Zinc Nutrition in ‘Nagpur’ Mandarin on Haplustert

ABSTRACT

Zinc (Zn) deficiency is the most prevalent nutritional disorder in citrus orchards world over. The management strategy of Zn deficiency today is still governed by the efficacy of two conventionally used methods of Zn supply to plants via soil or foliar fertilization. A field experiment with 12-yr-old ‘Nagpur’ mandarin (Citrus reticulata Blanco) orchard was, therefore, carried out during 2004–07 comparing soil application versus foliar application of Zn, each at three levels viz., 100, 200, and 300 g tree^?1 with constant doses of N (600 g tree^?1), P (200 g tree^?1), K (300 g tree^?1), and Fe(60 g tree^?1) on Haplustert soil type with reference to response on flowering intensity, fruit set, tree volume, fruit yield, changes in soil fertility/leaf nutrient status, fruit quality, and transformation of native soil Zn fractions. Soil application of Zn at all the three levels, produced significantly higher increase in tree volume over foliar application on equivalent rates viz., T₁ (2.53 m³) vs. T₄ (2.06 m³) and T₂(4.30 m³) vs. T₅ (2.23 m³). The yield-determining parameters like flowering and fruit set intensity (no. m^?1 shoot length) were, respectively, much higher with soil applied (135.74 and 21.90) than foliar applied Zn (31.20 and 11.6). These observations set the favorable conditions required for yield response, e.g., all the three treatments involving soil application of Zn, T₁ (32.1 kg tree^?1), T₂ (52.6 kg tree^?1), and T₃ (51.8 kg tree^?1) were correspondingly superior over T₄ (22.5 kg tree^?1), T₅ (34.3 kg tree^?1), and T₆ (42.1 kg tree^?1) as foliar application treatments. All the three major fruit quality parameters (juice, acidity, and TSS) were likewise more influenced by soil application than foliar application of Zn. Improvements in soil Zn fractions (mg kg^?1) viz., exchangeable Zn (0.25–0.60), complex-Zn (2.71 to 4.86), organically bound Zn (0.86 to 2.0), and Zn-bound to carbonates and acid soluble minerals (2.56–4.96) were observed in response to Zn fertilization with treatments T₁–T_3. On the other hand, foliar applied Zn treatments (T₄–T₆) produced no such changes in any of the soil Zn fractions.     

Effects of zinc fertilizer amendments on yield and grain zinc concentration under controlled environment conditions

The application of zinc (Zn) fertilizer to lentil is an agronomic strategy that has the potential to improve yield and enhance grain Zn concentration. A pot study was conducted to determine if Zn fertilizer applied to three popular Saskatchewan lentil cultivars could increase yield and concentration of Zn in the grain. The effects of soil and foliar applied Zn forms, including ZnSO₄, Zn chelated with EDTA, Zn lignosulphonate, and a control were evaluated. Forms of Zn were not found to significantly increase yield (P = 0.828) or grain Zn concentration (P = 0.708) in any of the lentil cultivars tested. Fertilization with soil applied ZnSO₄ resulted in significantly (P < 0.0001) higher amounts of residual available Zn in the soil relative to other Zn treatments. Soil fertilized with ZnSO₄ had 1.13 mg kg^?1 diethylenetriaminepentaacetic acid (DTPA)-extractable Zn compared to 0.84 mg Zn kg^?1 and 0.77 mg Zn kg^?1 in the soil and foliar applied chelated Zn, respectively.     

Effect of foliar and soil applications of zinc sulphate on zinc uptake,tree size,yield, and fruit quality of mango

To compare the effect of methods (foliar and soil) and rate of application of zinc sulphate on zinc and phosphorus uptake, tree size, yield and fruit quality of mango (Mangifera indica L.) cv. Dusheri, zinc sulphate was applied as a foliar spray application (0.25, 0.50, 1.0%) and soil (0.5, 1.0, 2.0 kg tree^‐1) treatments during the second week of October (during flower bud differentiation period). All the zinc sulphate treatments of soil and foliar spray were effective in increasing the leaf zinc concentrations above recommended adequate level of (>20 mg kg^‐1) whereas control trees maintained low leaf zinc concentrations (13.8 to 13.3 mg kg^‐1). The uptake of foliar‐applied zinc was more rapid than that of soil applied zinc. All the treatments of zinc sulphate except the foliar spray treatment of zinc sulphate (0.25%) significantly increased zinc concentrations in the fruit pulp as compared with those in the control trees. The percent increase in the stem girth of trees was highest with the soil application of zinc sulphate (0.5 kg tree¹) followed by foliar application of zinc sulphate (1.0%) as compared with all other treatments. The percent increase in the tree canopy volume was highest with the foliar application of zinc sulphate (1.0%) followed by soil application of zinc sulphate (1.0 kg tree¹) as compared with control and all other treatments. There was no significant (P<0.05) increase in yield, fruit size and weight, pulp or stone weight with any treatment of zinc sulphate. Total soluble solid (TSS) in the fruit was significantly higher (18.6%) with the treatment of soil application of zinc sulphate (0.5 kg tree¹) as compared with all other treatments of zinc sulphate and the control. Acid and sugar content of the fruit was not significantly affected by the foliar or soil application of zinc sulphate.     

Variability in Response to Zinc Application in 10 High-Yielding Wheat Varieties

A pot culture experiment was conducted to study the effect of zinc (Zn) on biofortification of 10 wheat (Triticum aestivum L.) varieties in the Zn-deficient soil of Lucknow. Treatments consisted of 0 and 20 mg Zn kg^?1 as a basal dose and 20 mg Zn kg^?1 basal dose with two foliar sprays of zinc sulfate (ZnSO₄) 0.5%. Foliar sprays of Zn were applied twice at the preflowering stage and 7 days after flowering. Results from the present study revealed that poor growth of plants grown in soil without Zn applications (0 mg Zn kg^?1) were improved by applications of Zn (20 mg Zn kg^?1) more when Zn was applied with two foliar sprays. Application of Zn (20 mg Zn kg^?1) with two foliar sprays also proved beneficial for maximizing Zn concentrations of grains and other plant parts. Wheat varieties NW 1076, K 3827, NW 2036, and UP 262 appeared highly responsive to the treatments.     

Assessment of ZN Interaction with Nutrient Cations in Alkaline Soil and its Effect on Plant Growth

An experiment was conducted to assess the zinc (Zn) availability to wheat in alkaline soils during Rabi 2009–2010. Wheat seedlings in pots having 2 kg alkaline sandy soil per pot were treated with 5, 10 and 15 kg Zn ha^?1 as soil and with 0.5 and 1.0% zinc sulfate (ZnSO₄) as foliar application. Results showed that Zn increasing levels in soil helped in phosphorus uptake up to boot stage but its conversion to grain portion lacked in Zn treated plants. Potassium (K) uptake also increased up to 6.24% in boot stage with treatment of 10 kg Zn ha^?1 + 1.0% ZnSO₄ foliar spray. Zinc (Zn) concentration increased in plant tissues with the increasing level of Zn application but this disturbed the phosphorus (P)-Zn interaction and, thus, both of the nutrients were found in lesser quantities in grains compared to the control. Despite of the apparent sufficient Zn level in soil (1.95 mg kg^?1), improvement in growth and yield parameters with Zn application indicate that the soil was Zn deplete in terms of plant available Zn. The above findings suggest that the figure Zn sufficiency in alkaline soil (1.0 mg kg^?1) should be revised in accordance to the nature and type of soils. Furthermore, foliar application of Zn up to 1.0% progressively increased yield but not significantly; and it was recommended that higher concentrations might be used to confirm foliar application of Zn as a successful strategy for increasing plant zinc levels.     

Nutrient Dynamics: Effect on Cropping Behavior,Nutrient Profile and Quality Attributes of Pomegranate (Punica Granatum L.) Under Rainfed Agroclimatic Conditions

The study was carried out between 2008 and 2010 on 8-year-old pomegranate (Punica granatum L.) trees cultivar ‘Kandhari Kabuli.’ The potential efficiency of bio-organics used along with chemical fertilizers on cropping behavior, quality attributes, nutrient availability, physico-chemical, and biological properties of soil were investigated. Bioorganic nutrient sources, namely, vermicompost (VC), biofertilizers (BF), farm yard manure (FYM), and green manure (GM), along with chemical fertilizers was evaluated in 13 different treatment combinations. Conjoint treatment application of VC at 20 kg tree^?1, BF at 80 g tree^?1, FYM at 20 kg tree^?1, GM as sun hemp (Crotalaria juncea L.) along with 75% of the recommended dose of nitrogen–phosphorus–potassium (N–P–K) chemical fertilizers significantly resulted in maximum fruit set (52.03%) and fruit yield (34.02 kg tree^?1). All of the fruit quality characteristics were also improved significantly when compared to nitrogen–phosphorus–potassium (N–P–K) chemical fertilizers. This superior combination also enhanced physical-chemical and biological properties of the rhizosphere soil. Microbial biomass of in terms of Pseudomonas, total culturable soil fungi, Azotobacter chroococcum, actinobacteria, and arbuscular mycorrhizal (AM) fungi improved 385.57, 60.26, 134.19, 168.02, and 39.87%, respectively, over control. This combination also resulted in considerable greater concentration of leaf macro-and micronutrients: N (2.63%), P (0.25%), K (1.57%), iron (Fe; 197.87 mg kg^?1), copper (Cu; 14.65 mg kg^?1), zinc (Zn; 59.36 mg kg^?1), and manganese (Mn; 200.45 mg kg^?1).     

MINERAL NUTRIENT CONTENT OF TOMATO PLANTS IN AQUAPONIC AND HYDROPONIC SYSTEMS: EFFECT OF FOLIAR APPLICATION OF SOME MACRO- AND MICRO-NUTRIENTS

Effects of foliar applications of some micro- and macro-nutrients on mineral nutrient content of tomato leaves and fruits were investigated in an aquaponic system in comparison with a hydroponic system. Fourteen days old tomatoes seedlings were transplanted on to growth bed of aquaponic and hydroponic systems. Foliar nutrients application began 30 days after transplantation. Eight treatments were used, untreated control and foliar application at the rate of 250 mL plant^?1 with 0.5 g L^?1 potassium sulfate (K₂SO₄), magnesium sulfate (MgSO₄ 7H₂O), ferrous (Fe)- ethylenediamine-N,N′-bis (EDDHA), manganese sulfate (MnSO₄ H₂O), boric acid (H₃BO₃), zinc chloride (ZnCl₂), and copper sulfate (CuSO₄ 5H₂O). Foliar application of potassium (K), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) increased their corresponding concentrations in the leaves of aquaponic-treated plants. On the other hand, foliar spray of K, Fe, Mn, Zn, and Cu caused a significant increment of applied element concentrations in the fruits of hydroponic-grown plants. These findings indicated that foliar application of some elements can effectively alleviate nutrient deficiencies in the leaves of tomatoes grown on aquaponics.     

MODULATION IN YIELD AND JUICE QUALITY CHARACTERISTICS OF CITRUS FRUIT FROM TREES SUPPLIED WITH ZINC AND POTASSIUM FOLIARLY

Citrus, especially K innow (Citrus deliciosa × Citrus nobilis), fruit yield and quality in Pakistan is not competitive with that of other countries which could be mainly attributed to the lack of good nutrient management for citrus orchards. The yield losses in this fruit crop occur mainly due to heavy fruit dropping. Experiments to overcome these problems were conducted at four different sites one each in Faisalabad, Toba Tek Singh, Jhang and Sargodha districts of Punjab, Pakistan. The soil and leaf chemical analysis showed severe deficiency of Zn and our pervious results have shown that soil amendment with potassium (K) at 75 K₂O kg ha^?1 improved the citrus fruit yield and quality at all selected sites. In the present experiments, effect of foliar application of Zn and K alone or in combination was studied on nutrient uptake, fruit yield, fruit dropping and juice quality. The fruit trees were pretreated with a selected K level of sulfate of potash (SOP) or muriate of potash (MOP), i.e., 75 kg K₂O ha^?1 along with recommended nitrogen (N) and phosphorus (P) doses. Zinc [Zn, 1% zinc sulfate (ZnSO₄) solution], K [1% potassium sulfate (K₂SO₄) solution] and Zn + K (solution containing 0.5% each of ZnSO₄ and K₂SO₄) were sprayed at the onset of spring and flush of leaves or flowers, fruit formation and at color initiation on fruit. Overall, application of Zn, K or Zn + K was effective in improving the nutrient uptake, yield and quality parameters of citrus fruit at all sites. Fruit dropping was also reduced by the foliar spray of Zn, K or Zn + K but the most promising results were recorded with foliar spray containing both Zn and K.     

Effects of Application of Boron on Growth,Yields, and Quality of Red Bayberry

ABSTRACT

Three field experiments at three sites in east Zhejiang Province were conducted to determine the influence of applications of boron (B) on growth, yield, and quality of the red bayberry trees (Myrica rubra Sieb. et Zuca) with a manure species of “Buqizhong” in Linhai city. Ground B application or foliar B spraying significantly improved length and incidence rates of spring and summer shoots and increased fruit set rates, which resulted in the increases in fruit yield (13.7–17.5% for ground B application or 13.2–27.3% for foliar B spraying) and in improvement of fruit quality. The optimum yields were recorded with the treatments of ground B application of 40 g tree^?1 of borax or foliar B spraying of 2.0 g L^?1 of borax. Spring shoot incidents for the treatment of ground application of 50 g borax tree^?1 every year during the experiment (4B₅₀) were significantly higher than that for the treatment of ground application of 50 g borax tree^?1 only in the first year of the experiment (B₅₀), but the yield difference between them was not significant at P = 0.05. The increased yield effect of ground B application could last for 3 years. Boron application of red bayberry trees can be carried out by foliar-spraying 2.0 g borax L^?1 every year or ground application of 50 g borax tree^?1 every 3 years. The results of this study showed that application B could significantly improve the growth and increased fruit yield and quality of the red bayberry trees not exhibiting any vegetative symptoms of B deficiency.     

Integrated Nutrient Management Affects Fruit Yield of Sapota (Achras zapota L.) and Nutrient Availability in a Vertisol

ABSTRACT

We studied the effect of integrated nutrient management (INM) combinations on supplement of plant nutrient for quantitative and qualitative fruit production in sapota. Thus, 17 combinations of INM practices were evaluated on fruit yield of sapota and nutrient availability in a Vertisol of Chambal region, India. The results demonstrated that almost all treatment combinations comprised of recommended dose of fertilizer (RDF), i.e. 1,000:500:500 g NPK plant^?1 with application of organic and inorganic sources of nutrients had a significant effect on the fruit yield of sapota, soil microbial biomass, NPK content of leaf, fruit and soil over control (T₁). Among different treatments, application of 2/3rd part of RDF + 50 kg FYM + 250 g Azospirillum + 250 g Azotobacter plant^?1 (T₁₁) significantly enhanced the number of fruits plant^?1 (327.88), yield plant^?1 (29.03 kg) and yield ha^?1 (4.52 t). However, the soil microbial count of fungi (8.89 cfu g^?1 soil), bacteria (11.19 cfu g^?1 soil) and actinomycetes (5.60 cfu g^?1 soil) at fruit harvest was higher under the 2/3 of RDF +10 kg vermicompost + 250 g Azospirillum + 250 g Azotobacter plant^?1 (T₁₅). The leaf nitrogen content (N, 2.03%) was higher in T_15, while phosphorus (P, 0.28%) and potassium (K, 1.80%) content were higher in T₁₁. It is evident that treatment T₁₁ increased fruit yield by 32% in Sapota cv. Kalipatti compared to control. Therefore, combined application of nutrient sources proved not only beneficial for enhancing fruit yield of sapota but also sustaining soil health in Chambal region of south-eastern Rajasthan.     

Agronomic biofortification of chickpea with zinc and iron through application of zinc and urea

ABSTRACT

Zinc (Zn) and iron (Fe) deficiency-related health problems in humans may be solved by improving their concentration in edible grains. The study, conducted in 2015–16 and 2016–17, investigated the effects of soil and foliar application of Zn and foliar application of urea on grain Zn and Fe accumulation of chickpea grains. Soil application of ZnSO₄ @ 25 kg ha^?1 + foliar spray of ZnSO₄ @ 0.5% at flowering and pod formation stages resulted in the highest Zn (45.06 & 44.69 mg Zn kg^?1 grain in the first and second year of study) and Fe (59.74 & 62.88 mg Fe kg^?1 grain) content. Urea application @ 2% at flowering and pod formation stages also resulted in the highest grain Zn (41.12 & 40.26 mg Zn kg^?1 grain) and Fe (58.95 & 61.95 mg Fe kg^?1 grain) content. Grain yield and protein content were significantly increased over control with these treatments. As compared to the sole application of Zn, the combined use of Zn and urea improved the grain Zn and Fe contents. Zinc and urea can be applied to improve Zn and Fe content in chickpea grains and, therefore, can help in ameliorating malnutrition in burgeoning human population.     

Yield,Uptake, and Retranslocation of Nutrients in Banana Plants Cultivated in Upland Soil of Central Amazonian

ABSTRACT

Banana cultivation is considered one of the most important agricultural activities of economic and social importance in Brazil. The objective of this work was to investigate the uptake, retranslocation and the effect of fertilization on the yield and uniformity of banana bunches (Musa spp.) cultivated in Central Amazonian, region with approximately 1.5 million km² or 150 million hectares. Two experiments were conducted in a Xanthic Ferralsol (dystrophic Yellow Latosol), the predominant soil of the region, examining: i) the nutrient uptake and translocation rate in twelve plants; and ii) the efficiency of zinc use, in a completely randomized blocks in a 4×2 factorial scheme in split plot design with four zinc sulfate (ZnSO₄) rates (0, 30, 60, and 120 g plant^?1 cycle^?1) and two application times (in the hole together with the seedling or as surface broadcast in the fifth month after planting), with four replicates. Uptake of macronutrients was in the order of potassium (K) > nitrogen (N) > calcium (Ca) > magnesium (Mg) > phosphorus (P) and micronutrients in the order of manganese (Mn) > iron (Fe) > boron (B) > zinc (Zn) > copper (Cu). The N, P, K, Mg, and Cu have a high retranslocation rate compared to other nutrients investigated. The bunch yield increased significantly in a quadratic fashion with increasing Zn rate and hole application method of zinc was more efficient compared to broadcast application. At high concentration, Zn presents a low mobility in the phloem from the leaves to the fruits. The critical leaf concentration of zinc at the start of inflorescence was 12.9 mg kg^?1.     

Nutrient Indexing in “‘Kinnow” Mandarin (Citrus deliciosia Lour.× Citrus nobilis Tanaka) Grown in Indogangetic Plains

Diagnosis and remediation of nutrient constraints in perennial fruit crop like citrus are the two important pillars of an effective nutrient management program. Efforts were made to develop nutrient indexing (NI) criteria based on generated leaf and soil analysis dataset for “Kinnow” mandarin (Citrus deliciosia Lour. × Citrus nobilis Tanaka) grown on illitic soils of Indogangetic plains (Entisol, Inceptisol, and Aridisol). NI through diagnosis and recommendation integrated system (DRIS) using leaf analysis data showed optimum value of leaf nutrient concentration as 2.22–2.32% nitrogen (N), 0.11–0.15% phosphorus (P), 1.10–1.41% potassium (K), 2.32–2.79% calcium (Ca), 0.38–0.61% magnesium (Mg), 22.4–58.3 ppm iron (Fe), 26.3–56.2 ppm manganese (Mn), 4.2–7.2 ppm copper (Cu), and 21.3–26.9 ppm zinc (Zn) vis-à-vis a fruit yield of 32.4–56.1 kg tree^?1. Using these NI criteria, Zn was observed as most deficient (64.7%) followed by Fe (61.5%), Mn (57.6%), N (96.1%), and P (38.5%) using percentage of orchards as basis. While, optimum NI (mg kg^?1) using soil analysis data was determined as 114.3–121.2 potassium permanganate (KMnO₄-N), 7.8–12.3 Olsen-P, 96.4–131.3 ammonium acetate (NH₄OAc)-K, 189.4–248.6 NH₄OAc-Ca, 72.3–89.9 NH₄OAc-Mg, 5.8–11.1, DTPA-Fe, 4.3–6.9 diethylenetriaminepentaacetic acid (DTPA)-Mn, 0.45–0.69 DTPA-Cu, and 21.3–26.9 DTPA-Zn for the optimum yield of 32.4–56.1 kg tree^?1. Soil analysis-based NIs displayed a good complementary with leaf analysis-based NIs evident from the diagnoses indicating Mn (52.2%) as most dominant constraint Zn (61.2%) followed by Mn (48.3%), N (41.2%), and P (35.6%). The recommended DRIS-based NIs would lay a scientific basis in formulating citrus fertilization program.     

RESPONSE OF ‘GRANNY SMITH’ APPLE TREES TO FOLIAR TITANIUM SPRAYS UNDER CONDITIONS OF LOW SOIL AVAILABILITY OF IRON,MANGANESE, AND ZINC

The aim of the study was to examine impact of foliar titanium (Ti) sprays on vegetative and reproductive response of apple (Malus domestica Borkh.) trees under conditions of low soil availability of iron (Fe), manganese (Mn), and zinc (Zn). The experiment was conducted during 2005–2006 at a Experimental Station in Isparta region, Turkey, on mature ‘Granny Smith’ apple trees/M.9, planted at a spacing of 3.5 × 1.5 m, on fine-textured soil with neutral reaction, medium status of organic matter, high amounts of available phosphorus (P), potassium (K), and magnesium (Mg), and low availability of Fe, Mn, and Zn. The trees were sprayed with Ti-ascorbate at the green and pink bud stage, petal fall, and 3, 6, and 9 weeks after full bloom, at a rate of 3 g Ti ha^?1 per spray. The efficiency of Ti sprays was compared to combined sprays of Fe, Mn, and Zn [chelated with ethylenediaminetetraacetic acid (EDTA)], applied at the same terms as Ti sprays, at rate of 36 g, 36 g and 24 g per spray, respectively. Trees unsprayed with Ti, Fe, Mn, and Zn served as the control. It was shown that summer leaf Ti concentrations of the trees untreated with Ti were high, varying from 34 to 36 mg kg^?1 dry matter. Foliar Ti sprays increased leaf status of this nutrient but they had no effect on nutrition of essential macro- and microelements, tree vigor, and fruit yield. Mean apple weight, coloring, firmness, soluble solids concentration, and titratable acidity of fruit were not also influenced by Ti sprays. Foliar sprays of Fe, Mn, and Zn improved leaf status of nitrogen (N), Mg, Fe, Mn, and Zn; leaves of the trees sprayed with those micronutrients were also greener, and contained more Fe²⁺ than those of the control plants. Combined sprays of Fe, Mn, and Zn improved tree vigor and fruit yield.     

Response of nectarines to organic fertilization under the rain-fed ecosystem of Northwest Himalayas

The comparative efficacy of organic sources on cropping behavior, nutrient dynamics, physico-chemical and biological properties of soil and fruit quality under rain-fed agroecosystem on “Silver King” nectarines was investigated. Bio-organic nutrients, namely vermi-compost (VC), biofertilizer (BF), farmyard manure (FYM), compost (comp), vermiwash (VW) and cow urine (CU) were evaluated in 11 different treatment combinations. The treatment application of VC at 25 kg tree^?1, BF at 40 g tree^?1, FYM at 30 kg tree^?1, comp at 15 kg tree^?1, VW_1:10 and CU_1:10 significantly improved plant growth and fruit quality characteristics of nectarine trees. This superior combination also enhanced physico-chemical and biological properties of the rhizosphere soil when compared to control as conventional chemical fertilizer application nitrogen, phosphorus and potassium (NPK) fertilizers. Different treatments of bio-organic sources changed pH of the soil to neutral. Available macronutrient contents of soil (viz. N, P, and K) increased by 57.8%, 27.7%, and 16.4%, respectively. Microbial biomass of soil fungi, total bacteria, actinobacteria, and arbuscular mycorrhizal fungi improved 66.0%, 73.8%, 133.3% and 350.0%, respectively, over control. Considerably, a higher amount of leaf macronutrients, N (3.53%), P (0.23%), and K (3.2%), was also recorded over control.     

Effect of different foliar zinc application at different growth stages on seed zinc concentration and its impact on seedling vigor in rice

This study evaluated how zinc (Zn) concentration of rice (Oryza sativa L.) seed may be increased and subsequent seedling growth improved by foliar Zn application. Eight foliar Zn treatments of 0.5% zinc sulfate (ZnSO₄?·?7H₂O) were applied to the rice plant at different growth stages. The resulting seeds were germinated to evaluate effects of seed Zn on seedling growth. Foliar Zn increased paddy Zn concentration only when applied after flowering, with larger increases when applications were repeated. The largest increases of up to ten-fold were in the husk, and smaller increases in brown rice Zn. In the first few days of germination, seedlings from seeds with 42 to 67?mg Zn?kg^?1 had longer roots and coleoptiles than those from seeds with 18?mg Zn?kg^?1, but this effect disappeared later. The benefit of high seed Zn in seedling growth is also indicated by a positive correlation between Zn concentration in germinating seeds and the combined roots and shoot dry weight (r?=?0.55, p?相似文献   

Nutritional Evaluation of Nitrogen and Potassium Fertilization of Carob Tree under Dry‐Farming Conditions

Abstract

The aim of this work was to assess how potassium (K) and nitrogen (N) fertilization might affect the variation of leaf and fruit nutrient concentrations in carob tree (Ceratonia siliqua L.) under low precipitation. A field study was conducted in 1997, 1998, and 1999 in a calcareous soil. Four fertilization treatments were tested: no fertilizer (C), 0.8 kg N tree^?1 (N treatment), 0.83 kg K tree^?1 (K treatment), and 0.80 kg N tree^?1 plus 0.83 kg K tree^?1 (NK treatment). During the hydrological cycle 1998/1999, only 250 mm of rain were recorded. Because of this, from 1998 to 1999 a decrease in the concentrations of mobile nutrients N, phosphorus (P), and K and an increase in calcium (Ca), iron (Fe), and manganese (Mn) were observed in leaves. The application of N led to higher leaf N concentration compared with other treatments. This response allowed the establishment of a linear model that relates soil plant analysis development (SPAD) readings with leaf N concentrations (r²=0.55; P<0.05). Compared with leaves, fruits showed similar amounts of N and P; less Ca, Mg, Fe, and Mn; and high concentrations of K. Fertilization did not change considerably the mineral composition of fruits, and because of large variation among trees, yield was similar for all treatments.     

Effect of Drip Boron Fertigation on Yield and Fruit Quality in a High-Density Apple Orchard

ABSTRACT

This study was carried out in 2001–2003 at the Experimental Orchard of the Research Institute of Pomology and Floriculture, Skierniewice, Poland, on mature ‘Jonagold’ apple (Malus domestica Borkh.) trees (M.26 EMLA) planted at 4 × 2.5 m spacing on a sandy loam soil with low boron (B) availability. The trees were drip fertigated with B at rates of 0.5, 1, or 1.5 g tree^{? 1} over 4 weeks at 3-d intervals beginning at the stage of bud break. Plants that did not receive B via drip irrigation system served as a control. Drip B fertigation effectively increased water-soluble B concentrations in the soil and the status of this microelement in leaves of current season shoots. However, the B fertigation had no effect on tree vigor. In 2 out of 3 years, the drip B fertigation improved flower B status, fruit set, and yield. The efficiency of the drip B fertigation was not influenced by B rate. In all growing seasons, the drip B fertigation increased B level and a soluble solids concentration in the fruit flesh, but had no effect on mean fruit weight, color, titratable acidity, and fruit firmness. It was concluded that on coarse-textured soils with low B availability, the drip B fertigation of mature apple trees in high-density orchards can be recommended from the stage of bud burst to petal fall at a rate of 0.5 g tree^{? 1}.     

Growth,Mineral Composition,and Biochemical Changes of Broad Bean as Affected by Sodium Chloride and Zinc Levels and Sources

Plants grown in salt‐affected soils may suffer from limited available water, ion toxicity, and essential plant nutrient deficiency, leading to reduced growth. The present experiment was initiated to evaluate how salinity and soil zinc (Zn) fertilization would affects growth and chemical and biochemical composition of broad bean grown in a calcareous soil low in available Zn. The broad bean was subjected to five sodium chloride (NaCl) levels (0, 10, 20, 30, and 40 m mol kg^?1 soil) and three Zn rates [0, 5, and 10 mg kg^?1 as Zn sulfate (ZnSO₄) or Zn ethylenediaminetetraaceticacid (EDTA)] under greenhouse conditions. The experiment was arranged in a factorial manner in a completely randomized design with three replications. Sodium chloride significantly decreased shoot dry weight, leaf area, and chlorophyll concentration, whereas Zn treatment strongly increased these plant growth parameters. The suppressing effect of soil salinity on the shoot dry weight and leaf area were alleviated by soil Zn fertilization, but the stimulating effect became less pronounced at higher NaCl levels. Moreover, rice seedlings treated with ZnSO₄ produced more shoot dry weight and had greater leaf area and chlorophyll concentration than those treated with Zn EDTA. In the present study, plant chloride and sodium accumulations were significantly increased and those of potassium (K), calcium (Ca), and magnesium (Mg) strongly decreased as NaCl concentrations in the soil were increased. Moreover, changes in rice shoot Cl^?, Na⁺, and K⁺ concentrations were primarily affected by the changes in NaCl rate and to a lesser degree were related to Zn levels. The concentrations of Cl^? and Na⁺ associated with 50% shoot growth suppression were greater with Zn‐treated plants than untreated ones, suggesting that Zn fertilization might increase the plant tolerance to high Cl^? and Na⁺ accumulations in rice shoot. Zinc application markedly increased Zn concentration of broad bean shoots, whereas plants grown on NaCl‐treated soil contained significantly less Zn than those grown on NaCl‐untreated soil. Our study showed a consistent increase in praline content and a significant decrease in reducing sugar concentration with increasing salinity and Zn rates. However, Zn‐treated broad bean contained less proline and reducing sugars than Zn‐untreated plants, and the depressing impact of applied Zn as Zn EDTA on reducing sugar concentration was greater than that of ZnSO₄. In conclusion, it appears that when broad bean is to be grown in salt‐affected soils, it is highly advisable to supply plants with adequate available Zn.