Shot-hole disease of Terminalia paniculata caused by Cylindrocladium quinqueseptatum - a new record1

A shot-hole leaf disease Terminalia paniculata caused by Cylindrocladion quinqueseplatium is reported from Kerala, India. Symptoms of the disease and pathogenicity of the isolate are described.     

Bacteria wilt of Casuarina equisetifolia in India

Pseudomonas solanacearum (Smith) was consistently isolated from the wilted plants of Casuarina equisetifolia. The isolate gave positive reaction to oxidase, catalase and gas production from nitrate and negative reaction for arginine dihydrolase and acid was produced from various carbohydrates. Wilt produced on tomato, egg plant and capsicum indicated that the pathogen belongs to Race I and Biovar III of P. solanacearum which is a new record from India.     

Anthropogenic Influences on Wild Nutmeg Fruit Crop in the Western Ghats of India

Myristica dactyloides is characteristic of the mid- and high-elevation evergreen forests of the Western Ghats of India. Aril and seeds of the species are valuable nontimber forest products and are harvested extensively. We made visual estimates of fruit crop size in nine populations. We assessed disturbance using five variables: distance from road, method of harvesting fruits, nonforest matrix around the population, seedling regeneration, and protected area status. Unsustainable harvest and proximity to road impacted fruit crop, as did the nonforest matrix (F = 38.17 df = 5,102, p < .001). While high protection and measures against harvesting keep some populations safe, the harvest method plays a crucial role in determining total fruit production and seedling recruitment in the species.     

A study of the potential of hedgerow intercropping in semi-arid India using a two-way systematic design

The potential of hedgerow intecrropping with Leucaena leucocephala was explored on vertic Inceptisols over 4 years at ICRISAT Center, Patancheru, India. The study was conducted using a systematic layout involving different alley widths ranging from 1.35 to 4.95 m and with varying distances between hedge and crops. The alleys were cropped with alternate rows of sorghum and pigeonpea. Hedges composed double Leucaena hedgerows 60 cm apart were periodically harvested for fodder. Sole crops of all components and a sorghum/pigeonpea intercrop were included in all four replications of the study.Starting in the second year, Leucaena was progressively more competitive to annual crops, causing substantial yield reduction. Competition (primarily for moisture) was most severe in narrow alleys and was greatest on pigeonpea.The growth of Leucaena was not sufficient to compensate for reduced crop yields. Land equivalent ratios (LERs) calculated on the basis of grain yield of crops and Leucaena fodder yields showed that hedgerow intercropping (HI) was advantageous over sole crops only during the first two years using wide alleys, but disadvantegeous in the last two years. LERs calculated on the basis of total dry matter indicated only a small advantage for HI (13–17 percent) over sole crops in wider (>4 m) alleys. Average returns per year from HI exceeded those of the most productive annual crop system (sorghum/pigeonpea intercropping) by 8 percent in 4.05 m alleys, and by 16 percent in 4.95 m alleys. Fodder production during the dry season was 40 percent of the annual total in these alley widths. Thus hedgerow intercropping at 4–5 m alley width is not very attractive for farmers in semi-arid India, which has 600–700 mm of annual rainfall. There is a need to examine the potential of HI in wider alleys. The merits and limitations of the systematic design are discussed.     

A new anxiolytic fatty acid from Aethusa cynapium

The present investigation was carried out with a view to separate bioactive constituent from Aethusa cynapium. Bioactivity guided fractionation of the anxiolytic methanol extract has led to the isolation of a novel unsaturated fatty acid. Structure of the acid characterized by UV, IR, 1H NMR, C13 NMR, MS techniques was found to be trideca-7, 9, 11-trienoic acid. Antianxiety activity was confirmed using the mCPP-induced hypolocomotion test. This new fatty acid—trideca-7,9,11-trienoic acid, isolated from A. cynapium was found to be responsible for the antianxiety activity of the plant.     

Cardamom, mandarin and nitrogen-fixing trees in agroforestry systems in India's Himalayan region. II. Soil nutrient dynamics

A study on seasonal soil nutrient dynamics was made in large cardamom (Amonum subulatum) and mandarin (Citrus reticulata) agroforestry systems in the Sikkim Himalaya, India. Alnus nepalensis was the N₂-fixing associate in the large cardamom system, and Albizia stipulata in the mandarin agroforestry system. Sites without N₂-fixing species in both agroforestry types comprised native non-symbiotic mixed tree species. Soil was acidic in the cardamom agroforestry and slightly acidic to neutral in the mandarin agroforestry system. Total-N in soils was the highest in the forest-cardamom stand and the lowest in the mandarin-based agroforestry systems. Soil ammonium-N and nitrate-N concentrations were highly seasonal, and the ratio of seasonal maximum and minimum varied up to six times. The C/N ratio was higher in cardamom agroforestry indicating lower N availability than in the mandarin agroforestry. Cardamom stand with Alnus showed a relatively narrower C/N ratio. N₂-fixing species help in maintenance of soil organic matter levels with higher N-mineralization rate as land use change from natural-forest system to agroforestry systems with sparse tree populations. Ratios of inorganic-P/total-P were lower in cardamom agroforestry than the mandarin agroforestry. Seasonal fluctuation in Ca-PO₄, Al-PO₄ and Fe-PO₄ contents regulated the availability of phosphates to some extent for plant uptake.     

A model of seasonal foliage dynamics of the subtropical mangrove species Rhizophora stylosa Griff.growing at the northern limit of its distribution

Background： Progress of forest production in response to the environment requires a quantitative understanding of leaf area development. Therefore, it is necessary to investigate the dynamics of seasonal crown foliage in order to understand the productivity of mangroves, which play an important role in the subtropical and tropical coastlines of the world. Method： Crown foliage dynamics of the mangrove Rhizophora styloso were studies to reveal patterns of leaf recruitment, survival and seasonal leaf area growth. Results： Flushing of leaves occurred throughout the year, but both flushing and leaf area growth pattern of leaves varied with season. Maximum flushing occurred in summer, but leaf areas did not differ significantly with season. The half-expansion period is longer, and the intrinsic rate of increase was lower in winter. Summer flushed leaves grew faster at their initial stage and reached their maximum area over a shorter period of time. The difference in temperature and air vapor pressure deficit （VPD） between summer and winter contributed to the present dynamics of foliage patterns. The mean leaf longevity was estimated to be 13.1 month. The crown foliage area was almost stable throughout the year. Conclusions： Homeostatic control of the crown foliage area may be accompanied by the existence of ecophysiological mechanisms in R. stylosa. Integrating crown foliage dynamics into forest models represents an important step towards incorporating physiological mechanisms into the models for predicting growth responses to environmental changes and for understanding the complex responses of tree growth and litter production.     

Height–diameter equations for boreal tree species in Ontario using a mixed-effects modeling approach

Height–diameter relationships based on stand characteristics (trees/ha, basal area, and dominant stand height) were investigated for balsam fir, balsam poplar, black spruce, jack pine, red pine, trembling aspen, white birch, and white spruce using data from permanent growth study plots in northern Ontario, Canada. Approximately half the data were used to estimate model parameters with the rest used for model evaluation. Multiple Chapman–Richards functions with parameters expressed in terms of various stand characteristics were fit to determine the best models for predicting height.     

Forest utilization patterns and socio-economic status of the Van Gujjar tribe in sub-Himalayan tracts of Uttarakhand, India

The present study was conducted on the Van Gujjar tribe inhabiting a sub-Himalayan tract in the North Western Himalayas of Uttarakhand State,India.The Van Gujjars have been practicing transmigration over hundreds of years.They migrate each year with their households and livestock between summer and winter pastures.A few years ago with the announcement of the establishment of the Rajaji National Park,the tribe has been forced out of the forest area and rehabilitated outside the park,which has affected their lifestyle.The newly established rehabilitation colony in the Gandikhata area of Haridwar District of Uttarakhand State was taken as a case study.The aims of the present study were to understand and evaluate the socio-economic status of the Van Gujjars in their newly established rehabilitation colony,the utilization pattern of forest resources by the tribe and their relative preference for selective trees for various uses.A total of 176 households were interviewed (giving equal weight to all economic classes and family every size) by using pre-structured questionnaires.The education level was very low (12.9%) and the average income per household was recorded as Rs.36000 (approximately $ 803) per year.The major source of income was dairy production (80.6%) followed by labor employment (13.9%),NTFPs (4.2%) and agricultural production (1.4%).More than 90% of fuel wood and fodder is extracted from the forest.The average fuel wood and fodder consumptions per household per day were recorded as 25.86 and 21.58 kg,respectively.A total of 35 species of cultivated plants and 89 species of wild plants were found to be utilized as food sources.Selectively 25 wild tree species are well known as being used by the Van Gujjars as fodder,fuel wood,agricultural implements,household articles,dye,medicine,fiber and other products.According to their utility value,the most preferred and useful tree species is Ougeinia oojeinensis,followed by Terminalia alata,Bombax ceiba,Shorea robusta and Dalbergia sissoo.