Method of Seed Production

Method of Seed Production

    Varieties
    • C-3, CO-1, CO-2 (Seed tapioca), CO-3, Mulluvadi, H- 165 - 226, Sree Vishaham (H 1687), Sree Sehaya (H 2304), H-97, H-165, H-226, Sree Jaya, Sree Vijaya, Nidhi, M-4, Sree Sahya and KMC
    Season
    • Throughout the year under irrigation. April is best for rainfed crop
    Isolation
    • Fields of other varieties and fields of same variety not conforming to varietal purity, the isolation distance for foundation-5m and for certified seed-5m.
    Seed and sowing
    • Seed rate 17,700 setts/ha at a spacing 75 x 75 cm. Setts should be 15 cm length with 8-10 nodes and should be collected from middle portion of the stem.
    Vegetative propagation
    Sett Preparation
    • Stem collected from the previous crops are generally used to raise new crop. Stem cuttings or stakes or setts are directly planted in the field. In some places cuttings are planted in a close spaced nursery. Stems are collected form the middle portion of stem are ideal for planting. Stems having a thickness of 2-3 cm are ideal for planting. The length of stake is related to the depth of planting. 20 cm long stakes are optimum size for planting.
    Sett treatment
    • The setts should be dipped in 0.1% Bavistin for 15 min and then it should be dipped in phosphate slurry 2 hours before planting. The phosphate slurry will be prepared with super phosphate, soil and water @ 1:1:2 ratio by weight. 75 kg super phosphate is enough to treat the setts required for one ha. The setts should be dipped up to 5 cm i.e., portion which goes into the soil.
    Method of Planting
    1. Raising nursery and transplanting
    2. Direct planting
    Nursery technology
    In this method, stakes are planted in the nursery at a very close spacing of 4.5 x 4.5 cm with irrigation for about 3 weeks prior for the regular planting time in the main field.
    Advantage
    1. Setts expressing symptoms of mosaic disease can be discarded in the nursery itself to reduce the incidence of mosaic in the main field
    2. In areas where the crop is raised under irrigation this technique can save water
    3. This technique will reduce the percentage of failure in the main field.
    Direct Planting
    • Different methods of planting of stakes, such as vertical planting (at 45◦ angle) and horizontal planting showed that vertical planting resulted in more tuber yield.
    Methods of planting
    • Three different systems are adopted for cassava planting, such as flat, mound and ridge. Both the ridge and mound systems facilitate easy weeding and also harvesting. Under irrigated cropping, the ridge system is commonly adopted. Another method known as ‘pit followed by mounds’ was found to be superior to other methods.
    Depth of Planting
    • Shallow planting facilitates production of more number of roots when the soil is sufficiently loose and friable, stakes can be planted to a depth of 5 to 10 cm. Deeper planting result in swelling of the mother stem and reduction on root size and yield.
    Fertilizer
    • Compost : 12.5 t/ha
    • Basal : 30:60:85 kg NPK/ha
    • Top dressing : 30: 75 kg NK/ha on 40-60 days after sowing
    Harvest and Storage
    • Optimum harvest time ranges between 7 to 12 months after planting. The storage capacity of cassava planting material depends on the variety; some varieties tolerate prolonged storage, whereas others do not. Stems should be cut as long as possible, because, overtime, increasingly larger portion of their extremes, especially the apical, deteriorate and need to be cut off. The middle part thus diminishes. Stems should be stored vertically, not horizontally to reduce loss of planting material and control weight loss in usable stakes. Treating stem with insecticides and fungicide solutions can help to prevent seed deterioration under poor storage conditions. Cassava stems should be moved to the storage site as soon as possible after harvest. Exposure to sun reduces the seed storage capacity.
    True Seed
    • The seeds are sown in ridges. Seed treatment with KNO3 0.5% and GA3 100 ppm reduces the initial dormancy. The seed matures 60 days after anthesis and harvesting is done with change of colour from green to yellow. During crop growth yellowing of leaves may take place due to Iron deficiency. Spraying of 0.15% ferrous sulphate 3-4 times at weekly intervals to the deficient symptom. The seeds can be processed using 12/64’ round perforated metal sieve. The seeds can be stored up to 1 year under ambient storage conditions.
    Plant protection
    Pests

    Mites
    • spraying with dicofol 18.5 EC 2.5 ml/lit during 3rd and 5th month.
    White fly (Bemisia tabaci)
    • Integrated pest management practices:
    1. Remove alternate weed hosts viz., Abutilon indicum.
    2. Installation of yellow sticky traps at 12 Nos/ha.
    3. Use of nitrogen judiciously.
    4. Avoiding excessive irrigation.
    5. Spraying of neem oil 3 % or fish oil rosin soap 25 g/lit or methyl demeton 25 EC 2 ml/lit. While using neem oil teepol or sandovit should be added at 1 ml/lit for better contact with foliage.Apply methyl demeton in the early stage and phosalone in the late stages of crop growth.
    Spiralling whitefly
    1. Growing resistant genotypes.
    2. Installation of sticky cum light traps between 4 to 6 am to attract the adult.
    3. Spray of dichlorvos 76 WSC @ 1 ml/lit or triazophos 40 EC 2 ml/lit
    Diseases
    Cercospora Leaf spot
    • Spraying of Mancozeb at 2 g/lit twice at 15 days interval.
    Tuber rot
    • Water stagnation should be avoided. Spot drenching with Copper oxychloride 2.5 g/lit.
    Iron deficiency
    • Spraying 3 to 4 times ferrous sulphate 2.5 g/lit on the appearance of deficiency symptom at weekly intervals. Equal quantity of lime should be added for neutralizing the solution.
    Specific seed certification requirements
    Factors Foundation seed Certified seed
    Offtypes (%) 0.10 0.20
    Plants showing symptoms of mosaic diseases (%) 0.10 0.50
    Plants infested with scale insect None None


Last modified: Monday, 25 June 2012, 4:33 AM