Saeed Ahmad

Paclobutrazol Soil Drenching Suppresses Vegetative Growth, Reduces Malformation, and Increases Production in Mango

Emergence of unproductive vegetative shoots/flushes is considered to be a main cause of low yield, irregular bearing, and malformation of inflorescences in mango. Selected mango trees of the cultivars ‘Chaunsa’, ‘Dushehare’, and ‘Anwar Ratool’ growing in the subtropical region of Khanewal (30°18′0N, 71°56′0E), a district of Pakistan, were characterized as having excessive vegetative growth, erratic flowering, and fruiting with declining productivity due to malformation of inflorescences. Paclobutrazol soil drenching was evaluated as a method to suppress excessive vegetative growth and to increase the number of reproductive shoots even during the ‘off’ season. Different rates of paclobutrazol was applied at rates of (0, 2, 4, 6, 8, 10, and 12 g a.i.) in September through soil drenching. Results showed that soil drenching with paclobutrazol at the highest rates (12, 10, and 8 g a.i.) was significantly effective in suppressing vegetative growth, reducing the increase in canopy volume, and flush length as compared to control trees in all treated cultivars of mango. Statistically significant differences were recorded in treated trees as compared to control regarding the emergence of reproductive shoots, fruit setting, panicle length, fruit drop, intensity of emergence of malformed panicles, and yield. Response of selected cultivars of mango to paclobutrazol was statistically different regarding various vegetative and reproductive growth characteristics. Paclobutrazol was more useful in ‘Seasonal Chaunsa’ as compared to ‘Dushehare’ and ‘Anwar Ratool’ for improving various vegetative and reproductive parameters studied in this research.

3-Benzoyl-4-hydr­oxy-2H-1,2-benzothia­zine 1,1-dioxide

There are two molecules in the asymmetric unit of the title compound, C15H11NO4S. The heterocyclic thiazine rings in both molecules adopt half-chair conformations with the S and N atoms displaced by 0.455 (4) and 0.254 (4) Å, respectively, in one molecule, and 0.480 (4) and 0.224 (5) Å in the other, on opposite sides of the mean planes formed by the remaining ring atoms. The crystal structure is stabilized by intermolecular N—H⋯O and C—H⋯O hydrogen bonds. In addition, intramolecular O—H⋯O interactions are also present.

2-(3-Oxo-3,4-dihydro-2H-1,4-benzothia­zin-4-yl)acetohydrazide

In the title compound, C10H11N3O2S, the thiazine ring exists in a conformation intermediate between twist-boat and half-chair. The dihedral angle between the mean plane of the thiazine ring and the hydrazide group is 89.45 (13)°. In the crystal, N—H⋯O hydrogen bonds link the molecules into (100) sheets and weak C—H⋯O interactions further consolidate the packing.

Preparation, morphology and sonication time dependence of silver nanoparticles in amphiphilic block copolymers of PEO with polystyrene or PMMA

Composite materials comprising arrays of silver nanoparticles in amphiphilic copolymers have been prepared by sonochemically enhanced borohydride reduction of precursor silver nitrate (AgNO3). The precursor was incorporated into the cores of polymeric micelles formed from block copolymers of polystyrene (PS) or poly(methyl methacrylate) (PMMA) with poly(ethylene oxide) (PEO). The copolymers were synthesised with varying hydrophobic block lengths from a PEO macroinitiator by atom transfer radical polymerization (ATRP). UV/visible spectroscopy was used to confirm the formation of elemental silver and the effect of sonication time on the appearance of the silver nanoparticles was determined. The growth was faster than when gold nanoparticles are formed in comparable block copolymers. Nanoparticles formed in copolymers with PMMA blocks were more stable to agglomeration than when polystyrene was used. Electron microscopy revealed the morphology of the nanocomposites which confirmed that both block copolymers are vehicles for the formation of well-defined films containing nanoparticulate silver. However, AgNP formation shows some significant differences from previous reports of gold NP containing materials formed under similar conditions.

Biochemical diversity in wild and cultivated pomegranate (Punica granatum L.) in Pakistan

ABSTRACT The present study was conducted to screen out elite pomegranates through determination of biochemical diversity in wild and cultivated genotypes for a breeding program and for fresh/processed use in industry. The results showed high morphological diversity in accessions of wild pomegranate fruits as compared to cultivated genotypes. The first six principal components covered 80.75 and 75.49% diversity in 53 wild and 62 cultivated pomegranate genotypes, respectively. High values of the coefficient of variance (10.78–18.62%), and a high range of minimum to maximum values of total soluble solids, titratable acidity, ascorbic acid content, total soluble sugars, and total phenolic content (0.10–1.25, 5.88–29.96, 9.69–19.85 and 175.05–595.42), respectively, were recorded in the studied genotypes. Ascorbic acid content had a strong correlation with antioxidant activity (0.952%), super dismutase oxides (0.94%), catalase (0.921%), and titratable acidity (0.91%). Peroxides had a strong correlation (0.88%) with catalase, and 0.81% each with super dismutase oxides and antioxidant activity. Wild and cultivated pomegranates were clustered successfully in separate groups, based on biochemical traits. A variety improvement program and selection of high-quality pomegranate genotypes could help to reduce pomegranate-related malnutrition issues in the human diet.

N-[(Methyl-sulfan-yl)meth-yl]benzamide.

In the title compound, C9H11NOS, the phenyl ring and formamide unit make a dihedral angle of 23.93 (14)°, whereas the (methylsulfanyl)methyl group is oriented at a dihedral angle of 61.31 (8)° with respect to the phenyl ring. There are intermolecular N—H⋯O hydrogen bonds, forming C(4) chains along the [010] direction. These polymeric chains are linked by C—H⋯O hydrogen bonds to form polymeric sheets in the (110) plane.

2-Fluoro-5-(4-fluoro­phen­yl)pyridine

In the title compound, C11H7F2N, the fluorobenzene and the 2-fluoropyridine rings are oriented at a dihedral angle of 37.93 (5)°. In the crystal, only van der Waals interactions occur.

N′-(2-Chloro­benzyl­idene)-2-(3,4-dimethyl-5,5-dioxo-2H,4H-pyrazolo­[4,3-c][1,2]benzothia­zin-2-yl)acetohydrazide

The asymmetric unit of the title compound, C20H18ClN5O3S, contains two independent molecules with significantly different conformations of the heterocyclic thiazine rings. In both molecules, the thiazine rings adopt half-chair conformations, with the S atoms displaced by 0.382 (3) and 0.533 (3) Å and N atoms −0.351 and −0.275 Å, respectively, from the planes formed by the remaining ring atoms. The crystal structure is stabilized by weak intermolecular N—H⋯O and C—H⋯O interactions.

2-(3,4-Dimethyl-5,5-dioxo-2H,4H-pyrazolo-[4,3-c][1,2]benzothia-zin-2-yl)-N'-(3-meth-oxy-benzyl-idene)aceto-hydrazide dimethyl-formamide hemisolvate.

In the title compound, C21H21N5O4S·0.5C3H7NO, the heterocyclic thiazine ring adopts a half-chair conformation, with the S and N atoms displaced by −0.451 (5) and 0.233 (5) Å, respectively, from the plane formed by the remaining ring atoms. The asymmetric unit contains a disordered half-molecule of solvent lying close to inversion centers. The crystal structure is stabilized by weak intermolecular N—H⋯O and C—H⋯O interactions.

4-[(2,5-Dimethyl-anilino)acet-yl]-3,4-di-hydro-quinoxalin-2(1H)-one.

In the title compound, C18H19N3O2, the dihedral angle between the benzene rings is 20.47 (10)° and an intramolecular N—H⋯O hydrogen bond occurs, generating an S(5) ring. In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds lead to R 2 2(8) loops.