IMPROVEMENT IN YIELD AND QUALITY OF KINNOW (CITRUS DELICIOSA X CITRUS NOBILIS) BY POTASSIUM FERTILIZATION

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.     

Influence of Foliar and Ground Fertilization on Yield,Fruit Quality,and Soil,Leaf, and Fruit Mineral Nutrients in Apple

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.     

Response of tomato to polyhalite as a multi-nutrient fertilizer in southeast Brazil

Abstract

Limited information on the agronomic performance of polyhalite (K₂SO₄.MgSO₄.2CaSO₄.2H₂O) motivated us to establish two field trials in Sao Paulo, Brazil. The objective was to evaluate the comparative responses of tomato to muriate of potash (MOP), sulfate of potash, potassium magnesium sulfate, and polyhalite at different graded doses of potassium (K) application supplying varied amount of secondary nutrients. Under very low soil K conditions, polyhalite resulted in significantly higher marketable fruit yield, and higher foliar and fruit K and sulfur (S) concentrations than other K sources. This was not the case under medium soil K levels, that is, 101?mg?kg^?1. Likewise, polyhalite enhanced postharvest residual soil calcium (Ca), magnesium (Mg), and S than other evaluated sources. Depending on soil nutrient status and the cost of polyhalite, tomato farmers of Brazil could consider polyhalite as an option to meet crop K and secondary nutrient requirements.     

EFFECT OF ZINC NUTRITION ON GROWTH,YIELD, AND QUALITY OF FORAGE SORGHUM IN RESPECT WITH INCREASING POTASSIUM APPLICATION RATES

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.     

Combined Application of Boron and Zinc Influence the Leaf Mineral Status,Growth, Productivity and Fruit Quality of ‘Kinnow’ Mandarin (Citrus nobilis Lour × Citrus deliciosa Tenora)

The deficiency of mineral nutrients, particularly of boron (B) and zinc (Zn) in many citrus orchards of Pakistan affect yield and quality. Effect of foliar application of B and Zn on leaf mineral nutrients, growth, productivity, and quality of ‘Kinnow’ were studied. Trees were sprayed with 37 mM boric acid and 49 mM zinc sulfate either alone or in combination at fruit setting stage or fruit setting and pre-mature stages. Leaf phosphorus (P), potassium (K), B, and Zn were significantly increased with treatments. Lowest fruit drop and maximum fruit weight and number, highest level of ascorbic acid, and reducing sugars were recorded in the trees sprayed with combine application of B and Zn at fruit set stage. In conclusion, combined application of B and Zn at fruit setting stage can be used effectively to increase nutrient uptake, reduce fruit drop, and increase yield with better quality of ‘Kinnow’ mandarin fruit.     

POTATO TUBER YIELD AND QUALITY AS AFFECTED BY RATES AND SOURCES OF POTASSIUM FERTILIZER

Among the major nutrients, potassium (K) not only improves yields but also improves quality parameters. Field experiments were conducted to assess the comparative effect of sources and rates of K fertilizer on potato yield and quality on a sandy loam soil. Graded doses of potassium, i.e., 0, 150 and 225 kg ha^?1 K₂O from sulfate and muriate of potash were applied in triplicate. Recommended dose of nitrogen (N) and phosphorus (P) applied uniformly. Significant increase in tuber yield was observed with 150 kg ha^?1 K₂O from both the sources over control. Increase in tuber yield with 225 kg ha^?1 K₂O was statistically non significant compared to 150 kg ha^?1. The dry matter and specific gravity were more affected with sulfate of potash (SOP) than muriate of potash (MOP). The quality parameters like dry matter, specific gravity, starch contents, vitamin C, chips color and taste were improved with K application.     

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.     

FOLIAR APPLICATION OF ZINC INFLUENCES THE LEAF MINERAL STATUS,VEGETATIVE AND REPRODUCTIVE GROWTH,YIELD AND FRUIT QUALITY OF ‘KINNOW’ MANDARIN

Deficiency of zinc (Zn) is widespread in many citrus orchards of Pakistan, consequently hampering fruit yield. Effects of foliar applications of zinc sulfate on tree nutrition, growth, productivity and fruit quality were studied on ‘Kinnow’ mandarin. Leaf nitrogen (N), calcium (Ca), and manganese (Mn) were highest for trees sprayed with 0.2% zinc sulfate, while phosphorus (P) and iron (Fe) were highest with 0.6% zinc sulfate and potassium (K) and Zn were highest with 0.8% Zn sulfate applications. Trees sprayed with 0.6% zinc sulfate exhibited highest increase in height, crown width and stem girth, fruit diameter, fruit weight, ascorbic acid contents, and total phenolics compared to all other treatments. Pre-harvest fruit drop was lowest and total number and weight of fruit per tree was highest at harvest with 0.4% zinc sulfate application. In conclusion, foliar application of zinc sulfate up to 0.6% improved tree mineral nutrients, growth, and productivity with better fruit quality in ‘Kinnow’ mandarin.     

Response of Wheat Plants to Zinc,Iron, and Manganese Applications and Uptake and Concentration of Zinc,Iron, and Manganese in Wheat Grains

This experiment was conducted at Zahak Agricultural Research Station in the Sistan region in southeast Iran. A factorial design with three replications was used to determine the effects of zinc (Zn), iron (Fe), and manganese (Mn) applications on wheat yield, Zn, Fe, and Mn uptakes and concentrations in grains. Four levels of Zn [soil applications of 0, 40, and 80 kg ha^?1 and foliar application of 0.5% zinc sulfate (ZnSO₄) solution], two levels of iron sulfate (FeSO₄; 0 and 1%) as foliar application, and two levels of Mn (0 and 0.5%) also as foliar application were used in this study. Results showed that the interactive effects of Zn and Mn were significant on the number of grains in each spike. The highest number of grains resulted from the application of 80 kg ZnSO₄ ha^?1 and foliar Mn. The interactive effects of Zn and Fe were significant on weight of 1000 grains. The highest weight of 1000 grains resulted from application of 80 kg Zn and foliar Fe. Application of 80 kg ZnSO₄ ha^?1 alone and 80 kg ZnSO₄ ha^?1 with foliar application of Mn significantly increased grain yield in 2003. The 2‐year results showed that foliar application of Zn increased Zn concentration and Fe concentration in grains 99% and 8%, respectively. Foliar application of Fe resulted in a 21% increase in Fe concentration and a 13% increase in Zn concentration in grains. The foliar application of Mn resulted in a 7% increased in Mn concentration in grains.     

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.     

Treatment of Pistachio Trees with Zinc and Copper in Time of Swollen Bud in Two Consecutive Years

This study was done to investigate the effects of foliar sprays of zinc (Zn) and copper (Cu) on fruit set, yield, yield components, vegetative growth, and leaf nutrient concentrations of pistachio trees (cv. Owhadi), over two consecutive seasons 2010 (ON) and 2011 (OFF). Tests were done at a commercial orchard in the region of Rafsanjan in Iran. Tests were designed as a 3 × 2 factorial experiment in a randomized complete block with four replications. Treatments tested in the study were three concentration levels of zinc sulfate (0, 1000, and 2000 mg L^?1) and two concentration levels of copper sulfate (0 and 200 mg L^?1). Results showed that Zn foliar application increased first fruit set, final fruit set, fresh yield, and dry yield. Nut weight was increased by Zn spray by 3 and 4% at the second and third levels of Zn, respectively, compared with the control. However, Cu application increased splitting and vegetative growth. Vegetative growth in the OFF year was greater than that of the ON year. Phosphorus, sodium, and Cu concentrations in leaf were greater in the ON year than in the OFF year, but concentrations of Zn and potassium in leaf were lower in the ON year than they were in the OFF year. These results show that Zn and Cu applications can affect growth and yield of pistachio, especially when the plant is grown in calcareous soils. However, the alternate bearing pattern had a significant effect on vegetative growth and some leaf nutrient concentrations.     

优化施肥对小麦品质和产量的效应研究

采用正交旋转组合设计,针对N、P、K、Zn 4种肥料对小麦产量和品质的效应进行探讨,结果表明:N、P对产量都达显著正效应,N对湿面筋含量达极显著正效应,P与湿面筋含量呈显著负效应,K、Zn对产量和品质效应微弱。4种肥料对产量的影响顺序为:N>P>Zn>K,对湿面筋含量的影响顺序为:N>P>K>Zn。小麦产量和品质都较理想的施肥区间为N 252.8～294.2 kg/hm2,P 111.0～139.1kg/hm2, K145.8～153.0kg/hm2, Zn 9.8～12.1kg/hm2, 合理的配比为N:P2O5:K2O:ZnSO4=1:0.46:0.55:0.04     

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.     

POTASSIUM FERTILIZATION AND FRUIT PRODUCTION OF PAGE CITRUS ON A PUNSIRUS ROOTSTOCK: QUANTITATIVE AND QUALITATIVE TRAITS

Determination of optimum rates of potassium (K) for high citrus production with great qualitative traits is of both agricultural and economical significance, particularly when performing long–term experiments. A five–year field experiment was conducted in the Citrus Research Center of Tonekabon, Iran in a silty clay loam. The objectives were to: 1) to apply different rates of K fertilizer and determine the optimum rates for citrus high production, and 2) to evaluate the effects of K fertilization on the fruit quantitative and qualitative traits for the production of tasty and great quality fruits for fresh or long consumption. Fifteen–year citrus trees were fertilized with five rates of potassium at control, 750, 1500, 2250 and 3000 g tree^?1 on the basis of a completely randomized block design in five replicates. Fruit parameters were determined. Potassium significantly increased fruit yield and qualitative traits at the optimum amount of 1500 g tree^?1.     

QUANTITY AND QUALITY OF CITRUS ON A CITROMELO ROOTSTOCK AS AFFECTED BY DIFFERENT TYPES OF N FERTILIZATION (CHEMICAL AND ORGANIC)

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.     

The effectiveness of seed priming and foliar application of zinc- amino acid chelates in comparison with zinc sulfate on yield and grain nutritional quality of common bean

Abstract

The efficacy of seed priming and foliar application of zinc-amino acid chelates including zinc-histidine [Zn(His)₂] and zinc-methionine [Zn(Met)₂] in comparison with zinc sulfate (ZnSO₄) on yield and grain nutritional quality of two common bean cultivars (Phaseolus vulgaris L., cvs Talash and Sadri) was investigated in a severely Zn-deficient calcareous soil (DTPA-Zn: 0.38?mg kg^?1 soil) in a pot experiment. Bean response to Zn application varied depending on the Zn fertilizer, application method and cultivar. In ‘Talash’, seed priming with [Zn(His)₂] and [Zn(Met)₂] led to 24.1 and 11.6% increase in the grain yield of bean in comparison with ZnSO₄ treatment, respectively. In both cultivars, foliar application of [Zn(His)₂] led to significant increase in the grain yield in comparison with ZnSO₄. The highest grain Zn concentration was obtained by seed priming with [Zn(Met)₂] in ‘Sadri’ and [Zn(His)₂] in ‘Talash’, respectively. For Zn-amino acid chelates, seed priming was more effective than foliar application in increasing grain yield and Zn concentration. Foliar application of [Zn(His)₂] and [Zn(Met)₂] in ‘Sadri’ and [Zn(Met)₂] in ‘Talash’ resulted in higher protein content in bean grain as compared with ZnSO₄. In both cultivars, foliar application of [Zn(Met)₂] was the more effective than seed priming to increase grain protein content. The highest water-soluble carbohydrates concentration of grain was obtained by seed priming with [Zn(Met)₂] and [Zn(His)₂] in ‘Sadri’ and ‘Talash’ cultivars, respectively. Therefore, seed priming with [Zn(His)₂] and ZnSO₄ in ‘Sadri’ and [Zn(Met)₂] in ‘Talash’ can effectively be used for improving yield of common bean in Zn-deficient calcareous soils.     

Polyhalite as a sulfur source for fresh market tomato production in Brazil

Abstract

Polyhalite (PH), a naturally occurring multinutrient fertilizer containing potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S), has improved tomato (Solanum lycopersicum L.) production in Brazil but a specific response by tomato to the S in PH is not confirmed. We compared four S sources – PH, sulfate of potash (SOP), sulfate of potash magnesia (SOPM), and single super phosphate (SSP) – applied at a target application rate of 40?kg?S?ha^?1 to fertilizers with no S (muriate of potash, MOP), and no K or S at commercial application rates in three commercial fields in Brazil with nitrogen (N), phosphorus (P), and K applied at recommended rates of 355, 500, and 200–300?kg?ha^?1, respectively. Consistent across locations, PH increased total yields over the control, MOP, and SSP, with SOP and SOPM higher than the control but not MOP or SSP. Only PH increased marketable yields compared to the control. Yields increased linearly with fruit numbers per plant which were higher for PH than the control or MOP, indicating higher fruit set in PH contributed to yield differences. While fertilizers increased leaf K and S concentrations and soil test K and SO₄–S, yield differences did not appear to be related solely to either K or S fertilization, nor to Mg fertilizers to which there was no response. Leaf and fruit Ca concentrations were higher in PH than the control and MOP at some locations suggesting Ca improved fruit set in PH. Results suggest tomato likely responded to the multinutrient content or solubility pattern of PH.     

Yield and Physico-Chemical Composition of Date-Palm (Phoenix Dactylifera) as Affected by Nitrogen and Zinc Application

The present study was carried out to investigate the effect of nitrogen (N) and zinc (Zn) fertilization on yield components and composition of Phoenix dactylifera L. cv. Kabkab during two growing seasons. This study was conducted by using factorial experiment in randomized complete block design with four replications. Aqueous solution of Zn was injected to trunk at the rate of 0, 1.15, and 2.30 g L^?1. N was applied at 0, 160, 345, and 460 g per palm tree. Sources of N and Zn were urea and zinc sulfate heptahydrate (ZnSO₄.7H₂O), respectively. Each year N fertilizer was added in two equal applications, one before flowering and one at fruit setting. N was applied at 1.5 m from the palm trunk. The trees were subjected to the usual farm management, for example, artificial pollination (only one source of pollen grains was used to avoid the metaxenic effects), pruning and irrigation. Results indicated that application of N and Zn had significant effects on fruit set, fruit yield, fruit weight, bunch weight, fruit size, N and Zn leaf contents, total soluble solids (TSS), reducing sugar and total sugar. However, more increments in these parameters were obtained with N in combination with Zn. The suitable combination of the nutrients found for date palm tree under the prevailing conditions was the application of 345 g N and 2.30 g L^?1 Zn for injection.     

Response of wheat genotypes to zinc fertilization for improving productivity and quality

Field experiments were conducted to evaluate the effects of zinc (Zn) fertilization on yield potentiality and quality of promising wheat varieties during winter seasons of 2013–14 and 2014–15 at the research farm of the Indian Agricultural Research Institute, New Delhi. Among genotypes, HD 2967 genotype proved as best in realizing the highest grain yield (4.89 Mg ha^?1), net returns and benefit–cost ratio besides increased protein (13.4%) and wet gluten (29.4%) content in grain. Highest grain Zn concentration and recovery efficiency (RE) recorded in HD 2851 and HD 2687, respectively. HD 2932 registered lowest grain hardiness index (GHI) followed by PBW 343, indicating their better bread-making quality. With respect to Zn fertilization, application of 1.25 kg Zn Zn–ethylene diamine tetra acetic acid (Zn–EDTA) + 0.5% foliar spray at maximum tillering and booting stages resulted in the highest yields, grain Zn concentration and RE followed by 2.5 kg Zn (ZnSO₄·7H₂O) + 0.5% foliar spray at both stages. These treatments are also superior most with respect to grain quality parameters such as protein, wet gluten and starch content. From profitability viewpoint, 2.5 kg Zn (ZnSO₄·7H₂O) + 0.5% two foliar sprays were most remunerative with maximum net returns and benefit–cost ratio.     

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.