P. S. Thakur

Abstract

Out of the four agroforestry tree species , namely Grewia optiva ,
Celtis australis , Bauhinia variegata Morus alba , and two tree speCies (i.e. G. optiva and M. alba) maintained higher growth , vigour and foliage and branch wood biomass production potential for longer period when pollarded at 1.5 or 2.0 m. G. optiva and M. alba , responded better to canopy management practices like coppicing and pollarding as compared to C. australis and B. variegata. Collar diameter increased with increase in cutting heights in G. opttva and M. alba , but remained unchanged in C. australis and B. variegata up to fourth year of canopy management treatments. Significant decrease in shoot number , Leaf Area , Leaf Area Index (LAI) and foliage and branchwood biomass production occurred by fourth year of treatments although decrease was of higher magnitude at lower cutting heights in all the four tree species. M. alba followed by G. optiva produced maximum foliage and branch wood biomass at 2.0 m cutting height during the entire experimentation period.

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P. S. Thakur

Abstract

Comparative growth performance in a three age-series plantations of 15 MPTs at degraded site was revealed that tree species namely B. retusa, L. leucocephala, A. altissima, B. ceiba, G. robusta, M. composita, U. laevigata and A. oblongum have excelled in height and diameter growth over the remaining tree species e.g. A. catechu, A. nilotica; T. arjuna, T. chebula, T. bellerica and Q. leucotrichophora up to 9 years of tree growth. Maximum height and diameter growth was attained by M. composita where values were 7.23 and 9.41 cm, respectively up to 9 years of growth. The minimum height was obtained for T. chebula during the same duration. Leaf area index (LAI) ranged between 1.14 and 2.50 for all the MPTs with G. robusta recording the highest (2.50) while T. chebula the lowest (1.14). Tree species with higher LAI have excelled in growth performance over the species with lower LAI.

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Anju Thakur , P. S. Thakur , Richa Mehta

Abstract

Seeds collected from two natural populations exhibited significant variation in their performance. Seeds from P₂ i.e. relatively drier, sunny, warm and lighted area performed well over the P₁ i.e. cool, shady, wet and less lighted area. Fresh seeds exhibited lesser germination. Maximum germination (77-83%) attained after 3 months, thereafter there was significant and considerable loss of germination capacity after 6 months of storage. Similarly viability of seeds also declined (20%) after 6 months of storage, however, it was not changed significantly after 3 months. Seeds showed better germination potential in light than in dark. Further, seeds of B. aristata were found to be facultatively photoblastic rather than the obligatively photoblastic. P₁ and P₂ registered maximum germination (77 and 83%) at 20°C, however, emergence was highest at 25 ° C, followed by emergence at 20 ° C. Germination completed earlier i.e. in 12 days at 25 ° C in comparison to 34 days at 28°C.

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Rachita Sood , P. S. Thakur

Abstract

An experiment was conducted to determine relative drought tolerance of multipurpose tree species. Five important fuel, fodder and timber tree species namely, Grewia optiva, Morus alba, Dalbergia sissoo, Acacia catechu and Populus deltoides, during first and second summer drought period from April to June (75 days) exhibited differential responses at physiological levels. Xylem water potential (ψ), photosynthesis, transpiration, drought tolerance efficiency, drought injury index and mean daily productivity were significantly less in water stressed plants within each species compared to unstressed plants during first and second summer droughts. Out of the five-agroforestry tree species, physiological attributes were more adversely affected in G. optiva, A. catechu and P. deltoides in comparison to M. alba and D. sissoo. Morus and Dalbergia were able to maintain highest xylem water potential up to 75 days under water stress, whereas G. optiva and P. deltoides recorded the lowest values during the first and second summer drought. Photosynthesis and transpiration rate was reduced to a greater extent in G. optiva, A. catechu and P. deltoides as compared to M. alba and D. sissoo. Drought injury index was minimum in M. alba, followed by D. sissoo, whereas drought tolerance efficiency was maximum up to 75^th day. P. deltoides exhibited maximum injury index during both the summer droughts. Inhibition of mean daily productivity over control was more in G. optiva, A. catechu and P. deltoides in comparison to M. alba and D. sissoo. The results of this study have exhibited relatively better drought tolerance of M. alba and D. sissoo as compared to G. optiva, A. catechu and P. deltoides.

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P. S. Thakur , Anju Thakur

Abstract

Triacontanol (commercial formulations, miraculan and vipul) and mixtalol applied exogenously as foliar spray at 2, 4, 10 ppm enhanced growth potential of Acacia catechu. All formulations increased growth in terms of length, fresh and dry weight at all concentrations, however, mixtalol at 4 ppm was most effective. Maximum increase in shoot length (25%) fresh weight (32%) and dry weight (25.4%) was recorded in mixtalol (4 ppm) treated plants. Regulator treatments not only enhanced growth but also increased total chlorophyll and amino acid content significantly over non-treated plants. Chlorophyll and amino acid increase over control was 77% and 25% respectively in mixtalol treated plants. Stomatal characteristics were significantly affected by regulator treatments. Stomatal pore width increased by 41% stomatal length by 25% and pore area by 78% in case of mixtalol 4 ppm.

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