I have found some more very interesting facts about the unique cotton plant as related to honey and the honey bee that I would like to add here.... delightful and enlightening information for both the beekeeper and the cotton farmer.... For the beekeeper the heading below should be taken into consideration, COTTON AS A HONEY PLANT:, being careful being choosy when to place your bees on cotton if you prefer this type of honey.
Chapter 9: Crop Plants and Exotic Plants
NECTARIES AND NECTAR SECRETION OF COTTON:
The different areas of nectar secretion are (1) floral, (2) inner or circumbracteal, (3) outer or subbracteal, (4) foliar or leaf, and (5) unipapillate (microscopic) areas on the flower peduncles and young leaf petioles (Mound 1962) (fig. 90). These unipapillate nectaries are rarely visited by pollinating insects, contribute nothing to pollination and little or nothing to the welfare of pollinating agents, and will not be further discussed. Trelease (1879) believed that the floral nectaries were associated with pollination but that extra-floral nectaries were associated with attracting harmful insects away from the delicate flower parts. Kottur (1921 ) believed that the nectar and pollen in the flower invited natural crossing.
In addition to the secretion from the nectaries, there is a saccharine exudation of certain aphids, white flies, and thrips on cotton, known in the Sudan as "asal" (Bedford 1921). When this material is present in abundance, it supports growth of a sooty fungus, causing a detrimental blackening of the cotton leaves. At times, the sticky material becomes mixed with the lint with damaging effects (Hadwich 1961). When honey bees are present in sufficient numbers, they collect this material as food, and by removing it they become beneficial in a sense other than as pollinators.
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FIGURE 90. - Nectaries of cotton plant. A, Honey bee collecting nectar from a subbracteal nectary; B, inner bracteal nectaries; C, section of calyx removed to show proboscis (tongue) of bee (while bee is inside flower) reaching for floral nectar droplets; D, underside of leaf, showing location of leaf nectaries.
FLORAL NECTARIES:
Within the flower, the nectar exudes from a ring of papilliform cells at the base of the inner side of the calyx (Tyler 1908). Secretion may begin a few hours to a few days before the flower opens, but, because of its unavailability to pollinators until the flower opens, this possible early secretion is of no consequence. The nectar reaches its maximum accumulation by mid-afternoon, the amount depending upon climatic factors, soil fertility, water, and cultivar involved (Kaziev 1959a, b, 1967), and ceases when the petal color begins to change, an indication, according to Kaziev (1964) and Mel'nichenko (1963) that pollination has occurred.
NECTAR COMPOSITION IN RELATION TO ATTRACTIVENESS TO BEES:
At times, honey bees appear to be noticeably reluctant to visit cotton blossoms, even though much nectar and pollen are present. Wykes (1952) studied the preference of honey bees for solutions of various sugars and found that preferences were shown for solutions of single sugars in the following descending order: Sucrose, glucose, maltose, and fructose, and that mixtures of equal parts of all these sugars was the most attractive combination. Vansell (1944a, b) studied the composition of sugars in orange and cotton floral nectar and found the percentages shown in table 13.
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TABLE 13. - Percentage of sugars and moisture content of cotton and orange nectars _________________________________________________________ Plant Levulose Dextrose Sucrose Approximate Moisture __________________________________________________________ Cotton: ?Acala? 14.27 13.06 0.71 70 ?Pima? 10.36 9.25 .35 80 Orange: ?Washington Navel? 6.46 5.42 12.87 75 ?Valencia? 6.08 5.06 12.38 77 __________________________________________________________
Butler et al. (1972) collected nectar from leaf, floral, and extra- floral nectaries of 'Hopicala', 'Deltapine Smooth-leaf', 'Deltapine 16', and 'Pima S-2' near Tucson, Ariz., and analyzed it by gas chromatography for its sugars. They also found low sucrose percentages in nectar from floral and subbracteal nectaries.
Ivanova-Paroiskaya (1950) showed the fructose - glucose - sucrose percentages of floral nectar of G. barbadense cotton, cv. '35-1', to be 39.78-37.50-1.63, and for upland cotton, cv. '36 - 7 M', to be 37.85-35.65- 6.89. Kaziev (1964) showed that the range of the sucrose content of cotton nectars was from 2.3 to 7.6 percent, with the total mono-sugars ranging from 21.2 to 46.9 percent. All samples were taken during mid-season flowering. Whether the percentages change with the season has never been determined.
Numerous observations have shown a relatively low percentage of honey bee visits to flowers of cotton during mid-season and a high percentage toward the beginning and the end of the season. For example in August 1952 (unpublished data), at Tucson, Ariz., eight blossoms of 'Pima S-1' were observed constantly from 8:45 until 11:30 a.m. During that time, they received visits from one honey bee, one Bombus spp., 100 Melissodes spp., and five unidentified pollen-collecting bees. In the same plot, on October 10 between 7 a.m. and noon, three blossoms of 'Pima S-1' were visited by 363 honey bees and seven Melissodes bees. The reason for this extreme difference in the number of bee visitors is unknown.
The volume of nectar in the blossoms of Pima cotton is greater than that in upland cotton, but the sugar concentration is lower. As much as 0.1 ml of nectar has been collected at one time from the former but never more than half this amount from upland. The sugar concentration of upland cotton floral nectar is greater (reaching a maximum of about 69 percent) than that of Pima nectar (a maximum of only 34 percent (fig. 91). The volume of floral nectar of both cottons exceeds the volume of extrafloral nectar, but, as previously stated, the floral nectar is less attractive to honey bees.
Nectar secretion of cotton is strongly influenced by soil fertility, as various tests made in Russia have shown. For example, superphosphate increased nectar secretion by 170 percent and potassium by 130 percent (Monokova and Chebotnikova 1955). Extensive studies by Kaziev (1964) showed that nitrogen had no effect on nectar production, but the greatest increases resulted from application to the soil of cattle manure alone or with complete fertilizers.
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FIGURE 91. - Average and range, in percent, of sugar (soluble solids) of floral nectar of 6 different cotton cultivars grown at the USDA Cotton Research Center, Phoenix, Ariz., August 1957.
SUGAR CONCENTRATION OF FLORAL NECTAR, PERCENT 7n . Approximate _ _ Plant Levulose Dextrose Sucrose Moisture Cotton: 'Acala' 14.27 13.06 0.71 70 ~ , 'Pima' 10.36 9.25 .35 80 60 _ Orange: _ t 'Washington Navel' 6.46 5.42 12.87 75 'Valencia' 6.08 5.06 12.38 77 50 _ ~ _ _ ~_ _
NECTARIES OUTSIDE THE COROLLA (INVOLUCRAL NECTARIES):
There are usually three nectaries just below the sepals at the union of the three bracts, and three others just below the base of the bracts. These have variously been referred to as calyceal and subbracteal, inner and outer involucral, extrafloral internal and extrafloral external, and bracteal nectaries. They begin to function several days before the flower opens, but the day before opening they secrete nectar in copious amounts and this secretion may then continue from several days to 2 to 3 weeks after flowering. When beekeepers report good honey flows from cotton, the bees are usually working these involucral nectaries more intensively than the other nectaries of cotton. Kaziev (1964) also showed that these involucral nectaries were highly attractive to bees. Some upland cotton plants may not have all of these nectaries.
In Hawaiian cotton (G. tomentosum Nutt. ex Seem.), the nectaries are entirely absent. This characteristic has been transferred to some commercial selections to provide a nectariless cotton (Meyer and Meyer 1961). These selections are studied to determine the effect of nectar deprivation on harmful lepidopterious insects on cotton (Lukefahr and Martin 1964, Lukefahr and Rhyne 1960). The nectariless characteristic has been suggested in connection with proposed production of hybrid cotton, the theory being that if only floral nectar were present the bees would visit the flowers more frequently. The opposite, however, may be true, that is, the bees may be attracted to the field by the extrafloral nectaries and then discover the floral ones. Research in this area is requisite for a successful hybrid cotton program if pollinating insects are used.
FOLIAR OR LEAF NECTARIES:
Nectar is also produced on the underside of the leaf in usually one nectary on the primary vein near the blade and petiole juncture. Occasionally, there are two additional nectaries, one on a vein on either side of the primary vein. The leaf nectary begins to function before the leaf reaches full size and may function for 2 or 3 weeks. Leaf nectar secretion on the plant begins when the first flower is in the early bud, or "square", stage and may continue as long as the plant is producing new leaves (Kaziev 1964). The structure of cotton leaf nectaries was described by Reed (191 7).
Honey bees show preference for all of the extrafloral nectaries over floral nectar but under certain conditions collect nectar from all. Ivanova-Paroiskaya (1956) showed the following relative number of honey bee visits to the nectaries: Floral 32, calycular 219, subbracteal 580, and leaf 389. Many other insect species show a preference for the floral nectary of cotton.
COTTON AS A HONEY PLANT:
In many of the areas where cotton is grown it is considered a major honey plant (Benson 1937, Kuliev 19S8, Minkov 1957, Parks 1921). It does not produce as much honey per acre per day as alfalfa, clover, or many other sources (Butler et al. 1972) but because of its longer flowering period, excellent crops of honey can be obtained. Pima cotton is recognized by beekeepers as a better honey source than upland cotton. Vansell (1944a) calculated that 1 acre of Pima cotton was equal to 30 acres of Acala in the production of nectar. Ivanova-Paroiskaya (1950) reported honey crops of 300 kg/ha (267 lb/acre) for G. barbadense compared to 75 to 90 kg/ha (66 to 80 lb/acre) for upland. Normally, when bees are working cotton blossoms, there is a steady, but not spectacular, storage of the high-quality cotton honey. Unfortunately, highly toxic insecticides, frequently used on cotton during the flowering period, kill many bees and prevent the harvest of a honey crop.
Pollination Requirements:
Cotton is usually referred to as a partially cross-pollinated crop, although many breeders have treated it as a completely self-fertile and self-pollinating crop except for accidental and unwanted cross- pollination caused by pollinating insects. Cross-pollination has been referred to as "natural crossing," and is considered detrimental because of the introduction of off-type plants into the progeny. Its impact on production has not been given much consideration. Breeders know that a cotton blossom isolated by any one of several techniques will usually develop a mature boll with viable seed. Breeders also know that they seldom obtain by this method quite as many seed or as much lint from such bolls as they obtain from open-pollinated ones (Stephens 1956). Because this difference can be altered to the benefit of the grower by the activity of pollinating insects, and because of the association of pollinating insects with natural crossing and resultant undesirable cotton types, the subject of natural crossing is reviewed.
Topic: Cotton Honey, A Taste Of Texas (Read 1231 times)