Selection of Candidate Plus Trees of commercially important agro forestry species in Punjab

Transcription

1 Selection of Candidate Plus Trees of commercially important agro forestry species in Punjab Suresh Chauhan 1, Mohit Gera 2 1. Introduction Low productivity of forest and considerable land use change from forest to agriculture in the past has resulted in to enhanced biotic pressure on the existing forests. Therefore, it is imperative to increase the productivity of forest and also the area under tree cover to meet the ever increasing demand for all kinds of timber, fuel wood and NTFP with in the country. Enhancing productivity, timber yield and quality require advanced forest management techniques coupled with superior technological inputs. Clonal technology is one such viable option. Genetically improved clonal planting stock can contribute immensely to meet the demand of timber and wood based products (Lal, 2007). In the cloning process, selection of superior phenotypes or Candidate Plus Trees (CPTs) is the most essential, critical and time consuming step. Selection of the CPTs is the first step towards obtaining stock for developing clonal and seedling seed orchards of superior phenotypes. These superior phenotypes can be selected for their superiority in a single or multiple traits of interest in a single individual. In the present paper, we have tried to develop a simple, scientific and systematic procedure and criteria of selecting the CPTs of various fast growing commercially important agro forestry species, viz., Eucalyptus spp., Dalbergia sissoo, Albizia procera, Acacia catechu, Azadirachta indica and Melia composita in the State of Punjab. The procedure and criteria comprise of a combination of quantitative and qualitative method. Superiority of growth rate of the selected CPTs was compared with the average of surrounding check trees and by ranking them after assigning score for various silvicultural and growth 1 Fellow, Forest and Biodiversity Group, The Energy and Resources Institute (TERI), IHC, Darbari Seth Block, Lodhi Road, New Delhi sureshc@teri.res.in 2 Member Secretary, J&K State Pollution Control Board, Narwal, Jammu. E- mail: mohitgera87@gmail.com

2 parameters. The ranking system helped in identifying the best individual for the progeny trials. 2. Material and methods 2.1 Study area Selection process of CPTs selection of the six tree species was finalised by considering almost all the forest areas of Punjab. The state is located between to N latitude and to E longitude and spread over 50,362 km 2, which is about 1.6 % of the total geographical area of the country. Administratively, the state is divided into 4 divisions, 17 districts, 72 tehsils and 81 developmental blocks. The human population of the state is around million (2001 census figures) with a population density of 484 person per km 2. The state has sub tropical climate with hot summers and cold winters. The minimum temperature in winter falls to 0 0 C and maximum in summer touches 47 0 C. The average annual rainfall varies between 480 mm in the plains to 960 mm in the hilly regions of the state. Agriculture is the backbone of the state s economy, covering an area of about 4.2 million hectare, constituting 84% of total geographical area of the state. The forest area in the state is merely 6% of the total geographical area and is mainly distributed in the northeastern belt of Shivalik hill ranges. Due to the dense population, per capita forest and tree cover is only 0.01 ha (State Forest Report, 2005). Table 1 provides the species wise details of selected CPTs in State of Punjab. Table 1: Number of C P Ts of selected agro forestry tree species in Punjab Forest Division Species and CPT No. Eucalyptus spp. Dalbergia sissoo Albizia procera Acacia catechu Azadirachta indica Melia composita Gurdaspur 3, 4 & 5 1 & 2 13 & Dasuya 1 & 2-7, 8 & 12 11, 12, & 14 Hoshiarpur - - 4, 5 & 6 6, 7, 8, 9 & 10-4 & 5

3 Garhshankar , 4 & Ropar 18-1, 2 & 3 1 & 2 1, 2 & 3 Patiala Sangrur 6, 7, 8, 9, 10 3, 4, 5 & & 5 - & 11 Bhatinda Faridkot 12, 13 & 14 8, 9 & 10 9, 10 & Jalandhar 16 & Ludhiana 15 11, 12, 13, , 9, 10 & 11 & 15 Mansa & 7 - Fatehgarh Sahib & 3 - Total Procedure and criteria developed for selection of CPTs. Since CPTs are the foundation of tree breeding program, one needs to assign high priority and sufficient resources to select them with trained and experienced staff. A team comprised of foresters, scientists (entomologist and pathologist), biomass expert and a field assistant spent almost 30 to 40 days in the field and surveyed almost all the forest divisions/ranges of the state to identify the CPTs of selected agro forestry tree species. The CPTs were selected from the population with age around half the rotation age of the species. Along with each selected CPTs, data of at least ten to twelve surrounding check trees was also recorded to compare the silvicultural parameters, viz., Height, GBH, Volume, Crown spread, Straightness, Natural pruning ability and Number of branches of selected individuals with respect to the average of surrounded check trees or the base population. The selection criteria for CPTs vary from species to species, but many of the basic characteristics remain the same. The individuals having diseases, dead branches, or attacked by any pathogen and pests were rejected in the initial stage of selection. Major characteristics considered for the CPT selection for timber purposes were the

4 straightness, cylindrical bole, non-forking, non-twisting bole, free from buttresses & flutes and minimum taper. The selected tree should dominate the height and girth compared to its surrounding check trees of the same species and age. The objective is that the selected individual should have fast growth, well formed crown, natural pruning ability and free from pests and diseases. In addition, the selected individuals should have thin branches with wide branch angles in case of Dalbergia sissoo, narrow branch angle for Eucalyptus spp. and narrow crown with acute branch angle for Acacia catechu. Besides these characteristics, site selection is also one of the most important aspects, which was considered carefully. Selection was made from even aged pure stands rather than mixed population. Selection was concentrated on plantations that were average or better in traits of interest. The stands where the selective felling has already taken place were avoided since the best trees have already been removed. The CPTs were not selected too close to each other to avoid genetic nearness. A thumb rule of one tree per 1000 trees was considered. After selecting the CPTs, scoring index was generated for each selected individual. Score was given on the basis of selected physical parameters, viz. height, girth at breast height, volume, crown spread, bole straightness, natural pruning ability and number of branches On the basis of the scoring, ranking was awarded to all the individuals. The score for all these parameters was calculated separately. If a candidate for any of the selected parameters is less than the checks, score was deducted in the same scale and is added when the candidate tree was superior to the checks. However, a candidate tree with a minus score in any of the parameter is usually not acceptable except under certain special conditions. Also, if there are no suitable comparison trees nearby, as is often the case, there is no yardstick for judging the candidate tree and thus superior trees may be passed up. a. Height superiority For height superiority, score was calculated as height of selected candidate tree versus average height of surrounding check trees. If the height superiority of selected candidate tree over the average of check trees was less than 10%, 0 score was awarded, if in between 11-12%, a score of 1 was awarded, if in between 13-14%, a score of 2 was

5 awarded, if in between 15-16%, a score of 3 was awarded, if in between 17-18%, a score of 4 was awarded, if in between 18-19%, a score of 5 was awarded, if 20%, a score of 6 was awarded and if more than 20%, a score of 7 was awarded. b. Girth at Breast Height (GBH) GBH superiority was also calculated in the same manner as of the height. If the GBH superiority of selected candidate tree over the average of check trees was less than 10%, a score of 0 was awarded, if in between 11-12%, a score of 1 was awarded, if in between 13-14%, a score of 2 was awarded, if in between 15-16%, a score of 3 was awarded, if in between 17-18%, a score of 4 was awarded, if in between 18-19%, a score of 5 was awarded, if 20%, a score of 6 was awarded and if more than 20%, a score of 7 was awarded. c. Volume For the volume, score was assigned from the formula (Vs/Vc)*10; where Vs = Volume of Candidate tree; Vc = Average Volume of check trees. Volume equation of Eucalyptus spp. was (V = D 2 H) (Chaturvedi, et al.,1982), Dalbergia sissoo (V = D 2 H) (Chaturvedi, et al.,1982), Acacia catechu (V = D D 2 H) (Mishra, et al., 1985), Albizia procera (V = D D) (State Forest Report, 2003) and Azadirachta indica (V = D 2 ) (State Forest Report, 2003) were taken. Volume equation for Melia composita was not available, so volume was not calculated for it. d. Crown spread Crown spread has been assessed ocularly and based on the crown characteristics a score of 0 to 5 was assigned to the candidate select tree on comparison to the average of the check trees.

6 e. Straightness No tree was accepted with excess spiral or crookedness. Scoring was carried out on ocular assessment between 0 to 5 score was awarded to the candidate select tree comparing relative straightness of check trees. f. Natural pruning ability Ability of candidate select tree to shed its lower limbs (dead or alive) as compared to checks was also judged subjectively. If the natural pruning ability of the selected tree is similar to the checks it receives 0 score. On superiority, a score of 1 to 3 was awarded. g. Number of branches Number of branches was also judged subjectively for fodder and fuel wood species, based on the comparison of candidate select individual against the average of checks. Similarly, if the number of branches is equal to average, 0 score was provided and in case of more branches a score of 1 to 5 was awarded. h. Superiority index Apart from this, we have also tried to work out the superiority index of all the CPTs of all the selected species. The superiority index was calculated as the sum of the percent increase in height, girth and volume of the selected CPTs over the average of check trees. While, in case of Melia composita, volume was replaced by GBH. 3. Results and discussion 3.1 Eucalyptus spp. Overall 19 CPTs of Eucalyptus spp. were identified throughout the State of Punjab. The selected CPTs have shown outstanding phenotypic expression with respect to the selected parameters during the selection. As per the scoring index, the height superiority of CPTs ranged from 17 to 50% and volume from 150 to 350% over the base population, which is considered quiet high. The total score varied from 25 to 54 among all the nineteen selected CPTs. CPT No. 9 ranked highest, followed by CPT No. 8, 10, 18, 12, 11, 5, 4,

7 13, 17, 16, 19, 3, 2, 14, 7, 15, 1 and 6 respectively in the descending order. The detail results of the scoring index along with ranking are provided in table 2. Table 2 Ranking of CPTs of Eucalyptus spp on the basis of scores assigned to. CPT No. Score assigned Height Volume Natural Self Pruning Straightness Crown spread Total score Rank Dalbergia sissoo 16 CPTs of Dalbergia sissoo were selected. The scores assigned reveal that the selected CPTs dominate height superiority from 20 to 50% and volume superiority from 120 to 340% over the check trees. The scores varied from 26 to 54 among all the sixteen selected CPTs. CPT No. 14 ranked at the top position, followed by CPT number 12, 15,

8 11, 5, 2, 8, 13, 10, 9, 6, 1, 16, 4,3 and 7 respectively in the decreasing order. The result of the scores assigned with ranking is shown in table 3. Table 3 Ranking of CPTs of Dalbergia sissoo on the basis of scores assigned to. CPT Score assigned No. Height Volume Natural Self Pruning Straightness Crown spread Branches Total score Rank Albizia procera A total of 15 CPTs of Albizia procera were selected and shown in table 4. It is evinced from the table that CPT No.10, 7, 12, 11, 15, 8 and 4 have scored better as compared to CPT No. 13, 3, 5, 1, 2, 6, 9 and 14. Selected CPTs have shown 20 to 40% for height and 130 to 200% for volume higher compared to the average of the checks.

9 Table 4 Ranking of CPTs of Albizia procera on the basis of scores assigned to. CPT No. Score assigned Height Volume Straightness Crown Pruning Branches Total score Rank Acacia catechu A total of 14 CPTs of Acacia catechu were selected. The selection has been done considering the straightness and diameter growth besides other general observations such as bark to heartwood ratio should be less. The scores assigned of selected CPTs are provided in Table 5. The selected CPTs ranking from 1 to 14 showed height superiority from 18 to 40% and volume superiority from 137 to 180% as compared to the base population.

10 Table 5 Ranking of CPTs of Acacia catechu on the basis of scores assigned to. CPT No. Score assigned Height Volume Straightness Crown spread Branches Total score Rank Azadirachta indica In all, 8 CPTs of Azadirachta indica were selected. It is evinced from the scores that the CPTs having rank from 1 to 8 showed height 15 to 50% and volume from 140 to 211% higher compared to the average of checks. CPT No. 3 ranked highest, followed by CPT. No. 4, 5, 1, 2, 6, 7 and 8 respectively in the decreasing order. Table 6 Ranking of CPTs of Azadirachta indica on the basis of scores assigned to. CPT No. Score assigned Height Volume Straightness Crown Pruning Branches Total score Rank

11 3.6 Melia composita A total of 11 CPTs of Melia composita were identified through out the entire state. The height superiority of the selected CPTs ranged from 15 to 45% over the base population. Local volume equation of the species was not available, so the volume was not calculated. The scores varied from 39 to 89 among all the eleven selected CPTs. CPT No. 10 ranked the top position, followed by CPT No. 4, 11, 5, 9, 1, 6, 8, 3, 2 and 7 respectively in the descending order. Table 7 Ranking of CPTs of Melia composita on the basis of scores assigned to. CPT No. Score assigned Height GBH Natural Self Straightness Crown Branches Total Rank pruning spread score Superiority index The finding reveals that the superiority index of Eucalyptus spp. varies between 50 to 138%, Dalbergia sissoo 34 to 131%, Albizia procera 56 to 116%, Acacia catechu 29 to 99%, Azadirachta indica 37 to 154% and Melia composita 18 to 84%. Variation of superiority index among the CPTs of each selected species was found very high. CPTs of each species at higher superiority index showed higher rank.

12 Table 8: Superiority index of selected farm forestry species CPT No. Eucalyptus spp. (%) Dalbergia sissoo (%) Albizia procera (%) Acacia catechu (%) Azadirachta indica (%) Melia composita (%) Conclusion It has been estimated that around 120 forestry species are utilized for various afforestation programs in India (Mohanan and Sharma, 2005). Eucalyptus spp., Dalbergia sissoo, Albizia procera, Acacia catechu, Azadirachta indica and Melia composita are amongst the species most commonly planted for reforestation and under farm forestry plantations. Despite the availability of methods for vegetative multiplication of these commercially important tree species, required progress has not been made for cloning of these tree species for large scale production of quality planting stock. Unfortunately, the country is far behind in exploiting the tremendous potential of

13 vegetative propagation and cloning techniques for improving productivity and wood quality of our plantations. The findings of the present study may be helpful in identifying CPTs in a scientific manner by taking into account the objective as well as subjective assessment of the parameters in a simple and systematic way. Also, one can easily identify the best individuals for laying out the progeny trials and multi locational clonal trials. This would further help in selection of clones with still higher productivity. The procedure and criteria of selecting CPTs of selected tree species presented in this article will benefit the state forest departments, farmers, nursery owners and private planters who are directly or indirectly engaged in clonal technology program within the country. The findings of the study will also help in enhancing the productivity of forestry and agro-forestry plantations through clonal technology program. Summary The present article aims towards the development of procedure and criteria for selecting the CPTs of six fast growing agro forestry species in State of PunjabSuperiority of growth rate of the selected CPTs was compared with the average of surrounding check trees and scores were assigned to each selected CPTs for various silvicultural parameters indicating higher productivity and good health. The CPTs were further ranked on the basis of assigned scores, which helped in identifying the best suitable CPTs for each selected species. A total 19, 16, 15, 14, 8, and 11 CPTs were identified for Eucalyptus spp., Dalbergia sissoo, Albizia procera, Acacia catechu, Azadirachta indica and Melia composita respectively through out the State. CPT No. 9, 14, 10, 1, 3 and 10 were ranked as the best among their group for Eucalyptus spp., Dalbergia sissoo, Albizia procera, Acacia catechu, Azadirachta indica and Melia composita species respectively. Besides, superiority index of all the selected species was calculated, which is expected to further help in identifying the best individuals for the progeny trials and multi-locational clonal trials.

14 Acknowledgement The authors are grateful to Punjab Forest Department for providing funding support under JICA and also supporting in the field. References: 1. Chaturvedi, A.N and L.S. Khanna (1982). Forest Mensuration and Biometry. International Book Distributors, Dehradun: Lal, P (2007). Productivity of clonal plantations in northern India. Indian Forester: Mishra, N.M and J. Singh (1985). Local volume tables of Acacia catechu and Lannea grandis. Indian Forester: 111(6): Mohanan, C and J.K. Sharma (2005). Improvement of seedling production system in forestry sector and its impact on seedling health. Working papers of the Finnish Forest Research Institute. ( papers/2005/mwp011.htm). 5. State Forest Report. (2003). Forest Survey of India. Ministry of Environment and Forest, Government of India. 6. State Forest Report. (2005). Forest Survey of India. Ministry of Environment and Forest, Government of India.