Bell Bean

Bell Bean

 

Growing Period Type Annual or Perennial Drought Tolerance Salinity Tolerance
Cool Season Legume Annual Intolerant Low

 

Common Name

This species has variously been termed bell bean (Duke, 1981; Munoz & Graves, 1988), broad bean (Hermann, 1960), faba bean (Bugg et al., 1989), Fava bean (Slayback, pers. comm.), field bean (Brinton, 1989), horse bean (Duke, 1981; Slayback, pers. comm.), tick beans (Duke, 1981; Brinton, 1989), and Windsorbean (Duke, 1981).

Scientific Name

Vicia faba L. (Duke, 1981). Some refer to bell beans as Vicia faba var. minor or equina (Brinton, 1989).

Cultivar

Small-seeded varieties of faba beans are called bell beans (Miller, 1988). Varieties include 'Windsor,' 'Longpod,' 'Dwarf Fan,' 'Julienne,' 'Lorraine,' 'Black Spanish,' 'Mazagan,' 'Piccardy,' and 'Winter' (Duke, 1981). Varieties of bell beans with the highest biomass production are 'Ackerperle,' 'Herz Freya,' 'Aladin,' and 'Minnesota Horsebean' (Brinton, 1989).

Stutzel and Aufhammer (1991) observed that the determinate variety 'Herz Freya' rarely produced side shoots even at low plant densities, whereas the indeterminate 'Ticol' produced side shoots, mainly from the basal nodes.

The variety that has often been sold in California is 'Diana.'

Seed Description

In the common variety known as Windsor or broad bean, the seed is flat and about 1 in long by 3/4 in broad. In the small seeded varieties, the seeds are more rounded and range 3/8 in to more than 1/2 inch in diameter (Madson, 1951). In small seeded races, seed are nearly globose and about 7 to 9 mm. in diameter, red-brown, purplish, greenish or black, sometimes spotted with gray; the hilum large, terminal, blackish, about 1/6 to 1/5 the circumference of the seed (Hermann, 1960).

Seedling Description

Germination is cryptocotylar (Duke, 1981).

Mature Plant Description

Bell bean is a coarse, erect, glabrous, very leafy annual, 5 to 20 dm. high; leaves fleshy, glaucous, turning black in drying, without tendrils; leaflets 2 to 6, oval, 4 to 10 cm. long, 1 to 3 cm. wide, obtuse, apiculate; stipules large, semisagittate, entire or shallowly dentate; racemes 2- to 4- flowered, very short-peduncled; flowers large (2 to 3 cm. long), white blotched with deep maroon or blackish violet; pods large (8 to 20 cm. long, 1 to 3 cm. wide), plump 2- to 4- seeded (Hermann, 1960). Madson (1951) described the plant as coarse, erect, and stemmy, with a large taproot, and large leaflets. The flower is white with a black spot on each wing and is borne in sessile axillary racemes. Seeds are large. Faba bean (cv 'Fiord') at maturity contained 50% of total dry matter and 78% (90 kg/ha) of total nitrogen in the seed, 30 kg/ha in the stubble, and 6-8% of the N fixed (less than 15 kg N/ha) in the root system (Herdina and Silsbury, 1990).

Figier (1968) distinguished 3 types of nectary cells in the stipular extrafloral nectaries: 1) cellules de la couche basale; 2) cellules du trichome; and 3) cellules compagnes. Acid phosphatase enzyme was detected in and around the plasmalemma, suggesting the transplant of sugar. Figier (1971) further examined the fine structure of these nectaries, discerning two types of cells, those concerned with excretion and those involved in transit processes between phloem and trichome.

Temperature

This species is adapted to a cool, temperate climate (McLeod, 1982) and does not endure heat (Duke, 1981; McLeod, 1982). High temperatures curtail seed production, and it generally cannot be grown where temperatures fluctuate rapidly (McLeod, 1982). Though mentioned as resistant to frost injury, with hardier varieties surviving temperatures as low as 15 F (McLeod, 1982) or 14 degress F (-10 degrees C) without serious damage (Duke, 1981), it is more susceptible to low temperatures than the vetches (Miller, 1988). Madson (1951) considered that it showed moderate resistance to cold but was more susceptible to low temperatures and other adverse climatic conditions than the vetches, and in many areas it was not as dependable in performance. Seedling growth and nodulation were both much slower at 10 degrees C than at 15 or 20 degrees C for faba bean cv 'Fiord'. This may suggest problems with late sowing (Herdina and Silsbury, 1989).

Geographic Range

Geographic range varies among cultivars or varieties (Slayback, pers. comm.). The seed production for bell beans is primarily in Canada where it is grown as a summer crop.

Water

Bell bean tolerates a wide variety of drainage conditions (Peaceful Valley, 1988) but will not tolerate drought (Duke, 1981; Pears et al., 1989; Husain et al., (1990), which at flowering or pod formation can cause severe reduction of seed yields (Koscielniak et al., 1989). In northern Germany, droughts during May and June cause low pod set of spring-sown faba bean. Bell bean is notorious for unstable yields, which appear in part due to its susceptibility to drought (Herzog, 1989). Bell bean can be grown from 23-209 cm of precipitation (mean of 95 cases = 12.1) (Duke, 1981). Husain et al. (1990) found that roots of drought-stressed faba bean (cv 'Maris Bead') extended as far as 0.85 m in depth. Average rooting depth was 0.70 m for drought-stressed and 0.52 m for irrigated plants. As drought stress increases, faba bean shows the following responses: (1) rate of shoot growth declines; (2) leaf area expansion decreases slightly; (3) root growth increases; (4) smaller leaves are produced; (5) leaves are shed; (6) shoot dry matter decreases. It has been thought that faba bean is most sensitive to drought stress during flowering because root growth ceases at this point for well-irrigated plants. This is not the case with drought-stressed plants, i.e., root growth can continue. Thus, sensitivity to drought is more or less uniform throughout the development of the plant. Reid (1990), based on simulation modeling, suggests that increased root growth was the most effective adaptation by which faba bean copes with drought stress, at least until 21 days from maturity. Breeding programs should probably emphasize the ability of plants to respond in this fashion. Deep tillage may also be beneficial in removing impediments to deep rooting.

Grashoff and Verkerke (1991) evaluated six cultivars of bell beans, detailing the effect of mild water shortage from flowering on. These workers showed that reduced turgor under these conditions promotes reproductive growth and reduces vegetative growth. Drought stress leads to lack of osmotic adjustment to maintain expansive growth.

Nutrients

P and K are applied before or at seeding (Duke, 1981).

Like all legumes, bell beans will also respond well to sulfur especially in high rainfall areas.

Soil pH

Bell bean has been said to tolerate basic to acidic soils (Munoz & Graves, 1988), ranging from pH of 4.5-8.3 (mean of 87 cases, 6.6) (Duke, 1981), and the crop is grown without liming throughout the U.S. (Duke, 1981). However, nodulation may be delayed under acid conditions (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 (Hartmann and Aldag, 1989).

In a pot experiment, Schubert et al. (1990) observed that at pH 4, chloride exclusion was disabled, and absorbtion of all other major ions decreased. ATPase activity necessitates release of protons. This is believed to be interfered with under low pH (i.e., high proton concentrations).

Schubert et al. (1990) conducted two pot and two water culture experiments on effects of low pH and soil buffering capacity, bell bean proton (H+) release, growth, and ionic content. Based on results of some of the experiments, these authors speculated that bell bean sensitivity to increasing soil acidity may be related to an inability to exclude chloride (Cl-) ion at low pH of soil solution.

Soil Type

Bell bean tolerates a wide variety of soils (Peaceful Valley, 1988), doing well in loam to clay soils (Madson, 1951; Munoz & Graves, 1988), and best in well drained, heavy silt or clay loams with large quantities of humus and calcium. Pears et al. (1989) say that it does best on heavy soils, whereas Duke (1981) maintains that it performs best on rich loam soils. This species can be grown successfully on light soil with ample moisture and lime (McLeod, 1982). According to Miller (1988), it can be useful on heavy soils, because residue persists after being disked in.

Bell beans will tolerate heavy soils better than most vetch and peas. It is often planted on new laser-leveled adope rice fields subjected to flooding. When submerged for 5-7 days bell beans will die.

Shade Tolerance

No specific information is available on shade tolerance, but bell bean has been successfully used in George Kresa's organic walnut orchards (Winters, Yolo County, California), as well as those of Deseret Farms (West Sacramento, Yolo County, California) (Bugg, pers. comm.). Duke's (1981) review suggested that soil moisture is more important than solar radiation or plant competition as regards seed yield.

Salinity Tolerance

Dua et al. (1989) reported that cvv 'VH 82-1-1' (yellow seeds) and 'VH 82-1-2' (brown seeds) (both derived from cv 'VH 82-1') were sown in plots with differing soil salinities. Both faba beans showed 100% germination up to salinities of ECe 9 dS/m. At ECe 12 dS/m, germination was 50-60%. Faba bean varieties had 50% reduction in yield at salinities of ECe 9.74 ('VH 82-1-1') and 9.86 dS/m ('VH 82-1-2'), but the threshold salinity was substantially higher for 'VH 82-1-2, suggesting that this statistic could be useful in evaluating germplasm in breeding programs for salinity tolerance.

Herbicide Sensitivity

In bell bean culture, suitable preemergence herbicides include chlorpropham, diuron, fenuron, and simazine. A suitable postemergence herbicide is dinoseb-acetate (Duke, 1981).

In NSW Australia, Lemerke and Hinkley (1991) observed that bell bean tolerated glyphosate (Round-Up) if application occurred 11 weeks after sowing or later.

Life Cycle

Bell bean has been regarded as a spring annual (Munoz & Graves, 1988) or as a winter annual (McLeod, 1982). A literature review summarized by Buttery and Gibson (1990) indicated that substantial N-fixation continues up to plant maturity, whereas N-fixation by pea reaches a maximum before or at flowering and drops during pod formation.

Seeding Rate

Seeding rates for bell bean have been given as 80 to 125 lb/acre (Peaceful Valley, 1988), 100 - 200 lb/acre (Miller, 1988; Munoz & Graves, 1988), 125 lb/acre (McLeod, 1982), 125 to 175 lbs/acre (Madson, 1951; Miller et al. 1989), and are 225-340 kg/ha for large-seeded varieties, and 190 kg/ha for small-seeded types (Duke, 1981).

Seeding Depth

Bell bean can be sown at depths of 5-10 cm (about 2-4 inches) (Duke, 1981).

Seeding Method

Bell bean should be sown in rows 75 cm (30 inches) apart; within rows, seeds should be 15 cm (6 inches) apart (Duke, 1981). McLeod (1982) suggestions are essentially identical: 6 inches spacing within the row; rows 30 inches apart.

Seeding Dates

Planting dates have been variously suggested as early Fall (Munoz & Graves, 1988), early to mid-Fall (Peaceful Valley, 1988), October - November (Madson, 1951), and with the earliest spring crops (Duke, 1981). Seedling growth and nodulation were both much slower at 10 degrees C than at 15 or 20 degrees C for faba bean cv 'Fiord' which may suggest problems with late autumn sowing (Herdina and Silsbury, 1989).

Inoculation

Beel bean needs Type "Q" inoculant (Nitragin Co.) (Burton and Martinez, 1980; Munoz & Graves, 1988). Rhizobial strains TA 101 and SU 391 prompted rapid nodulation on pea; the former was better at nodulating pea cultivar A102 than cv 'Early Dun'. Both rhizobial strains TA 101 and SU 391 were very slow to nodulate faba bean cv 'Fiord'. Seedling growth and nodulation were both much slower at 10 degrees C than at 15 or 20 degrees C for faba bean cv 'Fiord,' suggesting possible problems with late autumn sowing (Herdina and Silsbury, 1989).

Seed Cost

Madson (1951) cited high cost as the principal deterrent to use of bell bean.

Days to Flowering

When spring sown, bell bean requires 42-63 days from sowing to peak bloom (Brinton, 1989). Cv 'Fiord' flowered 60 days after sowing (Herdina and Silsbury, 1990). Cv 'Ipro' was sown on May 7 and produced extrafloral nectar from late June until the crop was plowed down in late July; flowering began on about June 19 (43 days to flower) (coastal Massachusetts) (Bugg and Ellis, 1989). Sown in October to November in much of California, bell bean flowers from mid- to late March to late May. (Bugg, pers. com.)

Days to Maturity

Bell bean matures from March to May (Peaceful Valley, 1988), 90-220 days after sowing (Duke, 1981). According to Zapata et al.(1987), physiological maturity occurs 126 days after planting.

Seed Production

Bell bean mean seed yield is 6,600 kg/ha in the U.S. (Duke, 1981). 'Herz Freya' seed yield was 145-549 g/m2 (Hartmann and Aldag, 1989). Bell bean is notorious for unstable yields, which appear in part due to its susceptibility to drought (Herzog, 1989). In particular, drought at flowering or pod formation can cause severe reduction of yields of faba bean (Koscielniak et al, 1989). In northern Germany, droughts during May and June cause low pod set of spring-sown faba bean (Herzog, 1989).

Growth Habit

Bell bean plant is stiff-stemmed and tall (Miller, 1988), stemmy, and with moderate to heavy density of growth (Madson, 1951).

Maximum Height

Heights range from 60 to 90 cm (Pears et al., 1989). Some varieties can attain a height of up to 6 ft. on fertile, warm soils (Peaceful Valley, 1988). Cv 'Ipro' reached a height of 0.85 m (Bugg and Ellis, 1989) and an unnamed variety sowed in a Mendocino vineyard reached 121.92 +/- 10.78 m (mean +/-1 - SEM (Bugg, pers. comm.).

Root System

Like most legumes, bell bean is taprooted (Miller, 1988) and is mentioned as having a strong root system (Peaceful Valley, 1988). Nevertheless, it is a drought-intolerant plant (Husain et al., 1990). Roots of drought-stressed faba bean (cv 'Maris Bead') extended as far as 0.85 m in depth. Average rooting depth was 0.70 m for drought-stressed and 0.52 m for irrigated plants. As drought stress increases, faba bean shows the following responses: (1) rate of shoot height increase declines; (2) leaf area expansion decreases slightly; (3) root growth increases; (4) smaller leaves are produced; (5) leaves are shed; (6) shoot dry matter decreases. It has been thought that faba bean is most sensitive to drought stress during flowering because root growth ceases at this point for well-irrigated plants. This is not the case with drought-stressed plants, i.e., root growth can continue. Thus, sensitivity to drought is more or less uniform throughout the development of the plant (Husain et al., 1990).

Simulation modeling suggests that increased root growth was the most effective adaptation by which faba bean copes with drought stress at least until 21 days from maturity. Breeding programs should probably emphasize the ability of plants to respond this way. Deep tillage may also be beneficial in removing impediments to deep rooting (Reid, 1990).

From a depth of 60-90 cm in the soil stratum, 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 and 86 g/square meter for faba bean (Hartmann and Aldag, 1989).

Faba bean (cv Fiord) at maturity contained 50% of total dry matter and 78% (90 kg/ha) of total nitrogen in the seed, 30 kg/ha in the stubble, and 6-8% of the N fixed (less than 15 kg N/ha) in the root system (Herdina and Silsbury, 1990).

Establishment

Duke's (1981) account suggested that the small-seeded varieties suitable as green manure can be sown using a common corn planter in rows 75 cm apart and at a depth of 5-10 cm, with intra-row spacing being 15 cm. Small-seeded varieties are sown at 90-122 kg/ha. Well-drained, firm seedbeds, cool weather and moderate moisture are important. Inoculation is not necessary in parts of England and Europe, where indigenous rhizobia suffice. No-till management reduces yields by 22%.

Maintenance

Per Duke's review (1981), bell bean can be grown without liming in most of the U.S. Moisture requirement is greatest 9-12 weeks after sowing. Bell bean is said to tolerate high and low pH, insects, slope, and virus.

Mowing

In general, bell bean does not respond favorably to mowing or grazing (Munoz & Graves, 1988). It can tolerate some high mowing for frost control (Peaceful Valley, 1988) but will not withstand close mowing (Bugg, pers. comm.). Pears et al. (1989) says that it can be cut down once and left to regrow.

Filik et al. (1996) stated taht detopping cv 'Nadwislanski' reduced nodule initiation, reduced aging of plants, and delayed pod shed.

Incorporation

Bell bean adds a large amount of organic matter to the soil when turned in as green manure (McLeod, 1982). The best time for incorporation is at blossom (McLeod, 1982; Munoz & Graves, 1988). The vegetation will decompose more rapidly if the plants are succulent, but in general, bell bean residue persists longer than that of other leguminous cover crops, which can help improve heavy soils (Miller, 1988).

Harvesting

Bell bean seed should be harvested when lower pods are mature and upper pods fully formed. If harvest is delayed until upper pods are mature, shattering is likely. Cut on cloudy day or at night, and shock the next day. A drop-rake reaper is better than an ordinary mower. Smaller-seeded varieties can be threshed with no problem (Duke, 1981).

Equipment

Large-seeded bell bean types can be sown with planters for lima beans; smaller-seeded types can be seeded using a common corn planter (Duke, 1981).

Uses

Uses include silage, hay, cover crop, green manure, vegetable and grain (McLeod, 1982); it makes excellent forage and silage (Duke, 1981; Peaceful Valley, 1988). Because of its large taproot and stemmy growth, bell bean is a good cover crop for opening up heavy soils (Madson, 1951).

Mixtures

Often bell bean is mixed with other legumes and grasses for use as forage or silage (Peaceful Valley, 1988). It may be grown in a mixture with fenugreek, vetch and oat. Drill in beans 2-3 weeks earlier (McLeod, 1982). Also, it may be sown in mixtures with common vetch, hairy vetch, and oat (Bugg, pers. comm.). Inclusion of barley, oat, or rye in a mix of cover crops along with vetches and bell beans appears to reduce infestation by common fiddleneck (Amsinckia intermedia) (Bugg, 1990).

Biomass

Varieties of bell bean with the highest biomass production are 'Ackerperle,' 'Herz Freya,' 'Aladin,' and 'Minnesota Horsebean' (Brinton, 1989). Brinton (1989) says that bell beans produce 1,800 lb/a of dry matter, but this seems extremely low in light of Duke's (1981) figures of 4,870-8,060 kg/ha. Faba bean (cv 'Fiord') at maturity contained 50% of total dry matter and 78% (90 kg/ha) of total nitrogen in the seed, 30 kg/ha in the stubble, and 6-8% of the N fixed (less than 15 kg N/ha) in the root system (Herdina and Silsbury, 1990). Bugg et al. (1996) reported that bell bean (no named cultivar) yielded 7.7+/-1.2 Mg/ha (Mean +/- S.E.M.) in dry above-ground biomass data, in Hopland, Mendocino County, California, May, 1991. When weeds were included with cover crop, above-ground dry biomass was 8.4+/-1.4.

N Contribution

Estimated amount of N fixed may range from 22.7-90.7 kg/acre (50-200 lb), but bell bean is regarded as a low nitrogen fixer in southern California (Munoz & Graves, 1988). In six weeks of growth, bell bean may fix up to 45.4 kg/acre (100 lb) (McLeod, 1982) and a total of up to 68.0 kg/acre (150 lb) on fertile soils (Peaceful Valley, 1988). Bell bean has a lower N content in above-ground biomass than most other legume cover crops. Less than 45.4 kg N/ac (100 lb) was fixed by late March in 1987 in an experiment in Davis (Stivers & Shennan, 1991). At plowdown, available N from bell bean can be estimated by multiplying harvested fresh weight of cover crop from a sixteen square feet (4 x 4 ft) sample plot by 10 (to estimate lbs of N/acre) (Miller et al., 1989).

Cv 'Wieselburger' at physiological maturity (126 days after planting) contained 209 kg N/ha, 79% (165 kg N/ha) of which came from fixation. After the mid-podfilling stage, N-fixation dropped to nearly nothing. If pods and and seeds were removed, faba bean residue would contribute approximately 27 kg/ha of N to the soil (Zapata et al.,1987).

Cv 'Fiord' began fixing nitrogen 53 days after sowing and accumulated 80% of its fixed nitrogen during grain filling; at maturity, it contained 50% of total dry matter and 78% (90 kg/ha) of total nitrogen in the seed, 30 kg/ha in the stubble, and 6-8% of the N fixed (less than 15 kg N/ha) in the root system (Herdina and Silsbury, 1990).

For cv 'Herz Freya,' N gain after seed harvest was 8 g/m2. Nitrogen fixation rates at different locations were approximately as follows during 1986: 60, 310, 180, 170, and 190 kg/ha2 (Hartmann and Aldag, 1989).

A literature review indicates that N-fixation by pea reaches a maximum before or at flowering and drops during pod formation, whereas in faba bean substantial fixation continues up to plant maturity (Buttery and Gibson, 1990). Bell bean cv 'Herz Freya' showed delayed nodulation where soil pH was low, whereas white lupin (cv 'Eldo') showed no decrease in N-fixation (Hartmann and Aldag, 1989). In Germany, winter crops of rape, barley, and Welsh ryegrass respectively accumulated in their above-ground structures 52.1, 36.2, and 22.9 kg N/ha following bell bean (cv 'Alfred') (Raderschall and Gebhardt, 1990). In an experiment on rotational cash crops ("break crops") for wheat farmers, fertilizer N requirements were increased by 10 kg/ha following winter oat, decreased by 30 kg/ha following winter rape, winter peas, spring faba beans, or cultivated fallow, and decreased by 40 kg/ha following spring peas (McEwen et al., 1989).

In Davis, Stivers and Shennan (1991) found that bell bean produced 80 lb N/ac. by March 28. This was less than for field pea (150, 3.5% N) or woolypod vetch (230, 3.6% N).

Effects on Water

In Germany, winter crops of rape, barley, and Welsh ryegrass, respectively, accumulated in their above-ground structures 52.1, 36.2, and 22.9 kg N/ha following bell bean (cv 'Alfred') (Raderschall and Gebhardt, 1990). In a greenhouse lysimeter study, winter wheat following faba beans yielded 8-25% more than following maize. Using faba bean led to an increase in N turnover in the soil but not to a net increase in soil N. Nitrate leaching was higher following faba bean (Huber et al., 1989).

Effects on Livestock

As livestock feed, bell bean is sometimes considered superior to field pea or other legumes (Duke, 1981).

Effects on Workers

Inhalation of bell bean pollen or consumption of beans can lead to hemolytic anemia (favism), resulting from an inherited enzymatic deficiency occasionally found among Mediterranean peoples (Duke, 1981).

Pest Effects, Insects

Peaceful Valley (1988) suggested that beneficial insects do well on the numerous blossoms, but extrafloral nectaries appearing as dark spots on the stipules are probably more important (Bugg, pers. comm.). These nectaries occur from early vegetative growth through late pod filling. From mid September through late October, sixty specimens of Ichneumonidae (Hymenoptera), representing 20 species and 4 subfamilies, were observed feeding at the extrafloral nectaries (cv 'Ipro'). Of the ichneumonids collected, 3 were known parasites of lepidopterous pests of agriculture, 2 of forest Lepidoptera, and three of both agricultural and forest Lepidoptera (Bugg et al., 1989). Trujillo-Arriaga and Altieri (1990) grew faba bean in tricultures with maize and squash. Faba bean provided extrafloral nectar that was fed upon by the lady beetles Hippodamia convergens and H. koebelei. This probably contributed to the observed greater densities of these lady beetles, the higher yield of maize, and the elevated total output per unit area (land equivalent ratio=2.89) in the tricultures. Densities of lady beetles appeared relatively low in all treatments, and inferential statistics were not presented.

Bell bean is regarded as more susceptible to aphid infestations than the vetches (Miller, 1988); in particular, it is attacked by bean aphid (Aphis fabae L.) which seldom affects its use as a cover crop but often interferes with the production of seed (Madson, 1951). Bugg and Ellis (1989) reported that a May-planted crop of faba bean was heavily infested by bean aphid, which apparently damaged the crop. Bean aphid was tended by Formica spp. ants, which were observed repelling some lady beetles. Nonetheless, faba bean sustained relatively high densities of aphidophaga (mainly lady beetles) during several weeks in late June. Thereafter, bean aphid densities plummeted during an outbreak by an unidentified entomogenous fungus, which occurred following several days of wet weather.

Pruter and Zebitz (1991) reported experiments on cvs 'Diana' and 'Bolero', which are respectively susceptible and partially resistant to bean aphid. (Aphis fabae). Bean aphid damaged both varieties, and reduced root dry weight, shoot dry weight, leaf area, and mean relative growth rate more than did broad bean rust pathogen (Uromyces viciae faba). Bean aphid reduction of all parameters mentioned was greater for the susceptible variety 'Diana'.

Grafton-Cardwell et al. (unpublished manuscript) found that pollen of bell bean, 'Austrian Winter' field pea, and New Zealand white clover sustained longevity and fecundity of the predatory mite Euseius tularensis (Acari: Phytoseiidae) as well as the standard diet of iceplant pollen. By contrast, reduced fecundity was observed for common vetch, woollypod vetch, and crimson clover, and E. tularensis did not survive more than one generation when fed pollen of rose clover or red clover. Inoculation with E. tularensis in early spring led to build-up of the mite by late spring in a cover crop of bell bean, field pea, and woollypod vetch. Most of the mites were found on the bell bean component of the mix. When the cover crop was mowed and the mowings placed in young citrus trees, significantly increased densities of the predatory mite were observed on the citrus foliage.

Pest Effects, Nematodes

McKenry (pers. comm.) expected bell bean to host Meloidogyne spp.

Pest Effects, Diseases

Winter oat, winter rape, winter peas, and spring faba beans as break crops greatly reduced the incidence of take-all of wheat (Gaeumannomyces graminis) (McEwen et al., 1989).

Faba bean is not susceptible to Sclerotinia minor (Koike et al., 1996).

Pruter and Zebitz (1991) reported experiments on cvs 'Diana' and 'Bolero', which are respectively susceptible and partial resistance to bean aphid. (Aphis fabae). Bean aphid damaged both varieties, and reduced root dry weight, shoot dry weight, leaf area, and mean relative growth rate more than did broad bean rust pathogen (Uromyces viciae faba). Bean aphid reduction of all parameters mentioned was greater for the susceptible variety 'Diana'.

Bell beans, especially in California, are frequently attacked by bacterial blast. It forms black lesions in cold damp weather especially on the stems. Observations in a Sonoma County field for forage production showed a 30% loss of the stand due to this disease.

Pest Effects, Weeds

Bell bean is not good at suppressing weeds and must be sown densely to avoid weed problems (Pears et al., 1989); cultivation is often required (Duke, 1981). Inclusion of barley, oat, or rye in a mix of cover crops along with vetches and bell beans appears to reduce infestation by common fiddleneck (Amsinckia intermedia) (Bugg, 1990). In bell bean (no named cultivar) plots, weed above-ground biomass (dry) was 0.7+/-0.3 Mg/ha (Mean +/- S.E.M.) (13.5% of the weed biomass in weedy control plots) at Blue Heron Vineyard, Fetzer Vineyards, Hopland, Mendocino County, California. Dominant winter annual weeds were chickweed, shepherds purse, rattail fescue, and annual ryegrass. Vegetational cover data by bell bean 85.0+/-7.4 % (Mean +/- S.E.M.) (Bugg pers. observation, 1990).