John T. Moraghan

Genetic diversity and mineral composition of common bean seed

Concentrations of nine elements essential for human nutrition were studied in seed of eight dry bean (Phaseolus vulgaris L) cultivars grown at five field locations. The cultivars (two Navy, one Great Northern, one Pinto, one Pink, one Cranberry and two Red Kidney) varied in seed weight from 167 to 560 mg per seed. Seed Ca (r  = −0.78, P < 0.001), Mn (r  = −0.67, P < 0.001) and Mg (r  = −0.45, P < 0.001) were negatively related to seed weight. In contrast, seed P (r  = 0.44, P < 0.001) increased with increasing seed weight. Concentrations of N, K, Fe, Zn and B were poorly related to seed weight but differed among cultivars. The two Navy bean cultivars, Voyager and Norstar, differed in concentrations of seed Ca and Fe. Voyager seed contained a mean of 49% more Ca and 19% more Fe than Norstar seed. Voyager also contained a mean of 67% more Ca than that reported for Navy bean in the USDA Nutrient Database. Genetic variability in bean seed may be utilised to increase the mineral content of common bean. © 2001 Society of Chemical Industry

Differential responses of five species to phosphorus and zinc fertilizers

Abstract The influence of a factorial combination of P (0 and 120 ppm) and Zn (0 and 16 ppm) treatments on growth of corn, flax, navy beans, soybeans and wheat was studied under greenhouse conditions. All crops responded to P and all, except wheat, responded to Zn; the P × Zn interactions were significant, except for wheat. Flax and navy beans showed the largest responses to added Zn and also differed from the other species in that added P without Zn decreased yields. Flax and navy beans treated with P without Zn had the largest P concentrations, 0.96 and 0.91%, respectively; the unifoliate leaves of these navy bean plants developed water‐soaked and necrotic zones prematurely and contained 3.3% P. The suppression in growth of navy beans resulting from added P appeared to be at least partly associated with P toxicity. The chief effect of added P without Zn on flax was an increase in main‐stem dieback, the principal symptom of Zn deficiency, from 40 to 100%.

Accumulation of Calcium in Bean Cultivars Differing in Seed Size

Accumulation of Ca, Mg and K, the principal cations in dry bean (Phaseolus vulgaris L) seed, was studied under field and greenhouse conditions. ‘Cran-09’, a cranberry bean and ‘Norstar’, a navy bean, were grown to maturity under greenhouse conditions. ‘Cran-09’ had a seed weight of 605 mg, a seed Ca concentration of 1·2 g kg-1 and a Ca harvest index of 0·032. The corresponding three parameters in ‘Norstar’ were a seed weight of 161 mg, a seed Ca concentration of 2·2 g kg-1 and a Ca harvest index of 0·064. The difference in seed Ca concentration was not due to increased absorption of Ca by ‘Norstar’, but rather was due to a larger proportion of Ca in plant tops being diverted to the seed component. The larger seed Ca concentration in ‘Norstar’ was compensated to some extent by a smaller seed K concentration. In contrast to Ca, cultivar had relatively little effect on harvest indices for Mg, K, N and P. The average seed Ca concentration in six navy bean cultivars grown under field conditions was 90% more than that of three kidney and three cranberry bean cultivars.

Distribution of selected elements between the seed coat and embryo of two black bean cultivars

Differences in distribution of minerals between the seed coat and embryo of plant seed can affect their bioavailability. Concentrations of iron [Fe], manganese [Mn], zinc [Zn], calcium [Ca], magnesium [Mg], potassium [K], and phosphorus [P] in these seed fractions of two black bean (Phaseolus vulgaris L.) cultivars (T39 and UI-911) were studied in field experiments conducted on acid and calcareous soils. Seed of T39 and UI-911 at the acid soil site had 34% and 45% higher [Fe], respectively, than at the calcareous soil site. Seed-coat [Fe] in UI-911 was substantially higher than that in T39. In contrast, embryo [Fe] was higher in T39 than UI-911. Mean percentages of the total seed Fe located in the seed coat were 33% and 32% for UI-911 at the acid and calcareous soil sites, respectively. The corresponding percentages for T39 were 14% and 18%, respectively. Although UI-911 accumulated higher percentages of Ca, Mg, and Zn in the seed coat than T39, the cultivar differences were relatively small. Mean percentages of dry matter and elements in the seed, averaged over cultivars and sites, found in the seed-coat fraction were: Dry matter=10%, Ca=84%, Fe=24%, Mg=18%, K=8%, Zn=7%, Mn=3%, and P=2%. There is apparently a genetically-controlled barrier to the movement of Fe between the seed coat and embryo during seed development in P. vulgaris.

Accumulation of zinc, phosphorus, and magnesium by navy bean seed

Abstract Considerable variation is found in zinc (Zn Concentration in navy bean (Phaseolus vulgaris L.) seed, an important food source of Zn and magnesium (Mg). The influence that phosphorus (P) and Zn fertilizers, and source of nitrogen (N) (inoculation with Rhizobium phaseoli versus 150 mg/kg NH4NO3‐N) had on growth and nutrient uptake of ‘Upland’ navy bean was studied under greenhouse conditions on a Glyndon loamy fine sand, a Calciaquoll low in available N, P, and Zn. Yields of stems (+ pod walls), blades, and seed were increased by N, P, and Zn fertilizers. Zinc concentration at maturity varied between 13 and 37 mg/kg for seed, 15 and 39 mg/kg for blades, and 5 and 30 mg/kg for stems. Zinc fertilizer was the chief factor responsible for this variability. Phosphorus concentration at maturity varied between 4.0 and 6.2 g/kg for seed, 1.9 and 11.8 g/kg for blades, and 1.0 to 2.7 g/kg for stems. Added P fertilizer increased P concentration in the three tissues, but the effect was most pronounced for blad...

Zinc concentration of navy bean seed as affected by rate and placement of three zinc sources

Abstract Increased zinc (Zn) concentration in seed may sometimes improve human health. The influence of rate and placement of three Zn sources (ZnEDTA, ZnSO4, and Rayplex‐Zn) on Zn concentration in navy bean (Phaseolus vulgaris L.) seed grown on a Calciaquoll was studied in the greenhouse. Application of 4 and 8 mg Zn/kg mixed throughout the soil increased seed Zn concentration by approximately 60 and 68%, respectively, and the responses were similar with the three Zn sources. The mixed‐throughout‐the‐soil ZnEDTA, ZnSO4, and Rayplex‐Zn treatments applied at 8 mg Zn/kg reduced seed phosphorus (P) concentration by 10,13, and 15%, respectively. The corresponding reductions with 4 mg Zn/kg were 10, 8, and 13%, respectively. Banding ZnEDTA, ZnSO4, and Rayplex‐Zn at 4 mg Zn/kg in 17‐cm‐long, 3‐cm‐deep bands reduced seed Zn concentration by 8, 34, and 31 % compared to their mixed‐throughout‐the‐soil counterparts. A significant Zn source x placement interaction resulted from marked reduction in Zn uptake as a res...

Removal of endogenous iron, manganese and zinc during plant washing

Abstract The influence of plant washing on removal of endogenous Fe, Mn and Zn from tops of flax (Linum usitatissimum L.) and soybean (Glycine max L. Merr.), species with vastly different leaf types, was studied. The two species were grown in separate randomized block experiments under greenhouse conditions in soil with 0, 0.5 or 2.0 mg FeEDDHA‐Fe/kg. The resultant plant tops contained different concentrations of Fe, Zn and especially Mn. Randomly selected plants with different antecedent Fe treatments were subjected, prior to analysis for Fe, Mn and Zn, to the following treatments: (a) no washing; (b) 10‐s wash in deionized water; and (c) washing in tap water containing detergent followed by four rinses in deionized water (immersion time approximately 150 s). Neither washing treatment affected the determination of Mn, an element reportedly easily leached from plants. Washing had no effect on the determination of Zn in flax, but slightly reduced Zn in soybean. Washing had little effect on Fe level in flax...

Different iron‐manganese relationships in two flax cultivars

Abstract Manganese content of flax (Linum usitatissimum L.) is greatly affected by Fe supply. Two flax cultivars, Clark and Culbert, were grown on a Calciaquoll under greenhouse conditions to compare their responses to FeEDDHA. Although the Mn concentrations of both Clark and Culbert were greatly reduced by FeEDDHA, the performance of the two cultivars varied as follows: (i) Culbert accumulated less Mn in tops, especially leaves, than did Clark, but the relative differences between cultivars were larger in the presence of the chelate; (ii) Culbert accumulated more Fe than Clark, particularly in young plants at low soil temperatures; (iii) necrotic spots were present on lower leaves of Culbert, but not of Clark, containing high levels of Mn in the absence of the chelate; (iv) a decrease in soil temperature appreciably lowered Mn concentrations in Clark but not in Culbert; and (v) FeEDDHA reduced Mn concentration of Culbert, but not of Clark, to such an extent that an apparent Mn deficiency was induced in C...

Influence of three chemicals on soil biological activity

Abstract The efficacy of 10 ppm phenylmercuric acetate (PMA), 2N KCl and 0.02N CuSO4 in suppressing ammonification, denitrification and CO2 accumulation was studied during short‐term anaerobic incubations of three soils at 25 C. KCl and CuSO4 almost completely suppressed ammonification in two of the soils and decreased it markedly in the third. Ammonification was suppressed to a lesser extent by the addition of PMA. The KCl treatment was much more effective than either PMA or CuSO4 in preventing NO3 ‐ disappearance and denitrification. Appreciable amounts of NO3 ‐ disappeared from the soils treated with PMA and CuSO4. N2 and not N2O was the major denitrification product; the suppressors had only a small effect on N2O accumulation. The influence of the chemicals on CO2 accumulation differed according to the soil. CuSO4 was least effective at depressing the accumulation of CO2, and, in fact, stimulated it in one soil. Neither 0.02N CuSO4 nor PMA (10 ppm) is recommended in the absence of a concentrated salt ...

Spring wheat response to fertilizer nitrogen following a sugar beet crop varying in canopy color

Experiments were conducted in the Red River Valley (RRV) of Minnesota to determine the responses of hard red spring wheat (Triticum aerstivum L.) to fertilizer N after a sugar beet (Beta vulgaris L.) crop that varied spatially in canopy color and N content. A color aerial photograph was acquired of the sugar beet field just prior to root harvest, and six sites were selected that varied in sugar beet canopy color, three each of green and yellow canopy sites. The three green sugar beet canopies returned 369, 265, and 266 kg N ha−1 to the soil while the three yellow sugar beet canopies returned 124, 71, and 73 kg N ha−1 to the soil. Spring wheat response to fall-applied urea-N fertilizer (0, 45, 90, 135, and 180 kg N ha−1) was determined the following year at each of the above antecedent canopy sites. Soil NO3-N in the top 0.6 m of soil varied among the locations with a range of 35 to 407 kg NO3-N ha−1 at the green canopy sites and 12 to 23 kg NO3-N ha−1 at the yellow canopy sites. Application of fertilizer N according to traditional recommendation methods would have resulted in fertilizer applications at all three yellow canopy sites and two of the three green canopy sites. At the antecedent green sugar beet canopy sites, fertilizer N had little or no effect on spring wheat grain yields, grain N concentration, anthesis dry matter, and anthesis N content. In contrast, fertilizer N increased all four parameters at the antecedent yellow sugar beet canopy sites. The data indicate that fertilizer N management can be improved by using remote sensing to delineate management zones according to antecedent sugar beet canopy color.