Chapter 4: Legumes and Some Relatives

BROAD BEAN AND FELD BEAN¹⁸Vicia faba L., family Leguminosae
Broad bean and field bean, also known as faba, fava, horse, spring (pigeon), tick, and windsor beans (Robinson 1968), are relatively unimportant in the United States, but they are important in England, parts of western Europe, and Australia. Yields vary considerably for these crops. Hawthorn and Pollard (1954*) stated that broad beans yielded an average of 1,300 to 1,700 lb/acre in England. Bond et al. (1966) reported yields of about 700 lb/acre. Scriven et al. (1961) reported field bean yields of 4,520 kilograms per hectare (3,978 lb/acre). Watts and Marshall (1961) reported yields of 3,377 kg/ha (2,971 lb/acre) from plots caged with bees as compared to yields of 2,687 kg/ha (2,365 lb/acre) on plots caged to exclude bees.
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¹⁸ See also: "Bean," p. 100; "Lima Bean," p. 244; "Scarlet Runner Bean," p. 332 and "Vetch," p. 369.

Plant:
Broad bean and field bean are coarse, erect, smooth-stemmed annuals, 2 to 6 feet tall, with pods 2 to 10 inches long, producing two to four flat brown seeds l/2 inch to 1 1/2 inches across. They are cool-season crops, tolerant to light frost, that are planted in the fall in areas of mild winter climate or in early spring in areas of cold winters.

Extrafloral nectaries are on the underside of the stipules, the small leaflike parts at the base of the leaf. Koreshkov (1967) showed that these nectaries function throughout the vegetative period of the plant, and that repeated removal of the nectar stimulates further production.

Inflorescence:
There are two to four white, blotched, deep maroon or blackish- violet flowers, each an inch or more across in clusters at the base of the leaf. Free (1970*) stated that a normal field bean plant has 50 to 80 flowers, bul a large proportion of these flowers or the young pods shed - 86.7 percent according to Kambol (1969). Sope, (1952) stated that less than a dozen pods per plant are harvested, although isolated plants may set over 60 pods. He concluded that this heavier set on the exposed plant was associated with better insect pollination Rowlands (1960) recorded an average of 24 percent sel in the open but only 7.3 percent set in the glass house He concluded that some plants are highly self-sterile and some cross better than others. Free (1970*) stated that the amount and concentration of field bean floral nectar was relatively low, so the flowers are not overly attractive to nectar collecting insects.

In discussing the field bean inflorescence, nectar secretion, and bee visitation, Free (1970*) stated that bee visitors to extra-floral nectaries were more numerous at midday, whereas those visiting the flowers were most numerous from 2 to 4 p.m., when pollen was available. He concluded that pollen was more attractive to bees than the floral nectar.

Pollination Requirements:
The pollination of broad bean and field bean was studied by Free (1966) who concluded that insect pollination greatly increased production of broad beans but had little effect on production of field beans. Later, Free (1970*) concluded that the pollination requirements of broad bean and field bean were similar although inadequate pollination limited seed production in broad beans more so than in field beans. Darwin (1889*) showed that 17 broad bean plants covered with a net to exclude pollinators produced only 40 seeds, whereas 17 exposed plants produced 135 seeds.

Probably the most important observation concerning the pollination of field bean was that by Drayner (1956,1959) and confirmed in more elaborate detail by Bond and Fyfe (1962) who showed that continued inbreeding causes a progressive loss in the ability of the plant to set selfed seed, but upon hybridization (cross-pollination) this ability is restored. This means that the plant can survive several generations (not indefinitely) without cross-pollination although production continually decreases. A similar situation apparently exists in many other so-called self-pollinated crops; continued inbreeding leads inevitably to elimination of the strain.

Holden and Bond (1960) concluded that 30 to 40 percent cross- pollination may represent an equilibrium point in a balanced breeding system in which the cross-pollinated third of the flowers self and the selfed flowers produce one-third selfed and one-third crossed seed. Such a system, they concluded, would be self-perpetuating, yielding one-third cross-breds and two-thirds inbreds each generation. They also observed that the pollen is in contact with the stigma 24 hours before the flower opens, therefore the cross-breds are capable of selfing.

The value of hybrids or cross-pollinated plants within the cultivar as shown by Bond (1968), is in their ability to self in the absence of bees, whereas inbreds would not set seed. However, Rowlands (1958) showed that only 2.3 percent of flowers set if they were not tripped or manipulated, whereas 12.4 percent set if they were gently hand manipulated but not tripped. This indicated that insects or the elements can influence the set of fruit without actually crossing the flowers. His open-pollinated flowers set 23.1 percent, showing that cross-pollination was more beneficial than mere manipulation.

Free (1966) showed that plants caged with bees produced about twice as many seeds as similar plants caged without bees. Scriven et al. (1961), Cooper (1966), Mart'yanova (1967), National Agricultural Advisory Service (1964, 1967), and Oschmann (1957) showed similar results. Fyfe and Bailey (1951) reported about 30 percent cross-fertilization of field bean in eastern England. Hua (1943) reported an average of 32.9 percent cross-pollination over a 3-year period in China.

The grower wants the plant to set its crop of seeds as soon as possible and to produce as much as possible. Bees can contribute in this respect. Wafa and Ibrahim (1960) excluded insects from some plants by use of cages and included bees in other cages over plants. At harvest time, the bee cage had ceased flowering and most of its pods were ripe. The plants from the cages without bees had many green pods when the cages were removed. This showed that bee pollination accelerated the rate of set of bean pods. Hanna and Lawes (1967) showed that the percentage of crossing was higher on the lower nodes (51 percent below, 33 percent at upper ones), showing that the plant strives first for cross-pollination then for survival.

Pollinators:
Bond and Hawkins (1967) and Free (1962) have studied the behavior of bees on field bean. Free (1962) concluded that the activity of the honey bees may vary. They may visit only the extrafloral nectaries, they may visit only the holes cut in the bases of the corollas by bumble bees, or they may visit the corolla for nectar and pollen. Only in the latter case are the bees of value to the beans as a pollinating agent. Bond and Hawkins (1967) placed two colonies by an acre of field bean, and the bees collected sizeable amounts of pollen. However, these workers concluded that bumble bees were primarily responsible for the cross-pollination that occurred. Wafa and Ibrahim (1960) concluded that the carpenter bee, Xylocopa aestuans (L.), was the most important wild pollinating insect in the Gaza region. Free (1959) concluded that better visitation to the bean flowers resulted when the honey bee colonies were moved to the crop after it started to flower.

Watts and Marshall (1961) showed about 26 percent increase in seed production due to the presence of bees. They also showed the value of bees in setting the seed early. In their plots caged with bees and also in their open plots, they found an average of nine, nine, and two pods, respectively on the bottom, mid- and top portion of the plant, but in the no-bee cage three, five, and four pods were in the same areas.

Free (1970*) concluded that only insects with long tongues could reach the nectar in the bean flower and that honey bees and short-tongued bumble bees that enter the flower probably obtain only pollen most of the time. However, some bumble bee species with short tongues, male carpenter bees (Xylocopa aestuans), and certain ants (Cataglyphis bicolor (F.)) bite holes in the base of the corolla and "rob" the nectar without contributing to pollination. Honey bees do not make holes, but they will rob nectar from holes made by other insects.

Pollination Recommendations and Practices:
Allen and Scriven (1957) concluded that one colony of honey bees per acre should give adequate coverage of field beans, but that most of the work by these insects resulted in self-pollination. In this respect, honey bees are no different from bumble bees. Brandenburg (1961 ) reported that the placement of colonies on the bean plots doubled the yield of seed. He suggested the bringing in of a new group of bees every 7 to 14 days.

Riedel and Wort (1960) studied set of pods in relation to their location on the plant and concluded that uniform set along the body of the plant was an indication of inadequate pollination.

Because bees collect pollen from beans mostly between 2 and 4 p.m., a study of the degree of collection might be used to determine the degree of pollination anticipated. For example, a grower might observe the number of bees per unit of flowers, then, later, the set of beans along the stalk, and, finally, the volume of seed harvested. In this way, he could determine the bee population needed for maximum production of both broad bean and field bean. This information should be determined experimentally also.

LITERATURE CITED:
ALLEN, H., and SCRIVEN. W. A.
1957. NOTES ON THE POLLINATION OF FIELD BEANS BOTH IN THE OPEN AND IN CAGES. Brit. Bee Jour. 85: 288-290.

BOND, D. A.
1968. HYBRID FIELD BEANS. Natl. Agr. Advisory Serv., East Midlands Reg. [England] Quart. Rev. 81: 1-6.

______and FYFE J. L.
1962. BREEDING FIELD BEANS. Plant Breed. Inst. [England] Rpt., 1960-61, pp. 4-26.

______and HAWKINS, R. P.
1967. BEHAVIOR OF BEES VISITING MALE-STERILE FIELD BEANS (VICIA FABA). Jour. Agr. Sci. [England] 68: 243-247.

______FYFE, J. L., and TOYNBEE-CLARK, G.
1966. YIELDS OF MIXTURES OF SINGLE-CROSS HYBRIDS WITH ONE OF THE PARENTAL INBRED LINES. Jour. Agr. Sci. [England] 67: 235-237.

BRANDENBURG, W.
1961. BROAD BEANS: CAUSES OF POOR YIELDS SOUGHT. New Zeal. Jour. Agr. 102: 277, 279-280.

COOPER, B. A.
1964. POLLINATION OF FIELD BEANS. 2d Internatl. Symposium on Pollination, London, 1964. Bee World 47(supp.): 199-206.

DRAYNER, J. M.
1956. REGULATION OF OUTBREEDING IN FIELD BEANS (VICIA FIBA). Nature 177 (4506): 489-490

______ 1959. SELF- AND CROSS-FERTILITY IN FIELD BEANS (VICIA FABA LINN.). Jour. Agr. Sci. [England] 53: 387-402

FREE, J. B.
1959. THE EFFECT OF MOVING COLONIES OF HONEYBEES TO NEW SITES ON THEIR SUBSEQUENT FORAGING BEHAVIOR. Jour. Agr. Sci. [England] 53: 1-9.

FREE, J. B.
1962. THE BEHAVIOR OF HONEYBEES VISITING FIEBD BEANS (VICIA FABA). Jour. Anim. Ecol. 31: 497-502.

______ 1966. THE POLLINATION REQUIREMENTS OF BROAD BEANS AND FIELD BEANS (VICIA FABA). Jour. Agr. Sci. [England] 66: 395-397.

FYFE, J. L., and BAILEY, N. T. J.
1951. PLANT BREEDING STUDIES IN LEGUMINOUS FORAGE CROPS. 1. NATURAL CROSSING IN WINTER BEANS. Jour. Agr. Sci. [England] 41: 371-378.

HANNA, A. S., and LAWES, D. A.
1967. STUDIES ON POLLINATION AND FERTILIZATION IN THE FIELD BEAN (VICIA FABA L.). Ann. Appl. Biol. 59: 289 - 295.

HOLDEN, J. W. H., and BOND, D. A.
1960. STUDIES ON THE BREEDING SYSTEM OF THE FIELD BEAN, VICIA FABA (L.). Heredity 15(2/3): 175-192.

HUA, H.
1943. [NATURAL CROSSING IN VICIA FABA.] Chin. Jour. Sci. Agr. 1: 63 - 65. [In Chinese, English summary. ]

KAMBOL, A. E.
1969. FLOWER DROP AND FRUIT SET IN FIELD BEANS, VICIA FABA L. Jour. Agr. Sci. [England] 72: 131-138.

KORESHKOV, V. M.
1967. [SECRETION OF NECTAR BY EXTRAFLORAL NECTARIES OF THE FIELD BEAN (VICIA).] Vest. Nauchno-Issled. Inst. Pchelovodstvo 15: 40-57. [In Russian.] AA-730/69.

MART'YANOVA, A. I. 1968. [EFFECT OF THE POLLINATION METHOD ON THE QUALITY, AND PRODUCTIVITY OF FIELD BEAN SEED.] Byull. mosk., Obshch. Ispyt. Prlr. 72(2): 83-92. [In Russian.] Abstract in Field Crop Abstracts 21(1): 308. 1967.

NATIONAL AGRICULTURAL ADVISORY SERVICE.
1964. POLLINATION OF FIELD BEANS. Ent. Dept., N.A A.S., Shardlow, Derby [England], East Midlands Reg. [England] Ent. Leaflet 12, 4 pp.

______ 1967. POLLINATION OF FIELD BEANS. Ent. Leaflet 21, 5 pp.

OSCHMANN, H.
1957. [IMPORTANCE OF HONEY BEE VISITS FOR THE SEED YIELD OF FIELD BEANS.] Deut. Landwirt. 8: 302-303. [In German.] AA-340/62.

REIDEL, I. B. M., and WORT, D. A.
1960. THE POLLINATION REQUIREMENT OF THE FIELD BEAN (VICIA FABA). Ann. Appl. Biol. 48: 121-124.

ROBINSON, R. G.
1968. FABABEANS - A NEW CROP FOR MINNESOTA? Minn. Agr. Expt. Sta. Misc. Rpt. 83: 1-8.

ROWLANDS, D. G.
1958. THE NATURE OF THE BREEDING SYSTEM IN THE FIELD BEAN (V. FABA) AND ITS RELATIONSHIP TO BREEDING FOR YIELD. Hereditas 12: 113-126.

______ 1960. FERTILITY STUDIES IN THE FIELD BEAN (VICIA FABA L.). 1. CROSS- AND SELF-FERTILITY. Heredity 15(2/3): 161 - 173.

SCRIVEN, W. A., COOPER, B. A., and ALLEN, H.
1961. P0LLINATION OF FIELD BEANS. Outlook Agr. 3(2): 69 - 75.

SOPER, M. H. R.
1952. A STUDY OF THE PRINCIPAL FACTORS AFFECTING THE ESTABLISHMENT AND DEVELOPMENT OF THE FIELD BEAN (VICIA FABA). Jour. Agr. Sci. [England] 42: 335-346.

WAFA A. K., and IBRAHIM, S. H.
1960. THE EFFECT OF THE HONEYBEE AS A POLLINATING AGENT ON THE YIELD OF BROAD BEAN. Bul. Fac. Agr. Cairo Univ. 205,36 pp.

WATTS, F. H., and MARSHALL, P. R.
1961. POLLINATION OF FIELD BEANS. YIELD RESPONSE DUE TO BEES. Rpt. Field Expts. Observ. Studies Hort., Natl. Agr. Advisory Serv., E. Midlands Reg. [England]: 76-79.