Determination of phosphorus-32 in wet-digested plant leaves by Cerenkov counting

Wahid, P. A.; Kamalam, N. V.; Sankar, S. Jayasree

doi:10.1016/0020-708x(85)90097-3

Cited by 27 publications

(9 citation statements)

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“…The digest was then transferred into a counting vial and made up to 20 mL volume. Vials were counted in a liquid scintillation counter (Model: Trialther-Hidex) by the Cerenkov counting technique (Wahid et al 1985). Bamboo clumps adjacent to turmeric beds were also sampled to assess the extent of root interaction.…”

Section: Leaf Sampling and Radioassaymentioning

confidence: 99%

Bamboo based agroforestry systems in Kerala, India: performance of turmeric (Curcuma longa L.) in the subcanopy of differentially spaced seven year-old bamboo stand

et al. 2015

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Bamboo-based agroforestry is a promising option for sustainable land management in India. Optimal management of bamboo-based mixed species production systems, however, requires an understanding of bamboo spacing, root activity and distribution of bamboo roots, and the soil nutrient capital of the site. We examined the performance of turmeric as an understorey crop in 7-year old bamboo (Dendrocalamus strictus (Roxb.) Nees) stands of varying spacing treatments (4 9 4, 6 9 6, 8 9 8, 10 9 10 and 12 9 12 m) at Kerala Agricultural University Campus, Thrissur, Kerala, India. In order to better understand turmeric and bamboo growth parameters, soil physico-chemical properties, understorey light availability and turmeric root activity by soil injection of 32 P were determined in mixed (turmeric ? bamboo) and sole turmeric situations. To characterize root activity, 32 P was applied at 10 cm depth to the turmeric plants in raised beds established between the two central rows of bamboo in all experimental plots. Growth attributes of bamboo were recorded and the soil was analyzed for physico-chemical properties before intercropping. Results revealed that spacing treatments exerted profound influence on bamboo growth. For instance, clump height decreased by 19 % in the widest (12 9 12 m) bamboo spacing compared to that of the closest (4 9 4 m) spacing. However, widely spaced bamboo exhibited better clump diameter, crown coverage and turmeric rhizome yield, whereas, closest (4 9 4 m) spacing of bamboo plot recorded least rhizome yield of 8 Mg/ha; this was 58 % less compared to widest spacing of 12 9 12 m (19.32 Mg/ha). Soil N, P and K at widest spacing was 56, 45 and 33 % less compared to that of the closest spacing. NPK uptake by turmeric also increased in the wider spacing treatments. Factors contributing to reduction in growth of turmeric in the denser bamboo stands may be the high LAI (6.77 in 4 9 4 m spacing) as compared to widest spacing (0.44 in 12 9 12 m spacing) of bamboo, low understorey PAR (107 lmol/ sec/m 2 ) and high root competition. Due to competition by bamboo, 89 % decline in 32 P absorption by turmeric at closest spacing of bamboo was observed compared to the bamboo-less plot. On a final note, turmeric, although a shade tolerant Zingiberaceae crop, may perform better if light transmittance is between 66 and 86 % and for optimal performance of the understorey turmeric in mixed species systems, wider bamboo spacings beyond 8 9 8 m are recommended.

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Section: Leaf Sampling and Radioassaymentioning

confidence: 99%

Bamboo based agroforestry systems in Kerala, India: performance of turmeric (Curcuma longa L.) in the subcanopy of differentially spaced seven year-old bamboo stand

et al. 2015

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“…The digest was then transferred into a counting vial and made up to 20 ml volume. Vials were counted in a liquid scintillation counter (Pharmacia-LKB, Finland) by the Cerenkov counting technique (Wahid et al 1985).…”

Section: Design and Installationmentioning

confidence: 99%

Root activity of young Acacia mangium Willd trees: influence of stand density and pruning as studied by 32P soil injection technique

et al. 2009

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Initial spacing and pruning are silvicultural strategies that influence the resource acquisition capabilities of trees. A field study was conducted in the humid tropics of peninsular India to test the assumptions that: (1) high stand density of Acacia mangium induces greater root uptake capacity close to the stem and from the subsoil; and (2) crown pruning stimulates greater root uptake capacity at proximal points. Root activity pattern of two-year-old A. mangium was evaluated as a function of three population densities (1,250, 2,500 and 5,000 stems ha -1 ), with, and without 50% crown pruning, using 32 P soil injection. The label was placed at 25, 50 and 75 cm lateral distances and at 30 and 60 cm depth. Low density stands (1,250 stems ha -1 ) generally showed higher 32 P recovery (P \ 0.01), which was exaggerated by pruning. Pruned low density stands had 34% root activity at 25 cm, as against 23% for unpruned. The low density stands also showed higher root activity at 75 cm, signifying greater root spread. We suggest that high stem densities favour restricted spread of absorbing roots and may facilitate competitive downward displacement of roots. Pruning the lateral shoots at low stem densities may simulate this to some extent. The net outcome of interactions, however, will depend on trade-offs between stem density and tree management over time.

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“…In the first method, 0.5 ml of the latex sample was dispensed into a background count examined counting vial. To these vials 15 ml each of Hisafe, a ready to use scintillator capable of dissolving organic materials was added and the counts were recorded by Liquid Scintillation counting (Wahid et al 1985).…”

Section: Leaf and Latex Sample Collection And Radio Assaymentioning

confidence: 99%

“…The leaves were sampled separately, dried at 65-70°C, powdered and acid digested (HNO 3 and HClO 4 ) for radio assay by Cherenkov counting technique (Wahid et al 1985).…”

Section: Leaf and Latex Sample Collection And Radio Assaymentioning

confidence: 99%

Active root distribution pattern of Hevea brasiliensis determined by radioassay of latex serum

et al. 2008

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The active root distribution pattern of mature rubber (Hevea brasiliensis Muell. Arg.) up to a lateral distance of 250 cm from the tree and to a soil depth of 90 cm was studied in an oxisol by employing 32 P soil injection technique in Kerala, the state which accounts for 83% of rubber cultivation in India. The trees were aged 18 years and grown at a spacing of 4.9 9 4.9 m. The extent of absorption of applied 32 P by the tree from various placements was assessed by radio assay of leaf and latex serum. Latex serum registered higher counts and variability was less compared to leaf indicating the suitability of latex serum as a potential source for radio assay for 32 P studies in rubber. The results revealed that rubber is a surface feeder with 55% of the root activity confining to the top 10 cm of soil layer. Root activity declined with increasing depths and the concentration of physiologically active roots at 90 cm depth was only 6%. A more or less uniform distribution of root activity was noticed with respect to lateral distance indicating more extensive spread of lateral roots. Concentration of physiologically active roots in the surface layer suggests the possibility for competition under intercropped situation in mature plantations.

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Determination of phosphorus-32 in wet-digested plant leaves by Cerenkov counting

Cited by 27 publications

References 0 publications

Bamboo based agroforestry systems in Kerala, India: performance of turmeric (Curcuma longa L.) in the subcanopy of differentially spaced seven year-old bamboo stand

Bamboo based agroforestry systems in Kerala, India: performance of turmeric (Curcuma longa L.) in the subcanopy of differentially spaced seven year-old bamboo stand

Root activity of young Acacia mangium Willd trees: influence of stand density and pruning as studied by 32P soil injection technique

Active root distribution pattern of Hevea brasiliensis determined by radioassay of latex serum

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