Genetic diversity in local cultivars of garden pea (Pisum sativum L.) conserved ‘on farm’ and in historical collections

During a national Swedish collection mission of vegetable varieties conserved ‘on farm’ more than 70 pea accessions were obtained, many of which had been grown locally for more than 100 years. In spite of a likely origin in the multitude of obsolete commercial pea varieties available on the Swedish seed market in the nineteenth century, the rediscovered local cultivars have lost their original names and cultivar identity while being maintained ‘on farm’. To analyze genetic diversity in the repatriated material, 20 accessions were genotyped with twelve SSR markers and compared with 15 obsolete cultivars kept in genebanks and 13 cultivars preserved as non-viable seeds collected in 1877–1918. Most of the local cultivars were genetically distinct from each other, and in only a few cases could a possible origin in a tested obsolete cultivar be suggested. These results reflect the wide diversity of pea cultivars present in Sweden during the nineteenth century. Both between and within accession genetic diversity was larger among the historical samples of obsolete cultivars compared to local cultivars and cultivars preserved in genebanks, indicating genetic erosion over time both in genebanks and during conservation ‘on farm’. The constraints on identifying and verifying historical cultivars using genetic markers are discussed.     

Effect of aluminum on soybean nodulation and nodule activity in a vertical split‐root system

Soybean plants (Glycine max L. cv Santa Rosa) grown hydroponically in nutrient solutions had reduced nodule mass and numbers in the presence of aluminum (Al). Reduced nodule number was attributed mainly to hydrogen (H) ion toxicity, whereas Al had a stronger effect on nodule growth. Using a vertical split‐root system with Al exclusively in the lower (hydroponic) layer also resulted in a significant reduction of nodulation and nodule growth in the surface compartment (vermiculite). This indirect effect could be attributed mainly to Al rather than H. Subsurface Al had no apparent effect on shoot growth or root growth of the upper compartment, but significantly limited root growth in the lower compartment where it was applied. The indirect effect of Al on nodulation could be a reflection of the abnormal root growth in the lower compartment. Split‐root experiments with a high Al soil, however, produced different effects. High Al in soil used exclusively in the lower compartment did not reduce nodule numbers or mass in the upper compartment despite being more harmful than the Al solutions to nodulation and growth of plants when used in a single compartment. Growth of roots in the subsurface compartment was also much less affected by the high soil Al compared with the Al‐containing nutrient solutions. Nodule activity, as estimated by xylem sap ureide levels, was only reduced after direct exposure of nodules to Al. A pronounced increase in the ratio of asparagine/glutamine occurred in all Al treatments where nodulation was reduced, and in some cases, there was an increase in total amino acid concentration of the xylem sap.     

The influence of the herbicide paraquat ‘Gramaxon’ on growth and metabolic activity of three chlorophytes

The acute toxicity of commercial herbicide, Paraquat was determined by 96-hr static bioassay on the freshwater chlorophytes Scenedesmus dimorphus (Trup.) Kuetz., Scenedesmus quadricauda (Trup.) de Brebisson and Ankistrodesmus falcatus (Cord) Ralfs. The 96-hr EC50 values of Paraquat for reducing growth and metabolic products of the three algae were determined. The number of days required for cell division increased with increasing Paraquat concentration. The three algae and their test parameters respond differently to Paraquat. Scenedesmus dimorphus was the most susceptible alga and the chlorophyll a was the most sensitive response parameter. On the other hand, the dry weight of the test algae was the most resistant parameter. It was observed that Paraquat has inhibitory effect on the primary producers.     

Effects of nitrogen forms and calcium amounts on growth and elemental concentration in Rosa hybrida cv. ‘Vendentta’

An experiment was conducted to investigate the effects of calcium and nitrogen on quality and quantity of Rosa hybrida in hydroponic culture, using factorial complete randomized design with different levels of ammonium-N (0, 2.5, and 5 mM) and calcium (1.6 and 4.8 mM). The results indicated that ammonium-N concentration of 2 mM increased the number of flowers, length of pedicles, and fresh weight of flower stem per plant. 5 mM of ammonium-N caused a significant decrease in most of the measured characteristics. Increase in calcium concentration enhanced nitrogen, calcium, manganese, and boron; while, potassium, zinc, and copper decreased in the leaf. Flower diameter and fresh weight of flower stems per plant increased significantly. With application of ammonium in the nutrient solution, calcium and potassium concentration in the leaf decreased, whereas phosphorus, zinc, manganese, iron, and boron significantly increased. Therefore, application of 2.5 mM ammonium-N and 4.8 mM calcium are recommended.     

Effect of nitrogen on the growth and photo‐synthetic activity of salt‐stressed barley

Pot experiments were conducted in the greenhouse to study the effect of nitrogen (N) nutrition on photosynthesis and water relations of barley plants under salinity conditions. Nitrogen decreased the sodium (Na) content and increased the potassium (K) content in shoots. The net photosynthetic rate of leaves increased significantly with added N increasing from 0 to 100 mg N/kg soil. The activity of ribulose 1,5 bisphosphate carboxylase (RuBPC_ase) in leaves of high‐salt plants was lower, and in leaves of the low‐salt plants higher than that in control plants. The photosynthetic rate was reduced by sodium chloride (NaCl) and was significantly correlated with total soluble protein per unit leaf area. At each N level, stomatal conductance in leaves was reduced considerably by salt. Proline content of leaves increased with increasing N level. It was higher in leaves of salt‐treated plants than in those of control plants. The osmotic potential of leaves decreased with increasing N applied, and the turgor pressure of high N plants remained higher under salt treatment condition.     

Effect of nitrogen and phosphorus on ‘delicious’ apple trees grown in caliche soil in the greenhouse

Abstract

In a greenhouse study, mono‐ammonium phosphate applications to ‘Delicious’ (Oregon spur cv) apple trees, Malus domestica Borkh., improved a low‐vigor condition associated with a caliche soil. The moderate rate of mono‐ammonium phosphate (6 grams per tree) resulted in trees with greater shoot extension, leaf numbers, a higher percent leaf phosphorus, and less purple leaf margins or spots than other soil treatments or the control. By September, trees treated with the highest rate of mono‐ammonia phosphate (12 grams per tree) had the highest level of leaf phosphorus and significantly higher levels of leaf phosphorus than all forms of nitrogen‐only fertilizer (ammonium nitrate, ammonium sulfate, calcium nitrate, and urea). In most cases, applications of the nitrogen‐only fertilizers, reduced leaf phosphorus levels throughout the experiment.     

Effect of root pruning and nitrogen fertilization on growth of young ‘fuji’ apple (Malus domestica borkh.) trees

This study examined the effect of root pruning (RP) and nitrogen fertilization (NF) alone or in combination (RP-NF) on growth properties of 3-year-old ‘Fuji’ apple (Malus domestica Borkh.) trees. The results of pot experiments showed that the trees were sensitive to RP and NF alone or in combination in terms of root architecture, leaf photosynthesis, and canopy growth. Compared with the control, NF and RP-NF increased root length density and tips, while RP and RP-NF decreased root surface area and volume. RP alone reduced coarse root length (2.0–4.0 and >4.0 mm diameter), while RP-NF simultaneously increased fine root length (≤1.0 mm diameter) and reduced coarse root length. Moreover, RP increased leaf chlorophyll content and transpiration rate, while RP-NF increased net photosynthetic rate and water use efficiency. RP-NF resulted in no differences in dry matter weight, root-shoot ratio, or leaf area compared with the control. Inhibiting vegetative growth by RP-NF provided an effective way to improve water use efficiency of young apple trees.     

Effect of Nutrient Solution PH on the Vegetative and Reproductive Growth and Physiological Characteristics of Rose Cv. ‘Grand Gala’ in Hydroponic System

The rose plants were cultivated in the pots containing 75% cocopeat+ 25% perlite and were nourished with ½ Hoagland nutrient solutions with pH of 4.5, 5.5, 6.5, and 8. The results revealed that plant fresh and dry weight, flower bud, and stem diameter increased with the increase in pH from 4.5 to 6.5, but then started to decrease with further increase in pH up to 8. The highest number of buds, chlorophyll content, F_v/F_m, performance index (PI), and leaf phosphorus, iron, manganese, and copper concentrations were obtained at pH 6.5 and the lowest one at pH 8. The highest and lowest zinc concentration was observed at pH 6.5 and 4.5, respectively. According to the results, pH 6.5 was evaluated as optimum for hydroponic culture of rose, which resulted in the higher uptake of elements and better vegetative and reproductive growth and higher quality of rose plants.     

Effect of N‐form on macronutrient and micronutrient concentration and uptake of creeping bentgrass 1

Abstract

Nitrogen‐form effect on nutrient uptake and the subsequent concentration of nutrients in turfgrass plant tissue has not been thoroughly investigated. This study evaluated the effects of clipping regime and N‐form on the tissue concentration of macronutrients and micronutrients and macronutrient uptake in ‘Penncross’ creeping bentgrass (Agrostis palustris Huds.). Turfgrass plugs were grown under greenhouse conditions in a modified Hoagland's solution with a combination of three nutrient solutions (100% NO₃ ^?, 100% NH₄ ⁺, and 50:50 ratio of NH₄ ⁺:NO₃ ^?) and two cutting regimes (cut and uncut). Concentrations of macronutrients and micronutrients were determined for shoot, root and verdure. Nutrient uptake was determined weekly. Uncut NO₃ ^?‐treated plants accumulated higher concentrations of K, Ca, Mg, B and Cu in the shoot tissue; P, K, Ca, Mg, B, Cu, Mn and Zn in the root tissue; and P, Ca, Mg, B, Fe and Mn in the verdure compared to uncut NN₄ ⁺‐treated plants. Nitrate uptake was greater with uncut NO₃ ^?‐treated plants than was NH₄ ⁺ absorption with uncut NH₄ ⁺‐treated plants. Plants grown with the uncut 50:50 treatment adsorbed more NH₄ ⁺ than NO₃ ^?. Plants grown with the uncut NO₃ ^? and 50:50 treatments adsorbed higher amounts of P, K, and Ca compared to the NH₄ ⁺ treatment. The cut NO₃ ^?‐treated plants accumulated higher concentrations of K in the shoot tissue; P, Ca, Mg, B, Cu, Fe and Mn in the root tissue; and B in the verdure than did the cut NH₄ ⁺‐treated plants. Cut NO₃ ^?‐treated plants adsorbed less NO₃ ^? than did cut NH₄ ⁺‐treated plants adsorbed NH₄ ⁺. The cut 50:50 treatment adsorbed more NH₄ ⁺ than NO₃ ^?. Plants grown with NO₃ ^? and 50:50 treatments, under both cutting regimes, resulted in higher concentrations of most macro‐ and micronutrients and greater nutrient uptake compared to the NH₄ ⁺‐treated plants.     

Interstock effects on growth and 45Ca distribution in ‘delicious’ apple seedlings 1

Comparisons were made of the ⁴⁵Ca uptake of ‘Redchief Delicious’ apple seedlings (Malus domestica Borkh) grown on ‘York Imperial’ rootstocks with interstocks of ‘Redchief Delicious’, M9 and short, medium and long internode ‘Delicious’ stocks. Seedlings were grown in aerated complete nutrient solutions. Applied ⁴⁵Ca was readily translocated to rootstocks, interstocks, scions and leaves of M9 and short internode combinations.

⁴⁵Ca accumulated to a much greater extent in rootstock and the interstock than the scion. Applied ⁴⁵Ca was translocated much more readily to the bark than to the wood.     

Effect of the Concentration of Phosphorus on Growth and Nutrition of Leucospermum cordifolium ‘Flame Spike’

The aim of this study was to determine how phosphorus (P) concentration affects growth, concentration and distribution of nutrients in Leucospermum cordifolium ‘Flame Spike’ (Proteaceae). The trials were performed at the School of Agriculture (ETSIA) of the University of La Laguna (28° 28′ 43′′ N, 16° 19′ 7′′ W) with 64 plants (1-year-old) grown for 12 months in silica sand, fed with nutrient solutions containing different levels of P_i (5, 10, 15 and 20 mg L^?1). At 6, 9, and 12 months, whole plants were taken from each experimental unit and divided into root, stem (main, first, second, and third growth) and leaves (adult, first, second, and third growth), which were measured, weighed, and analyzed. The data enabled a nutritional diagnosis, including the limiting P concentrations and nutrient interactions. P concentrations above 5 mg L^?1 caused a reduction in growth, which in the third samples was significant (P < 0.05). Plants treated with 15 and 20 mg L^?1 P attained similar dry weights (P > 0.05). Some young leaves showed a certain degree of chlorosis, probably due to iron (Fe) deficiency. Fully developed young leaves (YFEL) were suitable for nutritional diagnosis of P, and the P concentration of the nutrient solution affected the foliar manganese (Mn) concentration. This latter factor was related to the zinc (Zn) concentration in the roots.     

Interstock effects on growth,photosynthesis and mineral nutrition of ‘delicious’ apple seedlings

Tree growth, photosynthesis, and the mineral nutrient content were investigated in ‘Redchief Delicious’ scions double worked on seedling rootstock with a variety of interstocks. The interstocks used were ‘Redchief Delicious’, M9, and a range of F. generation hybrids with internodes designated short, medium and long. The long internode graft union consistently produced more growth and dry weight per tree than the other interstocks. The ‘Redchief Delicious’ interstock had an unexplained negative effect on leaf, shoot and new root dry weight. There was no effect of interstock on photosynthesis initially (56 days) however photosynthesis increased with shorter nodal interstocks after 111 days. There were significant differences in scion and interstock bark elemental composition due to interstock combination. However, leaf composition varied slightly among the different interstock combinations. Manganese levels, independent of tissue type, did not vary between interstocks.     

The Effect of Calcium Sprays and Fruit Thinning on Bitter Pit Incidence and Calcium Content in ‘Honeycrisp’ Apple

‘Honeycrisp’ is a recently released cultivar of apple (Malus x domestica) developed by the University of Minnesota, now in high demand by growers and consumers. This cultivar is susceptible to bitter pit, especially when the trees are young and the fruit load is low. The effects of calcium (Ca) sprays, fruit thinning, vegetative growth, fruit and leaf nutrient concentration on bitter pit incidence, and two sampling methods for nutrient analysis were studied. Bitter pit incidence was associated with several variables, including Ca and phosphorus (P) concentrations in leaves and fruits, magnesium (Mg) concentration in leaves, and yield parameters. Fruit Ca concentration and content for the growing season were modeled, which allowed the determinations of Ca levels associated with bitter pit incidence. Our data suggest that plug analysis was less sensitive than fruit-segment analysis for finding differences in Ca concentrations.     

Solution pH influences on growth and mineral element concentrations of ‘Waimanalo’ papaya seedlings

Two sand culture experiments were conducted to determine the influence of substrate pH on ‘Waimanalo’ papaya seedling growth, morphology, and mineral element nutrition. The seedlings were grown in clear, plastic tubes 7 cm in diameter and 21 cm in height with the rooting substrate being silica sand. The substrate was drenched daily with a complete nutrient solution. The solution was adjusted to target the pH at 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, or 9.0. Direct seeded plants were used in the first study and plants were harvested after 9.5 weeks of growth. Transplants were used in the second study, and plants were harvested after four weeks of growth. Dry mass of plants was relatively unaffected by substrate pH within the range of 4.0 to 9.0. In both studies, however, dry mass of plants receiving a target pH of 3.0 was reduced compared to those plants receiving the other pH level nutrient solutions. This response pattern was similar for other characteristics such as canopy/root ratio, total root length, root extension rate, lateral root thickness, and root density. Various root characteristics were decreased more by pH of 3.0 than other canopy characteristics. Unit leaf area per unit root length was greatly increased for plants receiving the pH 3.0 nutrient solution, indicating increased susceptibility to drought stress. Root accumulation of manganese (Mn), zinc (Zn), and iron (Fe) was markedly greater than the canopy accumulation. The influence of pH on mineral element concentrations was similar for roots and canopy for all elements except magnesium (Mg). Canopy tissue, but not root tissue, accumulated more Mg at lower pH than higher pHs. The greatest influence of pH on mineral element concentration was for iron (Fe). The concentration of Fe at pH of 3.0 was almost three times the concentration at the other pHs. No visual symptoms of mineral deficiency and/or toxicity were evident. These results indicate that the growth and morphology of papaya seedlings provided with complete nutrient solution are relatively unaffected by pH within the range of 4.0 to 9.0.     

Effects of Foliar Fertilization on Incidence of Berry Shrivel and Bunch Stem Necrosis in Vitis vinifera L. CVS ‘Pinot Blanc’ and ‘Zweigelt’

Berry shrivel and bunch stem necrosis are the economically most important physiological disorders of grapevine. The nutritional status of the plant is considered as one of the main elicitors for the occurrence of these disorders. For foliar fertilization trials, two vineyards that had previously been affected by both diseases were selected in Southwest Germany, one with the variety ‘Zweigelt’ and one with Pinot Blanc. By the use of potassium, magnesium, and calcium foliar fertilizers, a rapid increase of different nutrients in the plants should be caused and the effects on the diseases observed. In 2010, no significant differences in the fertilization treatments were found for both varieties. In ‘Pinot Blanc’, significantly more berries were affected by berry shrivel in 2011 in plots treated with calcium fertilizer compared to those treated with potassium and magnesium. Plots with magnesium fertilizer showed significantly less berries affected by berry shrivel than the untreated control.     

The effects of leaching surface‐applied amendments on subsoil aluminum and alfalfa growth in a Louisiana Ultisol

Abstract

A greenhouse leaching column study was conducted to compare the effects of surface‐applied langbeinite (LB), phosphogypsum (PG), Ca‐ silicate slag (SS), and calcitic lime (CL) on subsoil Al and growth of alfalfa (Medicago sativa L. ‘Florida 77') in Toula silt loam soil (Typic Fragiudult). Langbeinite was found to be more effective than PG in the reduction of subsoil exchangeable Al, apparently through SO₄ ^2‐‐induced Al precipitation. This study demonstrated that high exchangeable Al levels are not always indicative of Al toxicity in the soil solution phase. The primary factors limiting alfalfa growth in the Toula soil were found to be surface soil pH and Mn toxicity rather than subsoil Al toxicity. The liming materials, SS and CL, effectively corrected the surface soil Mn and pH problems, but had no effect on subsoil chemical properties.     

Effects of lime and applied Mn on plant Mn,growth and chlorophyll concentration of ‘Tifway II’ bermudagrass

Abstract

A glasshouse study was conducted to determine effects of lime and Mn applied to three Florida soils on plant Mn, growth, and chlorophyll concentration of ‘Tifway II’ bermudagrass (Cynodon dactylon x Cynodon transvaalensis). Four replications of three lime rates (0, 1000, and 2000 mg CaCO₃/kg as dolomite and Ca(OH)₂ for Astatula fine sand (Typic Quartzipsamment, hyperthermic, uncoated) and Pompano fine sand (Typic Psammaquent, siliceous, hyperthermic); 0, 2000, and 4000 mg CaCO₃/kg as dolomite and Ca(OH)₂ for Myakka fine sand (Aeric Haplaquod, sandy siliceous, hyperthermic) and three Mn applications (none, 10 mg Mn/kg as MnSO₄, and 5 mg Mn/kg as MnEDTA) were used in a randomized, complete block, factorial design. A wide range of plant Mn concentrations existed across treatments for each soil. Differences in plant Mn concentration did not cause significant differences in growth or chlorophyll concentration. The critical plant Mn concentration was not reached, but it appeared to be below 20 mg Mn kg for bermudagrass. Models for prediction of plant Mn concentration using soil pH and extractable soil Mn (Mehlich I, Mehlich II, DTPA‐TEA) were obtained. The applications of MnSO, and MnEDTA each resulted in increased plant Mn under acidic soil conditions. Neither Mn application resulted in increased plant Mn concentration in grass grown on Pompano fine sand with soil pH values of 7.0 or above.     

Effect of calcium spray materials,rate, time of spray application,and rootstocks on fruit quality of ‘red’ and ‘golden delicious’ apples

Calcium (Ca) spray materials improved fruit quality as measured by control of bitter pit, fruit finish (appearance), increased red skin color, reduced incidence of scald, increased juiciness, texture, and fruit firmness of ‘Red’ and ‘Golden Delicious’ apples (Malus domestica, Borkh.). Concentrations of Ca in leaf and fruit tissues were increased by Ca sprays, especially calcium chloride (CaCl₂)‐containing spray materials. Improved fruit firmness and control of bitter pit occurred for either standard recommended or high rates of Ca spray materials. At high rates of application, the only significant difference that occurred between early and late applications of Ca spray materials was that less leaf injury occurred with the early applications. Unsprayed ‘Red Delicious’ fruit from M.7 rootstocks had greater fruit peel Ca concentrations and a lower incidence of bitter pit but smaller fruit than fruit from trees on M.26 rootstocks. The above information is strong evidence that Ca sprays are important for the improvement of apple quality.