Search Results

You are looking at 1 - 10 of 688 items for :

  • Refine by Access: All x
Clear All
Open access

Bruce W. Wood

Abstract

Field observations indicate that conjunctive use of ethephon (Ethrel) and NAA (Fruitone-N) can induce early pecan [Carya illinoensis (Wangenh.) C. Koch] shuck (involucre) dehiscence, while greatly reducing undesirable leaflet abscission. Comparisons of the efficacy of 2,4-D and NAA in preventing undesirable leaflet abscission revealed that the comparative molar protective activity of 2,4-D greatly exceeds that of NAA, providing leaflets absolute protection against ethephon-induced abscission, but it was functionally inferior to NAA due to the induction of leaflet necrosis. Single ethephon treatments accelerated shuck dehiscence 3 to 6 weeks for several cultivars. Treatment of ‘Stuart’ and ‘Moneymaker’ pecan fruit and foliage, several weeks prior to the completion of natural shuck dehiscence, with a NAA-ethephon mixture accelerated shuck dehiscence by 5 and 3 weeks, respectively, without severe leaflet abscission or loss of nut quality. These data indicate possible development of harvest-aid technology for early harvesting of pecan without severe leaflet abscission. Chemical names used: (2-chloroethyl)phosphonic acid (ethephon); (2,4-dichlorophenoxy)acetic acid (2,4-D); and 1-naphthaleneacetic acid (NAA).

Free access

Martin J. Bukovac, Paolo Sabbatini, Philip G. Schwallier, and Michael Schroeder

The discovery of auxins provided the basis for current chemical fruit thinning of apples. The promotion of postbloom fruit abscission was first reported over 60 years ago ( Davidson et al., 1945 ), and since then, synthetic auxins, NAA and its

Open access

Ryan J. Hill, David R. King, Richard Zollinger, and Marcelo L. Moretti

-naphthaleneacetic acid (NAA) has been successfully used to control basal sprouts in several crops ( Boswell and McCarty, 1974 ; Eynard et al., 1986 ; Holt and Chism, 1988 ; Stover et al., 2006 ) and has shown some success in sucker control in hazelnut in Europe

Free access

Hong Zhu, Eric P. Beers, and Rongcai Yuan

and Palmer, 1982 ; Yuan and Greene, 2000b ). Some researchers reported that the primary mechanism of fruit thinning by chemical thinners such as naphthaleneacetic acid (NAA) and 6-benzylaminopurine (6-BA) is the result of reduced carbohydrates

Full access

C.R. Unrath, J.D. Obermiller, A. Green, and S.J. McArtney

preharvest fruit drop can occur independently of fruit ethylene production ( Sun et al., 2009 ). Losses resulting from preharvest fruit drop can be mitigated by applying either naphthaleneacetic acid (NAA; Fruitone L; AMVAC Chemical, Newport Beach, CA) or

Full access

Steven McArtney, Dick Unrath, J.D. Obermiller, and Ann Green

efficacy. Various growth regulators have been shown to promote flower bud formation in apple. Harley et al. (1958) reported that flowering in apple was increased by NAA to a greater extent than could be accounted for by fruit removal alone, providing

Free access

Rongcai Yuan and David H. Carbaugh

synthetic auxins reduced preharvest fruit drop of apples ( Gardner et al., 1940 ; Marini et al., 1993 ) and oranges ( Gardner et al., 1950 ; Zur and Goren, 1977 ). One application of naphthalene acidic acid (NAA) may delay apple fruit drop for ≈10 to 14 d

Free access

Rongcai Yuan and Jianguo Li

, color, and cro p value by as much as 20% while maintaining fruit quality ( Byers and Eno, 2002 ). Naphthaleneacetic acid (NAA), a synthetic auxin, and aminoethoxyvinylglycine (AVG), an inhibitor of ethylene biosynthesis are two compounds that

Open access

N.K. Lownds, J.M. Leon, and M.J. Bukovac

Abstract

Effects of the surfactants Pace, Regulaid and Tween 20 were determined on foliar penetration of NAA and on NAA-induced ethylene production by cowpea [Vigna unguiculata (L.) Walp. subsp. unguiculata cv. Dixielee]. All three surfactants decreased surface tension of NAA solutions, causing a marked increase in wetting and in droplet : leaf interface area. The greatest increase in NAA penetration was obtained with Regulaid followed by Pace and Tween 20. The surfactant effect was most pronounced during the droplet drying phase, but penetration continued to take place from the deposit after drying. The mode of action of surfactants in enhancing NAA penetration is complex. Regulaid-enhanced penetration closely paralleled the increase in interface area, but similar relationships were not found for Pace or Tween 20, particularly at concentrations above the critical micelle concentration. Surfactant-enhanced NAA penetration caused an increase in NAA-induced ethylene production. There was a strong correlation (r = 0.82) between NAA penetration and ethylene production for doses of 0.5 to 2.5 μg/disk. Above 2.5 μg/disk, ethylene production increased at a decreasing rate. The potential for using auxin-induced ethylene production as an index for quantifying auxin penetration is discussed. Chemical names used: l-naphthaleneacetic acid (NAA), polyoxyethylene polypropoxypropanol dihydroxypropane (Regulaid), polyoxyethylene (20) sorbitan monolaurate (Tween 20), surfactant blend in paraffin base petroleum oil (Pace).

Free access

Matej Stopar, Brent L. Black, and Martin J. Bukovac

the gift of Accel, Der-I Wang, AMVAC Chemical Corp. for the gift of NAA, and James Flore for loan of his instrumentation and valuable discussion. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal