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1.
Plants require nutrients including nitrogen (N), phosphorus (P), and potassium (K) for their growth and production. Although there have been previously extensive research work regarding the effects of NPK on plant growth, data related to the effects of long term application of NPK on the quality and quantity of citrus under rainfed and irrigated conditions are little. Accordingly, such effects were evaluated in this research work using different chemical fertilization factorially combined and on the basis of a completely randomized block design. Using ammonium sulfate (100, 150 and 200 g tree ? 1), triple super phosphate (0, 25, 50, and 75 g tree?1) and potassium sulfate (0, 50, 100, 150 g tree ? 1) the quantity and quality of citrus fruit, variety Thomson were determined in a 10-year experiment in two different research stations in Ramsar, Iran. NPK fertilization significantly affected the quality and quantity of citrus fruits, indicating the significance of NPK fertilization for citrus production.  相似文献   

2.
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.  相似文献   

3.
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.  相似文献   

4.
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–T3. On the other hand, foliar applied Zn treatments (T4–T6) produced no such changes in any of the soil Zn fractions.  相似文献   

5.
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).  相似文献   

6.
The purpose of this study was to determine optimum rates of soil dressing with nitrogen (N) and potassium (K) fertilization in the cultivation of potato with purple–blue peel and flesh, affecting the qualitative composition of tubers of a less known potato cultivar called Blue Congo.

The experimental results proved that the optimum rates of fertilizers applied to soil for the cultivar Blue Congo are 80 kg N ha?1 and 150 kg K ha?1. Application of 120 kg N ha?1 caused a decrease in the content of all macro- and micro-nutrients. In contrast, the content of all macronutrients was observed to increase up to the rate of 150 kg K ha?1.

Micronutrients responded to the increase in the K rate in different ways. No effect of the differentiated rates of K was noted in the case of iron. Vitamin C responded by its lower content to the increased rates of both N and K. It was determined that isoleucine was the limiting amino acid for the cv. Blue Congo potato. The highest level of isoleucine was found at the N rate of 80 kg ha?1.  相似文献   

7.
With respect to the important effects of nitrogen (N) on plant growth and fruit production, a five-year experiment was performed to evaluate the effects of different sources of N fertilization including chemical and organic on the quantity and quality of citrus fruit. Using five-year old trees, different types of fertilization including ammonium sulfate, urea coated with sulfur, ammonium nitrate and manure were tested using seven treatments in five replicates from 2002 to 2007. Different plant quantitative and qualitative parameters were determined. The most effective strategy on fruit yield production was the use of urea coated with sulfur and manure with 92.46 kg ha?1 fruit yield followed by ammonium sulfate and manure (87.06 kg ha?1) and ammonium sulfate (86.43 kg ha?1). The combination of mineral and organic fertilization may be the most suitable fertilization strategy for citrus production.  相似文献   

8.
《Journal of plant nutrition》2013,36(4-5):767-778
The effect of nitrogen (N), phosphorus (P), potassium (K) and lime additions to container-grown Schlumbergera x buckleyi were examined in two experiments. In each case rooted cuttings were grown in peat/perlite (1:1, v/v), with three plants per pot, for 17 months in a heated greenhouse. Foliage growth and flowering were strongly enhanced by added N and fertilization of between 1800 and 2200 g N m? 3 (105–130 g N m? 3 per month) and a foliar N content of 3.4–4.2% were recommended. Flowering was delayed by high N but promoted by added P. Added P also strongly influenced foliage growth and flowering but at lower rates than that for N fertilization. Recommended P rates were between 650 and 850 g P m? 3 (40–50 g P m? 3 per month) and a foliar P content of 1.3–1.5%. This species appeared tolerant of a wide range of pH levels, with a range of lime rates having no significant effect. A foliar calcium (Ca) content of 0.7% to 0.9% was suggested with a recommended media pH of 5.5–6.5. High K strongly influenced the production of stem segments and flowering in a small experiment and fertilization of 1500–2000 g K m? 3 (90–120 g K m? 3 per month) and a foliar content of 1.8–2.6% K were tentatively recommended.  相似文献   

9.
Citrus, especially Kinnow, fruit yield and quality in Pakistan is not competitive with other countries, which could be mainly attributed to a lack of good nutrient management for citrus orchards. Many of the soils under these orchards have been reported as deficient in potassium (K). Therefore, work was initiated for improving citrus fruit yield, size, and quality through K nutrition management. Experiments were conducted in four districts of Punjab including Faisalabad, Toba Tek Singh, Jhang, and Sargodha and four rates of potash, i.e., 0, 50, 75 and 100 kg dipotassium oxide (K2O) ha?1 were applied using sulfate of potash (SOP) along with recommended rates of phosphorus (P) and nitrogen (N). Soils of all the selected sites were clay loam or sandy clay loam and deficient in K. The leaf analysis also showed that all the selected orchards were deficient in K. Application of K increased the fruit yield and quality but K at100 kg K2O ha?1 was more effective in increasing the fruit weight and size, and peel thickness than other K rates in all the selected orchards. Juice volume and percentage significantly increased when K was applied at 75 kg K2O ha?1 at all sites. Nutrient uptake like K, P, and N enhanced with the increase in K application rate, however, the highest calcium (Ca)+ magnesium (Mg) was recorded at 50 kg K2O ha?1. The results indicated that all rates of K application improved the fruit yield and quality and reduced fruit dropping, however, 75 kg K2O ha?1 rate was more effective as juice volume and percentage, total soluble solid (TSS)/acid ratio and nutrient uptake showed significant improvement.  相似文献   

10.
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.  相似文献   

11.
ABSTRACT

The effectiveness of nitrogen (N)+ zinc (Zn) soil and foliar fertilizer applications on growth, yield, and quality of apple (Malus domestic Borkh ‘Golden Delicious’) fruit was studied in the Zanjan province, Iran. There were eight treatments 1) control (no fertilizer), 2) soil applied N, 3) soil applied Zn, 4) soil applied N+Zn, 5) foliar applied N, 6) foliar applied Zn, 7) foliar applied N+Zn and 8) combined soil and foliar applied N+Zn. The N source was urea [CO(NH2)2, 46% N] applied at 276 N tree? 1 yr?1 and the Zn source was zinc sulfate (ZnSO4,7H20, 23% Zn) applied at 110 g Zn tree? 1 yr? 1. The soil treatments of N and Zn, were applied every two weeks during June through August (total of 6 times/year) in a 1 m radius around the tree trunk (drip line of trees). The foliar solutions of N (10 g l? 1 urea) and Zn [8 g l? 1 zinc sulfate (ZnSO4)] were sprayed at the rate of 10 L tree? 1 every two weeks at the same times as described for soil applications. The highest yield (49 kg tree? 1), and the heaviest fruits (202 g) were obtained in the soil and foliar combination of N+Zn treatment. The lowest yield (35 kg tree? 1), and the smallest fruits (175 g) were recorded in the control. Nitrogen, and to a lesser extent Zn, foliar application resulted in decreasing fruit quality (caused russeting, and lower soluble solid), but increasing N leaf and fruit concentrations (2.4% DW and 563 mg kg? 1, respectively). There were significant differences among yield and leaf mineral nutrient concentration in different treatments. But there was no significant difference between fruit mineral nutrient concentration (except N). Ratio of N/calcium (Ca), potassium (K)/Ca, and [magnesium (Mg)+K]/Ca in fruits were found suitable for fruit quality prediction. Combining the zinc sulfate with urea in the foliar applications increased the concentration of Zn from 0.7 to 1.5 mg per kg of apple tissue. Leaf N concentration varied during growth season. Foliar applied nutrient can be more efficient than soil applied, but a combination of soil and foliar applications is recommended for apple tree nutrient management.  相似文献   

12.
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, VW1:10 and CU1:10 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.  相似文献   

13.
ABSTRACT

Diagnosis and recommendation integrated system (DRIS) norms were computed from the data on leaf mineral composition, soil available nutrients, and corresponding mean fruit yield of three years (1999–2002), collected from the set of 57 irrigated commercial ‘Nagpur’ mandarin (budded on Citrus jambhiri Lush) orchards, representing 26 locations and 3 basalt derived soil orders (Entisols, Inceptisols, and Vertisols) rich in smectite minerals. The DRIS norms derived primarily from spring-cycle index leaves from non-fruiting terminals sampled during August to October (6–8 months old) suggested optimum leaf macronutrient concentration (%) as: 1.70–2.81 nitrogen (N), 0.09–0.15 phosphorus (P), 1.02–2.59 potassium (K), 1.80–3.28 calcium (Ca), and 0.43–0.92 magnesium (Mg). While, optimum level of micronutrients (ppm) was determined as: 74.9–113.4 iron (Fe), 54.8–84.6 manganese (Mn), 9.8–17.6 copper (Cu), and 13.6–29.6 zinc (Zn) in relation to fruit yield of 47.7–117.2 kg tree? 1. Likewise, DRIS indices for soil fertility developed from dripline soil samples collected at 0–20 cm depth corresponding to similar level of fruit yield, the optimum limit of soil available nutrients (mg kg? 1) was observed as: 94.8–154.8 N, 6.6–15.9 P, 146.6–311.9 K, 401.0–601.6 Ca, 85.2–369.6 Mg, 10.9–25.2 Fe, 7.5–23.2 Mn, 2.5–5.1 Cu, and 0.59–1.26 Zn. Primary DRIS indices developed on the basis of leaf and soil analysis revealed deficiency of N, P, K, Fe, and Zn. The nutrient constraints so diagnosed were further verified through fertilizer response studies carried out on a representative Typic Haplustert soil type facing multiple nutrient deficiencies, and accordingly suggested the revised fertilizer schedule.  相似文献   

14.
A long-term field experiment (1998 to 2010) investigated the effects of vermicompost (VC) and chemical fertilizers (CF) application alone or in combination on biomass partitioning, nutrient uptake and productivity of arecanut. Trunk biomass (kg palm?1) was significantly higher with integrated treatments (40.8–43.0) than control (23.9). Biomass partitioning to kernel varied between 4.6% in control to 7.7% in CF 100 and 200% nitrogen (N)- phosphorus (P)- potassium (K). The leaf P and K content varied significantly among treatments. The N immobilized in trunk (g palm?1) was significantly higher in integrated treatments (119-127) than in control (93). Phosphorus and K uptake by trunk followed same trend. The leaf K uptake and total K removed were found significant. The nutrition treatments registered significantly higher kernel yield (2508–3176 kg ha?1) than control (1721 kg ha?1). The increased yield of arecanut from chemical fertilizers (73–85%) was more pronounced when compared to VC (48–59%) and integrated treatments (46–63%) over control.  相似文献   

15.
For 7 years (1997–2003), five nitrogen (N) rates (0, 60, 120, 180, and 240 kg N ha?1) were applied to sugar beets arranged in randomized complete block (RCB) design experiments with six replications and grown on light soils (sand content >50 g kg?1) in northern Greece. The aim of this work was to identify soil characteristics that affect yield, quality, and sugar beet response to N fertilization. Before sowing, soil analyses were conducted in control plots (0 kg N ha?1) at two depths (0–30 and 30–60 cm). Soils differed in their physical and chemical properties and especially in sand content, which ranged from 500 to 732 g kg?1. Quantitative (root number, RN; root yield, RY; and sugar yield, SY) and qualitative (percentage sucrose content in fresh root weight, SC; potassium, K; sodium, Na; and α-amino N) traits of control plots were used as soil fertility index. The RN was positively affected by clay content, and RY and SY were positively related with sand and negatively with silt content. The SC was negatively affected by soil (NO3)-N and sodium (Na) concentrations. Also, soil (NO3)-N concentration was positively related with root impurities (K, Na, α-amino N). In combined data over years, N rates had a negative effect on the RN. The RY was the only trait affected by years, N rates, and their interaction. The SC and SY differed significantly between years, and N rates affected significantly the former but not the latter. In combined data over years, N rates were curvilinearly related with Na concentration in roots, whereas a strong, linear relationship was found between α-amino N concentration and N rates. To study the significant years × N rates interaction evidenced for the RY, the relative response (RR) of the RY to N was introduced. Actually, the RR expresses the increase or decrease of the RY for a 150 kg N ha?1 rate compared to the control (0 kg N ha?1). The RR was strongly related with soil K concentration at the 0- to 30-cm depth (y = –0.00002x2 + 0.0082x + 0.5085, r2 = 0.92, P < 0.01, n = 7) and with total N concentration at the deeper layer (y = 1.8335x2 – 3.5312x + 2.6614, r2 = 0.88, P < 0.05, n = 6). Thus, the RY response to a rate of 150 kg N ha?1, which is the commonly applied to the sugar beet crop in Greece, can be predicted reliably by soil characteristics (K and total N concentration) determined before sowing. The strong relationship between soil K concentration and sugar beet response to N merits further research.  相似文献   

16.
Yield, dry matter production, nitrogen (N) uptake and nitrogen use efficiency (NUE) of Bangladesh Rice Research Institute (BRRI) dhan29 were investigated during two consecutive dry (Boro) seasons of 2009–10 and 2010–11. The experiments were set up in a randomized complete block design with three replication having six nitrogen (N) levels of 0, 40, 80 120, 160 and 200 kg ha?1. Nitrogen fertilization increased yield characters, dry matter production and N uptake. The economic optimum rate of N was 166 and 155 kg ha–1 in first and second year, respectively, with corresponding yield of 7.1 and 6.5 t ha?1. NUEs were higher in the first year, decreased with increasing N rates in most cases. Gross return over fertilizer reached the highest Tk 692 in 2009–10 and Tk 489 in 2010–11 with 160 kg N ha–1. The results suggest that BRRI dhan29 should receive an average of 160 kg N ha?1 for economic optimum yield.  相似文献   

17.
Compositional Nutrient Diagnosis technique involves a yield target for discriminating between high- and low-yield subpopulations when developing norms. Traditionally, this yield value is estimated by finding the inflection point of the cumulative variance ratio function versus yield relationship through a third-order equation. However, yield targets frequently lie outside of the experimental yield range. A comparison among traditional (unrestricted) and restricted cubic model, and restricted and unrestricted Boltzmann equations was performed using a database (n = 360) of fresh matter yield and nutrient concentrations in one–year old cladodes of Opuntia ficus-indica L. The unrestricted Boltzmann equation resulted to have the best goodness-of-fit. The yield target was 27.01 kg plant?1 associated to the unrestricted Boltzmann equation for phosphorus cumulative variance ratio function versus yield relationship. Proposed nutrient optimum concentrations are: 11.4 g kg?1 for nitrogen (N), 3.4 g kg?1 for phosphorus (P), 42.3 g kg?1 for potassium (K), 42.5 g kg?1 for calcium (Ca), and 16.2 g kg?1 for magnesium (Mg).  相似文献   

18.
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.  相似文献   

19.
A two-year field study was conducted to determine the effect of two zinc (Zn) levels [0 and 10 kg zinc sulfate (ZnSO4) ha?1] in respect with four potassium (K) levels (0, 20, 40 and 60 kg K2O ha?1) on growth, yield and quality of forage sorghum. The soil of the experimental field was loamy sand (Inceptisol), carrying 70, 08, 77, and 0.51 mg nitrogen (N), phosphorus (P), K, and Zn kg?1 soil, respectively. Increasing K levels significantly improved most of the growth, yield, and quality attributes gradually irrespective of the Zn levels. Zinc applied at 10 kg ZnSO4 ha?1 proved significantly better than no zinc application at various K application rates. The benefit of zinc application increased progressively with increasing K rates for most of the parameters studied, indicating significant response of the crop to positive K × Zn interaction in plants in respect with K and Zn application to the soil. Accordingly, 60 kg K2O ha?1 applied with10 kg ZnSO4 ha?1 boosted most of the attributes maximally. It resulted in about 20–40% increase in growth attributes, 25% increase in fresh matter yield, 36–38% increase in dry matter yield, and 38% increase in protein yield compared to the comparable K level applied without zinc. It also enhanced N uptake by 38%, P uptake by 5–19%, K uptake by 40–42%, and Zn uptake by 114–144%. Across the K rates, application of 10 kg ZnSO4 surpassed no zinc application by 30–35% in N uptake, by 8–15% in P uptake, by 33–36% in K uptake, by 120–140% in Zn uptake, by 19–21% in fresh matter yield, by 29–31% in dry matter yield, and by 30–34% in protein yield.  相似文献   

20.
A two-year experiment was conducted in an iron(Fe)-deficient orchard with calcareous soil to find out an alternate method for soil application of Fe ethylenediamine-N,N'-bis(2-hydroxyphenylacetic acid) (Fe-EDDHA) in orange trees. Foliar sprays of Fe-EDDHA (5 g l?1, pH = 7.8), sulfuric acid (pH = 3), citric acid (5 g l?1, pH = 2.4), Fe (II) sulfate solutions (250, 500, and 750 mg Fe l?1) with their initial pH (6.5, 6.35, and 6.12) and reduced ones to pH of 3 were compared with soil applied (75 g tree?1) Fe-EDDHA and a control test. Although optimum chlorophyll content, leaf Fe concentration, fruit quantitative and qualitative attributes were resulted from soil application of Fe-EDDHA, repeated sprays of Fe-EDDHA or acidified Fe solutions created suitable results. Acidification of Fe solutions made them more effective in alleviation of leaf Fe concentration and Fe chlorosis, probably due to remobilization of inactive Fe within the plant and prevention of Fe oxidation and precipitation in foliar solutions.  相似文献   

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