Potato and Tuber Crops

Details of improved techniques are as follows

Improved Techniques in Cassava

Preparation of Mini Setts

• For producing minisetts, first step is selection of mature, disease free stems (preferably those obtained from meristem culture).
• In a study conducted at CTCRI to standardize the optimum size of minisett planting material in cassava, three sizes of nodal cuttings: single node, two node and three nodes were tested under three spacings.
• Single node cutting was significantly inferior to the other two for all factors studied.
• The two node and three node minisetts were on par for all growth and yield parameters.
• Since the minimum number of nodes required was the essential criteria for optimization of minisett size, two node minisetts has been standardized as the optimum size for rapid production of planting materials in cassava.
1. Minisetts are prepared from healthy stems by making two node cuttings using a sharp hack saw.
2. Top one-third portion is usually discarded in the traditional system however in minisett technique, the whole stem is used.
3. When tip cuttings are taken, it is advisable to place them in water so as to prevent dehydration.
4. The stem just below the growing tip is very tender with prominent axillary buds.
5. Hence from this portion, cuttings with four nodes are taken instead of two as the latter may dry up very fast.
6. During the course of minisett preparation, sufficient care should be taken such that no damage is caused to the axillary buds.
7. The following are different types of minisetts made from a cassava plant
1. Tip portion minisett
2. Four node minisett, from the top tender portion
3. Two node minisett, from the matured (woody) portion.
4. The woody stock at the base is discarded.
5. About 50 to 70 minisetts could be prepared from a stem.

Shade Net House

• The shade net house should be ideally located on a flat field and the soil should be well drained and devoid of stones and pebbles, preferably near a water source.
• Since the minisetts ought to be free of any diseases and pests, it is essential to raise them in a protected environment.
• A shade net house of 30 x 7 m dimension would be ideal.
• The structural frame work comprises of GI- B class pipe with a flat roof and drooping sides.
• The shed is covered with shade net of 35 per cent shade. Studies revealed that 35 per cent shade is the optimum to regulate and limit the plant growth in the desired level, since higher shade would prompt etiolating crop growth.
• The roof as well as sides of the net house should be totally covered so as to ensure protection from insects and pests.
• Provision for one or two doors should also be given.