Kadar, I; Foldesi, D; Voros, J; Szilagyi, J; Lukacs, D
The effect of various N, P and K supply levels on the disease resistance, quality traits and nutrient uptake of poppy was studied in a 10-year mineral fertilisation experiment. The major results were as follows: 1. In the dry year of 1983 a seed yield of 200 kg/ha was obtained on soil unfertilised for 10 years, while the yield was 800 kg/ha in the optimum N1P1K2 treatment. The infection of the capsules with Cladosporium herbarum Link. was increased from 42 % to 52 % by excessive N supplies. The damage caused by the poppy ceutorrhynchid beetle (Ceutorrhynchus macula alba Hbst.) and the poppy fly (Dasineura papaveris Winn.) rose from 1 % to 5-6 % as the result of combined overfertilisation with N and P. Unjustifiably high rates of N and P thus not only promote the formation of useful yield, but also the more frequent occurrence of diseases and pest damage. 2. Excessive N supplies reduced the oil content of the seed yield from 45.3 % to 42.9 %. The oil contained on average 72 % linoleic acid, 17 % oleic acid, 8 % palmitic acid, 2 % stearic acid and 1 % linolenic acid. As the result of excessive NP supplies the quantities of olcic acid and linolenic acid decreased, while that of linoleic acid increased, thus changing the relative quantities and ratios of fatty acids. 3. The concentration of alkaloids in the capsule increased as the result of N fertilisation and generally decreased after P fertilisation. Narcotoline and narcotine responded sensitively to P overfertilisation, the quantities of these alkaloids dropping to half on overfertilised plots. On average the dry capsules contained 0.2 mg/g thebaine, 0.7 mg/g narcotine, 1.1 mg/g narcotoline and 7.2 mg/g morphine, with a total alkaloid content of 9.3 mg/g. In the rosette stage the roots had a total alkaloid content of 0.1-0.2 mg/g and the shoots 5.2 mg/g (4.6 mg morphine, 0.6 mg thebaine) in the dry matter. 4. With an improvement in the NPK supplies (compared with the control and calculated per hectare) the oil yield rose from 109 kg to 334 kg, the total alkaloid yield from 2.2 kg to 5.7 kg, the morphine from 1.6 kg to 4.4 kg, the narcotine from 232 g to 303 g and the thebaine from 33 g to 123 g. Although N or P fertilisation reduced the chemical quality parameters (oil or alkaloids) in some cases, it improved the oil and alkaloid yields through the yield surplus. 5. The yield surplus was not significant at above supply levels of 177 mg/kg AL-P2O5 and 232 mg/kg AL-K2O. On this type of soil poppy can satisfy its nutrient requirements with supplies of 100 kg/ha/year N and AL-soluble contents of 200 mg/kg P2O5 and 250 mg/kg K2O. On the basis of plant diagnostic optima, satisfactory supplies are indicated by 2.5-3.0 % N, 0.50-0.60 % P and 5.0-6.0 % K in the shoots at the rosette stage or 3.0-3.5 % N, 0.40-0.50 % P and 3.0-4.0 % K in well-developed leaves from the middle of the plant at the beginning of flowering. These data can be used as guidelines for the extension service. 6. The element requirements of 1 t seed and the relevant capsule+stalk yield can be characterised as 83 kg N, 16 kg P (37 kg P2O5), 93 kg K (112 kg K2O), 65 kg Ca, 11 kg Mg, 8 kg Na and approximately 800 g Fe, 200 g Mn, 50 g Zn and 30-40 g Cu on this type of soil. The seed yield contained 47 % of the N, 57 % of the P, 61 % of the Zn and 45 % of the Cu. The capsule accumulated 52 % of the Na, while the stalk yield contained 65 % of the K, 47 % of the Ca, 41 % of the Mg, 86.1 % of the Fe and 48 % of the Mn.