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Effect of 2,4‐D on Cotton Yield, Floral Nectar, Seed Germination, and Honeybee Visits
Author(s) -
Moffett Joseph O.,
Stith Lee S.,
Morton Howard L.,
Shipman Charles W.
Publication year - 1980
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1980.0011183x002000060017x
Subject(s) - nectar , biology , pollination , sugar , horticulture , pollinator , malvaceae , botany , pollen , food science
In Arizona honey bees, Apis mellifera L., frequently visit cotton flowers, Gossypium hirsutum L., in sufficient numbers to adequately pollinate the male sterile flowers and produce hybrid cotton seed. Yet in some other states and at times in Arizona, honey bee visits to cotton flowers are low or erratic. Since hybrid cotton seed may be in demand in the near future, this study was made to determine how spraying 2,4‐D [(2,4‐dichlorophenoxy) acetic acid] on cotton plants affected honey bee visits, seed yields, and nectar secretion. Small concentrations of 2,4‐D were sprayed on five cotton cultivars at three locations in Arizona from 1975 to 1977. Each year, 1 ppm applied in 187 liters of water/ ha at the beginning of bloom increased the volume of floral nectar more than 30%. An application of 10 ppm was harmful to the plants. Application of 2,4‐D when plants started to flower increased the amount of nectar more than application 3 weeks earlier or application at both times. One ppm of 2,4‐D had no significant effect on cotton yields or sugar concentration of the floral nectar.This dosage also had no significant effect on honey bee visits during the only year, 1977, that visits were counted. However, this year the visits were relatively high in both the check and unsprayed plots. Results might be different when the bees are not visiting the flowers well. None of the levels of 2,4‐D applied (0.01, 0.1, 1.0, and 10.0 ppm) affected germination or weight of the seeds produced or caused damage to seedlings grown from the sprayed plants.