E. Rafique

Diagnosing boron deficiency in rapeseed and mustard by plant analysis and soil testing

Abstract Boron (B) deficiency is a widespread nutritional disorder in crop plants, including rapeseed and mustard. However, plant analysis and soil testing diagnostic criteria for B are inadequately reported in the literature. Therefore, greenhouse and incubation studies were carried out using a B‐deficient alkaline calcareous soil (hot water extractable B, 0.11 mg/kg) of Pakistan to determine the internal and soil test B requirement of rapeseed and mustard. Boron fertilization substantially enhanced the growth of both species; the maximum increase in grain yield was 43% for rapeseed and 36% for mustard over the yield of respective control plants. Fertilizer requirement for near‐maximum (95%) grain yield was 0.7 mg B/kg for rapeseed and 0.9 mg B/kg for mustard. Critical plant tissue B concentration in rapeseed was 32 mg/kg in whole shoots and 38 mg/kg in most recently matured leaves. However, internal B requirement of mustard was relatively greater: i.e. 41 mg/kg in whole shoots and 49 mg/kg in leaves. Th...

Diagnosing zinc deficiency in rapeseed and mustard by seed analysis

Abstract Zinc (Zn) deficiency in crops, including rapeseed and mustard, is a widespread nutritional disorder especially in alkaline soils. However, plant analysis diagnostic criteria for interpreting Zn analysis in rapeseed and mustard are scarcely reported in the literature. Use of seeds for diagnosing Zn fertility status of soils has certain advantages over foliar analysis—ease of sampling, processing, and chemical analysis. Despite this, mature seeds of these species were hardly evaluated as an index tissue for this purpose. Our study determined Zn requirement in foliar tissues and also evaluated Zn composition of mature seeds as an index of Zn status of soils and plants. Zinc concentration in mature seeds of the test crops reflected the Zn status of the soil where plants were grown. In fact, the range of Zn concentration in grains was almost comparable with the ranges in foliar plant parts. Critical Zn concentration (mg/kg) in diagnostic plant parts of rapeseed was: whole shoots, 29; leaves, 33; and s...

Internal Boron Requirement of Young Sunflower Plants: Proposed Diagnostic Criteria

Abstract In a greenhouse study, a significant increase in sunflower (Helianthus annuus L., cv. Hysun 33) dry matter yield was observed with boron (B) application to a B-deficient (hot water-extractable, 0.23 mg B kg−1) calcareous soil of Missa series (Typic Ustochrept). Six rates of B, ranging from 0 to 8 mg B kg−1 soil, were applied as H3BO3 along with adequate basal fertilization of nitrogen (N), phosphorus (P), potassium (K), and zinc (Zn). Four plants of sunflower were grown in each pot; two were harvested after 4 weeks of germination and the other two after 8 weeks. Maximum crop biomass was produced with 1.0 mg B kg −1, and application of ≥2.0 mg B kg−1 proved toxic, resulting in drastic yield suppressions. Critical B concentration range for deficiency diagnosis in 4‐week‐old sunflower whole shoots appears to be 46–63 mg B kg−1. However, critical concentration in 8‐week‐old plants was much less (i.e., 36 mg B kg−l), presumably due to a dilution effect. As plants internal B requirement can vary, in fact manifold, depending on the species, plant part, and plant age, only a relevant criterion can help in diagnosing the deficiency effectively.

Heavy-Metal Phytoextraction Potential of Spinach and Mustard Grown in Contaminated Calcareous Soils

Laboratory batch and greenhouse pot experiments were conducted to determine the extraction efficiency of ethylenediaminetetraacetic acid (EDTA) for solubilizing lead (Pb) and cadmium (Cd) and to explore the natural and chemically induced Pb and Cd phytoextraction efficiencies of spinach and mustard after EDTA application. The EDTA was applied at 0, 1.25, 2.5, and 5.0 mM kg−1 soil in three replicates. Addition of EDTA increased significantly the soluble fraction Pb and Cd over the control and maximum increases for Pb (1.42- and 1.96-fold) and Cd (1.45- and 1.38-fold) were observed with the addition of 5.0 mM EDTA kg−1 in Gujranwala and Pacca soils, respectively. Similarly, addition of EDTA increased significantly the Pb and Cd concentrations in the plant shoots, soil solution, bioconcentration factor, and phytoextraction rate. Mustard exhibited better results than spinach when extracting Pb and Cd from both contaminated soils.

Zinc Nutrition of Onion: Proposed Diagnostic Criteria

ABSTRACT Zinc (Zn) deficiency is a global nutritional problem in crops grown in calcareous soils. However, plant analysis criteria, a good tool for interpreting crop Zn requirement, is scarcely reported in literature for onion (Allium cepa L.). In a greenhouse experiment, Zn requirement, critical concentrations in diagnostic parts and genotypic variation were assessed using four onion cultivars (‘Swat-1’, ‘Phulkara,’ ‘Sariab Red,’ and ‘Chilton-89’) grown in a Zn-deficient (AB-DTPA extractable, 0.44 Zn mg kg−1), calcareous soil of Gujranwala series (Typic Hapludalf). Five rates of Zn, ranging from 0 to 16 mg Zn kg−1 soil, were applied as zinc sulphate (ZnSO4·7H2O) along with adequate basal fertilization of nitrogen (N), phosphorus (P), potassium (K), and boron (B). Four onion seedlings were transplanted in each pot. Whole shoots of two plants and recently matured leaves of other two plants were sampled. Zinc application significantly increased dry bulb yield and maximum yield was produced with 8 mg Zn kg−1. Application of higher rates did not improve yield further. The cultivars differed significantly in Zn efficiency and cv. ‘Swat-1’ was most Zn-efficient. Fertilizer requirement for near-maximum dry bulb yield was 2.5 mg Zn kg−1. Plant tissue critical Zn concentrations were 30 mg kg−1 in young whole shoots, 25 mg kg−1 in matured leaves, 16 mg kg−1 in tops and 14 mg Zn kg−1 in bulb. Zinc content in mature bulb also appeared to be a good indicator of soil Zn availability status.

Zinc Application Affects Tissue Zinc Concentration and Seed Yield of Pea（Pisum sativum L.）

Abstract A 2-year field experiment was conducted to assess the effect of applied zinc (Zn) on the seed yield of pea (Pisum sativum L.) and to determine the internal Zn requirement of pea with emphasis on the seed and leaves as index tissues. The experiment was carried out at two different locations (Talagang, Chakwal district and National Agricultural Research Centre (NARC), Islamabad) in the Potohar Plateau, Pakistan by growing three pea cultivars (Green feast, Climax, and Meteor). The soils were fertilized with 0, 2, 4, 8, and 16 kg Zn ha−1 along with recommended basal fertilization of nitrogen (N), phosphorus (P), potassium (K), and boron (B). Zinc application increased seed yield significantly for all the three cultivars. Maximum increase in the pea seed yield (2-year mean) was 21% and 15% for Green feast, 28% and 21% for Climax, and 34% and 26% for Meteor at Talagang and NARC, respectively. In all cultivars, Zn concentrations in leaves and seed increased to varying extents as a result of Zn application. Fertiliser Zn requirement for near-maximum seed yield varied from 3.2 to 5.3 kg ha−1 for different cultivars. Zinc concentrations of leaves and seeds appeared to be a good indicator of soil Zn availability. The critical Zn concentration range sufficient for 95% maximum yield (internal Zn requirement) was 42–53 mg kg−1 in the pea leaves and 45–60 mg kg−1 in the seeds of the three pea cultivars studied.

DETERMINING THE ZINC REQUIREMENT OF ONION BY SEED ANALYSIS

Our study analyzed the effect of foliar tissues and seed tissue for determining the micronutrient status of a crop. Zinc (Zn) requirements of onion (Allium cepa L.) leaves and seeds were estimated from yield response curves based on field experiment conducted on a Zn-deficient calcareous soil. Three onion cultivars, i.e., ‘Swat-1’, ‘Phulkara’, and ‘Sariab Red’ were grown by applying 0, 2, 4, 8, and 16 kg Zn ha−1. Zinc application significantly increased seed yield of all the three cultivars of onion. The order of seed yield response to Zn fertilization was: ‘Swat-1’ < ‘Phulkara’ < ‘Sariab Red’. Fertilizer Zn requirement for near-maximum seed yield was 2 kg Zn ha−1. Zinc concentration in mature onion seed also appeared to be a good indicator of soil Zn availability status. Critical Zn concentration in seed was 18 mg Zn kg−1, and in matured leaves was 21 mg kg−1.

BORON REQUIREMENT OF CHILI (CAPSICUM ANNUUM L.): PROPOSED DIAGNOSTIC CRITERIA

Critical concentration in recommended plant tissue is an important tool for diagnosing nutrient deficiency. Internal requirement of five chili (Capsicum annuum L.) cultivars was estimated from yield response curves attained from a field experiment by applying 0, 0.5, 1.0, 2.0, 3.0, and 4.0 kg boron (B) ha−I. Boron application significantly increased dry fruit yield and maximum increase ranged from 11 to 19%. The cultivars varied in B efficiency and cv. ‘Nepali’ was most B efficient (90%) while cv. ‘NARC # 4’ was the least (84%). Internal chili B requirement, associated with 95% of maximum yield attained, was 0.90 kg B ha−1. Plant tissue critical B concentration was 20 mg B kg−1in whole shoot, 24 mg B kg−1in matured leaf, and 15 mg B kg−1in seed. Results demonstrate that proposed diagnostic criteria can successfully be used to cure the B problem in chili.

Nutrients transport through variably structured soils

Soil structure development has a direct and indirect relation with hydraulic properties that generally control the transport of surface applied nutrients in unsaturated zones causing environmental implications. Nitrate ( ) and phosphate ( ) transport was assessed using undisturbed columns of variably structured calcareous soils, i.e. Shahdara (massive to weak coarse sub-angular blocky silt loam), Sultanpur (weak coarse, sub-angular blocky very fine sandy loam), Lyallpur (weak, coarse and medium sub-angular blocky silt loam), and Pacca (moderate, medium and fine sub-angular blocky silty clay). After conditioning the columns with 0.01 M CaCl2 (≈2 pore volumes), a pulse of KNO3 (50 mM) and KH2PO4 (32 mM) solution was applied and afterwards leached with 0.01 M CaCl2. The experimental breakthrough curves (BTCs) of and were described with one-domain and two-domain (mobile–immobile) convective dispersive equations (CDEs). Results showed that both and , applied in the same pulse, appeared in the effluent almost immediately after pulse application and peaked after 0.4 pore volume cumulative drainage in Lyallpur and Pacca columns. In contrast, in the Sultanpur and Shahdara columns, appearance of in the effluent was delayed till 0.6 pore volume and 0.4 pore volume cumulative drainage, respectively, and peaked at ≈1.0 pore volume cumulative drainage. The appearance of in the effluent was further delayed until 0.8 pore volume and 0.6 pore volume cumulative drainage, respectively. The despersivity, λ, that occurred in the Lyallpur and Pacca columns was significantly greater than in Shahdara and Sultanpur columns. While the fitted mobile water fraction, β, was significantly greater in Shahdara (0.81) and Sultanpur (0.90) than that of Lyallpur (0.27) and Pacca (0.28). It was concluded that variable structured soils had significant effect on solute transport parameters and should be considered in nutrient management studies.

Plant analysis diagnostic indices for boron nutrition of mungbean (Vigna radiata L.) cultivars grown in a rainfed calcareous soil

ABSTRACT Boron requirement of mungbean was assessed from yield response curves based on field experiment during 2010-11. Four cultivars, i.e., NM-11, NM-2006, Chakwal Mung-2006 and AZRI Mung-2006 were grown in a boron (B)-deficient calcareous soil by applying B at 0, 0.5, 1.0, 2.0, and 4.0 kg ha−I. Boron application significantly increased grain yield and B uptake by all the mungbean cultivars over control. Maximum grain yield increases were: cv. NM-11, 20%; cv. NM-2006, 24%; cv. Chakwal Mung-2006, 26%; and cv. AZRI Mung-2006, 28%. The cultivars varied in B efficiency and cv. NM-11 was most B efficient (83%) while cv. AZRI Mung-2006 was the least B efficient (78%). Fertilizer B requirement (kg ha−1) for 95% of the maximum grain yield was: 0.60 for cv. AZRI Mung-2006, 0.70 for cv. Chakwal Mung-2006, 0.75 for cv. NM-2006, and 0.85 for cv. NM-11. Plant tissue critical B concentration in leaves was higher than in seeds.