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  • Author or Editor: L. E. Francois x
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Abstract

Bermudagrass (Cynodon spp.), a salt tolerant species, is frequently grown on saline soil. However, new cultivars or accessions used in breeding programs may further increase salt tolerance. Therefore, salt tolerance of the cultivar Tifway II and the accessions Tifton 10 (obtained from China) and Tifton 86 (obtained from Israel) was tested. Plants were grown in the greenhouse in 0.05 m3 pots filled with Pachappa fine sandy loam (mixed, thermic, Mollic Haploxeralf). Four salinity treatments were imposed by irrigating with waters salinized with NaCl and CaCl2 (1:1, by weight). Electrical conductivities of the irrigation waters were 0.9, 6.2, 11.7, and 17.2 dS·m–1. Top growth was measured at nine consecutive harvests. Relative top growth of Tifton 10, ‘Tifway II’, and Tifton 86 was unaffected by soil salinity until the electrical conductivity of the saturated-soil extract (κe) exceeded 2.7, 8.4, and 10.3 dS·m–1, respectively. Each unit increase above these thresholds reduced yield of Tifton 10 by 2.3%, ‘Tifway II’ by 2.8%, and Tifton 86 by 2.5%. These results place Tifton 10 in the moderately tolerant, and ‘Tifway II’ and Tifton 86 in the tolerant salt-tolerance categories.

Open Access
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This study, conducted in large, outdoor sand cultures, was initiated to determine the effects of excess B on garlic (Allium sativum L.) and onion (Allium cepa L.) and to establish their B tolerances as measured by yield and quality of the marketable product. Boron treatments were imposed by irrigation with culture solutions that contained 0.5, 1.0, 5.0, 10.0, 15.0, or 20.0 mg B/liter. Relative yields of garlic and onion were reduced 2.7% and 1.9% with each unit (mg·liter-1) increase in soil solution B (BSW) above 4.3 and 8.9 mg B/liter, respectively. Increasing BSW reduced garlic bulb weight and diameter but did not significantly affect onion bulb weight or diameter. Boron concentration in leaves and bulbs was directly correlated to BSW.

Free access
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The effect of salinity on germination, growth, and yield of turnips (Brassica rapa L. Rapifera group) was determined in artificially salinized laboratory germination cultures and field plots. Saline treatments were imposed by irrigating with water that contained equal weights of NaCl and CaCl2. Relative yield of turnip tops (greens) was reduced 4.3% with each unit increase in salinity above 3.3 dS/m (dS/m = mmho/cm). Storage root growth was reduced 9.0% for each unit increase in salinity above 0.9 dS/m. Top growth would be considered moderately tolerant to salinity and root growth as moderately sensitive. Turnips proved to be more salt-tolerant at germination than at later stages of growth. Root quality was not affected over the salinity range tested.

Open Access
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The salt tolerance of 2 squash cultivars (Cucurbita pepo L. ‘White Bush Scallop’ and ‘Aristocrat Zucchini’) was determined in artificially salinized field plots. Saline treatments were imposed by irrigating with water that contained equal weights of NaCl and CaCl2. Relative yields of ‘Scallop’ and ‘Zucchini’ fruit were reduced 15.9% and 14.7% for each unit increase in salinity of saturated soil extracts (κe) above 3.2 and 6.0 decisiemens per meter (dS/m), respectively [dS/m = millimhos per centimeter (mmho/cm)]. ‘Scallop’ was moderately sensitive and Zucchini moderately tolerant to salinity for both fruit yield and vegetative growth. Germination response to salinity was determined in the laboratory using artificialiv-salinized sand cultures. Both cultivars proved to be more salt-tolerant during germination than during vegetative, flowering, or fruiting stages of growth.

Open Access
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Salt tolerance of 8 ornamental tree species was determined in plots artificially salinized with NaCl and CaCl2. Tolerant species such as Italian stone pine (Pinus pinea L.) and evergreen pear (Pyrus kawakamii Hayata) were affected very little bv soil salinities of 9 dS/m (electrical conductivity of the saturation extract: ECe). Sweet gum (Liquidambar styraciflua L.), cherry plum (Prunus cerasifera J. F. Ehrh), Southern magnolia (Magnolia grandiflora L.), orchid tree (Bauhinia purpurea L.h crape myrtle (Lagerstroemia indica L.), and tulip tree (Liriodendron tulipifera L.) exhibited moderate to severe injury symptoms and a 33% or greater growth reduction. Injury symptoms became more severe with each growing season.

Open Access
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Abstract

The effect of excess B in the soil solution on snap bean (Phaseolus vulgaris L.) and cowpea [Vigna unguiculata (L.) Walp.] was determined in large, outdoor sand tanks. Boron treatments were imposed by irrigation with culture solutions that contained 0.5, 1.0, 3.0, 6.0, 9.0, or 12.0 mg B/liter for snap bean; and 1.0, 2.0, 3.0, 4.0, 6.0, or 8.0 mg B/liter for cowpea. Relative pod yield of snap bean was reduced 12.1% and cowpea seed yield was reduced 11.5% with each unit (mg·liter−1) increase in soil solution B (Bsw) >1.0 and 2.5 mg B/liter, respectively. Reduced yield of snap bean pods and cowpea seeds was attributed primarily to a reduction in pod number. Increasing Bsw significantly reduced plant size of both species.

Open Access
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Abstract

The effect of excess B on tomato (Lycopersicon esculentum Mill.) yield, fruit size, and vegetative growth was determined in large, outdoor sand cultures. Boron treatments were imposed by irrigation with culture solutions that contained 1.0, 4.0, 6.0, 8.0, 10.0, or 12.0 mg B/liter. Relative yield was reduced 3.4% with each unit increase in soil solution B (Bsw) above 5.7 mg B/liter. Market quality of the fruit was reduced significantly by increased B concentrations. The occurrence of leaf injury and reduction in vegetative growth were not reliable indicators for B tolerance.

Open Access
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Abstract

The effect of salinity on germination, first-year growth, and spear and fern yield of asparagus (Asparagus officinalis L.) was determined in germination dishes, crocks, and field plots, respectively. Saline treatments were imposed by irrigating with water that contained equal weights of NaCl and CaCl2. Spear yield was reduced 2.0% for each unit increase in salinity above 4.1 d S · m−1. Yield reduction was attributed primarily to a reduction in individual spear weight. Mature asparagus plants would be considered the most salt-tolerant crop commercially available. Asparagus possessed nearly the same salt tolerance for germination and spear production with soil salinities <7.2 d S·m−1. Above 7.2 dS·m−1, germination was less salt-tolerant. First-year growth was significantly more salt-sensitive than growth in subsequent years.

Open Access
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Abstract

The boron tolerance of broccoli (Brassica oleracea L. Italica Group), cauliflower (Brassica oleracea L. Botrytis Group), and radish (Raphanus sativus L.) was determined in large, outdoor sand cultures. Boron treatments were imposed by irrigation with culture solutions that contained 1.0, 4.0, 8.0, 12.0, 16.0, or 20.0 mg B·liter−1 for broccoli and cauliflower, and 1.0, 3.0, 6.0, 10.0, 13.0, or 16.0 mg B·liter−1 for radish. Relative yield was reduced 1.8%, 1.9%, and 1.4% with each unit (mg·liter−1) increase in soil solution B (Bsw) above 1.0, 4.0, and 1.0 mg B·liter−1 for broccoli, cauliflower, and radish, respectively. Increasing Bsw significantly reduced plant size of all 3 vegetables. Over the B range tested, no leaf injury was apparent for these 3 vegetables.

Open Access

Abstract

The salt tolerance of 3 muskmelon cultivars (Cucumis melo L. cv. Top Mark, PMR 45, and Hale's Best) was determined in plots artificially salinized with NaCl and CaCl2. Marketable yield, total dry weight, vine dry weight, and total fruit weight of all cultivars decreased with increasing salinity. ‘Top Mark’, the highest yielding cultivar at low salinity, yielded least at high salinity. ‘PMR 45’ was the least affected with increasing salinity. Na and Cl in the leaves and fruit and % soluble solids in the fruit all increased with increasing salinity levels.

Open Access