Poppy cultivation in Bulgaria, and the production of opium

Abstract

The opium poppy (1, 2) has been known in Europe since prehistoric times (3).* It is widely cultivated as an oil crop in almost all countries (4). It is cultivated for the sake of opium, however, only in Yugoslavia, Bulgaria and the USSR.

Details

Author: D. Dalev, L. Iliev, R. Ilieva
Pages: 25 to 36
Creation Date: 1960/01/01

Poppy cultivation in Bulgaria, and the production of opium

Prof D. Dalev
L. Iliev
R. Ilieva
Department of Pharmaceutical Chemistry, Higher Medical Institute, Sofia

Full size image: 5 kB

The opium poppy (1, 2) has been known in Europe since prehistoric times (3).* It is widely cultivated as an oil crop in almost all countries (4). It is cultivated for the sake of opium, however, only in Yugoslavia, Bulgaria and the USSR.

Poppy cultivation was brought over to Macedonia by the Turks at the beginning of the nineteenth century. The first experiments in cultivating it were made in Shtip in 1835, with poppy seed brought over by Aphion Karakhisarski, whence the frequently used appellation," aphion ", for opium. The first experiments were successful, and the Turkish Government initiated a series of measures to encourage the cultivation of this crop. Because of the favourable climatic conditions and the great demand for opium, its cultivation spread so rapidly that at the end of the nineteenth century the poppy was to be found as far as the Danube valley. It must be regarded as positively established that from this period the poppy was widely cultivated for the purpose of obtaining opium in the Blagoevgrad district (okrug). According to other accounts, the poppy was first cultivated within the confines of the old Bulgaria in the countryside around Ferdinandovo (now called Mikhailovgrad), in the Plovdiv area, in 1895, by immigrants from Macedonia. According to still other, unverified information, the poppy was first cultivated in Bulgaria in the Kyustendil sub-district (okolya) (5). Originally, it was grown in Bulgaria only as an oil crop, except in the Blagoevgrad district, where it was grown primarily for opium.

For general background information on opium (history, botany, etc.), see Bulletin on Narcotics, vol. V, No. 3 (special issue on the opium poppy, opium and its alkaloids).

Botanical Aspects

According to the classification given by Hegi (1906), the cultivated poppy, Papaver somniferum L., belongs to the

Papaveraceae family. The Papaver somniferum is sub-divided into six varieties, according to the colouration of its seeds:

  1. Var. album, with white seeds;

  2. Var. nigrum, with black seeds;

  3. Var. caesium, with blue seeds;

  4. Var. roseum, with red seeds;

  5. Var. griseum, with grey seeds;

  6. Var. luteum, with yellow seeds.

The poppy as it is now found in Bulgaria contains, according to A. Popov, all the above-named varieties, but the most commonly occurring forms are those with white seeds, followed by the blue-seed and the grey-seed forms. The other varieties are found only as mixtures.

According to Bazilevskaya's classification, the cultivated or soporific poppy Papaver somniferum L. belongs to the Papaveraceae family. The sub-species turcicum grows in Bulgaria; this sub-species occurs in the Mediterranean to eastern parts of Asia Minor, and its bordering regions of Macedonia, Palestine and the Transcaucasian republics of the USSR (6).

In Bulgaria, the poppy is an annual herbaceous plant; it has a fusiform main root, with a few lateral branchings in the surface soil. The stem is erect, and under Bulgarian conditions varies in height from 40 to 180 cm, with three to seven, and sometimes more (up to fifteen), branchings, which are sometimes slightly villous, and covered with a waxy bloom, which gives them a bluish-green colour. The leaves are large, entire or slightly serrated, and shot through with blue or grey-green colours. While the lower leaves are broad and spatulate with dentate margins, and are hairy along the midrib on the underside, the stem leaves are obovate, small, dentate-edged, with a cordate base which encloses the stem.

The buds are small, ovate, and twined round two large sepals which fall off when the flower is shaken. Before flowering, the buds droop.

The flowers are medium large, single, with four petals, usually white or violet. Occasionally, poppies with red or pink petals are found; these are usually entire, and only exceptionally have cut margins. There are 150 to 200 stamens, arranged in five circles.

The fruit consists of a large pod with an incomplete septum which has a smooth surface, or is very slightly segmented. The pod is spherical, oval, or conical in shape.

The stigma is a star-shaped flat disc, with 5 to 16 rays. The pod contains 800 to 2,000 seeds.

The seeds are very small, weighing 60 kg to the hectolitre. The most common colour of the seeds is white or grey. Bluish-grey, coffee-coloured or yellow seeds are sometimes found.

The white-flowered variety of poppy gives white seeds, and the blue-flowered variety, which in fact has violet petals, gives grey seeds (7).

Influence of Climate

For normal growth, the poppy requires a certain definite distribution of rain over the course of the year, according to the soil humidity. Moisture is particularly necessary during the vegetation period. In Bulgaria, climatic conditions suitable for the growth of the poppy exist, and can be utilized to greatest effect if the poppy is sown in autumn. In general, there must be an adequate supply of moisture in the surface layer of the soil if the poppy is to germinate. A large quantity of water is also particularly necessary from the first stages of the plant's growth until flowering begins. Conversely, after flowering is over, a dry soil is required for the cultivation of the poppy for opium. Under these circumstances, a high-quality crude opium is obtained, with a high morphine content. While the bud is growing, rain, and also wind, not only do not help, but are even injurious.

The poppy's response to heat also varies in the course of different stages of its growth. During sowing, cool weather is the most favourable - that is, moderate temperatures; otherwise, the plant grows quickly, but does not become well established, and may die during the winter. A sudden warm spell during late spring or autumn, or immediately after spring sowing, causes the plant to grow rapidly, but without establishing itself, because some pods fail to swell, with the result that the opium and seed yield is low. Conversely, high temperatures during the periods of flowering, harvesting the pods and gathering the opium are favourable for the opium and seed yield. Hot winds, however, are particularly unfavourable during these periods.

The poppy requires a temperature of at least 3 to 4°C in order to germinate; the optimum temperature for germination is 10 to 11°C. The young plants prefer a temperature of 4 to 7°C. For these reasons, in open soil, winter frosts are harmful to autumn-sown popies, and this means that the crop must be sown in spring. Once poppies have survived the winter, they are unharmed by late spring frosts.

The intensity of the sun's heat, especially in the flowering period and while the fruit pods are forming, is of major importance for the accumulation of alkaloids in the milky juice. Under the effect of abundant moisture, the poppy sickens, and the seeds grow in the pod during ripening, and risk becoming completely spoiled.

Influence of Soil

The poppy grows well in a not too dense soil which is sufficiently pervious. It does not take up water from the subsoil. When fertilized with well-rotted manure, it will flourish even in comparatively poor soil, although the field must still be well warmed and free from cold, and possess a good soil structure. Soils which form a spring crust are unfavourable, because they hamper not only germination, but also the subsequent growth of the poppy; this causes development to cease, and leads to a low seed and opium yield.

The poppy is exacting as regards the composition of the soil; it grows well, and gives a rich yield in rich, well-manured soil. Compared with rye, for example, it takes up two and a half times more phosphorous, twice as much potassium, and six times as much calcium. The poppy is successfully cultivated in the light, black earth soil in southern and northern Bulgaria,

BULLETIN ON NARCOTICS lJANUARY-MARCH 1960 27as well as in the grey mountain and brown mountain soil in the upland regions - that is, in soils where wheat and other cereals grow.

In the cultivation of the poppy, good results depend to a large extent on applying all the correct technical procedures. In the choice of field, apart from the conditions of soil composition and structure mentioned above, the previous crops must also be taken into account. The practice adopted to this end is to sow the poppy in soil which has been well fertilized with well-rotted manure for the previous crop. This prevents the field from becoming congested with weeds, thereby making it possible to prevent the appearance of the weeds in good time.

Under Bulgarian conditions, the poppy is generally sown either after the winter cereals - especially wheat - in the case of autumn sowing, or after a root-crop, in the case of spring sowing.

The poppy requires very well prepared soil. The soil is first deep-ploughed with plough and coulter, after which the surface is levelled. The early deep-ploughing is a particularly important part of this preparation. Through periodic cultivation and harrowing of the surface layer, the soil becomes friable, and at the same time weeds are kept down.

A great many experiments have been described in the literature, which show that the manuring of the poppy crop plays an extremely important part in securing a high yield (8). Surveys based on questionnaires issued to a large number of individual and co-operative farms, and analysis of their opium production have shown that practical experience confirms that fact. In Bulgaria, experiments carried out in the past on individual holdings and at the labour co-operative farms (TKZS) have provided practical evidence that the good results obtained under experimental conditions can be repeated.

Of the mineral fertilizers, nitrogenous and phosphorus fertilizers have a particularly pronounced effect; they are usually applied twice - the phosphorus fertilizers are, for preference, generally applied directly before sowing, and the nitrogenous preferably during the vegetation period.

Another important factor for good opium yield is the selection of the seed for sowing. In Bulgaria, seed is supplied through the responsible state organization. Before the seed is sown, it is cleaned by being steeped for fifteen minutes in 0.25% formaline solution, washed with water, and then left to dry in an airy, shaded place. Dry disinfection is also practised, by dressing with one of the agricultural preparations used for such purposes (0.5 to 1% tilantin-ceresine, or germisan-trakenboitse).

We use spring sowing only as a last resort. Given successful wintering, autumn sowing always ensures a very high seed and opium yield, in comparison with spring sowing.

Under the climatic conditions which exist in Bulgaria, the period suitable for autumn sowing is the time between 20 September and 10 October, depending on the presence of moisture in the soil. Until recently, sowing was done either by scattering the seed broadcast by hand, or else more or less sparsely in rows, in which case the seed was placed in a bottle with a goose quill attached to its stopper. These methods of sowing are steadily being supplanted as our co-operative farms are becoming equipped with up-to-date agricultural machinery, and there is a growing preference for seeders, which can distribute 1 kg of seed per decare (ca. 0.2 acre) to a depth of 1.5 to 2 cm.

According to the findings of the Sadovsk experimental station, where tests were performed during the period 1928-1931, the optimum distance between the rows is 30 cm, with 15 cm between the plants (relative yield, 101.30).

The yield is scarcely affected if the space between the rows is increased to 40 cm and the distance between the plants is kept at 15 cm (relative yield, 100), or if the distances are reduced to 20 and 15 cm (relative yield, 99.2). It is therefore economically useful to work with large distances between the rows when mechanical tillage instruments are used. On the other hand, experiments in increasing the distance between the individual plants within the rows from 20 to 25 cm led to a fall in the yield. But if advanced agricultural techniques ara used, according to the findings of the national experimental stations, the inter-row distance can be increased to 60 or even 75 cm, provided the number of plants per unit of surface is kept the same as before by reducing the distance between the plants in the rows from 15 cm to 7.5 cm.

The poppy seed takes 10 to 12 days to germinate, after which slow growth continues through the weeks preceding the onset of frosts and snow. After successful wintering, early spring hoeing and thinning are especially important if high yields are to be obtained. Still better results are obtained with autumn hoeing and thinning. Even spring-sown poppies require these operations to be carried out as early as possible. The number of hoeings depends on climatic conditions during the year. Generally, 3 to 4 hoeings are necessary; the soil is thereby kept friable, and weeds are kept down. The plants are usually fed at the same time as the hoeing is done.

Plant Enemies

Protective measures must be taken against a number of diseases to which the crop is subject. The most commonly encountered is pleosporosis(9), caused by the fungus Pleospora calvescens, which attacks the poppy at all stages of its growth. As a rule, irregular brown specks appear first on the leaves, and gradually grow into oblong spots up to 10 cm long, which spread over the rest of the plant.

Peronosporosis (mildew) is caused by the fungus Peronospora arborescens. This is particularly widespread during wet years in the hot weather. It can even wipe out the crop.

Bacterial spot is caused by the Bacterium papavericola. At first, numerous, almost circular, spots form; these are brown on top, and olive green underneath, and later become dark brown. The disease is carried by the seed. It is rarely encountered.

Bacterial wilt is caused by the Bacillus (Erwinia) papaveri. Dark brown to red spots form. The disease is carried by the seed, and is rarely encountered.

Bean aphid (Doralis fabae) is comparatively widespread in Bulgaria (10).

Full size image: 2 kB

Fig. 1. Examination of poppy capsules before harvesting

The poppy weevil (Ceutorrhynchus macula alba) may be up to 5 mm long. It has a light yellow body covered with grey and yellow hairs, and red antennae. It lays its eggs in the seed pod of the poppy. The larvae are covered on the upper side with a great number of small transversal folds. The chrysalis forms in the soil, where it winters.

The poppy midge (Cecidonia papaveris) attacks the fruit pods. Its development is similar to that of the poppy weevil.

The poppy pests can be successfully combated by using advanced agricultural techniques, crop rotation, collecting and burning all the plant refuse after the harvest has been gathered, deep-ploughing the field, using healthy seed for the sowing (decontaminating it before sowing), and by burning diseased plants.

Harvesting

The collection of the opium is done in Bulgaria by incising the poppy-heads during the period of what is known as industrial maturity. This occurs about twenty-five days after the flowering of the greater part of the plant is over, at the beginning of June in the plains of southern Bulgaria, and at the end of that month in the more northern and higher parts of the country. When the plant reaches industrial maturity, the poppy capsules gradually change their greenish colour for one with steely-blue tints, and become covered with a light down. With light pressure the inner sides can be felt, while in the uppermost part of the spathe under the pericarp itself, a light coffee-coloured ring appears. On incision of the pericarp, when only the epidermis and the milky ducts are touched, droplets of milky juice separate out on the surface of the walls. The incision is almost invariably made with a special sharp-edged knife, which penetrates 1 to 2 mm deep. About three-quarters of the capsule is incised horizontally, and the operation stops a little below the broadest part of the capsule. In calm weather, the droplets of milky juice form a string of beads like a pearl necklace. Strong winds, and especially rains, prevent normal collection of the opium. The incision is usually begun after midday, and finished before sunset. Early on the following day, immediately after the dew has evaporated, a milky juice exuding from above the capsule has already collected, dried, and from being white (occasionally pink) has become coffee-coloured and hard.

For collecting the opium, a broad, comparatively blunt knife is used. The opium is placed in a special box in the shape of a truncated cone, called a "safa ", which is belted on to the worker's body.

In Bulgaria, the poppy capsules are incised only once, usually with a single-bladed knife.

The opium yield is collected into a single pool, mixed well and made up into little cakes of 200 to 250 g, which are wrapped in poppy leaves and placed in a shady and sheltered spot to dry. The purchasing organizations sometimes accept it in a semi-liquid condition, and process (malax) it into cakes themselves.

The yield of crude opium per decare varies a good deal (from 0.400 to 2.500 kg).

About three weeks later, the seed is collected from the poppy capsules. This is usually done manually (as the poppy seed is exceptionally small, waste occurs if the collecting is done by machinery). The seed yield per decare varies from 60 to 120 kg.

Full size image: 3 kB

Fig. 2. Incision of poppy capsules. Region of Sandanski (Bulgaria)

Bulgarian opium is known on the world market for its high content of morphine (11). Our regular five-yearly surveys of the opium yield for the whole country show that Bulgarian opium is high on the world list in respect of quality.

TABLE 1

Morphine content of opiums produced in different countries

Producing country

Percentage of morphine in crude opium

Yugoslavia
13-16
Turkey
12-14
Iran
10
Afghanistan
10-16
India
7.5-10
China
6-8
Mexico
3-6

Bulgaria was not included in the above table. The figures for the percentage of morphine content of Bulgarian opium, according to our own researches, are given in table 2.

The tests were made on average samples taken from export lots of crude malaxed opium throughout the years indicated (13).

As regards opium yield, poppy cultivation in Bulgaria was until recently concentrated almost exclusively in the southwestern part of the country.

These regions were not in a position to satisfy the growing requirements of our export trade and our pharmaceutical

TABLE 2

Percentage of morphine content of Bulgarian opium

Year

Percentage of morphine with 15% moisture

Percentage of morphine with 10% moisture

1949 14.40 15.24
1952 15.58 16.50
1950 16.40 17.35
1948 16.41 17.38
1951 16.45 17.42

industry. It therefore became necessary to decide which regions were suitable for developing the cultivation of the poppy or opium so that the over-all area sown to poppy could be extended.

For five years (1948-1952 inclusive) we carried out regular research on opium samples taken from every part of the country, both from the old southern regions, and from the new northern regions where, on our advice, poppy sowing had been started. We took average samples from the whole quantity of opium obtained from a given locality, district or region.

For this purpose, the whole quantity of opium gathered from the given locality was thoroughly mixed when the opium was not very hard, and from each part of the general mixture a known equal quantity of opium was taken, which was then mixed on thick glass with a metal spatula until it became completely uniform. The entire quantity was then spread on the glass in an even layer, and proportional quantities

TABLE 3

Content of morphine in crude and anhydrous opium, by years and districts, for the whole of Bulgaria

(In percentages)

 

Year

 

1948

1949

1950

1951

1952

District

Season

Mor-phine in crude opium

Moist-ure

Mor-phine in dried sub-stance

Mor-phine in crude opium

Moist-ure

Mor-phine in dried sub-stance

Mor-phine in crude opium

Moist-ure

Mor-phine in dried sub-stance

Mor-phine in crude opium

Moist-ure

Mor-phine in dried sub-stance

Mor-phine in crude opium

Moist-ure

Mor-phine in dried sub-stance

Petrich
Autumn
11.80 35.54 18.40
-
-
-
12.34 34.50 18.84 12.03 37.50 19.10 10.97 34.74 16.81
 
Spring
-
-
-
12.91 23.10 16.79
-
-
-
-
-
-
-
-
-
Sandanski
Autumn
12.70 32.06 18.69
-
-
-
12.34 34.50 18.84 12.12 35.36 18.71 11.98 32.84 17.81
 
Spring
-
-
-
12.91 23.10 16.79
-
-
-
-
-
-
-
-
-
Blagoevgrad
Autumn
12.58 29.77 17.91
-
-
-
10.69 34.44 16.30 13.11 32.55 19.44 10.59 37.47 16.93
 
Spring
-
-
-
10.28 33.57 15.63
-
-
-
-
-
-
-
-
-
Stanke Dimitrov
Autumn
11.93 37.90 19.21
-
-
-
12.03 32.68 18.76 11.81 36.60 18.65 12.33 32.90 18.37
 
Spring
-
-
-
10.41 34.10 15.97
-
-
-
-
-
-
-
-
-
Kyustendil
Autumn
-
-
-
-
-
-
-
-
-
12.59 36.62 19.87 13.81 30.36 19.83
 
Spring
-
-
-
11.59 29.14 16.36
-
-
-
-
-
-
-
-
-
Panagyurishte
Spring
10.66 25.69 14.34 13.80 24.28 18.22
-
-
-
13.91 22.78 18.14 13.17 22.96 17.10
Kazanluk
Spring
10.63 28.80 14.92 11.12 28.30 15.15
-
-
-
-
-
-
-
-
-
Pirdop
Spring
-
-
-
-
-
-
-
-
-
11.91 34.03 18.08
-
-
-
Ihtiman.
Spring
10.44 30.82 15.09 13.24 27.20 18.18
-
-
-
12.65 30.19 18.12
-
-
-
Plovdiv
Spring
-
-
-
-
-
-
-
-
-
13.02 22.07 16.77
-
-
-
Peshtera .
Spring
-
-
-
-
-
-
-
-
-
11.23 21.05 14.22
-
-
-
Pazardzhik
Spring
-
-
-
-
-
-
-
-
-
12.93 32.50 16.67 11.77 21.92 15.08
Isperikh .
Spring
-
-
-
-
-
-
-
-
-
13.37 19.37 16.58
-
-
-
Popovo .
Spring
-
-
-
-
-
-
-
-
-
13.52 20.75 17.06
-
-
-
Kubrat
Spring
-
-
-
-
-
-
-
-
-
12.84 20.97 16.25
-
-
-
Bela Slatina
Spring
-
-
-
-
-
-
-
-
-
11.74 22.01 13.34
-
-
-
Mihailovgrad.
Spring
-
-
-
-
-
-
-
-
-
12.16 22.30 15.65
-
-
-
Tutrakan
Spring
-
-
-
-
-
-
-
-
-
13.83 13.19 16.39
-
-
-
Lom
Spring
10.01 31.00 15.88
-
-
-
-
-
-
11.60 16.04 13.82
-
-
-
Novi Pazar
Spring
-
-
-
-
-
-
-
-
-
11.17 28.67 15.66
-
-
-
 
Mixed
-
-
-
-
-
-
13.38 20.40 16.81
-
-
-
-
-
-
Orekhovo
Spring
12.63 27.82 17.52
-
-
-
-
-
-
-
-
-
12.12 24.30 16.01

BULLETIN ON NARCOTICS l JANUARY-MARCH 1960 31were taken from each part of the layer and placed in three jars; these were sealed and one was kept by ourselves, and one by the purchasing organization; one was put in the opium bank. When the opium was in the form of cakes, a proportional quantity of opium was taken from each cake, and a cut made along the radii of the cakes. The quantity thus obtained from the cakes was mixed in the manner described, until it became completely uniform. When the opium was both in cake form and in a form other than that of cakes, a general uniform mixture was again obtained according to the method described, and from this we finally took the average sample. The sample kept by ourselves was analysed. During these five years, we had no complaints about the analyses made. The results of analyses made by us according to the accepted lime method agreed with fair accuracy with the control analysis carried out in parallel by the Harrison Laboratory in London (for five samples, the differences were respectively +0.04%, +0.01%, -0.10%, +0.26% and -0.21%, or a mean difference of +0.0%) and also for the analysis carried out by the Vsesoyuz Khimek-sport,* Moscow (with four samples, the differences were respectively-0.10%,-0.05%, -0.03% and +0.01%- again, the differences were quite small). A polarographic method for determining the morphine content of opium has also been worked out.

The procedure described in the above paragraph eliminates the effect of certain local factors on the taking of samples, such as the situation of the field, the height above sea level, the composition of the soil, the subsoil moisture, the slope of the field, and so forth. In all probability, the former method of taking samples from separate small holdings had an effect on the morphine content (14). The results of these researches have been published in the scientific transactions of the VMI (Higher Medical Institute), Sofia (vol. I, No. 2, 1954) (13). From this it appears that latitude, or even the general combination of climatic, soil and other conditions, does exert a certain influence on the quality of the opium obtained (15), but this influence is not considerable. The following places have accordingly been designated as the most suitable: Kyustendil, Sandanski, Stanke Dimitrov, Petrich, Blagoevgrad, Panagyurishte and some other districts in southern Bulgaria, while certain districts in northern Bulgaria, such as Popovo, Kubrat, Orekhovo and others, give quite good quality opium.

The results of these investigations are set out in table 3.

Our investigations showed that the southern regions were the most favourable for the cultivation of the poppy from the point of view of obtaining the best quality opium, but that good quality opium was also obtained in certain northern regions. The same investigations also showed that areas for opium cultivation were to be found in northern Bulgaria. It further appears that the variations in the composition of the opium from one and the same locality, district or region during different years are due to climatic conditions (13, 15, 16). The analysis results for opium obtained from spring

Vsesoyuznyi ob edinenie po eksportn i importn khimicheskikh i meditsinskych tovorov (All-Union Corporation for the Import and Export of Chemical and Medicinal Goods). sowings in certain regions were also of interest, especially when compared with the analysis results for opium obtained from the same regions from autumn poppies. Table 4 shows this comparison.

TABLE 4

Content of morphine in anhydrous opium depending on the time of sowing of the poppy

(In percentages)

District

Autumn poppy

Spring poppy

Difference

Petrich
18.18 16.79 1.39
Sandanski
18.51 16.79 1.72
Blagoevgrad
17.64 15.63 2.01
Stanke Dimitrov
18.74 15.79 2.95
Kyustendil
19.85 16.36 3.49
Panagyurishte
-
16.95
-
Pirdop
-
18.08
-
Kazanluk
-
15.03
-
Ihtiman
-
17.13
-
Plovdiv
-
16.77
-
Peshtera
-
14.22
-
Pazardzhik
-
15.87
-
Orekhovo mixed
16.82 16.76 0.06
Isperikh
-
16.58
-
Popovo
-
17.06
-
Kubrat
-
16.25
-
Bela Slatina
-
13.34
-
Mihailovgrad
-
15.65
-
Tutrakan
-
13.69
-
Lom
-
14.85
-
Novi Pazar
-
15.66
-

It is clear that the autumn sowings invariably give opium with a higher morphine content. The conclusion is that wherever the danger of the crop's freezing is small, because of the presence of snow cover or of the absence of low temperatures as a rule during the winter, it is always better to sow during the autumn. If, however, spring sowing is practised, the earlier it is done, the better the harvest.

Studies have been made simultaneously by us and by the research station at Sadovo to discover how opium and seed yield are affected by incision of the pods. The findings obtained from these tests are shown in table 5.

The results of these tests show that with increase in the number of incisions above the poppy capsule, the yield of crude opium is increased by 14.3% with two incisions, and by 21.1% with three incisions, as against the single incision performed in the control experiment.

The quantity of seed obtained in each experiment when incision was performed was less than that obtained from the non-incised capsules (a 5.3% reduction in the seed yield with one incision as compared with the non-incised poppy; a 7.4% reduction with two incisions as compared with a single incision, or 12.7% as compared with the non-incised poppy; a 12.3% reduction with three incisions as compared with a single incision, or 17.6% as compared with the non-incised capsules).

TABLE 5

Effect of the number of incisions of the poppy capsules on the opium and seed yield

 

Crude opium

Seed

Serial No.

Number of incisions

Kg per decare

%

% mor-phine 1952

% mor-phine 1953

% mor-phine 1954

Kg per decare

%

1
No incisions
-
-
-
-
-
30.0 105.3
2
Incisions
0.280 100.0 19.58 19.49 12.45 30.0 100.0
3
Incisions
0.320 114.3 17.88 19.75 12.51 28.5 92.6
4
Incisions
0.340 121.1
-
19.64 12.12 25.0 87.7

A particularly important condition for high opium yield is that the poppy capsules should be incised, and the opium collected as soon as the appropriate moment occurs. Table 6 shows the results of a test made in this connexion.

TABLE 6

Influence of the time of incision of the poppy capsules on opium and seed yield (spring poppy, 1954)

 

Crude opium

Seed

Serial No.

Date of incision

Kg per decare

%

Kg per decare

%

1 21 June 0.240 75.0 23.0 98.5
2 26 June 0.320 100.0 26.0 100.0
3 30 June 0.280 87.5 26.2 100.8
4 4 July 0.160 50.0 26.5 100.9

During this experiment the poppy capsules themselves underwent visible changes during the days around 26 June, and these changes made it possible to determine the most favourable moment for making the incision (" industrial maturity ") according to the outward signs described above: the poppy capsules acquire a grey colour with a bronze lustre, and the "sides" of the capsule become stronger, showing a very characteristic whitish-coffee-coloured ring under the capsule itself.

Making the incision during the period of industrial maturity ensures the maximum opium yield and the minimum reduction in seed yield, as compared with later incision. Making the incision either before or after industrial maturity leads to a noticeable reduction in the opium yield. Premature incision causes a 25% reduction in opium yield, while if the incision is made after industrial maturity, the yield is reduced by 12.5% if four days have elapsed, and by 50% if eight days have elapsed. As can be seen from the table, the increase in seed yield when the incision is delayed is at the very least 0.8% or 0.9%.

Consequently, it is imperative to make the incision of the poppy capsules during the exact period of industrial maturity and after the signs described above have been noted.

Tests have also been made to determine the influence of incisions made at various times during the day. The results are shown in table 7.

The following conclusions can be drawn from the experiments.

A certain increase in the quantity of opium is observed when the incision of the poppy is made during the hottest hours of the day (the optimum quantity is obtained at 2 p.m.), and a certain diminution when it is made during the earlier and later hours of the day. The quantity is lowest when the incision is made early in the day.

TABLE 7

Opium and seed yield as affected by the time of day at which the incision is made

 

1954 and later crop

Crude opium

1952 / 53 crop Crude opium

Time of day

Kg per decare

%

% morphine

% moisture

% morphine in dried substance

Seed (Kg per decare)

% morphine

% moisture

% morphine in dried substance

8 a.m.
0.290 90.6 8.67 26.92 11.81 28.8 15.23 26.75 20.79
10 a.m.
0.300 93.7 8.71 27.98 12.10 26.8 16.22 29.71 22.98
Noon
0.320 100.0 8.87 32.25 13.10 26.8 17.77 28.98 27.99
2 p.m.
0.325 101.6 10.02 18.79 12.37 26.8 16.52 33.23 27.77
4 p.m.
0.310 97.0 11.25 17.25 13.12 26.8 17.88 22.98 23.22
6 p.m.
0.300 93.7 13.12 22.53 18.23 26.8 15.27 31.17 22.18

The time of day at which the incision is made also affects the percentage of morphine content in the opium. During the early hours of the day (8 a.m. to 10 a.m.), the opium obtained had a low percentage content in morphine, while the quantity increased during the hotter hours (noon to 4 p.m.). Investigations made by Milov, Nilov & Troshchenko in 1936 (17) show that the morphine content in the milky juice decreases exceptionally quickly when the juice is left standing in the open air. The main reason for this lies in the acidification processes which occur as a result of oxidation and peroxidation. Proceeding from this fact, the authors used various decoctions for the ferments, by means of which the process of morphine disintegration was considerably reduced. The substances acted as preserving media. It was considered to be worth establishing a similar process for Bulgarian opium.

Various preservative substances mentioned in the literature were used, although the method for their application is not indicated in the works concerned. We took samples of the milky juice and opium under different conditions of incision, collection and storing of samples, working with poppies taken from the same field. Samples preserved according to the method indicated below were kept in sealed jars for two years before being analysed.

The results are shown in tables 8, 9 and 10.

It can be seen from the experiment that when the milky juice is left to stand above the poppy head, a considerable portion of the morphine is lost. In our test this loss amounted to 36.13%. The result was similar to that obtained in the tests made by Nilov & Troshchenko. We obtained similar results with other tests also, when the analysis was made on the day when the milky juice and the opium were collected.

In order to establish the preservative action of certain chemicals, samples were taken from a few grammes taken under

TABLE 8

Sample

Percentage of morphine

Percentage of moisture

Percentage of morphine in dry substance

Milky juice collected immediately after cutting of the poppy head.
5.84 64.62 16.50
Normal standard sample of opium (milky juice collected on the following days)
3.73 63.14 10.12

identical conditions of cutting, collection and storing. To each sample we added 0.2 g respectively of calcium fluoride, aniline hydrochloride, calcium cyanide, hydroxylamine hydrochloride and sodium chloride, while one sample was treated in the classic manner for opium production. This then served as a standard. We mixed the chemicals by agitating thoroughly with a glass rod immediately after the milky juice had been collected. The analysis results from these tests are shown in table 9.

TABLE 9

Test

Percentage of morphine

Percentage of moisture

Percentage of morphine in dry substance

Normal (standard)
8.05 44.80 14.58
Calcium fluoride
7.44 46.87 14.00
Aniline hydrochloride
7.85 42.71 13.70
Calcium cyanide
7.94 46.40 14.81
Hydroxylamine hydrochloride
7.85 47.00 14.81
Sodium chloride
8.25 47.43 15.69

TABLE 10

 

In the presence of moisture

After drying at 40° C

Sample No.

Method of taking sample

% of morphine

& of moisture

% of morphine in dry substance

% of morphine

% of moisture

% of morphine in dry substance

1 2 3 4 5 6 7 8
I
Standard
13.30 26.16 14.11 14.33 7.2 15.44
    8.05 44.80 14.58 14.52 7.38 15.67
II
Poppy heads wetted with a solution of sodium hydrosulphide before cutting
14.11 62.50 10.96 12.61 7.9 13.7
III
Poppy heads wetted with a solution of sodium hydrosulphide after cutting
6.23 62.08 11.16 13.65 6.94 14.66
IV
0.20 g sodium hydrosulphide added after the opium was collected in the normal manner
4.50 64.16 12.56 14.20 7.38 15.33
V
Knife dipped in solution of hydroxylamine hydrochloride during cutting of the poppy head
12.16 18.46 14.91
-
-
-
VI
Knife dipped in solution of sodium chloride during cutting of poppy head
11.42 29.10 16.10 15.43 7.35 16.65
VII
Knife dipped in solution of sodium nitride during cutting of poppy head
15.74 8.45 17.17
-
-
-

Analyses were also made on a standard sample directly with the presence of moisture, and on a standard sample after primary drying at 40°C to a pre-determined moisture content. Samples obtained from poppy heads which had been wetted with solutions of various preservative media immediately after the poppy capsules had been cut were analysed in the presence of moisture and after primary drying at 40°C.

The results of these tests are shown in table 10.

It can be seen from the analysis of the figures that sodium chloride and sodium nitride are good preservative media for Bulgarian opium. The easily obtainable common salt, which is cheap, and available in every household, deserves special attention in this connexion. There is need for further work along these lines.

Alkaloids in Poppy Capsules

Opium production is fairly laborious work, and calls for skilled labour. Its promotion to the rank of an intensive crop has meant that a considerable additional part of the labour force in our rural areas is engaged in producing it, and this occurs at the very time when the poppy reaches industrial maturity. This makes it difficult to produce the opium required for the pharmaceutical industry and for export, as well as to produce the opium alkaloids.

For this reason, we have moved in the direction of isolating morphine not only from opium, but also from the poppy plant itself.

Comparative studies were made on the basis of the commonly accepted postulates and on the known methods suggested for isolating morphine from the poppy capsule (18). From these studies, it has been found that Kabay's method - which was until recently the most frequently suggested - and its modification according to Bognar (19), have the disadvantage that large quantities of the solvent (water, alcohol) evaporate under comparatively easy conditions (vacuum). A method which we have worked out for extracting the alkaloids by means of chloroform on a perforated grid base gives good results.

Of late, there has been a considerable development in the mixture of synthetic ion-exchange resins. These are steadily replacing the classic methods of isolating different plant substances. In Bulgaria, the Soviet method for isolating morphine from the poppy capsules by means of such a resin (Vofatite F) has been introduced.

In connexion with the above, we append notes on certain questions relating to the morphine content in the dried poppy capsules, incised and non-incised, obtained at various places in Bulgaria.

Research has been carried out in respect of the morphine content in the capsules of poppies cultivated in Bulgaria, after the seed has been collected. Incised and non-incised poppy capsules were analysed (20). The results are shown in table 11.

TABLE 11

Quantitative morphine content in samples of dried poppy capsules, incised and non-incised from various places in Bulgaria. 1955 harvest

Serial No.

Number of samples

Locality

District

Whether incised or not

% moisture

% morphine

Comments

1 1
Kavrakirovo
Petrich
Yes
8.66 0.395
-
2 7
Mikrovo
Sandanski
Yes
5.70 0.425
-
3 9
Sklave
Sandanski
Yes
5.30 0.375
-
4 11
Lozenitsa
Sandanski
Yes
2.25 0.40
-
5 13
Khotovoi
Sandanski
       
   
Spatovo
Sandanski
Yes
6.6 0.425
-
6 14
Sandanski (town)
Sandanski
Prelim. inc.
6.15 0.35
-
7 10
Lazarevo
Sandanski
No
5.45 0.53
-
8 12
Sandanski (town)
Sandanski
       
   
Dzhugorovo
         
   
Polenitsa
 
No
5.60 0.535
-
9 3
Khursovo
Blagoevgrad
Yes
6.40 0.41
-
10 4
Khursovo
Blagoevgrad
Yes
5.5 0.308
with 4-5 cm spathe
11 2b
Leshko
Blagoevgrad
Yes
7.08 0.37
-
12 2a
Leshko
Blagoevgrad
No
6.3 0.425
-
13 8
Blageovgrad (town)
Blagoevgrad
Prelim. inc.
7.3 0.333
-
14 6
Dzherman
Stanke Dimitrov
Yes
5.9 0.34
-
15 5
Dzherman
Stanke Dimitrov
No
4.5 0.408
-

On the basis of these investigations as well as of earlier research, the following main conclusions could be drawn.

  1. The poppy grown in Bulgaria yields dry capsules with a morphine content which is among the highest in the world.

  2. No significant difference has been noted with regard to morphine content in sample capsules obtained from different parts of the country.

  3. Given favourable conditions (experienced labour force and dry warm weather during the period of industrial maturity), it is recommended that the opium be collected, and after this the dried incised capsules; the seed is subsequently collected, so that the morphine and other alkaloids can be isolated.

In order to improve, if possible, the methods for isolating the morphine from the dried capsules through absorption, we carried out an investigation to establish the volume of some synthetic resins in relation to morphine hydrochloride. Comparative studies were made with the following resins: Vofatite KPS 200, Vofatite F, Vofatite P, Vofatite CN, Vofatite ND, Vofafite L.150, Vofatite L.165, Vofatite E, to establish the volume of these both under air drying conditions and when the sample was dried at 100 to 105°C and at 120°C. The results of these investigations are shown in table 12.

With some of the resins, the influence of the dropping rate on the volume of the absorbent (21) was also studied. Results are shown in table 13.

Certain conclusions can be drawn from the tests which have been made.

  1. It was found that all the cationites and anionites have the greatest total volume when they are air-dried, with the exception of Vofatite KPS200, which has a slightly increased volume after drying at 100-105°.

  2. The total volume of the cationites and anionites is small after drying at 100-105°, and is still smaller after drying at 120°.

  3. An exception is Vofatite KPS 200, which has its greatest volume, in comparison with all the other Vofatites studied, when dried at 100-105° and even at 120°. The volume of the air-dried resin KPS 200 is less by almost a half. Vofatite KPS 200 dried at 100-105° possesses almost the same volume as it does when dried at 120°. This Vofatite has the greatest total volume of all the Vofatites studied.

  4. Vofatite CN has the lowest total volume, practically equal to 0.

  5. It can be seen from the tables that the dropping rate greatly affects both the total volume, and also the volume, before opening, of the cationite Vofatites P and F before, since with slow dropping the volume is considerably greater. The volume is much greater with Vofatite P.

  6. With Vofatite MD the difference is much more considerable, both as regards the air-dried substance and as regards the substance heated at 120°.

Research for the purpose of separating morphine front the dry poppy capsules by means of the above-mentioned absorbants is being continued.

TABLE 12

 

Air dried

Dried at 100-105

Heated at 120°

Form of Vofatite absorbent

% before opening

% after opening

Total volume

% before opening

% after opening

Total volume

% before opening

% after opening

Total volume

KPS 200
60.04 2.67 64.71 82.69 38.87 121.56 98.08 21.98 120.06
F
8.02 39.23 47.25 8.76 19.54 28.30 1.92 9.28 11.20
P
10.33 8.91 19.24 5.7 10.71 16.41 7.48 6.43 13.91
CN
0 0 0 0 0 0 0 0 0
ND
-
-
15.99
-
-
11.60
-
-
8.91
L. 150
-
-
47.61
-
-
36.26
-
-
29.39
L. 165
-
-
48.78
-
-
53.02
-
-
29.39
E
28.56 27.81 56.37 5.82 1.24 7.06 4.13 1.61 5.74

TABLE 13

 

Air Drying

Heated at 120°

Form of absorbent

Dropping rate

% before opening

% after opening

Total volume

% before opening

% after opening

Total volume

Vofatite P
1 drop/4-5 sec.
54 19.3 73.3 39.5 8.3 47.8
 
1.15 drop/1 sec.
10.33 8.91 19.24 7.48 6.43 13.91
Vofatite F
1 drop/4-5 sec
57 5 62 42.2 6.4 48.6
 
1.15 drop/1 sec
8.02 39.23 47.25 1.92 9.28 11.23
Vofatite ND
1 drop/4-5 sec.
-
-
19.75
-
-
13.71
 
1.15 drop/1 sec
-
-
15.99
-
-
8.91

References

001

N. STOYANOV & B. STEFANOV, The Flora of Bulgaria , Sofia (1933).

N. N. IVANOV (ed.), The biochemistry of cultivated plants , vol.

6, Moscow (1938).

V. S. SOKOLOV, Alkaloid-producing plants of the USSR (1952). Encyclopedic dictionary of medicinal essential oil and toxic plants, Moscow (1951).

P. POPOV & I. DIMITROV, The poppy for opium and for seed, Zemizdat (1951).

IKONOMOV, BOICHINOV & NIKOLOV, Medicinal plants, Sofia (1941).

V. V. & O. G. ALEKSANDROV, "Comparative anatomical study of the structure of the pods of representatives of the opium poppy ", Treatises on applied botanical genetics and selection, Leningrad (1953).

M. A. VESELOVSKAYA, "The poppy, its classification and importance as an oil crop ", ibid. (1933), appendix 56.

N. A. BAZILEVSKAYA," The Semirechji races of the opium poppy and the problem of the origin of its cultivation ", ibid., vol. 19 (1938).

P. I. SARAYEV, The cultivation of medicinal plants, Medgiz (1952).

E. PERROT, Matières premières usuelles du règne végétal, Paris (1943).

A. VRGOC, Pharmacognosy, Zagreb (1931).

At. POPOV, Private agriculture, Part I. - Grain and seed plants (1945).

002

State pharmacopoeia of the USSR , 8th edition, Sofia (1951).

003

HAGER, Handbuch der pharmazeutischen Praxis , vol. 2 (1949).

004

S. D. OBRADOVI, "The opium question" (in The biochemistry of cultivated plants ) (1932).

005

JERMSTADT, Das opium , Leipzig (1921).

006

N. A. BAZILEVSKAYA, op. cit.

007

S. D. OBRADOVI, op. cit.

008

P. POPOV, I. DIMITROV & M. NIKOLOV, "The cultivation of the poppy in Bulgaria and Macedonia ", Reports of the Agricultural Research Institutes in Bulgaria , Year II, 3/4, Sofia (1922).

009

N. A. BAZILEVSKAYA, op. cit.

010

P. POPOV & I DIMITROV, op. cit.

011

"The biochemistry of cultivated plants ", ibid.

012

Al. KHRISTOV, Pleosporosis in the cultivation of the poppy (1930).

013

Al. KHRISTOV, "A new bacterial disease of the opium poppy ", Reports of the Agricultural Experimental Institute , vol. V, 9/10 (1933).

014

PERROT, op. cit.

015

JERMSTADT, op. cit.

016

UNITED NATIONS, ECOSOC, E/CN.7/l17/Add.2 (23 September 1948).

017

D. DALEV, L. ILIYEV & R. ILIYEVA, "Research on Bulgarian opium." L - The possibilities of extending the sowing of Papaver somniferum L and the possibilities of producing high morphine content opium, Proc. VMI (Higher Medical Institute) volumes issued the 2nd year, Sofia (1954).

018

The biochemistry of cultivated plants .

019

Meteorological Handbook for Bulgaria (1951).

020

Monthly agricultural meteorological bulletin for 1947-52.

021

SARAYEV, Meteorological bulletin for 1950-51.

022

The biochemistry of cultivated plants .

023

A. JORIS, "Préparation de la morphine à partir des capsules sèches du pavot ", Bulletin des Sciences Pharmacologiques , vol. 46 (August-September 1939).

024

J. KABAY, "Procédé pour obtenir les alcaloides de l'opium, particulièrement en partant des plantes de pavots ", brevet d'invention Gr. 14. Cl. 1, No. 748,308 République française.

025

K. BOGNAR," Darstellung und einige Verwandlungen der Mohnalkaloide ", Bulletin de l'institut chimique de l'académie bulgare des sciences , vol. II, Sofia (1953).

026

RASMUSSEN-BAGGESGAARD, H. & LANG, Ole, "Bestemmelse a morphin i valkulkapsler ". Dansk Tidsskrift for Farmaci (1948), Hefte No. 9-22, vol. 19.

027

D. DALEV & L. ILIYEV, "III. - The morphine content in dried poppy capsules obtained from various parts of the country ", Pharmacy, book 1 (1958).

028

D. DALEV & L. ILIYEV, "VI. - The isolation of morphine from dried poppy capsules by sorption (a) Establishing the volume of some Vofatites in relation to morphine hydrochloride ".