The effect of mother plant nutrition on the seed yield and quality of cauliflower (Brassica oleracea var. botrytis L.) cv. Snowball and mustard broad leaf (Brassica juncea Czern and Coss.) cv. Miike Giant were investigated under the field and glasshouse conditions. Increase in the levels of nitrogen (equivalent to 50 to 150 kg/ha), phosphorus (equivalent to 0 to 150 kg/ha) and potassium (equivalent to 50 to 100 kg/ha) all applied as base dressing did not affect the seed yield of cauliflower under glasshouse conditions. In field conditions, total nitrogen (equivalent to 50 kg/ha to 350 kg/ha) applied in three split doses and phosphorus (equivalent to 50 kg/ha to 200 kg/ha) had not significantly increased the seed yield of cauliflower. In a container grown crop of mustard broad leaf nitrogen equivalent to up to 300 kg/ha increased the seed yield but the application of phosphorus had no effect. The percentage distribution of graded seeds produced was not affected by mother plant nutrition in cauliflower or mustard broad leaf. Increase in the nitrogen level to the mother plant did not improve the seed quality of cauliflower as assessed by field emergence tests, controlled deterioration test and electrical conductivity test, but in mustard broad leaf, N2 produced seeds which showed poor performance in seed quality tests. A further increase in nitrogen to level N3 did not significantly affect seed quality. Phosphorus application generally increased germination percentage, 100 seed weight, field emergence percentage and germination percentage after controlled deterioration and decreased the electrical conductivity reading and mean time to emergence in cauliflower seeds. Addition of phosphorus had no effect on seed quality of mustard broad leaf. An increase in potassium application had generally no effect on the seed quality. There was a slight decrease in 100 seed weight and germination percentage with increase in potassium level. NP, NK, PK and/or NPK interactions effect was noticed in most seed quality tests. Generally higher levels of phosphorus with lower levels of potassium and medium level of nitrogen produced seeds which showed comparatively higher vigour in electrical conductivity, controlled deterioration, rate of emergence and field emergence tests. The small seeds (grade C below 1.7 mm in cauliflower and grade B, below 1.4 mm in mustard broad leaf) were consistently showing low vigour in the tests used. The differences in seed quality tests between grade A (above 2.00 mm), B (between 1.7 and 2.00 mm) or D (ungraded) seeds in cauliflower were not significant.
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