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Open access

R. H. Young, H. K. Wutscher, and L. G. Albrigo

Abstract

Orange trees (Citrus sinensis (L.) Osb.) with early-stage (sectored) and moderate blight were evaluated for zinc accumulation and water translocation characteristics. Zinc accumulated at above-normal levels in the outer 2 cm of trunk wood, but water uptake was at below-normal levels in the inner 2 to 6 cm of trunk wood of moderately blighted trees. Water-flux density of roots was not correlated with zinc accumulation. In trees with early stages of blight, zinc accumulated at above-normal levels in the healthy-appearing sides of the trunks, as well as in the blighted sides, but the water uptake in the healthy-appearing sides was similar to that in the trunks of healthy trees. Evidence suggested that the blight effect on abnormal zinc metabolism developed prior to the dysfunction of water translocation.

Open access

N. Zieslin, H. C. Kohl Jr., A. M. Kofranek, and A. H. Halevy

Abstract

Flowers of different cultivars of rose (Rosa hybrida L.) vary in their sensitivity to bent-neck after cutting with ‘Cara Mia’ the most sensitive, and ‘Samantha’ the most resistant of the cultivars tested. Bent-neck is influenced by several factors: water loss by leaves, differences in water uptake ability of the stem, and the ability of the bloom to absorb water from other plant organs on the flower shoot.

Open access

John W. White and Mark D. Shaw

Abstract

An instrument that actuates an irrigation system in response to a weight loss from a pot-soil-plant system, is described. The instrument utilizes the principle that the pot-soil-plant system can act as an integrator of all factors influencing water uptake and loss. The instrument is essentially a scale which continuously weighs the pot-soil-plant system placed upon it. Provisions are included in the design to compensate for gains in weight as the plant grows.

Open access

P. J. Tvergyak and D. G. Richardson

Abstract

Diurnal leaf and fruit water Potentials (Ψ) of sweet cherry (Prunus avium L.) showed that fruit pedicel Ψ was always lower at 6 AM then leaf Ψ but leaf Ψ as usually lower during the day. Varietal differences in Ψ occur but fruit maturity does not appear to have an effect. Minimum fruit pedicel Ψ was reached at about 2 PM and then recovered to the earlier higher Ψ as water uptake occured during the night.

Free access

R.E. Byers, D.H. Carbaugh, and C.N. Presley

Submerging `Stayman' apples in nonionic and anionic surfactant-water solutions caused increased water uptake and fruit cracking. The primary sites of water uptake were lenticels and injured areas of the fruit cuticle. Fruit cracking caused by submerging fruit in 1.25 ml X-77/liter surfactant was used to predict the natural cracking potential of `Stayman' strains and apple cultivars in the field. Submerging apples in aqueous pesticide mixtures did not Increase fruit cracking or water uptake. Fruit cracking and uptake of surfactant-water were not correlated between apple cultivars. In a surfactant-water bath, `Starkrimson Delicious' absorbed more water than `Stayman', `York', `Jonathan', and `Golden Delicious'; no `Starkrimson Delicious' fruits cracked, but 32% to 80% of the other cultivars did. In field tests, four airblast spray applications of GA4+7 in July and Aug. 1987 reduced fruit cracking from 56% to 21%, and five applications In July, Aug., and Sept. 1988 reduced fruit cracking from 93% to 75%. In 1987, daminozide reduced cracking, but, in 1988, neither daminozide, NAA, nor Vapor Gard alone reduced cracking. However, in 1988, a combination treatment of GA4+7, daminozide, NAA, and Vapor Gard reduced fruit cracking from 93% to 22%. Also, two scorings of the trunk with a carpet knife reduced fruit cracking 22%. Chemical names used: alkylaryl polyoxyethylene alcohol glycol (X-77); butanedioic acid mono(2,2-dimethylhydrazide) (daminozide); naphthaleneacetic acid (NAA); di-1-p-methene (Vapor Gard); gibberellic acid (GA4+7).

Free access

Rodney B. Jones, Margrethe Serek, and Michael S. Reid

The vase life of cut sunflowers given a simulated transport period (3 days dry storage at 8C) was significantly enhanced by a l-hour pulse with 0.01% Triton X-100 administered before storage. The Triton pulse increased solution uptake during the l-hour pulse, decreased fresh weight loss during dry storage, and significantly improved water uptake thereafter, resulting in greater leaf turgidity and longer vase life. Leaf stomata] conductance measurements indicated that Triton X-100 maintained stomatal opening at a higher level during the pulse and after storage, but had no effect during dry storage. Chemical name used: octylphenoxypolyethoxyethanol (Triton X-100).

Open access

B. Yaron, N. Zieslin, and A. H. Halevy

Abstract

One year old ‘Baccara’ roses budded on Rosa chinensis cv. ‘Major’ were planted in large containers and irrigated for 90 days with water containing various salinity levels (ca. 0.4 to 7.8 EC × 103). Salinization was obtained by either chloride or nitrate salts. Irrigation with water containing chlorides was more detrimental than with water containing nitrates at the same level of salinity. Stem and leaf growth and water uptake decreased with increasing soil salinity. A slight decrease was noticed even at 2.0 mmhos/cm, containing chlorides, the damage increasing with time, indicating a cumulative effect of soil salinity even at low salinity level.

Open access

Marihelen Kamp

Abstract

A polymer-based antitranspirant was compared to a fungicide, Acti-Dione PM for control of Erysiphe cichoracearum on Zinnia elegans and its effects on plant growth. Plants treated with the antitranspirant had a significant increase in height, fresh and dry weight, and length of the flowering period. In addition, the antitranspirant treated plants had significantly reduced powdery mildew. SEM studies showed that the antitranspirant treated plants had closed stomata, and presumably this had an effect on water uptake as well as the plant host interactions.

Open access

A. E. Einert

Abstract

The effects of several concn of growth retardant chemicals on the elongation of the last stem internode of cut tulips were studied. Compared to tap water, α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidine-methanol (ancymidol) at 25 ppm reduced intemode growth by 31% with no detrimental effects on vase life or flower quality. The 2,4-dichlorobenzyl-tributylphos-phonium chloride (CBBP) was ineffective at 6-25 ppm. CBBP at 125 did reduce stem elongation but was toxic to the flower. Ancymidol in the vase solution retarded growth without altering water uptake by the stem.

Open access

T. Venkatarayappa, M. J. Tsujita, and D. P. Murr

Abstract

Cut flowers of rose (Rosa hybrida L. cv. Samantha) exhibited a longer vase life when opened in solutions containing cobaltous ion (Co2+). The extended vase life in response to Co2+ was related to 1) an increased water uptake into the cut flower, 2) an improved water balance during opening, 3) a delay in loss of fresh weight, and 4) a prevention of the occurrence of bent-neck. A concentration of 1.5 mm Co2+ gave maximum beneficial effects without injury to the cut flower, while a 2.0 mm concentration induced some toxic symptoms on leaves.