"Lupin" can refer to any member of the genus Lupinus. (Bugg, pers. comm.). Various species are used in agriculture, including blue lupin or narrow-leaved lupin (Lupinus angustifolius L.) (Duke, 1981), European yellow lupin (Lupinus luteus L.) (Duke, 1981), white lupin (Lupinus albus L.) (Duke, 1981), and Spanish lupin (Lupinus hispanicus ssp. bicolor cv 'Bicolor') (Bugg, pers. comm.). Munz (1973) listed 82 species as occurring in California, of which the native annual Lupinus bicolor Lindley is sometimes used as a vineyard cover crop (Bugg, pers. comm.).

Various species are used in agriculture, including blue lupin or narrow-leaved lupin (Lupinus angustifolius L.) (Duke, 1981), European yellow lupin (Lupinus luteus L.) (Duke, 1981), white lupin (Lupinus albus L.) (Duke, 1981), and Spanish lupin (Lupinus hispanicus ssp. bicolor cv 'Bicolor') (R.L. Bugg, pers. comm.). Munz (1973) listed 82 species as occurring in California, of which the native annual Lupinus bicolor Lindley is sometimes used as a vineyard cover crop (Bugg, pers. comm.).

Duke (1981) mentioned that Lupinus albus includes high- and low-alkaloid varieties, and listed varieties 'Hope' and 'Egyptian.'

For Lupinus angustifolius, Duke (1981) mentioned the the sweet varieties 'Borre,' 'Blanco,' 'Frost,' and 'Rancher.' Bitter varieties include cv 'Richy.' Other varieties not listed as to alkaloid content were 'Unicrop' and 'Uniharvest.' For Lupinus luteus, Duke (1981) listed the cultivars 'Florida Speckled,' and the low-alkaloid and non-shattering varieties 'Weiko II,' and 'Weiko III.'

Duke (1981) wrote that Lupinus albus seed are 3-6 per pod, 8-14 mm mm in diameter, orbicular-quadrangular, compressed or depressed, smooth, and dull, light yellow, sometimes with dark variegation, and 3,308 seeds/kg.

Per Duke's (1981) account, Lupinus angustifolius seeds occur 3-7 per pod, are ellipsoid to subglobose, smooth and dull, 6-8 mm long, yellow-brown, dark brown, or gray with yellow spots; there are 5,513 seeds/kg.

According to Duke (1981), European yellow lupin (Lupinus luteus) seed are 4-6 per pod, 6-8 mm long, 4.5-7.0 mm broad, orbicular-quadrangular, compressed, smooth and dull, black marbled white with a white curved line on each side or all white, and the species has 8,820 seeds/kg.

Lupinus albus and Lupinus angustifolius show phanerocotyledar germination (Duke, 1981).

Lupinus albus cotyledons are yellowish; stipules are absent (Duke, 1981).

Seedling emergence and growth are quite sensitive to cold temperatures and wet soil conditions. (Mark Van Horn, pers. comm.)

According to Duke (1981), Lupinus albus is a short-hairy annual up to 120 cm tall; leaflets of lower leaves 25-35 mm long, 14-18 mm wide, of upper leaves 40-50 mm long and 10-15 mm wide, obovate-cuneate, all mucronate, nearly glabrous above, sparsely villous beneath; stipules setaceous; racemes 5-10 cm long, seesile, flowers alternate; calyx 8-9 mm long, both lips shallowly dentate; corolla white to blue, 15-16 mm long; fruit flattened, 60-100 mm long, 11-20 mm broad, becoming longitudinally rugulose, short-villous, glabrescent, yellow.

Per Duke's (1981) description, Lupinus angustifolius is a short-hairy annual 20-150 cm tall; leaflets 10-50 cm (sic, probably means 10-50 mm) long, 2-5 mm wide, linear to linear-spathulate, glabrous above, sparsely villous beneath; stipules linear-subulate; racemes 10-20 cm long; upper lip of calyx aboutt 4 mm long, 2-dentate, lower lip 6-7 mm long, irregularly 3 dentate to subentire; corolla 11-13 mm long, blue, occasionally pink, purple, or white; legume shortly hirsute, yellow to black, to 6 cm long, 1.5 cm broad.

Duke (1981) described Lupinus luteus as a hairy annual 25-80 cm tall, the stems hairy; leaflets 40-60 mm long, 8-12 mm wide, obovate-oblong, mucronate, sparsely villous; stipules dimorphic, those of the lower leaves 8 mm long, subulate, those of upper leaves 22-30 mm long, 2-4 mm wide, linear-obovate; racemes 5-16 cm long, flowers verticilllate, scented (violet-scented); petals bright yellow; legume 4-6 cm long, 1-1.5 cm wide, densely villous, black.

Lupins were listed as cold tolerant by Peaceful Valley (1988), but cold tolerance varies among species, biotypes, and cultivars.

Based on the account by Duke (1981), frost tolerance in descending order is white lupin > blue lupin > yellow lupin. Based on observations in Tifton, Georgia, the cultivar 'Bicolor' or Spanish lupin shows better frost tolerance than does blue lupin (John Miller, pers. comm.). White lupin tolerates mean annual temperatures of from 5.7-26.2 C, with a mean of 38 cases of 12.7) temperatures of -6 - -8 C are harmful at germination and -3 - -5 C is harmful during flowering (Duke, 1981). White lupin requires a 5-month period with mean monthly temperatures ranging from 15-25 C, with the optimum being 18-24 C (Duke, 1981). Blue lupin tolerates mean annual temperatures of from 5.6-26.2 C, with the mean of 39 cases being 12.3 (Duke, 1981). When vegetative, it tolerates temperatures as low as -6 C, and has a lower germination threshold than do other economic lupins (Duke, 1981). Yellow lupin tolerates mean annual tempteratures of from 6.6-26.2 C, with the mean of 42 cases being 13.0 C (Duke, 1981).

According to Duke (1981), Lupinus albus is probably derived from wild forms on the Balkan Peninsula, and it is widely cultivated in the Mediterranean region, the Canary Islands, Madeira, and the Upper Nile. It is occasional in central and southeastern Europe.

Per Duke's (1981) description, Lupinus angustifolius is native to the Mediterranean Basin and southwestern France. It has been introduced and is now widely grown in Australia, Tasmania, New Zealand, South Africa, northern Europe, and the southeastern U.S.

Duke (1981) described Lupinus luteus as native to the Mediterranean Basin from the Iberian Peninsula and Italy through the Islands of the Meditteranean to the Middle East and Israel. It has been introduced and is cultivated in northern Europe, South Africa, Australia, and the southern U.S.

Lupins will thrive in areas with more than 15" rainfall, according to Peaceful Valley (1988). Duke (1981) listed the precipitation requirements of the three principal economic lupins as follows: white: 3.6-17.8 dm (mean of 38 cases, 8.4 dm [optimal is 4-8 dm]); blue: 3.5-16.6 dm (mean of 39 cases, 8.4); and yellow: 3.5-20.9 dm (mean of 42 cases, 8.5). White lupin is the most tolerant of waterlogging of the three species, but is nevertheless listed as intolerant of this condition (Duke, 1981).

White lupin requires higher soil fertility than do blue or yellow lupins and is susceptible to P deficiencies (Duke, 1981). Blue lupin is suceptible to deficiencies of P, K, and Co. Yellow lupin is susceptible to Fe and Mn deficiencies on basic or neutral soils but tolerates high Al concentrations (Duke, 1981).

White and Robson (1989) stated that lupins suffer iron deficiency when grown on calcareous soils, much more so than does field pea. However, this is not due to a lesser ability to acidify the root zone or to an incapacity to reduce Fe3+, as shown with studies of field pea, Lupinus anugustifolius and L. cosentinii in solution culture.

Barrow and Mendoza (1990), in reporting on an experiment concerning a study of crop yields in response to P levels, stated that sigmoid yield responses to increasing levels of a nutrient (in this case, P) suggest that there is a lower threshold concentration below which plants cannot take up the nutrient, and diminishing returns to further addition of the nutrient above an upper threshold. Trials with freshly-applied vs. incubated phosphate using a yellowish brown loamy sand (pH 5.6) showed markedly sigmoid response curves for subterranean clover (cv 'Yarloop') and narrow-leafed lupin (Lupinus angustifolius), but not for L. cosentinii or L. luteus. The results suggest that the lupins (especially L. cosentinii) grew better than subterranean clover at low phosphorus concentration. At low levels of phosphate application, roots of subterranean clover were heavily infected with vesicular-arbuscular mycorrhizae; infection but no arbuscules were detected with the lupins. Previous studies had suggested that responses of subterranean clover to added phosphorus are not sigmoid in the presence of mycorrhizal fungi. Findings of the present study are contrary to this.

Duke (1981) listed the pH tolerances of the three principal economic lupins as follows: white: 4.8-8.2 (mean of 35 cases, 6.4); blue: 4.9-8.2 (mean of 12 cases, 6.6); and yellow: 4.5-8.2 (mean of 41 cases, 6.5). White lupin is native to acid soils and also tolerant of mildly-acid to slightly-calcareous soils. Blue lupin is adapted to mildly-acid to neutral soils. Yellow lupin is adapted to strongly to mildly acid soils.

Hartmann and Aldag (1989) reported that faba bean (cv 'Herz Freya') showed delayed nodulation where soil pH was low but that white lupin (cv 'Eldo') showed no decrease in N-fixation. White lupin cv 'Eldo' was compared with faba bean cv 'Herz Freya' and soybean cv 'Gambit' on five sites. White lupin showed no decrease in N2-fixation at pH < 5.5.

According to Peaceful Valley (1988), lupins can tolerate any soil except heavy adobe soils with standing water in winter.

A summary of Duke's (1981) accounts of lupin soil adaptation follows. White lupin is adapted to well-drained, fertile, neutral loams, and moderately-acid to calcareous sandy loams or loamy sands, and is intolerant of waterlogging (although more tolerant than either blue or yellow lupins). It is tolerant of salinity. Blue lupin is said to be tolerant of sand, and of high pH, and is adapted to neutral to moderately-acid sandy loams or loamy sands. Yellow lupin tolerates strongly to mildly acid infertile soils. In its native range, it grows on acid sandy loams.

White and Robson (1989) stated that lupins suffer iron deficiency when grown on calcareous soils, much more so than does field pea. However, these researchers found that this is not due to a lesser ability to acidify the root zone or to an incapacity to reduce Fe3+, as shown with studies of field pea, Lupinus anugustifolius and L. cosentinii in solution culture.

White and Robson (1990) conducted studies on field pea and narrow-leaf lupin (Lupinus angustifolius) grown in nutrient solution at various Fe III EDDHA concentrations, with bicarbonate (HCO3) used in half the cases, to induce iron deficiency. Fe deficience led to rapid distortion and brown discoloration of lupin roots, followed by resumption of apparently normal, though slower, growth. Pea was less affected than lupin in terms of plant growth and tissue concentration of Fe III.

According to Duke (1981), some forms of Lupinus albus are tolerant of saline soils, and others are not.

Some Yugoslavian forms of Lupinus angustifolius are said to tolerate maritime sands (Duke, 1981).

Blue lupin is intolerant of even low levels of 2,4D herbicide (Duke, 1981). Based on an account from Spain concerning white lupin, herbicides are required in the culture of sweet Lupinus, yields of which are otherwise severely reduced by weeds (Posuelo et al., 1989).

All three of the commercially-used species, Lupinus albus, Lupinus angustifolius, and Lupinus luteus, are annual plants (Duke, 1981).

Duke (1981) gave seeding rates as follows: white lupin: 56-180 kg/ha; blue lupin: 65-90 kg/ha: yellow lupin: 45-80 kg/ha. Peaceful Valley (1988) suggested 2-4 lb per 1000 sq ft or 80-125 lb/acre.

Henderson (1989) investigated the effects of sowing density of blue lupin (Lupinus angustifolius L. cv 'Illyarrie') following a wheat crop (Triticum aestivum L. cv 'Gutha') on a compacted, earthy sand soil. Lupin population densities were established over a range of from 25 to 200 plants per m2. High-density plantings of lupin were better able to alleviate compaction, although lupin biomass declined with indensity increased. Peak biomass production was about 260 g/m2; as density increased, biomass declined about 25%. The reduced soil compaction was apparently due to the increased numbers of taproots penetrating the soil. The contribution to improved wheat yield by the decreased copmaction was estimated to be about 100 kg/ha. In comparison to improvements due to nitrogen fixation and breakage of disease cycles, this contribution is minor, but it could be important on compacted sandplain soils. Other benefits of high stand densities include reduced erosion and crop disease, and better weed control and harvesting.

Duke (1981) gave seeding depths for white lupin as 2.5-5.0 cm and stated that cultivation techniques are similar for blue and yellow lupins. Peaceful Valley (1988) gave the seeding depth as 1".

In areas with mild winters, Lupinus albus is usually seeded from mid September to late October 56-180 kg/ha (Duke, 1981). A grain drill can be used, or seed can be broadcast and disked to incorporate (Duke, 1981). Lupinus angustifolius and Lupinus luteus are cultured similarly, but seeding rates are 65-90 kg/ha and 45-80 kg/ha respectively (Duke, 1981).

The three principal economic lupins are grown mainly as winter annuals in the southeastern U.S. (Duke, 1981). Peaceful Valley (1988) suggested sowing from September thru November 15.

The three principal economic lupins take the "H" strain of Rhizobium lupini (Duke, 1981; Nitragin Company, Inc., No Date). Peaceful Valley (1988) stated that proper inoculation is essential for successful lupin crops.

Lupin is usually inoculated with Rhizobium lupini WU425, but this strain is susceptible to the fungicide iprodione with which lupin seed are treated to protect the plants from a foliar pathogen, Pleiocheata setosa. Another strain of R. lupini, CC606B was much more tolerant of the fungicide but did not nodulate lupin as well. A soil spray of WU425 could be used to inoculate fungicide-treated lupin, but farmers seem not to use this practice. Based on regression analysis, dry matter and seed yields showed a trend (P=0.075) toward an inverse relationship (Evans et al., 1989).

The Southern Seedsmen's Association (1992) listed one supplier of sweet white lupin. Seed is available for import from Australia for several varieties. (Fred Thomas, pers. comm.)

Lupinus angustifolius and Lupinus luteus are both long-day plants; flowering of the latter is also affected by vernalization, but the relative importance is not known (Duke, 1981).

According to Duke, Lupinus albus flowers from May-June, Lupinus angustifolius from April-June, and Lupinus luteus, March-July.

White lupin produces some 800-1,000 kg/ha of seed; blue lupin, 500-600 kg/ha, and yellow lupin, 800-1,000 kg/ha (Duke, 1981). For white lupin, non-shattering cv's lead to less loss of seed; also, defoliants are typically applied prior to harvest. Harvesting is best done under fairly cool conditions, leading to less shattering and seed damage; a normal header type harvester is used in Australian production (Duke, 1981).

For white lupin cv 'Eldo,' seed yield was 48-450 g/m2 (Hartmann and Aldag, 1989).

Lupinus albus seed can be stored for 2 years without major loss of viability (Duke, 1981).

Lupinus albus is a short-hairy annual up to 120 cm tall; Lupinus angustifolius is a short-hairy annual from 20-150 cm tall, and Lupinus luteus is a hairy annual from 25-80 cm tall (Duke, 1981).

Lupinus albus is up to 120 cm tall; Lupinus angustifolius is from 20-150 cm tall, and Lupinus luteus is from 25-80 cm tall (Duke, 1981).

Lupins are strongly and deeply taprooted (Peaceful Valley, 1988; R.L. Bugg, pers. comm.). The roots of yellow lupin can penetrate to a depth of 2 m in dernopodzolic sandy loam soils of Russia, with a root biomass yield of yellow lupin of from 3-8.7 Mg/ha (Duke, 1981). Gardner et al. (1982) found that white lupin could acquire P through acidification of the rhizosphere and subsequent absorbtion. This can lead to enhanced uptake of P, Mn, and N by intercropped of wheat. The former two nutrients were probably mobilized of by exudates from the lupin roots, then taken up by the closely-associated wheat roots (Gardner and Boundy, 1983). Gardner, W.K., D.G. Parbery, and D.A. Barber. 1982. The acquisition of phosphorus by Lupinus albus L. I. Some characteristics of the soil/root interface. Plant and Soil 68:19-32.

Hartmann and Aldag (1989) compared white lupin cv 'Eldo' with faba bean cv 'Herz Freya' on five sites. White lupin developed a deeper root system than did faba bean. In the soil stratum of from 60-90 cm depth, white lupin (cv 'Eldo') root mass was 6 times that of faba bean (cv 'Herz Freya'). Overall root mass was 125 g/square meter for stands of white lupin vs 86 g/square meter for faba bean.

For Lupinus albus, seeding with the first rains of autumn or dry seeding apparently leads to the best results because of the rapid growth lupins while the weather is still warm, and the resultant improved competition with weeds (Duke, 1981). Lupinus angustifolius is less tolerant of infertile soils than are other lupins.

If lupins have been grown on a site recently, repeated inoculation may not be needed (Duke, 1981).

Grain lupins should not be grazed (Duke, 1981).

Lupins should be harvested when weather is moderately cool, to reduce the likelihood of pod shattering. In Australia, a normal header type harvester is used (Duke, 1981).

For seeding, a grain drill can be used, or seed can be broadcast and disked to incorporate (Duke, 1981). In Australia, a normal header type harvester is used (Duke, 1981).

Uses of lupins were summarized by Duke (1981). Bitter lupins are typically used for green manuring alone, whereas alkaloid-free varieties are also used for forage and silage. Blue and yellow lupins are mentioned as good honey plants. Yellow lupin is a major grain crop in in the Baltic countries. Seed of bitter strains of white lupin can be cleansed of alkaloids by soaking or boiling in water.

Lupins are often grown in mixtures with oat, other cereals, or forage legumes like serradella (Ornithopus sativus) (Duke, 1981).

Duke (1981) summarized biomass production for the three principal economic species: white: 5.0-7.5 Mg/ha, but production can be as high as 10 Mg/ha; blue: 5-7.5 Mg/ha, but values ranging from 7.5-12.5 Mg/ha are reported in India; yellow lupin: 5-7.5 Mg/ha, with root biomass ranging from 3-8.7 Mg/ha. As related by Larson et al. (1989), white lupin cv 'Buttercup' produced 9.14 Mg/ha during 1986-1987, whereas cv 'Multolupa' during 1985-1986 produced 15.44 Mg/ha and in 1986-1987, 10.64 Mg/ha, and cv 'Ultra' in 1985-1986 produced 11.63 Mg/ha.

Duke (1981) presented values for N contents of white, blue, and yellow lupins; all were stated to range from 250-450 kg N/ha. Duke (1981) indicated that yellow lupin roots could accumulate 147-160 kg N/ha. However, Peaceful Valley (1988) stated that lupins are moderate N fixers (40-75 lb N/acre).

Based on a study by Hartmann and Aldag (1989), faba bean (cv 'Herz Freya') showed delayed nodulation where soil pH was low, whereas white lupin (cv 'Eldo') showed no decrease in N-fixation. 'Eldo' was compared with faba bean cv 'Herz Freya' on five sites. White lupin showed no decrease in N2-fixation at pH < 5.5. Nitrogen gain after seed harvest was 8 g/m2 for both white lupin and faba bean. Nitrogen fixation rates at different locations were approximately as follows: white lupin in 1986: 30, 360, 280, 120, and 240; and in 1988: 20, 250 230, 290, 330 kg/ha2.

Larson et al. (1989) gave N data on white lupin cv's as follows: (1) 'Buttercup': N in whole plant, 1986-1987: 275 kg/ha, 215 (78%) from fixation, 90.9% in seed, biomass: 9.14 Mg/ha; (2) 'Hamburg': N in whole plant, 1986-1987: 279 kg/ha, 219 kg/ha (78%) from fixation: 258 kg/ha, 87.8% in seed, biomass 11.06 Mg/ha; (3) 'Multolupa': N in whole plant, 1985-1986: 345 kg/ha, 247 kg/ha (72%) from fixation, 79.4% in seed, biomass: 15.44 Mg/ha; 1986-1987: 258 kg/ha, 197 (76%) from fixation, 85.7% in seed; biomass 10.64 Mg/ha; (4) 'Ultra': N in whole plant, 1985-1986: 286 kg/ha, 193 (90.9%) in seed, biomass: 11.63 Mg/ha.

Palmason et al. (1992), using 15N isotope dilution method in a field study in Iceland, evaluated N-fixation by narrow-leaf lupin (Lupinus angustifolius and possible N transfer to intercropped grasses. Estimated N fixation was ca 200 kgN/ha for the lupin, of which ca only 2 kgN/ha was transferred to Italian ryegrass.

Lupins are excellent accumulators of "unavailable" phosphorus for future crops, according to Peaceful Valley (1988). Wheat intercropped with white lupin has access to a larger pool of phosphorus, manganese, and nitrogen than wheat grown in monoculture; the former two nutrients were probably mobilized of by exudates from the lupin roots, then taken up by the closely-associated wheat roots (Gardner and Boundy, 1983).

The deep taproots of lupins can open and aerate soil, according to Peaceful Valley (1988). A similar improvement was demonstrated in Henderson's (1989) study of effects of sowing density of blue lupin (Lupinus angustifolius L. cv 'Illyarrie') on a following wheat crop (Triticum aestivum L. cv 'Gutha'). The experiment was conducted on a compacted, earthy sand soil, and blue lupin population densities were established over a range of from 25 to 200 plants per m2. High-density plantings of lupin were better able to alleviate compaction, although lupin biomass declined with density increase. Peak biomass production was about 260 g/m2; as density increased, biomass declined about 25%. The alleviation of compaction was apparently due to the increased numbers of taproots penetrating the soil. The contribution to improved wheat yield was estimated to be about 100 kg/ha. In comparison to improvements due to N fixation and breakage of disease cycles, this contribution is minor but could be important on compacted sandplain soils. Other benefits of high stand densities include reduced erosion and crop disease, and better weed control and harvesting.

Gardner et al. (1982) found that white lupin could acquire P through acidification of the rhizosphere and subsequent absorbtion. This can lead to enhanced uptake of P, Mn, and N by intercropped of wheat; the former two nutrients were probably mobilized of by exudates from the lupin roots, then taken up by the closely-associated wheat roots (Gardner and Boundy, 1983).

When grown on calcareous soils, lupins suffer more from iron deficiency than does field pea (White and Robson 1989a). However, studies by these workers of field pea, Lupinus anugustifolius and L. cosentinii in solution culture indicated that this is not due to to a lesser ability of the lupins to acidify the root zone or to an incapacity to reduce Fe3+.

Lupin poisoning of cattle has been due to quinolizidine alkaloids or their N-oxides. In order of increasing importance are the toxins d-lupanine, sparteine, lupanine, spathulatine, and hydroxylupanine (Duke, 1981).

"Bitter" lupins have more toxins. "Sweet" lupins have less or none. Wild bitter lupins grazed by goats may pass toxins on into their milk. (D. Brown, according to Mark Van Horn, pers. comm.)

Lupin flowers are attractive to bees and beneficial insects, according to Peaceful Valley (1988), and Duke (1981) mentioned lupins as important honey plants. Bugg et al. (1990) studied 20 cool-season cover-cropping regimes and evaluated associated insects for 17 of these regimes in southern Georgia. Convergent lady beetle (Hippodamia convergens Guerin-Meneville]) and seven-spotted lady beetle (Coccinella septempunctata [L.]) first were found in substantial numbers on rye, then on crimson clover and lentil, later on subterranean clover, still later on a low-alkaloid cultivar of narrow-leafed (blue) lupin (cv 'SNLL-87') (which harbored high densities of thrips [Frankliniella spp., Thysanoptera: Thripidae]), then hairy vetch, and lastly on mustard and collard. Insidious flower bug (Orius insidiosus [Say]), an important predatory insect that attacks numerous agricultural pests, was abundant on several dates on narrow-leafed lupin, hairy vetch (in monoculture and in biculture with annual ryegrass), and lentil. A low-alkaloid strain of narrow-leafed lupin ('SNLL-87') was the only one that harbored high densities of leaffooted bug (Leptoglossus phyllopus [L.]), a pest of row, field, and orchard crops. Therefore, this strain of lupin should be used with care as a cover crop.

A subsequent study (Bugg, unpublished data) showed that adult leaffooted bug survived significantly longer when caged in on low-alkaloid strains of blue lupin than on alkaloid-rich (bitter) strains.

White lupin is attacked by Heterodera glycines, H. goettingiana, H. marioni, H. schachtii trifolii, Meloidogyne arenaria thamesi, M. hapla, M. incognita acrita, and M. javonica (Duke, 1981).

Blue lupin appears to be more susceptible to plant-parasitic nematodes than are other lupins. Nematodes attacking blue lupin include Aphelenchoides bicaudatus, Belonolaimus gracilis, Ditylenchus dipsaci, Helicotylenchus dihystera, Meloidogyne hapla, M. incognita, M. incognita acrita, M. javanica, M. thamesi, Pratylenchus brachyurus, P. coffeae, P. penetrans, P. zeae, and Tylenchus costatus (Duke, 1981).

Duke (1981) stated that white and blue lupins or varieties thereof are tolerant of weeds, whereas yellow lupin is deemed susceptible. The alkaloids of white lupin are said to act as a natural herbicide when the crop residue decomposes in the soil.

Based on an account from Spain, principally concerning white lupin, herbicides are required in the culture of sweet Lupinus, yields of which are otherwise severely reduced by weeds (Pozuelo et al., 1989).