VI - Utilisation

Use of Prosopis juliflora pods in enhancing the growth of fungal pathogens in culture medium - M.D. Bohra, S.K. Sharma and Satish Lodha

Central Arid Zone Research Institute, Jodhpur 42003, India

Introduction

Prosopis juliflora is indigenous to arid and semi-arid zones from Mexico to Peru, and can be grown as a tree, shrub or hedge. Trees can produce 20 kg of pods per year, ripe pods having a high nutritive value, with 13% protein and more than 40% sugar. In view of the high sugar content, Santos and Pereira (1986) used Prosopis pods instead of dextrose in culture media to grow various different fungi. Since P. juliflora grows abundantly in arid parts of India, it was thought worthwhile to determine the applicability of such pods in replacing chemical sources of sugar in basal medium to culture some phyto-pathogenic fungi isolated from diseased arid land crops.

Materials and methods

Pods of P. juliflora collected in January 1993 were crushed in a fodder machine and stored at 4^oC (± 1^oC) for further use. These pods contained 40% (w/w) total soluble carbohydrates as estimated by Anthrone’s method. The quantity of pods used was based on the experiments of Santos and Pereira (1986) to replace a known amount of dextrose in commonly used media. The constituents of different media were as follows:

-Potato Dextrose Agar (PDA): potato - 200 g; dextrose - 20 g; agar - 15 g; distilled water - 1000 ml;

-Richard’s: potassium nitrate - 10 g; potassium dihydrogen phosphate - 5 g; magnesium sulphate - 2.5 g; sucrose - 50 g; ferric chloride - 20 mg; agar - 15 g; distilled water - 1000 ml;

- Prosopis Pod Agar (PPA): potato - 200 g; P. juliflora pods - 31 g boiled in 300 ml water for 30 min; agar - 15 g; distilled water - 1000 ml.

All the media were autoclaved and equal amounts (20 ml) were poured into sterilised Petri dishes. The fungi used were Alternaria alternata (Fr.) Keissler, Macrophomina phaseolina (Tassi) Goid. and Fusarium solani (Mart.) Sacc., isolated from diseased leaves and roots of jojoba (Simmondsia chinensis (Link.) Schneider). These were multiplied on PDA for 7 days. Discs of these fungi 5 mm in diameter were placed in the centre of each Petri dish and kept at 30^oC (± 2^oC), with 3 replicates used for each fungi. The fungal diameter was measured on alternate days, until it reached 90 mm in any one set of Petri dishes.

Prosopis pod broth (PPB) was prepared by boiling 10.5 g crushed pods (equivalent to 4.2% sugar) in 300 ml of distilled water for 15 min, and the decoction was poured into 100 ml of potato extract to make the final volume up to 300 ml (with no pH adjustment). Discs 5 mm in diameter of Macrophomina phaseolina and Fusarium solani were inoculated separately in 100 ml flasks (6 replicates) containing 30 ml of PPB, PDB or RLM and incubated at 30^oC (± 2^oC). Fungal mats were harvested after 7 days on Whatman filter paper no.1. The total dry weight of each fungal mat was recorded after drying at 80^oC for 48 h.

Results and discussion

Of the 3 solid culture media, the fastest growth was recorded on PPA (Table 1), with the maximum growth on PPA recorded in the case of A. alternata. Fungal mycelium covered 90 mm (the entire Petri dish) in only 2 days, compared to 32 mm and 9 mm on Richard’s and PDA respectively. The growth of F. solani and M. phaseolina were also significantly faster on PPA. With liquid media, dry mycelial weights of both the soil borne fungi were significantly higher on PPB compared to PDB and Richard’s liquid media (Table 2). Maximum increment in dry weight was recorded for F. solani (170%) followed by M. phaseolina (14%), when compared with PDB, the next best medium.

Table 1. Mean radial growth (mm) of 3 phytopathogenic fungi on Richard’s, Potato Dextrose Agar (PDA) and Prosopis Pod Agar (PPA) culture media.

Table 2. Dry mycelial weights of 2 soil borne fungi in 3 liquid media, Richard’s liquid medium (RLM), Potato dextrose broth (PDB) and Prosopis pod broth (PPB), and the LSD at p = 0.05.

These preliminary studies demonstrate the high order of efficacy of P. juliflora pods as an enriching nutritive source and as a replacement for dextrose. To carry out laboratory experiments, fast multiplication of fungi on culture media often becomes an essential requirement. The use of Prosopis pods in solid and liquid media can fill this gap, and also provides a cheap and readily available source of sugar. Better growth on PPA and PPB can be attributed mainly to high sugar content, however the possible involvement of growth regulating substances present in the pods, such as triacontanol (Khan et al., 1992) cannot be ruled out. Further investigations on these aspects would provide more information on the specific roles of different constituents present in Prosopis pods.

References

Khan, H.A., V. Lodha and A. Ghanim, 1992. Triacontanol from leaves of Prosopis cineraria and Prosopis juliflora. Trans. ISDT 17: 29-32.

Santos, G.L.C. and M.S.V. Pereira, 1986. Utilization of P. juliflora as culture medium and as an enriching source for phytopathogenic fungi culture. In Habit, M.A. and Saavendra, J.C. (eds.), The Current State of Knowledge on Prosopis juliflora. FAO, Rome. pp35-337.

Prosopis juliflora - its uses - M.K. Kanzaria^[5] and A.K. Varshney^[6]

Introduction

Prosopis juliflora is one of 44 species of Prosopis, and has the ability to thrive in hostile climatic and edaphic conditions. It grows even in salt affected soils, wasteland and rocky terrain. It requires little water, fixes nitrogen, has a fast growth rate, and because of its coppicing nature, it can grow in very dense stands and recovers rapidly after cutting.

This species has of late become a subject of controversy throughout the world amongst environmentalists, social activists, agriculturalists, politicians, policy makers and scientists. The environmentalists view P. juliflora as a hazard, claiming that birds and other fauna cannot inhabit stands, and that grass will not grow underneath. The thorny nature of the plant is the main cause of its unacceptability by the rural population. Again, its rapid spread in productive areas has also invited concern, as in the state of Gujarat, especially Saurashtra, north Gujarat and Kutch, where vast stretches of land have been completely occupied by this species.

Although it is not liked by a section of society, the fact is, that it has established itself very firmly and has become naturalised wherever it has grown. It is wise therefore to compromise between the positive and negative aspects. There is enough scope for exploring the possibility of utilising the different parts such as the stem, roots, bark, leaves, flowers and pods of P. juliflora for the benefit of the human population (Vimal and Tyagi, 1986). The following discussion is based on the authors experience while working with development aspects of P. juliflora in the northern and Kutch areas of Gujarat state.

Firewood

Great efforts have been made to study its value as firewood, charcoal and its use for gasification. The wood is hard with a specific gravity of 0.7 (Tyagi and Singh, 1986), burns slowly and evenly and holds heat well. There are many reports on the biomass yields per unit area but the results have been found to vary considerably in different regions. A study carried out by the Forest Research Institute (Dehra Dun) in Ganhinagar, Gujarat, found that that the utilisable dry matter biomass (stem and branches) of P. juliflora was 133 t/ha and the non-utilisable biomass (leaves and roots) was 35 t/ha, 4 years after out-planting (Patel, 1986).

The calorific value of the firewood has been reported to be 4,800 Kcal/kg. Its value as a firewood is already realised in Kutch, where the fuel requirements of the entire rural population of close to 1 million inhabitants is met by P. juliflora wood (Dave, 1990).

Charcoal

The average firewood yield in the region has been estimated to be approximately 30 t/ha/yr, dry matter, which if converted to charcoal would yield approximately 10 t. With about 1.75 million ha of P. juliflora plantations in Kutch alone, the potential for charcoal production from the region can be seen. A fraction of the total charcoal produced in the area is processed by the Gujarat State Forest Development Cooperation (GSFDC). Table 1 summarises the details of charcoal produced from P. juliflora by the GSFDC and man days generated through this activity between 1986 and 1993.

Gasification

The biomass of P. juliflora has been found ideal for utilisation in power generation. The fuelwood requirement to generate 150 MW of power is estimated to be 0.6-0.7 million t/yr of dry wood, and P. juliflora is the only reliable source of such quantities of wood. The technology of gasification is advancing rapidly, which would make it possible to use this abundant natural resource.

Animal feed

The seed pods are known to be a good source of cattle feed, and the average yield of pods/tree/year has been found to be 18.95 kg, with the main fruiting seasons being winter and summer. At the Vevekanand Research andTable 1. The production and sale of charcoal prepared from P. juliflora wood in Kutch by the Gujarat State Forest Development Cooperation (* 1 U.S.$ = approx Indian Rs. 35).

Table 2. Chemical composition of P. juliflora pods during different seasons.

Training Institute (VRTI), special pod threshers and cleaners have been developed, and a number of these have been installed at various places in Gujarat. P. juliflora provides a permanent and inexhaustible source of livestock feed, but with maximum production of pods obtained during the summer. The chemical composition of the pods over different seasons is given in Table 2. Thus pods are ideal for the manufacture of animal feed on a large scale, and it is recommended that this can be used to supplement concentrate rations by as much as 30% of the total feed.

Timber

Timber of P. juliflora is used for the construction of houses and the manufacture of farm implements throughout Gujarat state. Its use as a timber is limited by its small size, but it can still provide a good substitute to rural people who cannot afford to use other high quality and more costly woods such as teak (Tectona grandis).

The possibility of using the wood of P. juliflora or the preparation of particle board was examined by VRTI in collaboration with M/S Central India Board Products, Itarsi, Madhya Pradesh, and the board produced compared very well with, and was denser than, that of Nova teak wood. The chips prepared from P. juliflora wood tend to be larger in size, thus leading to a coarser finish of the board. Efforts have also been made to examine the possibility of producing writing and printing papers from the bleached sulphate pulp of P. juliflora wood (Vimal and Tyagi, 1986).

Honey

P. juliflora trees flower twice a year, and the flowers of this species are a very good source of nectar for honey bees. In parts of Kutch where dense plantations exist, apiculture has developed. With the recent involvement of bee breeding techniques, honey production in the region is now approximately 300 t/yr (Dave, 1990).

Soil amelioration

When planted in saline lands, it has been observed that the roots absorb the salts from the ambient soil solution and preserve it in the stem, and thus the salt concentration in the soil is slowly reduced. The fallen leaves on decomposition also enhance the process of soil reclamation. By providing a vegetative cover, it also reduces soil erosion, and has proved beneficial in stabilising coastal belts and sand dunes.

Other uses

All tree parts yield a variety of secondary products after undergoing various treatments, finding uses in different fields. Vimal and Tyagi (1986) reported that the wood contains high molecular carbohydrates such as pentasan, cellulose and lignin, and also a tannin content of 3-8%. The bark exudes a gum which is soluble in cold water. Bark fibres are used in rural areas for making string, ropes and baskets.

References

Dave, S.M., 1990. Kalpavriksha Gandbaval. Dave Exports 4, Prabhu Flat, Bhuj, India.

Patel, V.J., 1986. Economics of energy plantations on wasteland. In: Patel, V.J. (ed.), The Role of Prosopis in Wasteland Development. Javrajbhai Patel Agroforestry Center, Surendrabag, Gujarat, India.

Tyagi, P.D. and L. Singh, 1986. Prosopis juliflora in bio-energy. In: Patel, V.J. (ed.), The Role of Prosopis in Wasteland Development. Javrajbhai Agroforestry Center, Surendrabag, Gujarat, India.

Vimal, O.P. and P.D. Tyagi, 1986. Fuel wood from wastelands. Yatan Publications, New Delhi.

Nutritive value and palatability of Prosopis juliflora pods: A review - B.K. Mathur and H.C. Bohra

Central Arid Zone Research Institute, Jodhpur 342003, India

Introduction

Prosopis juliflora provides highly palatable and nutritious pods in large quantities, and the flowers produce good quality nectar for honey and which is also consumed by birds. Ripe pods which have fallen on the ground are avidly consumed by domestic stock and wild ungulates. These are rich in protein and free sugars which gives them a sweet taste (Muthana and Arora, 1983). In Mexico, ripe pods of some Prosopis species are ground into a coarse flour (pinole) for human consumption and baked after removing the seeds, and pods are also fermented and brewed into a weak beer, possible because of the high carbohydrate and protein content. The present paper summarises the chemical composition, palatability and nutritive value of P. juliflora pods and discusses their use in cattle rations.

Pod productivity

A mature P. juliflora tree can, on average, yield 19 kg pods a year (Anon, 1981), although Felker and Waines (1977) harvested 73 kg of pods from a single 8.5 m tall tree, and Felker et al. (1984) reported the yield of pods to range from 7.2 to 90 kg/tree/year. Garcia (1916) recorded only 17 kg pods/tree in New Mexico, while Jurriaanse (1973) reported production of 90 to 150 kg pods from a 10 year old South African tree. Smith (1953) and Douglas (1967) recorded 4 t to 20 t pods/ha in plantations. According to Shukla et al. (1986), a 1 ha Prosopis plantation could yield about 12 t pods/ha/year (19 kg pods/tree and 625 trees/ha) and thus from the 44,830 ha of P. juliflora plantations in Gujarat state alone, over 0.5 million tonnes of pods could be harvested each year. Assuming that pods could be harvested from only 40% of all plantations of P. juliflora, the pod production from the whole country is estimated to be 1 million t/yr.

Chemical composition

Fresh, ripe pods contained 7-10% preformed water, and on a dry matter basis contain 9-17% crude protein, 1.2-4.3% ether extractives, 16-34% crude fibre, 47-61% nitrogen free extracts, 28% acid detergent fibre, 8% acid detergent lignin, 4-5% ash, 0.14-0.29% silica, 0.3-0.5% calcium and 0.40-0.44% phosphorus (Shukla et al., 1984). According to Vimal and Tyagi (1986), the pods are composed of 16.5% protein, 4.2% fat, 16.8% crude fibre, 57% carbohydrates, 5.4% ash, 0.33% calcium and 0.44% phosphorus.

Shukla et al. (1986) reported the amino acid composition of P. juliflora pods to be (on a dry matter basis): 0.99%. aspartic acid, 0.28% threonine, 0.14% cystine, 0.43% valine, 0.10% methionine, 0.27% isoleucine, 0.52% leucine, 0.29% tyrosine, 0.33% phenylalanine, 0.37% alanine, 0.19% histidine, 0.32% lysine, 0.56% arginine, 0.41% serine, 1.4% glutamic acid and 0.51% glycine. The dry pods contained reasonable amounts of iron (208-639 ppm), copper (13-16 ppm) and manganese (22 ppm), but the zinc content (13-16 ppm) was below the level desired (40 ppm) for animal feeds.

The seed alone contained 31-37% crude protein and 3.4-8.5% crude fibre. Excluding the seed coat, the true seed on a dry matter basis contained 60-69% crude protein (Felker and Bandurski, 1979). The seed yielded 17.3% fatty oils of 8.55 acid value, 69.75 iodine value and 179.1 saponification value. The raw seeds had 10.9% moisture content and on a dry matter basis contained 39.3% protein, 4.5% fat, 18.6% carbohydrates and 3.8% ash (Vimal and Tyagi, 1986). Seed protein is constituted of 3.19% alanine, 3.80% arginine, 11.23% aspartic acid, 9.44% glutamic acid, 7.31% glycine-serine, 2.13% isoleucine-leucine, 1.77% histidine, 2.01% lysine, 0.53% methionine, 0.90% phenylalanine, 3.87% proline, 0.41% threonine, 0.43% tyrosine, 0.84% valine and traces of tryptophan.

Palatability and digestibility

Johnson and Ching (1918) found that whole P. juliflora pods could provide 55% digestible carbohydrates (DC) and 6% digestible crude protein (DCP), and the seed alone contained 41% DC and 25% DCP. Schneider (1947) and Mahadevan (1954) reported 5.9-6.9% DCP and 57.8-70.5% total digestible nutrients (TDN). Talpada et al. (1979) recorded 7% DCP and 75% TDN when fed to buffalo calves, and nitrogen and calcium balances were positive but the phosphorus balance was negative. Gujarathi et al. (1982) however, could not find any negative phosphorus balance in Kakrei bullocks offered 0%, 15% and 35% pods in the cattle ration, but in those who were offered a 45% level exhibited a marginal negative phosphorus balance.

Garcia (1916) suggested that the pods must be ground to secure their full nutritive value, since 25% of the total weight is seed, which would otherwise pass through the animals gut undigested. Alder (1949) observed that 1% of cattle fed solely on P. juliflora pods became sick and died due to compaction of undigested pods in the rumen. Deleterious effects on the health of livestock eating P. juliflora pods as well as dry leaves has been observed in the Kutch and Banaskantha regions of Gujarat state, attributed to indigestion and impaction (Anon, 1981). This fatal effect was caused by the regression of rumen bacterial cellulose activity due to the high sugar content (30%) of the pods.

Thus the pods should not be given as the sole ration to animals because such feed has occasionally fatal constipating effects. Secondly, animals offered higher levels of pods should be supplemented with phosphorus rich feeds such as rice polish or wheat bran and cakes. However, Prosopis pods did not show the presence of any cyanogenic glycosides unlike other conventional feeds (Mahadevan, 1954). In fact, the pods are very low in tannins (1.5%) and oxalates (1.1%) (Talpada, 1985) and are devoid of alkaloids (Gujarathi, 1979).

Shukla et al. (1984) found no adverse effect on the digestibility of various nutrients and also on nitrogen, calcium and phosphorus balances in Jersey x Kakrei F1 calves when offered P. juliflora pods at 0%, 10% and 20% levels in their concentrate ration. Similarly, Rao and Reddy (1983) also did not observe any effects on the digestibility in the growing calves when offered 40% level of pods in their concentrate ration. A similar trial on Kakrei bullocks, offered a concentrate ration incorporating 0%, 15%, 30% and 45% levels of P. juliflora pods was reported by Shukla et al. (1984), where an increase in live weight gain and positive balances of nitrogen, calcium and phosphorus were found with feeding levels up to 30%. At 45% level of pod feeding, a slight negative phosphorus balance was observed, with the live weight gain reduced as compared to animals offered pods at the 30% level. A lower nitrogen retention and negative phosphorus balance was also reported by Shukla et al. (1984) in a lactating herd of Kakrei cattle offered 30% level of pods in their concentrate ration, with no change in the flavour of the milk. However, Wilcox (1910) noticed a slight change in the flavour of milk from cows offered too many pods, but suggested this could be overcome by feeding pods after milking rather than before.

References

Alder, A.E., 1949. Indigestion from unbalanced kiawe (mesquite) bean diet. American Veterinary Medical Association Journal 153: 263.

Anonymous, 1981. Utilization of agricultural by-products and industrial waste materials for evolving economic rations for livestock. Annual Progress Report of the AICRP. Animal Nutrition Department, Gujarat Agricultural University, Anand, India.

Douglas, J.S., 1967. 3-d forestry. World Crops 19: 20-24.

Felker, P. and R.S. Bandurski, 1979. Uses and potential uses of leguminous trees for minimal energy input agriculture. Economic Botany 33: 172-174.

Felker, P., P.R. Clark, J.P. Osborn and G.H. Cannell, 1984. Prosopis pod production, comparison of north American, Hawaiian and African germplasm in young plantations. Economic Botany 38: 36-51.

Felker, P. and G. Waines, 1977. Potential use of mesquite as a low energy and machinery requiring food. Proceedings of Energy Farm Workshop. Sacramento, California, USA.

Garcia, F., 1916. Mesquite beans for pig feeding. New Mexico Agric. Exp. Sta. 29th Annual Report, New Mexico, USA. pp77-79.

Gujarathi, J.M., 1979. Utilization of Prosopis juliflora pods in the rations of adult kakrei bullocks for maintenance. M.V.Sc. Thesis, Gujarat Agricultural University, Anand, India. (unpublished).

Gujarathi, J.M., P.C. Shukla and M.B. Pande, 1982. Utilization of Prosopis juliflora pods in the ration of kakrei bullocks for maintenance. Gujarat Agricultural University Research Journal 6: 91-93.

Johnson, M.O. and K.A. Ching, 1918. Composition and digestibility of seedling stuffs grown in Hawaii. Hawaii Agricultural Experimentation Station Press Bulletin 53: 1-12.

Jurriaanse, A. 1973. Are they fodder trees? South Africa Forestry Dept., Pretoria 116: 1-32.

Mahadevan, V., 1954. The composition and nutritive value of Prosopis juliflora pods. Indian Veterinary Journal 31: 185-186.

Muthana, K.D. and G.D. Arora, 1983. Prosopis juliflora (Swartz) D.C., a fast growing tree to bloom the desert. CAZRI Monograph No. 22, Central Arid Zone Research Institute, Jodhpur, India. 19p.

Rao, N.S.R. and M.R. Reddy, 1983. Utilization of Prosopis juliflora pods in the concentrate feed of cattle and sheep. Indian Journal of Animal Science 53: 367-372.

Schneider, B.H., 1947. Feeds of the World, Their Digestibility and Composition. Agricultural Experimentation Station, Morgantown, West Virginia, USA.

Shukla, P.C., P.C. Talpada and M.B. Pande, 1984. Prosopis juliflora pods, a new cattle feed source. Animal Nutrition Department, Gujarat Agricultural University, Anand, India.

Shukla, P.C., P.M. Talpada, M.B. Pande, M.C. Desai and H.B. Desai, 1986. Prosopis juliflora pods and their utilization as cattle feed. In: Patel, V.J. (ed.), The Role of Prosopis in Wasteland Development’. Javrajbhai Patel Agroforestry Center, Surendrabag, Gujarat, India.

Smith, J.R., 1953. Tree Crops - A Permanent Agriculture. Devin Adair Pub. Co., New York.

Talpada, P.M., 1985. Study on Prosopis juliflora pods and utilization as cattle feed by lactating cows. Ph.D. Thesis, Gujarat Agricultural University, Anand, India. (unpublished).

Talpada, P.M., M.B. Pande, H.B. Patel and P.C. Shukla, 1979. Feed value of Prosopis juliflora D.C. pods for growing calves. Indian Journal of Dairy Science 32: 482-483.

Vimal, O.P. and P.D. Tyagi, 1986. Prosopis juliflora: chemistry and utilization. Prosopis juliflora pods and their utilization as cattle feed. In: Patel, V.J. (ed.), The Role of Prosopis in Wasteland Development’. Javrajbhai Patel Agroforestry Center, Surendrabag, Gujarat, India.

Wilcox, E.V., 1910. The algaroba in Hawaii. Hawaii Agric. Exp. Sta. Press Bull. 26: 1-8.

Variation in some horticultural traits in Prosopis cineraria in Rajasthan - Vishal Nath, R.S. Singh and N.K. Dwivedi*

Bikaner 334003, Rajasthan, India

* Senior Scientist (Econ. Botany) NBPGR, Regional Station, Jodhpur, India

Introduction

The “Queen of the Desert”, khejri (Prosopis cineraria (L) Druce) belongs to the subfamily Mimosoidae of Leguminosae family, and has an important place in the economy of the Indian desert. It is known by several vernacular names such as; Janti and Chonksa (Delhi), Jhind, Jhand and Jand (Punjab and Haryana), Banni (Karnataka), Sumri (Gujarat), Kandi (Sindh) and Shami (Sanskrit). Khejri is the only leguminous tree which grows well against all the climatic odds of the desert.

Growth of new foliage, flowering and fruiting occurs during the driest months (March-June) when other plants generally become leafless and dormant. This may be due to its extensive, penetrating root system, thus behaving as a phreatophyte (Lahiri, 1968). Its roots have been found at a depth of 36 m in an alkali soil with 9.8 pH (Khan, 1955). Arid land forms having an annual rainfall of 150 to 500 mm, except hills and saline depressions, have good Khejri population, however optimum density is confined to areas receiving 350 to 400 mm rainfall.

Owing to the deep root system, a monolayered canopy and the ability to fix atmospheric nitrogen, P. cineraria is compatible with agri-horticultural crops. The trees not only boost the growth and productivity of companion plants, but also provide fuel, fodder, food, small timber, medicines, gum and tannin (Arya et al., 1991). Its foliage is a nutritive fodder for animals and the wood is of good quality for domestic fuel purposes.

Unlopped trees produce green, immature pods (sangri) used as a vegetable (fresh and also dried), and ripe pods (khokha) are used for fresh consumption and for the preparation of flour. Khokha flour is mixed with wheat flour to make bread (chapati) and bakery products. Foliage and pods of khejri are very nutritious, being rich in protein, carbohydrates and mineral matter (Table 1). Green leaves of P. cineraria contain 14-18% crude protein, 13-22% crude fibre and about 6% ash, with a high calorific value of 5000 Kcal (Bhimya et al., 1964; Bhandari et al., 1979). Unripe pods are also nutritious and are used to prepare curries and pickles.

The tree yields a pale yellow to amber coloured gum with properties similar to that of gum acacias. Bark is used as a tonic, blood purifier and for the treatment of skin diseases. Trees are also planted for sand dune stabilisation and reclamation. To utilise the natural biodiversity of the species in relation to its horticultural attributes in terms of both immature and ripe pods, a study was conducted to locate suitable types of P. cineraria having the following pod characters:

- good taste with low tannin content,

- tender pods with less fibre at the immature stage and high pulp content at ripening,

- a higher number of smaller tender seeds at vegetable stage.

Materials and methods

An exploration programme was undertaken during May-June 1995 in collaboration with the NBPGR Regional Station, Jodhpur. A survey was conducted of the districts of Bikaner, Ganganagar, Hanumangarh, Churu, Jhunjhunu, Sikar, Jaipur, Dausa, Jodhpur, Pali, Nagaur, Barmer, Jaisalmer and Ajmer, covering 5 agroclimatic zones of Rajasthan. The Bikaner district of the arid western plain zone was also surveyed during March, 1994 when the pods were at the vegetable stage. Pod length, pod thickness, number of seeds per pod, and weight of seeds were recorded for each pod, and an average was taken from the 10 pods tested for each different tree. Horticulturally important genotypes were selected and observations were made in different zones. Oranoleptic scores of these types were also recorded. Analysis of leaves and pods for nutrient composition were also carried out following standard procedures.

Results

Khejri was found growing wild in almost all the agroclimatic zones, existing in cultivation along with some seasonal crops as an agrosilvicultural system of agroforestry (Table 1). Variations in plant density, morphological characters, fruiting characters and fruits in P. cineraria exist in the different agroclimatic zones.

Table 1. Salient features of the agroclimatic zones of Rajasthan

Table 2. Variation in ripe pod characteristics of sweet pods collected from P. cineraria in various zones of Rajasthan.

Table 3. Variation in immature pod characters of P. cineraria at Bikaner

Data presented in Table 2 reveal that ripe pod (khokha) length and thickness varied from 9-39 cm and 1.0-3.4 cm respectively in different zones. The pod length was minimum at NRCAH Farm and maximum at Beechwal forest (Bikaner). Minimum pod thickness was recorded in Didwana (Nagaur) while maximum was in Dhorimanna (Barmer). The number of seeds per pod varied from 3 to 35, being minimum in the curled pods of Bikaner and maximum in longest pods of Beechwal forest. Average seed weight varied from 0.4 g/seed in Didwana (Nagaur) to 1.8 g/seed at Bandiqui (Dausa).

After ripening, all khejri pods normally become sweet, but a type was observed near Osyan at Osyan-Phaloodi road which was acrid after ripening. Data presented in Table 3 shows the variation in khejri pods at the vegetable stage, recorded from Bikaner and surrounding areas. Pods were medium to large, thin, with a fairly large number of small seeds of 0.01-0.06 g weight. The pods were tender to slightly hard having variable levels of fibre and parchment. The results of analysis of leaves and pods for nutrient composition exhibited a wide range of variation in protein, carbohydrate, crude fibre contents etc. (Table 4). The pods were found to be rich in carbohydrates while the nitrogen free extracts were maximum in the leaves.

Discussion

A wide range of variation in pod shape, size and taste, number and weight of seeds were observed in different agroclimatic regions These characters were found to be influenced by the general health of the plant and the agroclimatic conditions as well as their genetic constituents. Arya et al. (1991) found pods of khejri in Shekhawati region to be 12-15 cm in length and 5-8 mm in width, containing 2-24 brown or black seeds, oblong in shape, and 4.5-8.0 mm long and 3.5-5.0 mm wide. Pod taste seems to be dependent on the genetic constituents, as some pods were bitter/acrid at the immature stage. The tenderness of pods at the vegetable stage is governed by the amount of fibre present, with more fibre resulting in the development of parchment at the immature stage.

Table 4. Composition of P. cineraria leaves and pods

Conclusion

Khejri is a very important leguminous tree of arid ecosystems. As well as its various uses for domestic purposes and a source for atmospheric nitrogen fixation, the pods are rich in nutrients and minerals. A wide range of variability in horticultural traits of this species is available in the Indian arid zone. It will be of immense value to select types having desirable attributes which can uplift the economy of the Indian arid zone and improve nutrient and health standards of the population in arid regions.

References

Arya, S., O.P. Toky, R.P. Bisht and R. Singh, 1991. Prosopis cineraria - promising multipurpose tree for arid lands. Agroforestry Today 3: 13-14.

Bhandari, D.S., H.N. Govil and A. Hussain, 1979. Chemical composition and nutritive value of Khejri (Prosopis cineraria) tree leaves. Annals of Arid Zone 18: 170-173.

Bhimya, C.P., R.N. Kaul and B.N. Ganguli, 1964. Studies on lopping intensities of Prosopis cineraria. Indian Forester 90: 19-23.

Khan, M.I.R., 1955. Tropical thorn forest of west Pakistan. Pakistan Journal of Forestry 5: 161-171.

Lahiri, A.N., 1968. Plant water relationship under arid conditions of western Rajasthan. Proc. Symp. National Resources of Rajasthan, University of Jodhpur (Mineo), India.

Prosopis cineraria: pods in the human diet - Pratibha Tewari

Central Arid Zone Research Institute, Jodhpur 342003, India

Introduction

Of the 44 known species of genus Prosopis, only P. cineraria is endemic to the Indian sub-continent (Burkart, 1976). Arid western Rajasthan, better known as the Thar desert, accounts for more than 60% of the total hot arid region of India (slightly more than 0.3 million km²). P. cineraria is the predominant constituent of the vegetation complex (Mann and Saxena, 1990). Commonly known as khejri, the species is an integral part of the life support systems of rural communities. Traditional agroforestry practices, such as the growing of food crops in association with tree species, is an age-old tradition in the Thar desert, and largely practised in sparsely distributed, P. cineraria dominated landscapes. P. cineraria trees in agricultural fields act as an insurance against crop failure due to drought, a common phenomenon in arid regions (Harsh et al., 1993).

Besides providing fuel for domestic energy needs and fodder for livestock, the pods of P. cineraria are utilised as a vegetable in the dried and green form. The present paper summarises the use of P. cineraria pods in traditional dietary.

The traditional perspective

Khejri trees occupy a special place in the life of desert dwellers, especially those of rural communities. People often protect khejri trees, as religiously it is considered sacred. About 250 years ago, 663 people of the ´Vishnoi’ caste laid their lives in protecting khejri trees against the order of the then ruler of Marwar state, who wanted to fell the trees for making bricks for his castle (Malhotra, 1986). It is a true multipurpose species and often referred to in ancient Indian literature as the ‘Kalpvriksha’ of the desert.

The leafy portion of the tree is known locally as ´loong’ and is available for 4-5 months (June-October). It is used as dry fodder for animals and it is sometimes also mixed with animal feed and cooked, and as such is called ´banta’. The tree is generally lopped in November at the beginning of the winter season. A special method known as ´changni’ is used for lopping the trees, acquired through traditional wisdom in farm families, and by employing this method minimum damage occurs in lopped trees. It is a common belief that such lopped trees bear lush green leafy fodder in the subsequent year.

Branches left after removal of ´loong’ are use for fuelwood purpose. The green pods of khejri, commonly known as ´sangri’, are utilised for human consumption. Green as well as dried pods are used for making vegetables and pickles in a variety of dishes. Dried pods are more commonly used in the daily diets of rural people.

Pods in the human diet

Khejri provides nutritious ´sangri’ for human consumption as a vegetable. ´Sangri’ is eaten in either the green, dried or ripe form. The use of ´sangri’ in the green or ripe form is limited, whereas the dried form enjoys primacy. Traditional recipes were collected through surveys in rural and urban areas and were further subjected to laboratory refinements. For the drying of green ´sangri’, pod collection is carried out in April when they are still tender. Tender ´sangri’ are washed in fresh water and are boiled for 10-15 min until the water turns muddy green in colour, then the pods are immediately dipped in cold water for 1-2 min. Such blanched ´sangri’ are germ free and are then sun dried for 2-3 days. Dried sangri are stored in air-tight containers. For use in any recipe as a prepared vegetable, the dried sangri are first soaked in water for 10-12 h. Extra water is drained off and ´sangri’ are then ready for use in a variety of recipes, the most common of which being described below for dried sangri. Green ´sangri’ is boiled in sufficient water until a waxy layer appears on top of the water. The extra water is drained off and the boiled ´sangri’ is washed in fresh water 3 or 4 times before being air dried for 10-15 mins.

Recipes for dried sangri

1. Sangri with onion

Chop the onion finely. Heat oil in a saucepan and fry the chopped onion till golden brown in colour. Add all spices, salt and sangri and pressure cook for 4-5 min.

2. Lak-ki sangri

Soak the gram flour in the butter milk. Heat oil, add fenugreek seeds, asafoetida and chillies and heat until spluttering. Add butter milk mixture and keep stirring. Add remaining ingredients and boil for 10-15 min. Serve hot with chapatis.

3. Pachkutta vegetable

One of the most prestigious vegetables of western Rajasthan, made by mixing fruits of 5 traditional food plants; ´sangri’ (P. cineraria), ´kumti’ (Acacia senegal), ´gunda’ (Cordia mixa), ´ker’ (Capparis decidua) and ´kachara’ (Cucumis sp.).

Soak all dried vegetables overnight and then boil with salt and turmeric powder for 10 minutes. Drain extra water and wash 4-5 times. Keep under the sun for 5-10 minutes. Heat oil in a pan, add asafoetida, pachkutta vegetable and other spices and fry for 10-15 minutes. Turn off and cover with lid. This will keep for 7-8 days when kept in a dry place and turned upside down once daily.

Recipes for green sangri

1. Green sangri vegetable

Mix salt, chilli powder, mango powder, turmeric powder, coriander powder and ´sangri’, and keep for 10 min. Heat the oil in a saucepan and add asafoetida. Add the vegetable and stir until it is evenly fried. Turn off flame and cover the pan. Keep for 1-2 h and then serve.

2. Sangri Pickle

Cut sangri into small pieces, blanch and dry for one hour. Heat oil, add all spices to sangri and roast for 5 min. Add acetic acid and store in a clean container

Nutritional importance of P. cineraria pods

P. cineraria provides protein, iron, vitamins A and C and other micro minerals. Due to insufficient rains, standard vegetable growing is difficult in the arid zones, and sometimes no fresh vegetables are available for months in rural areas. In such times, ´sangri’ provides essential vitamins and minerals in the human diet and thus its place as a drought food is very important. If this plant is allowed to grow extensively, it could provide a substantial vegetable source for human food. Projected estimates of ´sangri’ production from 12 districts of arid western Rajasthan are given in Table 1.

According to a World Bank report (Anonymous, 1992), the world’s projected population in 2000 and 2025 is estimated to be 6 billion and 8 billion people respectively. In that case, annual food production by 2025 must be around 7.4 billion t. Keeping in mind that dietary standards may also increase in developing countries by 2025, the demand for food may exceed 8.2 billion t. Executing research technology may increase crop yields by 50-80%, but a gap of 20-40% will still exist in meeting the world’s food demands in 2025. To bridge this gap and ensure food security at household, regional, national and international levels, popularisation of traditional food plants assumes importance in the extension sector today. Also, special efforts are needed to fund research on traditional food plants.

Table 1. Projected annual dry pod (sangri) production of P. cineraria (khejri) in different districts of arid western Rajasthan, India (for total production values, only 60% of the total area in each district was taken in account).

References

Anonymous, 1992. World Development Report, World Bank, Washington D.C.

Burkart, A., 1976. A monograph of the genus Prosopis (Leguminosae, sub family Mimosoideae). Journal of the Arnold Arboretum 57:217-249, 450-525.

Harsh, L.N., J.C. Tewari, U. Burman and S.K. Sharma, 1992. Agroforestry in arid regions. Indian Farming 42: 32-37.

Malhotra, S.P., 1986. ´Bishnois’ - their role in conservation of desert ecosystem. In: Shankarnarayan, K.A. and Shankar, V. (eds.), Desert Environment Conservation and Management. Central Arid Zone Research Institute, Jodhpur.

Mann, H.S. and S.K. Saxena, 1990. Khejri (Prosopis cineraria) in the Indian Desert - Its Role in Agroforestry. Central Arid Zone Research Institute, Jodhpur. 78p.