Seasonal Changes in Nutrient Concentrations of ‘Newhall’ and ‘Skagg's Bonanza’ Navel Oranges

Seasonal changes in nutrient concentrations of leaf and fruit structural parts (rind and pulp) from ‘Newhall’ (Citrus. sinensis Osbeck) and ‘Skagg's Bonanza’ (C. sinensis Osbeck) navel oranges were investigated during fruit development in two successive years. Leaf calcium (Ca), manganese (Mn), and potassium (K) concentrations were relatively constant throughout the whole season with the exception of an increase of K at stage 1, the period of fruitlet growth [before 80 days after full bloom (DAFB)], whereas the magnesium (Mg), boron (B), iron (Fe), and zinc (Zn) concentrations declined distinctly during stage 2 (80–180 DAFB), the period of fruit rapid enlargement. In rind, Ca, B, Fe, and Mn concentrations reached the greatest levels at stage 2, different from K and Mg, which increased at stage 1 and decreased thereafter. In pulp, concentrations of Ca, K, Mg, and Mn declined gradually with time, whereas a small rise in B toward the end of sampling and a clear increase of Fe at stage 2 were observed. It was suggested that ‘Newhall’ required greater B inherently in fruits as the cultivar had greater B concentrations in fruit parts and had greater rind/leaf B concentration ratios than ‘Skagg's Bonanza.’ ‘Newhall’ had relatively greater rind Ca content and exhibited Ca distribution more uniformly within its fruit parts, which probably enhanced the crack resistance.     

Application of henriksen's ‘acidification indicator’ and ‘predictor nomograph’ to two adirondack lakes

During the period 1977–1980 we studied the effects of highly acidic precipitation (mean pH 4.1 to 4.2) on the chemistry of three Adirondack lakes: Woods Lake, Panther Lake, and Sagamore Lake. Two of these lakes (Woods and Panther) are enough like those lakes of southern Sweden and Norway studied by Henriksen that they should constitute a valid test of his ‘acidification indicator’ and ‘predictor homograph’. In our comparison we used data from weekly samples taken near the surface of the lakes during unstratified summer and fall conditions over a 3 yr period. The acidification indicator and predictor nomograph were developed using data from lake samples taken under similar conditions in Scandinavia. Our principal finding is that with regard to the empirical line of the acidification indicator (that Henriksen found separated data from lakes receiving precipitation greater or less than pH 4.6) and with the precipitation pH axis of the predictor nomograph, these two methods of evaluation are not directly applicable ‘as is’ to our lakes. The reason for this is that the chemistry of precipitation in the Adirondacks is significantly different from (and for) which the acidification indicator and predictor nomograph were developed. In the Adirondacks, acids other than H₂SO₄ play a much greater role in the overall acidity of the precipitation. This causes relationships between precipitation pH and lake chemistry in the two regions to be different.     

Effects of irrigation and fertilizer application methods on Dianthus ‘Telstar™ White’ and ‘Telstar™ Red’

The objective of this study was to evaluate the effect of fertilizer and irrigation application methods on plant quality of Dianthus ‘Telstar? White’ and ‘Telstar? Red’ grown in the greenhouse. Fertilizer treatments of 0, 10, and 20 g of 16 nitrogen (N)-3.9 phosphorus (P)-10 potassium (K) controlled release fertilizer were topdressed or incorporated. Pots were drip irrigated or hand watered. Irrigation interacted with treatment (P = 0.037) and irrigation interacted with cultivar (P = 0.013) for plant survival. Plant survival was greater for both irrigation treatments using 10 g of fertilizer incorporated. Fewer ‘Telstar? Red’ plants survived with hand irrigation than drip irrigation. ‘Telstar? White’ plants averaged 53% survival regardless of irrigation method. For all treatments drip irrigated plants had greater height, width, and number of flowers than hand watered plants. For fall greenhouse production of dianthus, irrigation and fertilizer application method, cultivar, as well as leaching fraction should be considered.     

Seasonal Changes of Mineral Nutrients in Fruit and Leaves of ‘Newhall’ and ‘Skagg's Bonanza’ Navel Oranges

In southern Jiangxi province of China, ‘Newhall’(Citrus sinensis Osbeck) navel orange presented a conspicuous symptom of boron (B) deficiency in mature leaves, whereas B deficiency symptoms were not manifested on ‘Skagg's Bonanza’(C. sinensis Osbeck) navel orange. In this study, changes in concentrations of B, calcium (Ca), potassium (K), magnesium (Mg), manganese (Mn), and zinc (Zn) were comparatively investigated in the structural parts of the fruit (rind and pulp) and leaves (old leaves from last season and spring-flush leaves from current year) of ‘Newhall’ and ‘Skagg's Bonanza’ navel orange during the growing season. Two peaks of B concentrations were observed in the rind of the two cultivars during fruitlet growth and fruit enlargement, respectively. Boron concentrations were relatively high in the rind during fruitlet growth, and then decreased in both rind and pulp, whereas, during middle and late fruit enlargement significant increases were found for B in both rind and pulp of the two cultivars. Boron concentrations in old leaves of ‘Newhall’ decreased progressively and remained relatively low, whereas that of ‘Skagg's Bonanza’ was relatively high and changed slightly as the season progresses. Both Ca and K concentrations were above the critical threshold values, while their dynamics were reverse to that of B in fruit and leaves during certain times. Old leaf Mg concentrations of samples at 140 days after full bloom from the two cultivars and spring-flush leaves from ‘Newhall’ were below the threshold limit for sufficiency. In addition, Mg in old leaves was much lower from ‘Newhall’ than from ‘Skagg's Bonanza’. Spring-flush leaf concentrations of Mn and Zn and Mn concentrations in old leaves from ‘Newhall’ were relatively lacking during middle and late season, which accelerated the occurrence of B deficiency symptoms on mature leaves of ‘Newhall.’     

‘Decomposer’ Basidiomycota in Arctic and Antarctic ecosystems

Current knowledge concerning ‘decomposer’ Basidiomycota in Arctic and Antarctic ecosystems is based on two sources: (a) collections and surveys of basidiomata, which have resulted in high-quality catalogues of species, although much of the species’ distribution and ecology are tentative and (b) isolations from soils and plant litter which typically result in a “low incidence of basidiomycetes” [Dowding, P., Widden, P., 1974. Some relations between fungi and their environment in tundra regions. In: Holding, A.J., Heal, O.W., MacLean Jr., S.F., Flanagan, P.W. (Eds.), Soil Organisms and Decomposition in Tundra. Tundra Biome Steering Committee, Stockholm, Sweden, pp. 123–150], probably because of selectivity in isolation methods. In the few molecular studies carried out in Arctic and Antarctic soils to date, basidiomycetes, particularly yeasts, have been found. These techniques should give better estimates of the order of magnitude of fungal species richness in Arctic and Antarctic soils, although caution should be used concerning primer choice and amplification conditions. From collections in Arctic regions, species of basidiomycetes appear to be circumpolar in distribution with restricted endemism. Using culture-independent methods, it should be possible to test whether selected Arctic or Antarctic species are truly cosmopolitan, circumpolar, endemic, or are cryptic phylogenetic species.Particularly in Arctic ecosystems, potential ‘decomposer’ fungi in soils and roots may be from phylogenetically diverse taxa, and currently it is unclear whether ‘decomposer’ basidiomycetes are the fungi undertaking the majority of organic matter decomposition in Arctic and Antarctic ecosystems. For example, in some recent studies, wood decomposition in cold Arctic and Antarctic sites appears to proceed via ‘soft rot’ by anamorphic ascomycetes (e.g. Cadophora species), rather than by ‘white rot’ or ‘brown rot’ basidiomycete species. Additionally, it appears basidiomycetes and ascomycetes as ericoid and ectomycorrhizal fungi have the potential to be involved directly in decomposition.Given that profound changes are likely to occur in patterns of vegetation (Arctic and Antarctic) and size of soil carbon (C) pools (particularly in the Arctic) by the end of this century, it is necessary to know more about which species of ‘decomposer’ basidiomycetes are present and to try to define their potentially pivotal roles in ecosystem C (and N) cycling. One solution to characterise further the identity and roles of these fungi in a logical way, is to standardise methods of detection and ‘function’ at networks of sites, including along latitudinal gradients. Results of functional tests should be related to community structure, at least for ‘key’ species.     

Start-Timing for Calcium Chloride Spray Programs Influences Fruit Calcium and Bitter Pit in ‘Braeburn’ and ‘Honeycrisp’ Apples

Early-season sprays of calcium chloride (CaCl₂) have been reported to sometimes be more effective than later-season sprays for controlling bitter pit in apple (Malus × domestica Borkh.). We conducted a two-year study examining the influence of start-timing of CaCl₂ spray programs on fruit Ca concentrations and at-harvest bitter pit incidence in ‘Braeburn’ and ‘Honeycrisp’ apples in Washington State, USA. Six biweekly sprays of CaCl₂ were applied starting in mid-May (early-start), mid-June (mid-start, the normal commercial start timing), or mid-July (late-start) 2002 and 2003. Although leaf marginal necrosis occurred in all of the CaCl₂-treated plots, no spray damage on fruit was observed. All of the CaCl₂ spray treatments consistently reduced bitter pit incidence relative to the unsprayed control treatment and usually but not always increased the Ca concentration of subdermal cortical tissue at harvest. The early and mid-start spray programs produced lower bitter pit incidence than the late-start program in only one of four situations. Fruit Ca concentrations in the control and early-start spray program did not differ. Fruit Ca concentrations in the mid- and late-start spray programs were not different, and often were higher than that of the early-start spray program. Bitter pit incidence for each cultivar was inversely related to fruit Ca concentration. Substituting cortical Ca/potassium (K) or Ca/magnesium (Mg) concentration ratios for Ca concentration failed to substantially improve and usually degraded the correlations with bitter pit incidence. The results confirm that starting CaCl₂ spray programs in June sometimes is more effective at controlling bitter pit that delaying the start of the spray program until July. The later season sprays tend to be more effective at increasing fruit Ca concentration. There appears to be no detectable advantage for starting spray programs earlier than June. Applying CaCl₂ sprays throughout the growing season, starting sometime in June, appears to be the most economical and effective spray management practice for maximizing fruit Ca and minimizing risk of bitter pit development.     

BMBF-research-focus ‘percolation water prognosis’ concept and current activities

The 41 participants of the BMBF-research-focus ‘percolation water prognosis’ are working out the scientific basis of the methods, which are needed to carry out this ‘percolation water prognosis’. They are either focussing on the further development of methods for determining the source strength of materials or on improving existing models for predicting the contaminant transport through soils. Validity and transferability of these developed methods/models are evaluated by including the core projects ‘reference materials’ and ‘lysimeter experiments’ . Scientific co-ordination is carried out at the HSL, where — among other activities — a central database will be created to compare and interpret the results of the different projects. A routine procedure for carrying out the ‘percolation water prognosis’ in most cases must be easily applicable and generally accepted. Nevertheless, the research projects are examining the arising questions from different perspectives and apply highly sophisticated methods in order to provide a sound scientific basis [8]. Most of the projects have started in the course of the year 2001, so first results may be expected during 2002.     

‘碧香早’‘乌牛早’在重庆茶区的适应性研究

2009—2012年,在重庆市永川区进行了茶树品种‘碧香早’‘乌牛早’与对照品种‘福鼎大白茶’的区域引种比较试验。结果表明,‘碧香早’在重庆区域移栽成活率高,生长势旺盛,产量高,适制当地的名优绿茶,可作为优良品种引进种植;‘乌牛早’具有发芽特早的特性,也适制当地的名优绿茶,但采摘周期短,为满足该区域对早市名优茶的需求,可作为搭配品种,适当引种栽植。     

Diversity of arbuscular mycorrhizal fungi associated with the rhizosphere of tea growing in ‘natural’ and ‘cultivated’ ecosites

The colonization and diversity of arbuscular mycorrhizal fungi (AMF) associated with the rhizosphere of tea [Camellia sinensis (L.) O. Kuntze] growing under ‘natural’ as well as ‘cultivated’ conditions in the Kumaun region of Uttaranchal Himalaya (India), during the periods of active growth and dormancy were investigated. Root and rhizosphere soil samples, collected from both the ecosites (natural and cultivated), were monitored for root colonization. While the percent root colonization was quite high (77.66 ± 4.40 and 86.40 ± 3.02%, in the natural and cultivated tea, respectively) during the period of active growth in both the ecosites, relatively higher colonization (97.33 ± 0.78 and 98.13 ± 0.80%, in the natural and cultivated tea, respectively) was recorded during the period of dormancy. The rhizosphere of cultivated tea bushes was found to be dominated by Glomus morhpotypes (88.89% of the total isolates) along with three morphotypes of Acaulospora; occurrence of 35 morphotypes belonging to four genera viz. Acaulospora (11.43%), Gigaspora (11.43%), Glomus (68.57%) and Scutellospora (8.57%) was recorded in the rhizosphere of tea plants from the natural ecosite. A total of 51 AMF morphotypes were detected. Shannon–Weaver index of diversity was higher (1.80 ± 0.13 and 2.05 ± 0.10 during periods of active growth and dormancy, respectively) at the species level for the natural ecosite over its counterparts from the cultivated ecosite. Values for the diversity indices of natural and cultivated ecosites did not show much variation in the period of dormancy. These data suggest that collectively, various cultural practices negatively affect AMF diversity at the genus level in tea plantations of the colder regions.     

Effects of Nitrogen Deficiency on Leaf Chlorophyll Fluorescence Parameters in Two Olive Tree Cultivars ‘Meski’ and ‘Koroneiki’

Effects of nitrogen (N) deficiency on photosynthetic carbon dioxide (CO₂) assimilation, photosystem II (PSII) photochemistry and photoinhibition were investigated in young trees of two olive cultivars ‘Meski’ and ‘Koroneiki’ grown in a greenhouse under controlled conditions. The trees were subjected to four different levels of N supply. N deficient trees had a significantly smaller CO₂ assimilatory capacity, but showed little changes in maximum quantum efficiency of PSII photochemistry. However, modifications in PSII photochemistry induced by N deficiency were observed. This was reflected in decreases in quantum yield of PSII electron transport (Φ_PSII) and efficiency of excitation energy capture by open PSII reaction centres (F_v’/F_m’) and in an increase in non-photochemical quenching (NPQ). These results suggest that modifications in PSII photochemistry might be a mechanism to down-regulate photosynthetic electron transport so that production of adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide phosphate (NADPH). would be in equilibrium with the decreased demand in the Calvin cycle in the N deficient trees. Therefore, both CO₂ assimilation rate and total electron flow (J_t) with its compound electron flows devoted to either carboxylation (J_c) or oxygenation (J_o) can be considered as useful tools to assess the N nutrition status of the trees. Clear relationships were found between A_max and the nitrogen nutrition index (NNI) on the one hand, and between J_t and NNI on the other hand. The results demonstrate that ‘Meski’ is more efficient than ‘Koroneiki’ when subjected to N deficiency.     

LEAF MINERAL COMPOSITION OF ‘NOVA’, ‘ROBINSON’ AND ‘FREMONT’ MANDARIN CULTIVARS ON DIFFERENT ROOTSTOCKS

Rootstock selection has a critical importance for mineral nutrition of budded cultivars. This study was conducted at the experimental farm of Mustafa Kemal University, Dörtyol, Turkey. The aim of this study was to investigate the effect of sour orange, Troyer and Carrizo citrange rootstocks on the leaf nutrient contents of ‘Nova’, ‘Robinson’, and ‘Fremont’ mandarin cultivars in the 2004 and 2005 growing seasons. Carrizo citrange was examined for nitrogen (N), potassium (K), magnesium (Mg), sodium (Na), and manganese (Mn); Troyer citrange for iron (Fe); and sour orange for calcium (Ca) and zinc (Zn) were superior on the others. Nitrogen, phosphorus (P) and Mg levels of mandarin leaf budded on sour orange were under or just above the deficiency threshold. Potassium, Mn, and Zn content of ‘Robinson’; P, Ca and Fe content of ‘Fremont’; and Cu content of ‘Nova’ were statistically higher. Therefore, it can be concluded that Carrizo rootstock may be suggested for the region and regions with similar ecological conditions.     

Potassium and sodium fertilization affects leaf nutrient content and growth of ‘Shawnee’ blackberry

Aluminum (Al) has many detrimental effects on plant growth, and shoots and roots are normally affected differently. A study was conducted to determine differences among sorghum [Sorghum bicolor (L.) Moench] genotypes with broad genetic backgrounds for growth traits of plants grown at 0,200,400,600, and 800 μM Al in nutrient solutions (pH 4.0). Genotypes were categorized into “Al‐sensitive”, “intermediate Al‐tolerant”, “Al‐tolerant”, and SC 283 (an Al‐tolerant standard). As Al increased, shoot and root dry matter (DM), net main axis root length (NMARL), and total root length (TRL) became lower than controls (0 Al). Aluminum toxicity and/or nutrient deficiency symptoms become more severe, and shoot to root DM ratios and specific RL (TRL/root DM) values also changed as Al in solution increased. Root DM had greater changes among genotypes than shoot DM, and NMARL at 400 μM Al, and TRL at 200 μM Al had greater differences among genotypes than root DM, ratings for toxicity and/or deficiency symptoms, and other DM and RL traits. The wide differences among genotypes for NMARL and TRL could be used more effectively to evaluate sorghum genotypes for tolerance to Al toxicity than the other growth traits.     

草莓品种‘红颜’和‘丰香’果实营养成分初步分析

对四川省双流县的草莓试验品种‘红颜’(代号2008-2)和主栽品种‘丰香’85%~95%着色率的果实进行主要营养成分和17种氨基酸含量检测。结果表明,红颜的可溶性固形物、总糖和维生素C含量高于丰香,氨基酸总量及11种氨基酸含量低于丰香。     

Nutritional status of ‘Hass’ and ‘Fuerte’ avocado (Persea americana Mill.) plants subjected to high soil moisture

Abstract

In this study, the effect of increased soil moisture on the nutritional status of two key commercial avocado (Persea americana Μill.) cultivars, ‘Fuerte’ and ‘Hass’, was examined. The results revealed that prolonged exposure of plants to high soil water content conditions (waterlogging) reduced the total nutrient content (absolute quantity) of almost all of the nutrients in scion’s tissues (leaves and stems) of both cultivars. The decrease of nutrient content in the ‘Fuerte’ leaves was more prominent/severe compared to the ‘Hass’ leaves, which could be the outcome of the reported higher sensitivity of the cultivar to soil waterlogged conditions in previous studies. Interestingly, the inability of ‘Fuerte’ avocado plants to withstand high soil moisture conditions was not reflected in the relative concentrations of most nutrients, both in leaves and stems. Indeed, significantly higher concentrations of P, K, B, Fe, and Zn were found in the leaves of ‘Fuerte’ waterlogged plants than in well-watered ones. This fact reveals that under marginal/stressful conditions, like waterlogging, nutrient concentration in tissues does not reflect potential negative effects on total nutrient uptake of avocado plants, obviously due to concentrated nutrient phenomena primarily created by the stress-dependent growth inhibition. Therefore, total nutrient content is proposed as a more representative indicator for assessing plant response to waterlogged conditions.     

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.     

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.     

EFFECT OF CITRUS ROOTSTOCKS ON LEAF MINERAL COMPOSITION OF ‘OKITSU’, ‘CLAUSELLINA’, AND ‘SILVERHILL’ MANDARIN CULTIVARS

Citrus performance is strongly related with rootstock. This study was conducted to investigate leaf nutrient contents of ‘Okitsu’, ‘Clausellina’ and ‘Silverhill’ mandarin cultivars budded onto sour orange, ‘Carrizo’ and ‘Troyer’ citrange rootstocks in Dörtyol, Turkey in 2004 and 2005. The maximum nitrogen (N), potassium (K), and copper (Cu) contents were determined for ‘Clausellina’; phosphorus (P) for ‘Okitsu’; and sodium (Na) for ‘Silverhill’. Calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), and zinc (Zn) uptake were similar for the mandarin cultivars. ‘Carrizo’ citrange at N, K, Mg, Mn, and Cu uptake; ‘Troyer’ citrange at N, P, K, and Fe uptake; and common sour orange at Ca, Zn, and Na uptake was superior on the other rootstocks. It was observed that ‘Carrizo’ and ‘Troyer’ citrange rootstocks had advantages over sour orange in nutrient uptake. Thus, growth performance, yield, and quality parameters considered, ‘Carrizo’ and/or ‘Troyer’ citranges could be suggested as rootstocks for the studied mandarin cultivars under similar ecological conditions.     

Collection and conservation of ‘Morado de Huetor’ Spanish tetraploid asparagus landrace

A cultivated tetraploid asparagus landrace ‘Morado de Huetor’ growing in the South of Spain has been collected and conserved ex situ in two experimental plots. This landrace has been reported to have an interspecific hybrid origin (A. officinalis × A. maritimus). A 59% of the total farmer plots cultivated in the region were visited and ripe fruits collected from 10 female plants per plot. Fruits from a total of 300 plants were collected and two half sibs descendents from each one were sown separate in two plots. Of the 88 farmer plots visited, the landrace was growing only in 34, in the rest the crop had been removed. Hence, ‘Morado de Huetor’ is in a very high risk of disappearing. Now this landrace is conserved ex situ in two experimental plots with sufficient number of plants to represent their maximum variability in order to be used in plant breeding.     

潼南县大豆新品种(系)‘9769’和‘9753’适应性研究

2001—2004年,在重庆市潼南县进行了丘陵旱地1~5台土"果树//大豆"间套作大区对比适应性试验研究,结果表明,大豆新品种(系)‘9769’和‘9753’的农艺性状表现明显优于对照(渝豆1号),随丘陵旱地台位升高,各品种产量都陆续下降,以‘9769’降低幅度最低。1~2台土,‘9753’表现最优,第3台土‘9753’表现略优于‘9769’,667 m2产量差异小,4~5台土‘9769’跃居第1,表现最优。这2个优良新品种(系)从2005年开始在潼南县陆续示范推广,2013年达到年种植‘9769’1540 hm2、‘9753’2160 hm2的规模。适宜净作、间套作(含"果树//大豆"、"麦//玉+豆//苕"、"菜//玉+豆//苕"、"麦//玉+豆"、"玉+豆//苕"、"麦—豆//苕"、"油菜—豆//苕"等熟制)。