Influence of sources and doses of N and K on herbage,oil yield and nutrient uptake of patchouli [Pogostemon cablin (Blanco) Benth.] in semi-arid tropics

Patchouli oil is one of the most important essential oils used in modern perfumery and cosmetic industries. There is hardly any preparation of oriental nature where patchouli oil is not used. It is used mainly because of fixative property as it gives tenacity to other perfumes. Field experiments were conducted at Bangalore, India, to study the influence of sources and doses of N and K on herbage, oil yield, nutrient uptake, nitrogen utilization efficiency and oil content of patchouli [Pogostemon cablin (Blanco) Benth.]. The results revealed that application of 200 kg N/ha and 41.5 kg K/ha produced significant higher patchouli herbage and oil yields compared with controls. Similarly, N and K uptake were also higher at 200 kg N and 41.5 kg K/(ha year) compared with controls. DCD-coated urea produced higher herbage, oil yield and N uptake and utilization efficiency compared with prilled urea. There was no effect of sources of K on the yield of patchouli. The oil content was not influenced by N, K doses or sources applied. N and K depletion were noticed in the soil.     

Decomposition of algal cells and components and their stabilization through complexing with model humic acid-type phenolic polymers

Axenic cultures of Anacystis, Microcoleus, Plectonema and Synechococcus isolated from Greenfield sandy loam and of Anabaena flos-aquae, Nostoc muscorum and Chlorella pyrenoidosa from other sources were cultured under light and constant aeration and with [U-¹⁴C]-glucose in the nutrient medium. Whole cells, cell walls, cytoplasm and extracellular polysaccharides of selected species readily decomposed in the soil and after 22 weeks between 61 and 81% of the added C had evolved as CO₂. Complexing of cell wall and cytoplasmic preparations from A. flos-aquae and N. muscorum with model humic acid-type phenolic polymers reduced decomposition of the cell walls by 40% and of the cytoplasm by 70%. Over 50% of the residual 14C activity in the soil amended with whole algal cells remained in the 0.5% NaOH-extracted soil. With exception of Microcoleus sp. more of the residual ¹⁴C from cell walls, cytoplasm and polysaccharide fractions was present in the humic acid or fulvic acid fractions.     

Pearl Millet Phenology and Growth in Relation to Thermal Time under Arid Environment

Pearl millet ( Pennisetum glaucum L.R.Br.) hybrid MH 179 was grown under two moisture regimes viz., optimal moisture and rainfed conditions. The field experiment was continued for three consecutive rainy seasons to quantify the pearl millet development with thermal time. The possible influence of variation in natural sowing date on the relationships between crop development and thermal time have been described. At cardinal temperatures of 10°C (base temperature below which pearl millet development ceases), 33°C (optimal temperature for development) and 45°C (maximum temperature at and above which no development takes place), the crop required 1490–1794°Cd thermal time to reach physiological maturity. The thermal time requirement for different developmental stages was influenced by the sowing time and moisture availability during the growing season of the crop.
The leaf tip appearance on the main shoot of pearl millet in relation to thermal time was almost linear under both moisture conditions requiring about 44–50°Cd ± 2.6 °Cd leaf⁻¹, till the appearance of the flag (last) leaf. However, leaf tip appearance on primary tillers was slightly slower and required 53-58°Cd ± 4.7°Cd for each new leaf. Appearance of first primary tiller was later (at 320°Cd after emergence) under the rainfed condition as compared to the crop under the optimal moisture (at 250°Cd).Thereafter, the tiller appearance in relation to thermal time under both moisture conditions was at a linear rate of about 53-56°Cd ± 9.5°Cd tiller⁻¹.
Effect of microclimatic variations, canopy temperature, radiation and photoperiod on the phenology-thermal time relationships have been discussed under both the moisture conditions.     

Intercropping Studies in Lemongrass (Cymbopogon flexuosus) (Steud. Wats.)

Lemongrass ( Cymbopogon flexuosus (Steud.) Wats) is a perennial, multicut aromatic grass, which yields an essential oil used in perfumery and pharmaceutical industries and Vitamin A, has a long initial lag phase. To utilize the crop growth resources more efficiently during this phase, studies were made to explore the possibility of intercropping food legumes with lemongrass. An experiment conducted during 1992–93 revealed that the food legumes like blackgram ( Vigna mungo (L) Hepper), cowpea ( Vigna unguiculata (L) Walp) or soybean ( Glycine max (L) Merr.) could be intercropped in the initial stages of lemongrass to get extra yields over and above that of lemongrass, without affecting the yield of lemongrass.     

Assessment of clonal fidelity of micropropagated gerbera plants by ISSR markers

True-to-type clonal fidelity is one of the most important pre-requisites in micropropagation of crop species. Genetic fidelity of in vitro raised 45 plants of gerbera (Gerbera jamesonii Bolus) derived from three different explants, viz., capitulum, leaf and shoot tips, was assessed by 32 ISSR markers, for their genetic stability. Out of 32 ISSR markers, 15 markers produced clear, distinct and scorable bands with an average of 5.47 bands per marker. The markers designed from AG motif amplified more number of bands. The markers anchored at 3′ ends produced high number of consistent bands than unanchored markers. Fifteen ISSR markers generated a total of 3773 bands, out of which 3770 were monomorphic among all the clones. The Jaccard's similarity coefficient revealed that out of 45 clones derived from different explants, 44 were grouped into a single large cluster alongwith the mother plant with a similarity coefficient value of 1.00, whereas one clone (C38) remained ungrouped. The clones derived from capitulum and shoot tip explants did not show any genetic variation, whereas, one of the leaf-derived clones exhibited some degree of variation.     

Nutritional stress as a cause of thymic atrophy in broiler chickens

A study was conducted to examine the effect of nutritional stress on the development of the thymus, bursa, and pancreas of 7-to-14-day-old commercial meat-type chickens. One group of 7-day-old chickens was given access to food for only 30 minutes daily for 7 days. The birds were necropsied, and the thymus, pancreas, and bursa were compared with those of the control chickens fed ad libitum and necropsied at 7 and 14 days of age. The thymuses from birds on the restricted diet were atrophied (0.45 +/- 0.08 g) and congested compared with the thymuses from chickens fed ad libitum (1.32 +/- 0.31 g). The bursae from chickens on a restricted diet were also smaller (0.26 +/- 0.08 g) than the bursae from birds with free access to food (0.74 +/- 0.11 g). The restricted diet did not appear to cause any gross or histological pancreatic changes. The thymic lesions produced by nutritional stress were similar to those observed in the runting/stunting syndrome.     

Community forestry for revitalising rural ecosystems: A case study

A case study focusing on the socio-economic and ecological aspects of a forest-based village, Debrasai, in the Singhbhum District of Bihar, India was undertaken in 1980 to evolve village-specific community forestry package programmes that could bring stability to the village both economically as well as ecologically. The village extending over 365.07 ha is inhabited by 361 people comprising 195 males and 166 females in 81 households. The villagers are by and large dependent on agriculture and forestry for their livelihood. The largest proportion of the land in the village is under agriculture whereas forests, in a highly degraded state, occupy only 5.7% of the total area. The villagers exploit the protected forests in their vicinity removing nearly 350.9 mt of fuelwood, 22.8 mt of small timber and 393.4 mt of fodder annually.The village has a manpower potential of 40 035 man days a year. Agriculture is the main source of employment at the moment absorbing 14 266 man days. The non-agricultural sector provides employment to an extent of 4433 man days. Fresh employment opportunities are needed to absorb nearly 53% of man days of the village at present unused. Three land-resource, skill-based package programmes, a tasar silk culture, an energy plantation, and dairying have been suggested to generate employment opportunities and to meet the basic needs of the villagers. About 115 ha of the hitherto neglected land resource has been located in the village to sustain such community forestry (CF) programmes. Tasar culture suggested on 35 ha will alone generate employment to an extent of 18 690 man days from the fourth year of tasar silk plantation. A plantation, to provide energy and fodder, on 25 and 30 ha respectively is expected to yield fuelwood, timber and fodder to more than satisfy village needs. A dairy has been recommended as it will generate income, provide nutrition and promote gobar gas production — an alternative energy source to fuelwood. The cost—benefit analysis of these projects indicates their economic feasibility with the cost likely to be recovered in 4.5 years. Debrasai being an agricultural village, a land-inequity compensatory scheme has been suggested for CF project net benefit sharing, ensuring reasonable benefit flows to the landless and marginal farmers.     

Reclamation of saline‐sodic soil under a rice–wheat system by horizontal surface flushing

Saline sodic soil with a high content of soluble carbonates is one of the important agricultural soils on the Central Indo‐Gangetic plains and elsewhere. Conventional reclamation procedures using gypsum application followed by vertical leaching (GC) is uneconomic; high ECe and precipitation of applied gypsum, reacting with soluble carbonates, reduce the efficacy of gypsum in these soils. This paper reports results from a project designed to evaluate reclamation by irrigation of the ploughed soil and turning of soil with a power tiller followed by flushing of standing water after 24 h, a second flushing after 7 days and subsequent application of gypsum and vertical leaching (GF2). Average rice and wheat production after GF2 significantly increased (25 and 62%, respectively) over the conventional practice. Compared with conventional treatment, GF2 significantly reduced the ECe and SAR of the soil and improved physical properties such as ζ‐potential, dispersible clay content, water stable aggregates expressed as MWD, and saturated hydraulic conductivity. Split application of gypsum between flushing (GF1/2 and GF2/3) gave similar results to GF2 in terms of soil amelioration and crop production.