Climate and Soil
Radish main season varieties develop best flavor, texture and'root size when the temperature is between 10-15'C. In temperate types, maximum root growth occurs initially at 20-30'C and later at 10-14'C. More foliage growth is favored at temperature above 20'C.In hot weather, roots become pungent and tough before attaining marketable maturity.Turnip roots develop best flavor, texture and size at 10-15'C.Long days and high temperature induce early bolting even without adequate development of roots. In hot weather, roots become fibrous,tough and pungent. The Asiatic types can tolerate fairly high temperature but flourish under cool weather.Radish and turnip can be grown on all types of soil but a sandy loam, friable soil is considered best. These crops can be grown in fairly acidic soils having pH of 5.5-6.8. Sandy loam soil is ideal for quick growth of roots. Soils with high clay content are not desirable,as they tend to produce misshapen roots with numerous small laterals.
Punjab Pasand (1997) : It is an early maturing variety and roots attain edible maturity after 45 days of sowing. Roots are long,pure white, semi-stumped and free from hair. Its top is light, erect and leaves have complete lamina. It is suitable for sowing in main season and gives an average yield of 215 q/acre. During off season it gives 140 q/acre yield.
Pusa Himani (1995): It is a temperate variety suitable for sowing in second fortnight of January. Roots are white, semi-stumped with green shoulder. Roots are fleshy, crisp, mildly pungent, 30-35 cm. in length and 10-12 cm in girth. Roots are ready for harvest 60-65 days after sowing. It yields 160 quintals of roots per acre.
Pusa Chetki (1988) : Roots snow-white, smooth, medium long(15.5 cm), thick (3.5 cm), stumpy and mildly pungent. Leaves medium sized (40.5 cm ) with complete lamina. Leaf root ratio is 1:1.5. An early maturing with good seed setting under Punjab conditions. This variety is most suitable for sowing from April to August. The average root yield is 105 q/acre and seed yield is 4.5 q/acre.
Japanese White (1962) : It is an introduction from Japan and is recommended for late sowing in the main season in north Indian plains and July to September in hills. Its top is medium and leaves have deep cuts. The roots are cylindrical, pure white with blunt end.Average yield is 160 q/acre.
L-1 (1974) : The roots are round, pure white, smooth rat-tailed and crisp with mild flavor. It can be harvested between 45 to 60 days of sowing. It yields about 105 quintals of roots per acre.
Sowing Time and Seed Rate: Although radish is a winter season crop but varieties have been developed that can be grown in summer and spring seasons. Except Pusa Chetki, other varieties do not tolerate high temperature if planted early in the season. Asiatic varieties if planted late in the season, start bolting without forming edible roots. With careful selection of varieties, radish can be grown almost throughout the year. The schedule of sowing radish varieties and their root availability is given as under:
For desi varieties of turnip, August-September is the best time of sowing. European types should be sown in October-November.A seed rate of 4 to 5 kg. for radish and 2-3 kg. for turnip is sufficient for one acre. A spacing of 45 cm between ridges and 7.5 cm between plants in the row is common for these crops. The plant spacing is maintained by thinning at the time of true leaf formation. Thinning isvery important for producing superior quality roots.
Manures and Fertilizers
15 tonnes of farmyard manure, 25 kg. of N (55 kg of Urea) and 12 kg. of P205 (75 kg. of Single Superphosphate) per acre is the common fertilizer dose. Apply all fertilizers at sowing and always apply well rotten farmyard manure.
Weeding and Earthing up: In radish and turnip, one weeding about 2-3 weeks after sowing is sufficient. Weeding is immediately followed by earthing up especially in desi varieties of radish where roots have tendency to protrude above soil surface.
Irrigation: First irrigation should be given immediately after sowing of seed. Subsequent irrigation should be given at 6-7 days interval during summer and 10-12 days during winter, depending upon soil type. Radish requires 5-6 irrigation. Excessive irrigation results in misshapen roots and numerous hair growth. Pre-harvest light irrigation is useful for summer crop of radish because this keeps the roots fresh and reduces pungency.
Radish and turnip are harvested when roots are tender. A few days delay in harvesting particularly of European types, render the roots pithy and unfit for consumption. Punjab Pasand, a quick growing main season variety and Pusa Chetki, an early season variety attains marketable maturity 45 days after sowing. Other varieties of radish and turnip are ready for harvest in about 45-60 days depending upon variety and season.
Radish: Roots raised in one acre are sufficient to plant 4 to 5 acres of seed crop. Sow Pusa Chetki in August, Punjab Pasand inSeptember and Japanese White in October for raising roots for seedproduction. Transplant stecklings of Pusa Chetki in September and Punjab Pasand and Japanese White after middle of November.Transplant stecklings of ¾ root length at 60 x 22 cm. spacings.Apply 30 kg N (65 kg Urea) and 8 kg P205 (50 kg. Superphosphate)per acre. Add whole of P205 and half of N before planting and the remaining half of N after 30 days of planting.
Turnip: Roots raised in one acre are sufficient to plant 3 to 4 acres of seed crop. Seed of L-1 can be produced by sowing in midSeptember and transplanting in the first week of December. Selectroots having diameter more than 5 cm for seed production. Keeprows 45 cm. and plants 15 cm apart. Apply same fertilizers as incase of radish.
Note : For motorised knap-sack sprayer, use the same quantity of pesticides per acre, as mentioned above, but the quantity of water for dilution will be approximately 1/10th.