The present study was conducted to examine the changes in some key metabolites in drought-stressed sunflower plants supplied with glycine betaine externally. Imposition of drought stress at the vegetative or reproductive growth stages decreased the plant dry matter production and increased the accumulation of organic solutes (glycine betaine, proline, soluble proteins, free amino acids and soluble sugars) in two sunflower lines, i.e., Glushan-98 and Suncross. In general, decrease in dry matter production and increase in the endogenous levels of organic solutes, were more pronounced when drought stress applied at the vegetative stage than at the reproductive stage. Glycine betaine applied as a pre-sowing seed treatment was not found to be effective in reducing the negative effects of drought stress in sunflower plants. Foliar application of GB further enhanced the leaf endogenous levels of GB, soluble proteins and total soluble sugars in drought stressed plants without exerting any negative effects on other osmotica. However, this GB-induced increase in endogenous levels of organic solutes was found to be not associated with plant dry matter production under stress conditions.

Cholistan desert located in the southeast of the Punjab province, Pakistan, covering an area of 25,800 km 2 is a part of Greater Thar desert. The soil types characteristically include: sand dunes, sandy soils with patches of non-saline non-sodic loamy soils and sodic clayey soils. Vegetation structure and density are greatly influenced by the rainfall. During low rainfall years even drinking water gets scarce and both the plant and animal communities are adversely affected. Biodiversity assessment survey was carried out during 1997-98. The dominant species of the lesser Cholistan among grasses were Aristida adscensionis, Ochthochloa compressa, Lasiurus scindicus, Cymbopogon jwarancusa, Cenchrus biflorus, Sporobolus ioclados and Aeluropus lagopoides, whereas that of Greater Cholistan Aeluropus lagopoides, Aristida adscensionis, Cenchrus biflorus, Cenchrus pennesetiformis, Cymbopogon jwarancusa, Lasiurus scindicus, Panicum antidotale and Panicum turgidum. Like other deserts, the major problem in the area is the scarcity of good quality water. The subsoil water in most places of Cholistan is brackish and unfit for normal plant growth. It is highly probable that by adopting biological approach the vast area of Cholistan can be economically exploited. Salinity tolerance of four potential forage grass species, Cenchrus pennesetiformis, Panicum turgidum, Pennisetum divisum and Leptochloa fusca, including one highly tolerant exotic grass species Puccinellia distans was assessed after 6 weeks growth at four salinity treatments, 2.4 (control), 8, 16 and 24 dS m -1 . Shoot biomass production in Leptochloa fusca and Puccinellia distans was not affected by any of the salinity levels and these grasses had greater shoot fresh and dry matter than the other species at all salinity treatments. Pennisetum divisum was the worst affected, whereas Cenchrus pennesetiformis and Panicum turgidum were intermediate in biomass production. Every species showed a specific accumulation pattern for different ions (Na + , Cl-, K + and Ca 2+ ) in the shoots or roots. Levels of leaf monosaccharides (glucose + fructose) were similar in Cenchrus pennesetiformis and Panicum turgidum under both control and salt treatments. Leptochloa fusca accumulated lesser amounts of monosaccharides, although its monosaccharides doubled in the salt treatment. Disaccharides (sucrose), in the leaves of Cenchrus pennesetiformis, decreased markedly due to the addition of salts in the rooting medium. Trisaccharides (raffinose) were very low in relation to monosaccharides and disaccharides. In another experiment six accessions of Panicum antidotale, eight of Cenchrus ciliaris and one of Lasiurus scindicus from Cholistan were examined for salinity tolerance under five NaCl levels viz. 1.25 (control), 10, 15, 20 and 25 dS m -1 . Although significant reduction in growth attributes of all accessions was recorded, accessions KS 1/2 and Local-2 of Cenchrus ciliaris, LS 3/6 of Lasiurus scindicus, and KS 1/1 of Panicum antidotale were superior to the other accessions in all growt...

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Phosphorus (P) efficiency from inorganic fertilizers is very low and major cause of lower crop productivity, thus proper remedy is required for maintaining optimum P supply from soil to ensure higher wheat productivity. Two-years (2015-16 & 2016-17) field trials have shown that application of phosphoric acid (PA) at 54 kg P ha-1 along with farmyard manure (FYM) produced maximum wheat grain (5159 kg ha-1), 23% higher over its sole application. Phosphorus uptake was increased with the increase in P rates (18, 36, 54 kg P ha-1) which was usually associated to higher grain yield than P concentration in grain. The manure amended inorganic P fertilizers were found more effective in P uptake and grain yield than their sole application. In greenhouse, a similar trend as occurred in field condition was observed for P recovery and biomass production. The manure amended PA (followed by diammonium phosphate) exhibited maximum P derived from applied fertilizer (Pdff = 40.03%) by a 45-day old wheat plant, as determined by 32 P labeling technique. Phosphorus recovery efficiency (PRE) and phosphorus agronomic efficiency (PAE) were found lowest at highest P rate (54 kg P ha-1). However, co-amended phosphate fertilizers showed higher PRE and PAE as compared to their sole application. Therefore, manure amended phosphate fertilizers application seemed appropriate to attain higher P availability from soil, improve efficiency of inorganic fertilizers and enhance wheat productivity grown in alkaline calcareous soils.

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