P. N. Nair

Abstract

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P. N. Nair

Abstract

Till recently the forest areas including forest plantations were intented only for production of timher and other forest produces. In Kerala where population is heavy, land scare, forests limited in extent and agro-c1imatic conditions highly suitable for many cash crops, agro-forestry and multiple cropping are desirable and possible in selected plantation areas. Recently the Kerala forest department has launched a novel scheme of cultivating cash crops such as pepper and cocoa and also valuable medicinal plants as an inter (under) crop in selected areas within forest plantations of Teak, Bombax, Silver oak, Aini etc. The scheme locally known as Venalakshmi scheme was commenced in 1979-80 and will cover 1800-2000 ha in five years. In teak plantations on the banks of perennial streams and rivers, in which final thinning operations have been completed pepper is grown on teak as well as newly introduced additional standards, and cocoa and medicinal plants planted in the interspace, with all facilities for intensive management. Similarly pepper is grown in other plantations such as Aini, Bombax and Silver oak in their early stages. The scheme is financially viable. From the observations made so far the results are highly encouraging and it is hoped that more and more plantation areas can be brought under this scheme. The main advantages are: (I) no forest area is lost, (2) production of crops such as pepper, cocoa and medicinal plants, is possible without affecting timber production in the same area, (3) generates rural employment particularly to the tribals, (4) increases revenue returns from the same area, (5) does not deteriorate the environment otherwise contributed by forest plantations.

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P. N. Nair

Abstract

About one fourth of the forests in the world belongs to the U.S.S.R. The wooded forest area in the Soviet Union comes to about 33.2 per cent of the country's total area. There are different forest types with many sub-divisions differing in their geographical distribution, composition and productivity. Most of the forest wealth in the country is mainly concentrated in the north temperate zone. The predominant species are spruce, fir, pines, larch, birch, aspen, oaks, chestnut, etc., and each genus is represented by many species and forms. Natural regeneration of these forests is satisfactory. The forests in the U.S.S.R. are very important natural resources and they playa very important role in the national welfare. The resourCes of timber in this country comprises about 80 billion cu m. Considerable portions of these forests have not yet been tapped. Attempts are afoot in increasing the productivity of the forests particularly the low productive forests by artificial and natural regeneration m ethods. About 2.5 million hectares are thus being regenerated annually in recent years, of which about 1.2 million hectares are tackled by artificial means. The magnitude of various forestry operations is so huge that a variety of mechanical device, have been developed to ensure their speedy excution. The world wide accepted theme of multiple use of forests is the main aim of Soviet forestry also. A variety of products are being manufactured out of the forest produces . One of the increasing use of forest timber is for the production of pulp and paper. Spruce and fir arc mainly used in this industry. A beginning has been made in the use of broadleaved species also in this industry. A brief outline on the forests and forest resources in U.S.S.R. is the aim of this article.

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P. N. Nair

Abstract

The forcsts in U.S.S.R. are subject to considerable damage caused by a variety of insect pests and disease causing organisms. Some of them are more or less specific in their choice of hosts and the other ecological conditions, whereas the others are not so specific. The intensity of damage also depends on the environmental conditions, the worst being in a set of conditions in which the pests or the pathogen can multiply profusely. Various control measures have been devised to protect the forests from pests and diseases. The main principle of forest protection lies in keeping the forests in proper sanitary conditions and applying timely measures for the prevention or destruction of pests and diseases. Generally, prophylatic prescriptions aimed at preventing, the outbreak of injurious insects and diseases in forests are made in the plans drawn out for the management of the forests. The sanitary maintenance of the forests is a State responsibility and is regulated by Enactments. The control methods can generally be classified as silvicultural, biological and chemical. Chemical control measures are commonly resorted to in Russian Forestry. The application of the chemical is either by dusting or spraying. Various devices have been made to make the chemical treatment effective 3nd economical. Both aerial and ground applications are made either alone or in combination, depending on the terrain of the forest area, its extent and the nature of pest damage. Special machines, known as aerosol generators, which are used for treatment from ground, are particularly effective in small areas. The spray chat results from this device is in the form of mist thereby enhancing the coverage . The aim of this article is to give a brief and general account of the main pests and diseases that are economically important in U.S.S.R. forestry and the principles and methods of their control. Latest developments: in this field are briefly described.

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P. N. Nair

Abstract

Results of trials so far carried out with tropical conifers in Kerala since 1965 indicate that a few species at least are suitable for introduction in this State. Of these, pines such as Pinus patula, P. insularis (P. kesia) and P. caribaea appear to be best suited for raising plantations at higher altitudes above 1200 m. Other species such as P. roxburghii, P. elliottii, P. pseudostrobus and P. oocarpa also come up fairly well in such altitudes. P. caribaea var. hondurensis, can come up fairly well in lower altitude and foot hill areas also. Among the other conifers Araucaria cunninghamii, Taxodium mucronatum and Cupressus lusitanica come up fairly well at higher altitudes above 800 m whereas Agathis robusta is more tolerant of altitude ranges extending down to 100 m. In general the higher altitude areas in Kerala above 1000 m with better distribution of rainfall appear to be good from a climatic point of view for selected tropical conifers such as P. patula, P. insularis, P. caribaea. P. oocarpa, Araucaria cunninghamii, Taxodium mucronatum and Agathis robusta.

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P. N. Nair

Abstract

The weed Eupatorium odoratum Is a menace in the plantations of Kerala. An experiment was designed and carried out to find the effectiveness of the weedicide Gramoxone on this weed at various concentrations ranging from 0.1% to 0.3% by single and repeated sprayings at three different times of the year at three different localities. In two localities the treatment plots were In the open and In the other locality they were under partial shadc. The results have shown that in the open DO lasting control of the weed could be achieved even with 0.3% concentration of the weedicide sprayed three times a year. The hardier woody portions of the weed remained alive after treatment and new sprouts appeared after some time. The general indications are that under partial shade some control of the weed can be obtained at concentrations of 15% and above. Here when the concentration Is low the number of applications should be three or even more. On the whole, control of Eupatorium by spraying with Gramoxone is not very effective or economical as compared to manual methods.

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