation is done by tribals and rural people in unorganized manner. Hence, there is considerable loss during drying and storage of kernels. Kernels contain 50% oil.
Storage of Kernels: The storage condition determines the quality of expelled oil, as the kernels are susceptible to both fungus and insect attack during the storage. Aspergillus flavus and Rhizophus sp. are chief among the fungi and Oryzaephilus surinamensis, an insect, is known to cause maximum damage. Storage of kernels at about 8% moisture level or better at 5 to 6% moisture level in Gunny bags with aluminum phosphide, would preserve the kernels well. Fresh oil from properly stored seeds is yellow in colour, while commercial oils are generally greenish yellow with a disagreeable odour and taste. The FFA of oil from fresh kernels is 1 to 2 percent. Poorly stored kernels yield oil of 30% FFA or even higher.
Oil: Mahua seed contains 35% oil and 16% protein.
Propagation: The tree reproduces through seed and coppice. The suitable sowing time in India is July to August. The seeds germinate after a good shower of monsoon rains. The seeds which get covered under the soil, germinate better and give rise to the seedlings while those lying exposed are either attacked by insects or fungus or their emerging radicals dry up before getting a hold in the soil. Some seedlings get suppressed and killed by all weeds and grasses. Forest fires, trampling and browsing by animals also take a heavy toll of the seedlings. Seedling growth of seed origin is slow and except in the open, seedling regeneration is quite scanty.
Nursery site: The soil of the nursery should be sandy in nature, though mahua can be grown in all types of soils.
Seed Collection and Storage: Collection of seeds and kernel separation is done by tribals and rural people in an unorganized manner. Hence, there is considerable loss during and storage of kernel. Each seed contains two kernels of size 25 x 17.5 mm. Kernel contains about 50% oil. If oil extraction is done by local oil mill, 20 to 30% of oil is obtained, whereas expeller yields 34 to 37% oil. Residual oil from the expelled cake can be extracted by solvent extraction.
Seed Storage: The storage condition of kernel determines the quality of expelled oil, as the kernels are susceptible to both fungus (Aspergillus flavus and Rhizopus sp) and insect (Oryzaephilus surinamensis) attack during the storage. Studies carried out on storage have revealed that it is better to store the kernel at 5 to 6% moisture levels in gunny bags treated with Cephos (Aluminium Phosphide). Proper storage ensures lower FFA and higher recovery of neutral oil free from colour and odour arising partly from fungal growth.
Seed Sowing: The soil of nursery beds should be sandy in nature. Seed is sown, soon after collection, in the nursery beds and covered with about 20 mm of soil. Beds are irrigated after sowing. Germination takes place in about 10 days. Seeds may be sown in polythene bags or baskets.
Picking Out: One month old small seedling from mother beds are picked out and replanted in baskets or other containers and kept till fit for planting. For stump planting, seedlings are put into transplant beds spaced about 200 to 250 mm apart. In nursery, watering is done immediately and thereafter at regular intervals for proper growth. Sown seedlings require weeding and soil work for first two years to simulate proper growth.
Vegetative Propagation / Cloning Techniques: Propagation of mahua tree by means of cuttings and layering has been found to be unsuccessful.
Plantation: Before undertaking plantation, the site is cleared by cutting and burning all woody growth. Pits at a distance of 9m x 9m or 10m x 10m should be dug in summer. Pit size 300 x 300 x 300 mm is best for planting of mahua in lateritic soil. However, pits of smaller sizes can also be used depending on the nature & soil thickness of the site.
Block Planting: The trees can be raised by direct sowing or by planting of nursery raised seedlings. In direct sowing of 4 to 6 seeds per pit are sown, covering them with 15 to 25 mm soil in June or July or as soon as seeds are ripe. Before sowing the seed pit should be filled with mixture of soil, sand and farmyard manure (FYM) in the ratio of 3:2:1. After sowing, the pit should be watered, if monsoon rains are delayed. Direct sowing give survival of 24 to 66%.
Diseases: Fungii like Aspergillus flavus, A. niger, Penicillium Sp. and Stathmopoda basiplectra causes deterioration in seeds and fruits. Leaf spots, leaf blight and leaf rust diseases are common in nursery as well as in plantation.
Pests: Defoliation and flower drop are common insect pests problems associated with mahua both in nursery and plantation.
Parasites: Dendrophthoe Falcate (L.f.) is serious parasite for attacking the growth and productivity of Madhuca. There is considerable reduction in the formation of inflorescence and the flower size of the plant. The parasite simultaneously weakens the plants and on ageing the plant dies. The parasite can be controlled by applying certain weedicides like 2,4D and Gramoxone. The manual cutting or removal of parasite from infected plants is also suggested.
Mahua cake can be used as a cheap organic manure. Mahua cake contains 3.5% Nitrogen, 50.51% Proteins.
The flowers are used as vegetable, for making cake, liquor. Flower juice is used in the treatment of enlargement of auxiliary gland, neurotic disorder and taken with cow�s milk as an aphrodisiac, in cough and bronchitis. The derived liquor desired from the fermentation of flowers is considered to be a tonic and nutritive.