Methods of seed production

1. Insitu Method or Seed to Seed Method

• This method is popularly practiced for seed production in Broccoli.
• The field preparation and cultural practices are similar as in market crop production
• Plants are allowed to overwinter in their original field/position where they are first planted.
• Spacing for early varieties = 45 c.m×30-45 c.m, mid season = 60 c.m×45-60 c.m and for late varieties =60 c.m×45- 60 c.m
• At head maturity, longitudinal/horizontal half cut of head surface is made to induce flowering shoots for those cultivars which have compact head. It makes easier bolting, early flowering and higher yield of seed.
• To produce quality seeds, the terminal head is removed and several auxiliary heads produce flower to produce seeds. Sometimes the thinning of central flower clusters of central head is practiced to produce quality of seeds.

Field Inspection and Rouging :

• To maintain the varietal purity, at least three times field inspection and rouging are recommended. Any plot rejected previously by the certifying agencies should be rejected.

1. At head initiation stage: Check the vegetative characters and remove the off types.
2. Full head formation i.e. marketable stage: Check head characters such as shape, size, and compactness, color and remove off types.
3. Flowering and pod formation: Check flower color, Remove early and late bolters. Check the pod size, shape. Diseased and off type plants should be removed.

Isolation Distance

• Isolation is necessary in broccoli for the maintenance of purity of cultivars.
• Broccoli intercross rather freely among the crops and cultivars within the same group, and therefore, isolation would be necessary when two crops of the same groups are grown at the same isolation.
• Generally, at least 3000 m isolation is recommended for the production of breeder’s seed, while at least 1600 m and 1000 m will be needed for foundation and certified seeds.
• Broccoli can be crossed with cauliflower, cabbage, knolkhol and thus, isolation distance must be maintained.