Published online by Cambridge University Press: 27 March 2009
Opium poppy (Papaver somniferum Linn.) was sown at three sowing dates (10, 25 November, 10 December), row spacings (15, 30, 45 cm) and population densities (6 × 105, 3 × 105, 1·5 × 105 plants/ha) in a split-plot design at Lucknow. Sowing on 10 November resulted in higher yields of opium, seed, total dry matter and morphine content. Delayed sowing, higher plant density and narrow spacing produced low yields with less morphine content. Decline in opium yield was associated with decrease in plant height, leaf area index, capsule size and number of capsules per plant. The crop sown on 10 November removed most N. N concentration and uptake also increased when the number of plants per unit area was decreased. The study suggests that to achieve maximum yields poppy should be sown in rows 30 cm apart on 10 November with 3 × 105 plants/ha.