Jagdev Sharma

Atmospheric deposition studies of heavy metals in Arctic by comparative analysis of lichens and cryoconite

Lichens and cryoconite (rounded or granular, brownish-black debris occurring in holes on the glacier surface) from Ny-Ålesund were used for understanding the elemental deposition pattern in the area. Lichen samples collected from low-lying coastal region and cryoconite samples from high altitudinal glacier area were processed and analysed for elements such as aluminium (Al), arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), cesium (Cs), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), vanadium (V) and zinc (Zn) through inductively coupled plasma mass spectrometry. Results showed that heavy metals, Al and Fe, are present in high concentration in the cryoconite samples. Al was also present in high amounts in seven of the eight lichen samples studied. The general scheme of elements in the decreasing order of their concentrations for most of the cryoconite samples was Al > Fe > Mn > Zn > V > Pb > Cr > Ni > Cu > Co > As > Cs > Cd while that for the lichen samples was Al > Fe > Zn > Mn > Pb > Cu > Cs > Cr > Ni > V > Co > As > Cd. Similarity in trends in the two sample types confirms that the environment indeed contains these elements in that order of concentration which overtime got accumulated in the samples. Overall comparison showed most elements to be present in high concentrations in the cryoconite samples as compared to the lichen samples. Within the lichens, elemental accumulation data suggests that the low-lying site (L-2) from where Cladonia mediterranea sample was collected was the most polluted accumulating a number of elements at high concentrations. The probable reasons for such deposition patterns in the region could be natural (crustal contribution and sea salt spray) and anthropogenic (local and long-distance transmission of dust particles). In the future, this data can form a baseline for monitoring quantum of atmospheric heavy metal deposition in lichens and cryoconite of Svalbard, Arctic.

Moisture and Salinity Stress Induced Changes in Biochemical Constituents and Water Relations of Different Grape Rootstock Cultivars

Ten grape rootstocks were subjected to moisture and salinity stress in two separate experiments. The influence of these stresses on gas exchange, water relation, and biochemical parameters was monitored at various stages of stress cycle. Both stresses indicated significant changes in the physiological and biochemical parameters studied. Some biochemical constituents increased by several folds in few rootstock cultivars which also recorded increased osmotic potential suggesting their role in osmotic adjustment. Some of the rootstock cultivars such as 110R, 1103P, 99R, Dogridge, and B2/56 recorded increased phenolic compounds under stressed conditions. The same rootstock also recorded increased water use efficiency. The increased accumulation of phenolic compounds in these cultivars may indicate the possible role of phenolic compounds as antioxidants for scavenging the reactive oxygen species generated during abiotic stresses thus maintaining normal physiological and biochemical process in leaves of resistant cultivars.

Effect of Climate Change on Grape and Its Value-Added Products

In India, majority of the grape vineyards are located in semiarid climate. Climate change may aggravate the already serious problems of irrigation water availability and salinity. The elevated CO2 levels may increase productivity in arid and semiarid regions, but the drought stress caused by higher evaporative demand may override beneficial effects of increased CO2 in the atmosphere unless irrigation is increased to compensate the evaporative demand. Higher temperature may advance the ripening of berries and alter the berry composition in both table and wine grapes, thereby affecting the quality of the produce. Developing heat-tolerant grape varieties and salt- and drought-tolerant rootstocks, though essential, requires long period. Until new varieties/technologies are developed to improve water use efficiency and cope up with salinity, the emphasis needs to be given on propagation of existing crop production techniques that can mitigate the impact of climate change. There is also likelihood of change in the incidence and pattern of insect pests like mealy bug, thrips and mites. Similarly the disease incidence pattern is also likely to be affected with the change in climate. This is evidenced by decrease in productivity during the recent years from more than 25 t/ha to 8.3 t/ha during the year 2009–2010 and11.7 t/ha during 2010–2011 due to unseasonal rains which lead to serious downy mildew incidence. Changes in cropping season to adjust to changed climate will bring market competition-related issues particularly for Indian table grape industry in domestic as well as global markets.

SUSCEPTIBILITY OF THOMPSON SEEDLESS GRAPEVINES RAISED ON DIFFERENT ROOTSTOCKS TO LEAF BLACKENING AND NECROSIS UNDER SALINE IRRIGATION

Saline irrigation water having high sodium (Na+) content leads to the development of black leaf disorder in the vines resulting in reduced productivity and death of permanent vine parts. The response of the vines raised on different rootstocks differs under such conditions. Investigation was carried out to study the susceptibility of grafted and own-rooted Thompson Seedless (Vitis vinifera L.) vines to black leaf disorder. Grapevines grafted on four different rootstocks viz. Dog Ridge (Vitis champini), Salt Creek (Vitis champini), B2-56 (Vitis berlandieri x Vitis rupestris) and 1613C [Vitis longii x (Vitis labrusca x Vitis riparia) x Vitis vinifera] were studied. The variations in nutrient content of various vine parts under saline irrigation in relation to leaf blackening and necrosis symptoms were also studied. Thompson Seedless vines grafted on Dog Ridge, Salt Creek and own rooted vines started developing leaf blackening and necrosis symptoms during the ripening stage. Vines exhibiting these symptoms contained significantly lower potassium (K+) and higher Na+ content in the leaf blades as compared to healthy vines. Vines grafted on Salt Creek showed most severe leaf blackening and necrosis symptoms and had the lowest K+ content in blades and petioles. Amongst the rootstocks, vines raised on B2-56 had the lowest Na+ concentration in leaf blades whereas those on Dog Ridge and Salt Creek accumulated Na+ in leaf blades to a toxic level. Significantly higher K+ content was found in vines raised on B2-56 and 1613C rootstocks in all the vine parts compared to other stock-scion combinations. Vines grafted on B2-56 and 1613C could maintain higher K+: Na+ ratio and tolerated saline irrigation better than other stock-scion combinations. All the rootstocks reduced chloride concentration significantly in the vine parts (petioles, blade and canes) compared to own rooted vines. Vines raised on their own roots and on B2-56 rootstock had significantly higher phosphorus (P) concentration in petiole, blade and canes compared to vines grafted on Dog Ridge and Salt Creek. Total biomass (petiole + blade + cane on dry weight basis) and yield was the highest in B2-56 rootstock and least in 1613C.

Elemental composition and bacterial incidence in firn-cores at Midre Lovénbreen glacier, Svalbard

The present study was conducted to measure the elemental concentration and bacterial deposition in the firn-cores at the Midre Lovenbreen glacier, Svalbard. Firn-cores up to 1m deep were collected and divided into three subsections. These were subjected to elemental analysis using inductively coupled plasma mass spectroscopy (ICPMS). In all 20 elements were analysed. The crustal enrichment factors calculated for these elements on the basis of Fe values, demonstrate that the elements have derived from both crustal and anthropogenic sources. For certain elements there also exists a possibility of input from sea salt spray. Total bacterial counts in these firn samples ranged from 1.03 × 10 5 to 3.67 × 10 5 per ml of meltwater. Culturability of these bacterial cells, in comparison to the total count was very low. At 4°C the maximum culturability was

Elemental composition and bacterial occurrence in sediment samples on two sides of Brøggerhalvøya, Svalbard

The present study was conducted to determine the elemental concentration and bacterial presence in the ocean on the two sides of Brøggerhalvøya, a peninsula in Svalbard. Sediments from 25 different locations were collected and subjected to elemental analysis using inductively coupled plasma mass spectrometry (ICPMS). In total, 21 elements were analysed. The elements in their decreasing order of concentrations on the Kongsfjorden side of Brøggerhalvøya were Fe> Mn> Ba > V > Zn > Sr > Rb > Cr > Li > Ni > As > Pb > Cu > Co > Cs >Ag > Be > U> Bi >Tl > Cd while that for Forlandsendet side of Brøggerhalvøya they were Fe > Ba >Mn > V> Sr > Zn > Rb > Cr > Li > Ni > Pb > Cu > As > Co > Cs > Be > U> Tl > Bi > Cd. On the other hand, at a coastal outcrop, elements in their decreasing order of concentration were Fe > Mn > Cr > Sr > Ba > Rb > Cr > Zn > V > Rb > Ni > Li > Co > Cu > As > Pb > Cs > Be > Cd > Tl > U > Bi. AMS dates confirmed the age of outcrop sediment to be 12,496 to 42,500 BP. The crustal enrichment factor calculated for all the elements with reference to Fe values, demonstrates that the elements have derived from a crustal source. Total bacterial counts ranged from 3.30 × 105 to 3.02 × 106 per gm soil sediment. Culturable bacterial counts in these sediments were between 2.00 × 102 to 2.09 × 105 CFU’s per gm. Overall comparison showed high Fe and Mn concentrations around Brøggerhalvøya, due to the presence of specific bacteria which play key roles in metal cycling and carry out biogeochemical transformations.

Site-specific nutrient requirements of NPK for potato (Solanum tuberosum L.) in Western Indo-gangetic plains of India based on QUEFTS

Abstract Potato productivity in India is static due to unbalanced use of nutrients and intensive cropping system. Nutrient use efficiency and yield can be increased by application of nutrients based on quantitative approaches. We calibrated the quantitative evaluation of fertility of tropical soils (QUEFTS) model for the estimation of NPK requirements for different targeted yields of potato. Published data sets were used to calibrate the model. The results of the study showed that to produce one ton of potato tubers, 18, 4, and 24 kg N, P, and K, respectively, would be needed with internal efficiencies of 55, 285, and 42 kg tuber dry yield/kg N, P, and K removed. The observed yields of potato with different amount of nutrients were in agreement with the values predicted by the model. Therefore, the QUEFTS model based NPK fertilizer recommendations can be adopted for site-specific nutrient management of potato.