རྒྱལ༌ཡོངས༌སོ་ཤིང༌སྲུང༌སྐོབས༌ལྟེ༌བ། སོ་ནམ་ལས་ཁུངས། སོ་ནམ་དང ... · viii

རྒྱལ ༌ ཡོངས ༌སོ ་ཤི ང ༌སྲུང ༌ སོྐབས ༌ལྟེ ༌ བ ། སོ་ནམ་ལས་ཁུངས། སོ་ནམ་དང་ནགས་ཚལ་ ལྷན་ཁག།

NATIONAL PLANT PROTECTION CENTREDEPARTMENT OF AGRICULTURE

MINISTRY OF AGRICULTURE & FORESTSSEMTOKHA

ANNUAL PROGRESS REPORT2016-2017

Annual Progress Report 2016-2017 • iii

FOREwORd

The National Plant Protection Centre (NPPC) is pleased to publish its Annual report 2016-17 reflecting its major achievements and challenges that were made and faced during the past year. As usual, this Annual Report represents a joint efforts put in by all our researchers, support staff and all the collaborating agencies. The documentation of annual activities is purely focused to serves as a referral material and to present possibilities of collaboration and cooperation with the agencies and institutions from both within and outside the Ministry of Agriculture & Forests.

The NPPC is mandated to function as National Referral and Coordinating Centre for all Plant Protection (PP) activities including: (i) information management system (surveillance & pest database) and pest risk analysis,(ii) research and development in all areas of plant protection, (iii) provide diagnostic services in identifying pests, diseases, weeds and vertebrate pests, (iv) laboratory and advisory services (v) education and awareness services and (vi) Regional and International coordination and collaborative activities.

In view of these mandates and the efforts put forth by the Centre and its staff, the document briefly highlights the major achievements and challenges faced in carrying out the following activities under each individual units.

i. A survey on insects pests of brassica vegetables and their management practices in Bjemina under Mewang Gewog, Thimphu Dzongkhagwas carried out by the Entomology Unit of the Centre. It was conducted to collect information on pest types infesting brassicas so as to develop and generate effective pest management strategies.

ii. Survey to document rice pests in Chuzergang Gewog under Sarpang Dzongkhag

iii. Chilli blight management and awareness program in major chili growing areas Testing of citrus samples for HLB

རྒྱལ ༌ ཡོངས ༌སོ ་ཤི ང ༌སྲུང ༌ སོྐབས ༌ལྟེ ༌ བ ། སོ་ནམ་ལས་ཁུངས། སོ་ནམ་དང་ནགས་ཚལ་ ལྷན་ཁག།

NATIONAL PLANT PROTECTION CENTREDEPARTMENT OF AGRICULTURE

MINISTRY OF AGRICULTURE & FORESTSSEMTOKHA

iv • Annual Progress Report 2016-2017

iv. Pest and disease identification survey of mango and avocado

v. Development of National Pest Database to serve as a repository and a reference bank for all pests and disease

vi. Enhancement of the e-pest surveillance system for all pest surveillance activities in the country

vii. Supply of all plant protection products

viii. Development of weed control technology in transplanted rice in Bhutan

ix. Hands on training on the Global Positioning System (GPS) for the agricultural officials of the Wangduephodrang Dzongkhag.

All these activities, both planned and ad-hoc, highlighted in this document and those gone unaccounted are achieved through strong collaboration with the Dzongkhags and the Gewog Extension officials and the ARDCs. Therefore, the NPPC team would like to take this opportunity to thank all our collaborators in making the year a successful one. Lastly, hearty congratulations to all the staff of NPPC for their unwavering support and dedication in making this year a very successful one.

Trashi Delek!

Yeshey DemaProgram director

Annual Progress Report 2016-2017 • v

TAbLE OF CONTENTS

1. Entomology Unit ....................................................................................................... 1

1.1 Farmers survey on insect pests of brassica vegetable and their managements in Bjemina, Mewang Gewog ........................................................................................ 1

1.1.1 Introduction ..................................................................................................... 1

1.1.2 Materials and Methods ................................................................................... 1

1.1.3 Results ............................................................................................................... 1

1.1.4 Discussion ........................................................................................................ 5

1.2 Farmers survey on rice insect pests in Chuzergang ............................................. 6

1.2.1 Introduction ..................................................................................................... 6

1.2.2 Materials and Methods ................................................................................... 6

1.2.3 Results ............................................................................................................... 7

1.2.4 Discussion ........................................................................................................ 8

2. Pathology Unit ........................................................................................................... 9

2.1 Chili blight management awareness program ....................................................... 9

2.1.1 Introduction ..................................................................................................... 9

2.1.2 Activities ........................................................................................................... 9

2.1.3 Question and answer session ....................................................................... 10

2.1.4 Field operation practices .............................................................................. 10

2.1.5 Highlights of the program ........................................................................... 11

2.1.6 Future direction ............................................................................................. 11

2.2 Pest and disease identification survey of mango and avocado .......................... 13

2.2.1 Introduction ................................................................................................... 13

2.2.2 Methods .......................................................................................................... 13

2.2.3 Results ............................................................................................................. 13

2.2.4 Recommendation .......................................................................................... 16

2.3 Survey of potato wart disease ................................................................................ 17

2.3.1 Introduction ................................................................................................... 17

vi • Annual Progress Report 2016-2017

2.3.2 Survey method .............................................................................................. 18

2.3.3 Results ............................................................................................................. 18

2.3.4 Discussion ...................................................................................................... 18

2.4 Testing of citrus samples for HLB in 2016 ........................................................... 19

3. Surveillance Unit ..................................................................................................... 22

3.1 National Plant Pest Database (NPPD) .................................................................. 22

3.1.1 Introduction ................................................................................................... 22

3.1.2 Structure of NPPD ........................................................................................ 22

3.1.3 Result .............................................................................................................. 23

3.1.4 Conclusion ..................................................................................................... 23

3.2 Enhancement of ePest surveillance system .......................................................... 23

3.2.1 Introduction ................................................................................................... 23

3.2.2 Surveillance system enhancement .............................................................. 24

3.2.3 Conclusion ..................................................................................................... 24

4. Plant Protection Product Unit ............................................................................... 25

4.1 Supply of plant protection products ..................................................................... 25

5. Weeds and Vertebrate Unit .................................................................................... 27

5.1 Development of Weed Control Technology in Transplanted Rice in Bhutan . 27

5.1.1 Introduction ................................................................................................... 27

5.1.2 Materials and methods ................................................................................. 27

5.1.3 Results ............................................................................................................. 30

5.1.4 Conclusion ..................................................................................................... 31

5.2 Training on the Global Positioning System to Agriculture Officials of Wangduephodrang Dzongkhag to Collect Wildlife Crop Damages Information .............................................................................................................. 31

5.2.1 Introduction ................................................................................................... 31

5.2.2 Training outcome and future work ............................................................. 33

Annual Progress Report 2016-2017 • 1

1. ENTOmOLOGy UNIT

1.1 Farmers survey on insect pests of brassica vegetable and their managements in bjemina, mewang Gewog

1.1.1 Introduction

Brassica vegetables such as cabbage, cauliflower and broccoli are prone to insect attack. Most common pests are cabbage white butterfly, diamondback moth, cutworms, cabbage loopers, aphids and harlequin bugs. Damages due to these pests reduce yield and market value. Farmers are known to practice cultural methods such as broadcasting of ash and removal of infested plants. Additionally, some farmers also use pesticides to prevent and control pest infestations. However, insect pests in these vegetables still remain a problem. Frequent outbreaks of pests, especially diamondback moth, are reported where pesticides are not effective. One factor may be due to development of insect’s resistance because of prolonged use of insecticides in these crops.

Therefore, this survey was conducted to gather information on the types of pests infesting brassica vegetables (cabbage, cauliflower and broccoli) and pest management measures used by the farmers including use of insecticides and performance of pest scouting before and after use of insecticides. The results of the survey will be used to develop and generate effective insect pest management strategies.

1.1.2 materials and methods

The survey was conducted from 1-2 August 2016 in Bjemina (27.4298°N, 89.5410°E, 2467 m ASL), Mewang Gewog under Thimphu Dzongkhag.

Vegetable growers were interviewed using a questionnaire developed by the Entomology Unit of the NPPC based on the methods and parameters used by Alibu et al. (2016). A total of 33 farmers were chosen randomly for the interview. Interview questions included types of varieties cultivated, types of insect pests and ranking of pest according to their damage, whether pest scouting is conducted or not, and where famers get information on pest management. Farmers were also asked about prevention and control of pests and the types of pesticides used. To help identify the different pests and to record the significance of their damage, pictures of pests were shown to farmers who were then asked

2 • Annual Progress Report 2016-2017

to rank the pest(s) on a scale of 1 to 5 with 1 being the most damaging and 5 the least damaging. Pest ranking was determined by calculating the number of respondents ranking a particular pest and converting into percent of respondents. Data were analysed using pivot table in Microsoft Excel.

1.1.3 Results

1.1.3.1 Varieties cultivated

The commonly cultivated varieties of cabbage in the gewog are Green Cornet, Golden cross and Bondey Cross. Cultivars of cauliflower are R.K and Snow Mastique, and that of broccoli is Centauro.

1.1.3.2 Ranking of pests

Figure 1.1 shows the ranking of different pests by the farmers. On a scale of 1 to 5, ~61% (20 farmers) of the respondents ranked diamondback moth as the most damaging pest (a scale of 1) while cabbage white butterfly and cutworm were ranked as most damaging by 24% (8 farmers) and 12% (4 farmers) of the respondents respectively. Only 3% (1 farmer) reported cabbage loopers as damaging. No damage was reported by cabbage aphid and harlequin bugs.

Figure 1.1. Percentage of respondents ranking each pest type as the most damaging.


1.1.3.3 Pest scouting

The percentage of farmers performing pest scouting is given in Table 1.1 Results show that 94% of respondents conduct pest scouting. Majority (50%) of the farmers responded scouting for pests on a daily basis while 18% responded to perform pest scouting 2-3 times per week. About 15% perform pest scouting on a weekly basis. Three percent (1 farmer) perform pest scouting five times a week while another 3% responded to scout on irregular basis.

1.1.3.4 Source of information on pest management

When asked about sources of information on pest management, 58% (19 farmers) responded that they get pest management information from the extension agent while 18% (6 farmers) responded to get information from their neighbours (Figure 1.2). Others indicated IPM publications, media and other sources as their source of information.

1.1.3.5 Preventive measures against infestation of pests

Regarding use of pest infestation prevention measures, 40% of the farmers responded to maintain good field sanitation like weeding, removing infested plants and hand picking of pests while 15% responded not to do anything. Eighteen percent of the farmers used ashes and maintained good sanitation while 9% used only ashes to prevent pests. Another 9% of the farmers used insecticides while the remaining 9% refused to answer (Figure 1.3).

1.1.3.6 Control of pests

Farmers’ responses to pest control measures are given in Figure 1.4. Results show that 70% of the farmers sprayed pesticides once infestation is detected while 15% rely on hand picking of pests and destruction. Three percent of the farmers responded not do anything and 12% of the farmers refused to answer.

Table 1.1 Percentage of farmers performing pest scouting. Perform pest

scouting % of

respondents2-3 times per week

5 times per week

daily Irregular weekly

Yes 94 18 3 55 3 15No 6


Figure 1.2. Source of pest management information for farmers

Figure 1.3. Percentage of farmers responding to different types of pest prevention measures.


Figure 1.4. Percentage of farmers using different pest control measures (NA= no answer).

1.1.3.7 Types of pesticide use

On the use of types of pesticides, 64% of the farmers used fenvalerate and cypermethrin (Figure 1.5). Only 9% used fenvalerate only while the remaining used others such as dimethoate and malathion together with cypermethrin. One farmer did not use any synthetic pesticide and, when asked, responded to use ashes and cow urine. Fifteen percent of the farmers refused to answer (Figure 1.5).

Figure 1.5. Percentage of farmers using different types of pesticides and other products.


1.1.3.8 Post pesticide spray monitoring of crops When asked about monitoring crops after pesticide sprays, 58% of the farmers responded to always check the crop within in a few days or a week after spray (Figure 1.6) while 27% of the farmers responded to check sometimes. Six percent of the farmers refused to answer.

Figure 1.6. percentage of farmers monitoring crops after pesticide application.

1.1.4 discussion

The current survey was conducted to gather information on pests infesting brassica vegetables (cabbage, cauliflower and broccoli) and pest management measures used by the farmers. Results indicated that diamondback moth was the most damaging pest followed by cabbage white butterfly, cut worm and cabbage loopers in the decreasing order.

Although 40% of the farmers claimed to maintain good field sanitation as a measure against pest infestations, the survey findings also indicated that only 3% of the farmers did not use any pesticides and most farmers resort to pesticides to control insect pest in the vegetables. More common insecticides used by the farmers were cypermethrin and fenvalerate while some used malathion and dimethoate also. Further, more than half of the famers responded to conducting pest scouting daily and monitoring the crops after pesticide spray within a few days. While pest scouting on a daily basis is a good practice, entering fields within a few days after pesticide spray is not recommended.

Although direct assessment of insecticide resistance development was not covered by the survey, the findings that most farmers used insecticides to


manage insect problems indicate that resistant development may be an issue. This requires further assessment including campaign on insecticide uses and resistant development.

The study provides information on damaging pests and pesticide use and is useful for future research and development activities and training programs in the area. Additionally, the NPPC should focus to prepare pest management protocols on diamondback moth, cabbage white butterfly and cutworm in these crops. Future studies should focus on issues such as the type and frequency of insecticide used, and how long the farmers had been using the same type of insecticides. Aspects of pesticide usage such as safe handling, knowledge on calibration and disposal/handling of pesticide left overs and containers could also be studied.

References

Alibu S, Otim M H, Okella SEA, Lamo J, Ekobu M and Asea G. 2016. Farmer’s knowledge and perceptions on rice insect pests and their management in Uganda. Agriculture 6 (38): 1-10. Online at www.mdpi.com/2077-0472/6/3/38/pdf.


1.2 Farmers survey on rice insect pests in Chuzergang

1.2.1 Introduction

Chuzergang is considered as the rice bowls of Bhutan where farmers of nine villages with 420 households cultivating rice. The best possible Chhuzhings (paddy fields) are found in Chuzergang. The gewog is benefited by the Taklai irrigation channel. The total paddy production targeted is 1354 MT with 2200 acres under cultivation in 2017-2018 (Source: DoA APA 2017-2018). Forty percent of the total rice production is marketed to the neighbouring Indian markets and Sarpang Town which is the local commercial centre. The common local varieties grown are Khamti, Chanphay, Mama, Agumsali and Masino. Varieties Bd28 and Br26 are improved paddy varieties grown in the gewog.

Frequent incidences of rice pests especially rice armyworms, caseworms and stem borers occur during the rice season. Rice growers in the gewog have limited knowledge on rice pests/diseases. Insecticides, mainly chlorpyrifos and cypermethrin, are used to control the rice pests. Farmers are also not aware of technologies such as use of pheromone traps to monitor pests. Therefore, the NPPC initiated a survey to gather information on types of insect pest infestation and the crop stage at which infestation occur which can help the NPPC to develop cost effective IPM strategies for managing insect pests in rice.

1.2.2 materials and methodsThe survey was conducted in Shawapong, Yueling and Pangzor Chiwogs under Chuzergang Gewog (Figure 1.7) from 19-20 November 2017. A total of 44 farmers were used for the interview survey by randomly selecting 13, 15 and 16 farmers from Shawapong, Pangzor, and Yueling Chiwogs respectively. Farmers were interviewed using a questionnaire that was developed by the Entomology Unit of the NPPC. During the interview, pictures of rice insect pests were shown to farmers. Then, the farmers were asked to identify the most damaging pest(s) and indicate the paddy stage at which each insect pest occurred. Data were analysed using Microsoft Excel.

1.2.3 Results

Based on the percent respondents, rice case worm was recorded as the most damaging pest in all three chiwogs and occurred during tillering stage (Figure


1.8). Rice stem borer was ranked as the second most damaging pest in both Shawapong and Pangzor Chiwogs and occurred during panicle initiation. Rice gundhi bug was reported as the second most damaging pest in Yueling Chiwog and occurred during ripening stage. Other pests such as rice armyworm, leaf folder, green horned caterpillar, and rice leaf folder were identified as less damaging. Rice army worm was the only pest reported to occur during seedling stage and occurred only in Yueling. Rice leaf and plant hoppers, and mealy bugs were not known to cause any damage (Figure 1.8).

Figure 1.7. Map of Chuzergang Gewog. Chiwogs where the survey was conducted are indicated with stars (Photo courtesy: Election commission of Bhutan).


Figure 1.8. Percent of respondents and rice insect pests at different growth stage in Shawapong (S/pang, n=13), Yueling (Y/ling, n=16), and Pangzor (P/zor, n=15) Chiwogs.

1.2.4 discussion

The survey found that rice case worm was the most damaging pest with tillering stage being the most susceptible stage for the infestation. Caseworm is found mostly in rice fields with standing water, in both wetland and irrigated environments. Transplanting young seedlings also favours the development of rice caseworm. A rice field with standing water increases the pest’s abundance. Results also showed that rice stem borers were the second most damaging rice pest. Rice stem borer attack can occur more commonly in rice grown under flooded condition and larvae bores through the emerging panicles that are whitish and unfilled or empty. Gundhi bugs are found in all rice environments and are found sucking out the contents of developing grains. In Bhutan, most rice cultivation are done under flooded or standing water condition. Hence, it is not surprising to find these insect pests in the rice fields in Chuzergang.

Farmers had not reported leaf and plant hoppers during the survey. This is probably because most of the farmers were not able to identify hoppers. Some farmers had never seen plant and leaf hoppers. The results of the survey suggest that the NPPC should focus pest management activities on rice case worms, stem borers and gundhi bugs at the appropriate plant stage.

Comments:

1. Replacedthegraphatpageno10withAbovegraph2. Addtelephonenumberininsidecoverpage:Telephoneno:+97502351016Faxno:+97502

351656


References

Simon Alibu, Michael H. Otim, Stella E. A. Okello, Jimmy Lamo, Moses Ekobu and Godfrey Asea: Farmer’s Knowledge and Perceptions on Rice Insect Pests and Their Management in Uganda

Karthikeyan, K. Report of a new parasitoid attacking rice case worm, Paraponyx stagnalis (Zeller) from India, Regional Agricultural Research Station, Pattambi, Kerala

http://www.knowledgebank.irri.org/


1. PAThOLOGy UNIT

1.1 Chili blight management awareness program

1.1.1 Introduction

Phytophthora blight, more commonly as known chili blight, is caused by the Phytophthora capsici. The pathogen can infect all parts of the chili plant at any growth stage. The main symptoms of the disease are sudden wilting, collar rot, discolouration of the stem at the soil line, water-soaked lesions on leaves, stems, and fruit. Infected fruits appear blanched due to coalescing of lesions. The pathogen is spread within and between plants by irrigation water and rain. Moving infected plant material, soil and farm equipment can also spread the pathogen.

Chili cultivation is one of the main activities of farmers of Ramjar in Trashi Yangtse, and Kangpar and Thrimshing in Trashigang. It is the main source of income for the farmers of these gewogs. Although they have been into chili cultivation for years, managing chili blight has been their main constrain. Therefore, this awareness program was conducted at Ramjar in Trashi Yangtse, and Kangpar and Thrimshing in Trashigang to advocate the management practices to the farmers of these gewogs. During the awareness campaign, the team also visited chili fields and recorded field operation practices adopted in these areas.

1.1.2 Activities

1.1.2.1 Trashi Yangste

In Trashi Yangtse, the awareness program was conducted at Ramjar on 28 December 2016. One day before the program, the team visited various fields to select a suitable site for conducting the demonstration on blight management. The program was attended by 51 farmers and eight extension agents from each of the eight gewogs of Trashi Yangtse.

The program was conducted in two sessions per day. The morning session comprised of presentations covering topics on general agronomic practices of chilli cultivation, biology and ecology of the pathogen, and blight management practices. The management part mainly focused on cultural methods which


include crop rotation, use of raised beds for nursery and transplanting, proper plant spacing, furrow irrigation, mulching, weeding, and destruction of infected plants. Participants were also introduced to fungicide (copper oxychloride and/or ridomil) treatments of seeds and seedlings in cases where chili blight has occurred in the previous years.

The afternoon session focused on practical demonstrations on preparation of fungicide solutions for treating seed and seedlings, bed preparation and transplanting operations, and other agronomic practices. All participants took part in preparing beds and transplanting. During the demonstration, participants were also sensitized on importance of handling plant protection (PP) products, using safety gears and proper disposal of PP products and containers.

1.1.2.2 Trashigang

In Trashigang, the awareness program was first in conducted at Merdha Chiwog under Kangpar Gewog in Trashigang on 31 December 2016. The chiwog is two hours walk from the nearest motorable road. The extension agent of Kangpar Gewog accompanied the team. A total of 50 participants attended the program. The program was executed in the same manner as in Ramjar Gewog except that the team could not demonstrate the methods of transplanting as the farmers did not have any seedlings.

The second part of program in Trashigang was conducted in Thrimshing Gewog on 3 January 2017. The program held at the gewog’s meeting hall was attended by 50 chili growers of Thrimshing Gewog. For the demonstration part, the transplanting method was not demonstrated because seedlings were too small. All other operations such as bed preparation and irrigation methods were demonstrated.

1.1.3 Question and answer session

In all three gewogs, a question and answer session intercepted the theory presentations. The followings were some of the issues and/or feedbacks of the farmers and the advice provided by the NPPC team:

• InRamjar,TrashiYangtse:

o Some farmers were of the opinions that some PP products were ineffective against chili blight. Upon inquiry, the rate, method of application, and in some cases, chemical used were found to be


incorrect. One farmer had used mancozeb as soil application for control of chili blight which was never recommended. The team recommended them to spray copper oxychloride and ridomil instead of mancozeb. Use of fungicide was advised to be based on disease prevalence and severity, and weather conditions.

o A farmer reported chili borer infestation in the previous year and sought advice on managing chili borers. The team advised him to try pheromone trap which is available with the Centre.

• InKangpar,Trashigang:

o Farmers showed more interest in seed and seedling treatment. The team cautioned them to be precise on rates of fungicides.

• InThrimshing,Trashigang:

o Advice and recommendations were given on the participants’ enquiry about potato tuber moth (PTM) infestation in potato, red ant infestation on vegetables, citrus fruit drop and system of procuring PP products.

1.1.4 Field operation practices

The team observed the following during field visits:

• Most farmers in Ramjar prepared bed for nursery but not as per thespecification.

• Farmers inKangparandThrimshingdidnotuseraisedbeds forraisingnurseries or for transplanting.

• Except for one farmer, none of the farmers from Ramjar had used PPproducts for treating seed and seedling.

• Mostof the farmersseemtohaveobservedchiliblight infectionbutnoproper measures were taken to manage it.

• Participants were interested in seed and seedling treatment but weredoubtful about measuring fungicide for solution preparation.

• A lotofunreportedplantprotectionproblems inother cropswere alsoobserved: garlic rust infection in Kangpar, and citrus HLB and fruit drop in Thrimshing.


1.1.5 highlights of the program

• Since most of the participants were interested in seed and seedlingtreatment, the team advised them to be precise in rate of application.

• AdviceonsafehandlingofPPproduct.

o Proper disposal of unused PP product solution in a pit away from water source.

o Not reusing PP Product containers and wrappers.

o Importance of cultural methods before opting for use of PP products

• Importanceofusingraisedbedsfornurseryandtransplantingtoreducedisease development.

• Water management in chili field through use of furrow irrigation anddraining of stagnant water.

• Importanceoffieldmonitoringespeciallyduringwetweatherconditionsand taking the appropriate management steps.

1.1.6 Future direction

• Futureworkshould involve thePlantProtectionStaff fromtheregionalresearch centres.

• TheNPPCshouldcontinuewiththetrainingsofextensionagents(EAs)onpests and diseases of major crops so that the respective EAs can conduct trainings or pest management campaign in the respective gewogs.


Figure 2.1: Chili blight management awareness campaign in Trashigang and Trashi Yangste.


1.2 Pest and disease identification survey of mango and avocado

1.2.1 Introduction

Many farmers in southern Bhutan are taking up mango (Mangifera indica) and avocado (Persea americana) cultivation. In the recent years, the NPPC has been getting reports of insect pest and disease incidences in mango and avocado from the farmers. Therefore, the Centre initiated a pest record survey at Panbang and Nganglam, where mango and avocado are reported to be cultivated on large scale, to record the different insects and diseases.

1.2.2 methods

The NPPC team visited four mango and three avocado orchards in Panbang Gewog under Zhemgang Dzongkhag, and three orchards each of mango and avocado in Nganglam Gewog under Pemagatsel Dzongkhag. The respective extension agent of each gewog accompanied the team. During the visit, the team examined the orchards and recorded the incidences of insect pests and diseases based on signs and symptoms.

1.2.3 Results

1.2.3.1Diseases

The most common diseases observed in mango and avocado based on symptoms are listed below.

Anthracnose Anthracnose was the most common disease observed in almost all plantations of mango and avocado. Anthracnose is caused by the ubiquitous fungus Colletotrichum gloeosporides Penz and Sacc. The spores (conidia) of the pathogen are dispersed by splashing rain. Wet, warm, and humid environmental condition favour anthracnose infection. New and young leaves are said to be most susceptible especially when their emergence coincides with frequent rainfall.

Symptoms were observed on leaves, twigs and fruits (Figure 2.2). On leaves, small angular brown to black spots were seen. Extensive dead areas were also seen on the infected leaves which could have been caused by enlargement and


coalesce of small spots. Similar spots were also observed on the twigs which exhibited die-back symptom in mango. On fruits, dark brown spots causing rotting and fruit drop were seen in both mango and avocado. Linear necrotic regions called ‘tear stain was also observed on mature mango fruits.

Sooty mould in mangoSooty mould disease was observed in mango orchards but not on avocados. Black flake-like mycelium growth covering the leaves, twigs and branches were observed on mango trees. Most plants in one of the orchards in Panbang appeared as if covered by a layer of soot indicating quite a severe infection in the orchard. Sooty mould is reported to be caused by several fungi such as Capnodium sp., Fumago sp. and Scorias sp. which grow on the honeydew excreted by insects such as aphids, scales, leafhoppers, mealy bugs, etc. However, during the survey those pests were not observed. Sooty mould damage results from reduced photosynthesis which in turn is caused by premature leaf fall and stunting due to coatings on the leaves. Sucking insect infestations, high humidity and moist environment favour sooty mould. Spores are dispersed by wind.

Figure 2.2. (a) Anthracnose infected avocado leaf, (b) Anthracnose infected mango leaf, (c-d) anthracnose infected mango fruit.


Figure 2.3: (a) Sooty mould infected mango tree, (b) Green-black flaky mould on mango leaves.

Algal leaf spot of mango and avocadoBased on the symptoms exhibited, both mango and avocado plantations showed what appeared to be like algal leaf spot problem. Algal leaf spot, caused by species of Cephaleuros are known to affect a wide range of crops. During the survey, algal leaf spot was observed on both mango and avocado. It was more severe on mango particularly in Panbang. It infected almost all the aerial parts: leaves, twigs and branches. Lesions appeared as greenish to whitish spots which were 2-4mm in diameter. The spots were flattened with furry growth and with no distinct margin. Although not observed in the field, algal leaf spot can cause leaf fall, dieback of twigs and fruit distortion. Spores of the algae are formed on the spots and are dispersed by wind and splashing water. Algal leaf spot is said to be common in areas of high temperature and rainfall. Poor nutrition and drainage also favour infection.


Figure 2.4. Algae leaf spots on (a) avocado; (b) mango1.2.3.2 Insect pests

Mango leaf gall midgeSevere symptoms of leaf galls that appeared like warts on leaves were observed at Choekhorling in Nganglam (Figure 2.5). Leaf galls are said to be induced by midges. Many gall inducing species are known to occur in India. The most common species belong to the genus Procontarinia. However, the midge occurring in Nganglam is yet to be determined. Galls were observed on the underside of the leaves. Eggs were observed inside these galls. Small reddish spots were observed on the upper surface of the leaf corresponding to the galls on the underside of the leaf. Galls are said to occur on young buds, flowers, fruits and shoots. However, during the field visits, galls were mostly observed on older leaves and infestations on fruits and shoots were not observed. Heavy infestations on leaves, flowers and fruits are said to affect photosynthetic capacity, fruit set and cause blemishing fruits.


Figure 2.5. (a) Galls on the under surface of infested leaf; (b) Gall midge infestation on mango

1.2.4 Recommendation

Based on the insect pests and diseases recorded during the survey, the following recommendations are drawn:

Management of Anthracnose

• Alldiseasedanddead leavesand twigswhichgenerally carry inoculumshould be removed and burnt.

• Fornewplantations,plantingtreeswithwiderspacingmustbeconsideredto help reduce disease severity.


• Mangotreesshouldbeinterplantedwithothertypesofplantswhicharenot host of anthracnose to reduce disease spread in the field.

• Asapreventativemeasure,spraysofneemoil@5ml/Latthefirstsignofspring budding should be carried out. If orchard is already infected, then neem oil must be applied at 7 days interval. Foliar application of Carbendazim@1g/Lorcopperoxychloride@3g/Lwhenthepaniclesfirstappear are also known to provide some protection.

Management of Sooty mould

• Affectedpartsmustbeprunedtopreventdiseasespread.

• Sucking insects such as aphids, whiteflies, scales and hoppers must becontrolled by use of strong water flush to remove colonies. Ant infestation must be controlled by use of physical techniques such as destroying nest of ants or banding tree trunk with sticky substance. Ants feed on the honey dew secretions and, therefore, may protect the sucking insects from predators. Horticultural mineral oils can reduce sucking insect population and can help peel off sooty mould. However, phytotoxicity test must be performed on few branches before treating many trees.

• Use of fertilizers must done in appropriate manner because overfertilizations can attract certain insects due to excessive vegetative growth.

• Forheavyinfestationofsuckinginsectsrequiringinsecticidesprayswithchlorpyriphos@2ml/Lat10-14daysintervalprovideadequatecontrol.

Management of gall midge

• Makingbasin around theplant andcovering thebasinwithplasticwillreduce pupation of the midge, thereby reducing their population.

• Affectedpartsmustbeprunedandburnttopreventanygrowinglarvaetodevelop.

• Sprayswithdimethoate@2ml/Lcanprovidecontrolinseverelyinfestedorchards.

Management of algal leaf spot

• Agingbranchesmustbeprunedbecausesuchpartsarethefirsttoshowsigns of the disease.

• Reduce humidity within tree by opening canopy through thinning


branches, and in the orchard by pruning off overhanging trees.

• Improvedrainageifthegroundbecomeswaterlogged.

• For very poor growthorchards, soil nutrient analyseswill help identitynutrient deficiency so that appropriate nutrient supplement can be incorporated

• Maintaining orchard floor cleanliness through removal of weeds fromaround the trees will help reduce humidity in addition to reducing nutrient competition.

1.3 Testing of citrus samples for HLB in 2016

A total of 42 citrus samples were tested for HLB pathogen between August and November 2016 using nested PCR (Ding et al 2005) (Table 2.2). Of these, four samples were from the National Seed Centre (NSC) nursery in Samtenling, 25 from Wengkhar and 13 from ARDSC Tsirang. The PCR results showed that samples from all three locations yielded positive results with 14 out of 25 samples from Wengkhar, 1 out of 4 samples of Samtenling, and 4 out of 13 samples from ARDSC Tsirang showing positive reactions (Table 2.2). All tests included extraction control (or healthy control consisting of apple leaves) which did not yield any positive reactions.

The results indicate that HLB is present in all three areas. This confirms with previous tests, using both conventional and real-time PCR, that detected positive reaction in samples tested from NSC Samtenling and ARDSC Tsirang. However, previous samples from ARDSC Tsirang were from a germplasm evaluation field while the samples tested during this period (Aug-Nov 2016) were from the citrus repository. The HLB positive and symptomatic orange trees in germplasm block of ARDSC Tsirang have since been removed. Previous tests on samples from Samtenling and Tsirang had also been confirmed through sequencing of the HLB pathogen by Namgay Om during her PhD studies in Western Sydney University. Thus, it is affirmative that samples from NSC nursery need not be tested again and that seedlings from the nursery are not fit for supply to growers. As for the citrus repository in ARDSC Tsirang, and citrus plants in ARDC Wengkhar, it is urgent to test more samples for re-confirmation using both real-time and conventional PCR.


Tabl

e 2.

2. R

esul

ts o

f PC

R pe

rfor

med

on

citr

us sa

mpl

es in

201

6.

Sl. N

o.Sa

mpl

e ty

peSa

mpl

e N

o. &

lab.

N

o.

Loca

tion

Sym

ptom

atic

(y

es/N

o)d

ate

rece

ived

&

proc

esse

dPC

R re

sult

1C

itrus

leav

es1

&1

ARD

C W

engk

har

No

05-A

ugus

tPo

sitiv

e2

Citr

us le

aves

2 &

2A

RDC

Wen

gkha

r N

o05

-Aug

ust

Posit

ive

3C

itrus

leav

es3

& 3

ARD

C W

engk

har

No

05-A

ugus

tPo

sitiv

e4

Citr

us le

aves

4 &

4A

RDC

Wen

gkha

r N

o05

-Aug

ust

Posit

ive

5C

itrus

leav

es5

& 5

ARD

C W

engk

har

Yes

05-A

ugus

tPo

sitiv

e6

Citr

us le

aves

6 &

6A

RDC

Wen

gkha

r Ye

s05

-Aug

ust

ND

7C

itrus

leav

es7

& 7

ARD

C W

engk

har

Yes

05-A

ugus

tN

D8

Citr

us le

aves

8 &

8A

RDC

Wen

gkha

r Ye

s05

-Aug

ust

ND

9C

itrus

leav

es9

& 9

ARD

C W

engk

har

Yes

05-A

ugus

tN

D10

Citr

us le

aves

10 &

10

ARD

C W

engk

har

Yes

05-A

ugus

tPo

sitiv

e11

Citr

us le

aves

11 &

11

ARD

C W

engk

har

Yes

05-A

ugus

tPo

sitiv

e12

Citr

us le

aves

12 &

12

ARD

C W

engk

har

No

05-A

ugus

tPo

sitiv

e13

Citr

us le

aves

13 &

13

ARD

C W

engk

har

No

05-A

ugus

tN

D14

Citr

us le

aves

14 &

14A

RDC

Wen

gkha

r N

o05

-Aug

ust

ND

15C

itrus

leav

es15

&15

ARD

C W

engk

har

No

05-A

ugus

tN

D16

Citr

us le

aves

16 &

16

ARD

C W

engk

har

Yes

05-A

ugus

tPo

sitiv

e17

Citr

us le

aves

17 &

17

ARD

C W

engk

har

Yes

05-A

ugus

tPo

sitiv

e18

Citr

us le

aves

18 &

18

ARD

C W

engk

har

Yes

05-A

ugus

tPo

sitiv

e19

Citr

us le

aves

19 &

19

ARD

C W

engk

har

Yes

05-A

ugus

tPo

sitiv

e20

Citr

us le

aves

20 &

20

ARD

C W

engk

har

No

05-A

ugus

tN

D21

Citr

us le

aves

21 &

21A

RDC

Wen

gkha

r N

o05

-Aug

ust

ND

22C

itrus

leav

es22

& 2

2A

RDC

Wen

gkha

r N

o05

-Aug

ust

ND

23C

itrus

leav

es23

& 2

3A

RDC

Wen

gkha

r Ye

s05

-Aug

ust

ND

24C

itrus

leav

es24

& 2

4A

RDC

Wen

gkha

r N

o05

-Aug

ust

Posit

ive

25C

itrus

leav

es25

& 2

5A

RDC

Wen

gkha

r N

o05

-Aug

ust

Posit

ive


Sl. N

o.Sa

mpl

e ty

peSa

mpl

e N

o. &

lab.

N

o.

Loca

tion

Sym

ptom

atic

(y

es/N

o)d

ate

rece

ived

&

proc

esse

dPC

R re

sult

26Tr

ifolia

te le

aves

B1A

& 2

6N

SC S

amte

nlin

gN

o3

& 5

Aug

N

D27

Trifo

liate

leav

esB1

B &

27

NSC

Sam

tenl

ing

No

3 &

5 A

ug

Posit

ive

28Tr

ifolia

te le

aves

B2A

& 2

8N

SC S

amte

nlin

gN

o3

& 5

Aug

N

D29

Trifo

liate

leav

esB2

B &

29

NSC

Sam

tenl

ing

No

3 &

5 A

ug

ND

30C

itrus

leav

esC

MP

I & 1

ARD

SC T

siran

gN

R29

Oct

& 2

Nov

Po

sitiv

e31

Citr

us le

aves

CP

I & 2

ARD

SC T

siran

gN

R29

Oct

& 2

Nov

Po

sitiv

e32

Citr

us le

aves

TK I

& 3

ARD

SC T

siran

gN

R29

Oct

& 2

Nov

N

D33

Citr

us le

aves

LP II

& 4

ARD

SC T

siran

gN

R29

Oct

& 2

Nov

N

D34

Citr

us le

aves

OP

I & 5

ARD

SC T

siran

gN

R29

Oct

& 2

Nov

ND

35C

itrus

leav

esV

P I &

6A

RDSC

Tsir

ang

NR

29 O

ct &

2 N

ovPo

sitiv

e36

Citr

us le

aves

DO

I &

7A

RDSC

Tsir

ang

NR

29 O

ct &

2 N

ovN

D37

Citr

us le

aves

DO

II &

8A

RDSC

Tsir

ang

NR

29 O

ct &

2 N

ovN

D38

Citr

us le

aves

TP I

& 9

ARD

SC T

siran

gN

R29

Oct

& 2

Nov

Posit

ive

39C

itrus

leav

esH

T I &

10

ARD

SC T

siran

gN

R29

Oct

& 2

Nov

ND

40C

itrus

leav

esH

T II

& 1

1A

RDSC

Tsir

ang

NR

29 O

ct &

2 N

ovN

D41

Citr

us le

aves

HT

III &

12

ARD

SC T

siran

gN

R29

Oct

& 2

Nov

ND

42C

itrus

leav

esLP

II &

13

ARD

SC T

siran

gN

R29

Oct

& 2

Nov

ND

NR=

not

reco

rded

; N

D=

not d

etec

ted

Refe

renc

eD

ing

F, W

ang

G, Y

i G, Z

hong

Y, Z

eng

j, Zh

ou B

. 200

5. In

fect

ion

of w

ampe

e an

d le

mon

by

the

citr

us h

uang

long

bing

pat

hoge

n (C

andi

datu

s Lib

erib

acte

r asia

ticus

) in

Chi

na.

Jour

nal o

f Pla

nt P

atho

logy

87:

207

–212

.


2. SURvEILLANCE UNIT

2.1 National Plant Pest database (NPPd)

2.1.1 Introduction

The Pest Surveillance Unit in collaboration with Dr Reiks Van Klinken, Australian Volunteer, developed the National Plant Pest Database (NPPD).

The National Plant Pest Database (NPPD) contains all the pests present in Bhutan (arthropods, molluscs, nematodes and micro-organisms), their importance to different crops, and their identification and management. This database seeks to be both the authoritative repository of plant protection knowledge developed over the past 30 years, and a platform for prioritizing and guiding future research, surveillance and extension activities.

2.1.2 Structure of NPPd

The overall structure of the NPPD within Excel spread sheet is illustrated in Figure 3.1. The three data sheets are linked by crop common name and pest scientific name using the VLOOKUP function.

Figure 3.1. Structure of NPPD in spread sheet.

There are three inter-linked spreadsheets: hosts, species and host-species

• Thehost spreadsheet includes common name, species name, importance of the host to production and for export, and any supporting information. It is linked to the host-species data-sheet through the host common name. Any changes to other fields will be automatically updated in the host-


species worksheet

• Thespecies worksheet captures species-level information relevant to each species record. This includes its’ classification, synonyms and common names relevant to Bhutan, confidence around identification, its’ first record in Bhutan, its’ origin and global distribution, and the source of the record. It is linked to the host-species worksheet through the species name.

• Thehost-species worksheet includes a row for each host record for each pest record in Bhutan. Relevant information is included from the host and species worksheets using VLOOKUP to prevent double-entry of data. This worksheet also includes information on species identification, biology and management. In cases where species have multiple hosts, this information is entered for each host where biology and recommendations differ, entered for a single host (cross-referenced from other hosts), or a composite host is entered (e.g. “brassica”).

Linkages between worksheets (host common name and pest species name in host-species worksheet) were established using drop down menus developed by generating a list of names using “naming a field” and developing a drop-down list using “data validation”.

Additional spreadsheets provide background information:

• A definitions worksheet defines the fields (where not self-explanatory) and the categories within fields (where used).

• A citation spreadsheet provides details on version history and tracks acknowledgements

• ID Specialist spreadsheet provides records of specialist who could assist in identifications.

Linkage to other resourcesAssociated resources such as supporting documents and images will not be in the NPPDbut will be accessible to NPPC staff through a shared google-drive directory.

2.1.3 Result

The NPPD currently includes data on 711 pest species, 63 crops and 949 pest-crop interactions. Of those, at least 105 pests cause at least minor damage (i.e. at


least occasionally cause farm-scale impacts) in Bhutan. Included are several pests that cause on-going, severe, national-scale impacts on important commodities, such as citrus greening on mandarins, and late blight on potatoes. All pests of at least minor importance are shared with neighbouring India, which is also the primary trading partner, and over 80% are widely distributed in Asia.

2.1.4 Conclusion

The NPPD will require continual updating as new information gets generated by NPPC and its partners. Changes will include such things as new pest or host-pest records, new studies on management, and taxonomic revisions. The NPPD Technical Working Group (reporting to the NPPC Program Director) will be responsible for keeping the NPPD up to date, releasing updated versions internally and externally, and helping to establish and maintain a culture where all new information generated by NPPC and other stakeholders is submitted for entry. They will be the only people with access to make changes to the NPPD.

2.2 Enhancement of ePest surveillance system

2.2.1 Introduction

The ePest surveillance system development was initiated in 2011 with the financial assistance from Decentralize Rural Development Project (DRDP) to address the issues related to difficulty in pest identification and management in the field, lack of pest database, and development of a reliable pest forecasting and early warning system in the country. The system development was completed, and formal operation began in June 2015 including rigorous training for the pilot gewogs from Western and Southern Bhutan and distribution of gadgets, for field data collection, to the field staffs. However, numerous technical issues were encountered when the field extension workers started to use it under field conditions such as screen black out and data fetching timing out because the system was hosted on MS operating system. Therefore, there was a need to migrate existing system to another system to correct the technical issues and make it more user friendly. Thus, the enhancement of surveillance system was carried out.


2.2.2 Surveillance system enhancement

Since the system has been developed and managed by NGN Technologies Private Limited, the surveillance system enhancement was also carried out by the same company. The system enhancement was done within three months under the Change Management Contract as provisioned under RFP document with the financial assistance from FAO TCP project of worth Nu. 600,000/-, from the project title: Strengthening of the e-agriculture environment and developing ICT-mediated agricultural solutions for countries in Asia-Pacific. The system was modified and developed into much simpler and user friendly. Training of Trainers on enhanced ePest Surveillance system was also conducted through demonstrations of mobile application and explanation of each component in the application and web application and viewing of data submitted.

2.2.3 Conclusion

The enhanced ePest surveillance application is being piloted in some gewogs under Chukha Dzongkhag. In the coming years NPPC will replicate application in rest of the gewogs in the country. It would help in generating information for timely intervention thus helping to reduce crop losses to pests and diseases.


3. PLANT PROTECTION PRODUCT UNIT

3.1 Supply of plant protection products

The quantities of plant protection (PP) products supplied from July 2016 to June 2017 is presented in Table 4.1. Among all types of PP products, the highest quantity supplied was that of herbicides followed by tree spray oil (TSO) and insecticides. The high quantity of herbicide resulted from the sale of butachlor in the rice growing areas with the highest supply to Paro Dzongkhag (Table 4.1; Annex 2a). High quantity of TSO and insecticides were mainly supplied to Thimphu and Paro Dzongkhags (Table 4.2; Annex 2a & 2c).

Table 4.1. Quantity of specific plant protection products supplied from July 2016 – June 2017.Product Quantity (kg/litre)InsecticidesChlorpyrifos 20EC 320.1Cypermethrin 20EC 2552.4Dimethoate 30EC 321.5Fenvelerate 0.4D 2633Alphacypermethrin 10SL 144Azadirachtin 0.3% 94Total 6065FungicidesCaptan 50WP 175.5Carbendazim 50WP 620Copper oxychloride 50WP 171.3Hexaconazole 5 EC 68Mancozeb 75WP 3174.75Metalaxyl 8WP 727.5Sulphur 80WP 40Tricylazole 5EC 55.3Total 5032.35herbicidesButachlor 5G 384260Glyphosate 41SL 6106Metribuzin 70WP 3300Total 393666Others Zinc phosphide 14.19Tree Spray Oil 7847Stickers 319.5


Tabl

e 4.

2. Q

uant

ities

of p

lant

pro

tect

ion

(PP)

pro

duct

s sup

plie

d to

diff

eren

t dzo

ngkh

ags.

Ty

pes o

f PP

prod

ucts

and

thei

r qua

ntity

(kg/

litre

)

dzo

ngkh

agIn

sect

icid

es

Fung

icid

es

TSO

her

bici

des

Stic

ker

Tota

l*

Bum

than

g30

.416

8.25

1049

7.3

070

5.95

Chh

ukha

41.5

250

5425

.30

5491

.8D

agan

a96

.715

.214

5082

.50.

552

08.4

Gas

a0

00

00

0H

aa33

1.7

231.

528

552

85.2

261

33.4

Lhun

tse

13

050

00.5

050

04.5

Mon

ggar

479.

864

.150

6136

567

29.9

Puna

kha

798.

136

.70

6502

7.5

065

862.

3Pa

ro16

13.1

905.

5532

6213

7913

.834

.514

3694

.45

Pem

agas

hel

89.3

0.7

00

090

Sam

tse

1019

050

030

5032

Sam

drup

Jong

khar

00

01

01

Sarp

ang

224.

213

4.4

2015

111.

810

1549

0.4

Tsira

ng73

.833

.10

9518

096

24.9

Tron

gsa

7247

.50

1526

50

1538

4.5

Tras

higa

ng44

08

00

044

8Tr

ashi

Yan

gtse

108

044

000

044

018

Thim

phu

1543

.890

0.4

4206

2252

1.5

77.5

2917

1.7

Wan

gdue

phod

rang

205.

624

30.4

50

5187

7.6

190

5451

3.65

Zhem

gang

251.

50

00

26.5

Tota

l 60

8550

32.3

578

4739

3666

319.

541

2630

.35

*exc

lude

s qua

ntity

of s

ticke

rs;

TSO

= Tr

ee sp

ray

oil


4. WEEDS AND VERTEBRATE UNIT

4.1 development of weed Control Technology in Transplanted Rice in bhutan

4.1.1 Introduction

Rice, Oryza sativa L., is the staple diet in Bhutan and is the most important cereal crop grown. In 2016, the total production was 83, 332 MT harvested from 53, 055 acres (PPD, 2016). Various constraints hinder increased rice production. Weeds are invariably the most important. They not only entail cost for control but also harbor pests and diseases. In Bhutan, at least 19 different species infest transplanted rice. The most important are Potamogeton distinctus, Schoenoplectus juncoides, Monochoria vaganalis, Blyxa aubertii, Paspalum distichum, Echinochloa spp., Cyperus difformis, Alternanthera sissilis, Acmela uliginosa, Fimbristylis littoralis and Commelina diffusa (Dorji et al. 2013).

In Bhutan, weed is controlled using hand weeding and the herbicide Butachlor. Farmers hand weed at least two times per rice growing season in areas where P. distinctus is the most dominant weed. The first hand-weeding occurs at 25-30 days after transplanting (DAT) followed by second hand weeding at 40-45 DAT. The Butachlor, which is the only herbicide available for use in transplanted rice in Bhutan is applied 3-5 DAT at the rate 10 kg/ac.

Despite hand weeding and the use of Butachlor, weed control in Bhutan is not efficient. While no –records are available on how much weeds cause yield loss in rice in Bhutan, in areas where P. distinctus is the most dominant weed, at least 37% yield loss is reported (Dorji et al. 2016). There is a need to develop an efficient weed control technology in Bhutan to avoid yield losses. This study was therefore taken up with the following objectives:

General objective

• TodevelopweedcontroltechnologyintransplantedriceinBhutan

Specific objective

• ToevaluateEthoxysulfurontocontrolP.distinctusintransplantedrice

• Toevaluatedifferentweedcontrolmethodstoidentifyasuitablecontroltechnology


4.1.2 materials and methods

Location and duration of studyThe study was conducted at rice fields in Tendrelthang, Thimphu Dzongkhag for one rice growing season from May – November 2016.

Land preparation A large terrace that was enough for conducting an experiment was identified at Tendrelthang, Thimphu Dzongkhag. The terrace was prepared by ploughing the field two times using a power tiller. The land was then levelled by harrowing using a power tiller and puddled manually using a plank. The large terrace was divided into 16 equal plots. Using a flexible pipe, water was introduced in each field for transplanting. Each plot was watered at a saturated level.

Figure 5.1. Field preparation for experiment at Tendrelthang, Thimphu Dzongkhag.

TransplantingThe seedlings for transplanting were obtained from the National Organic Agriculture and Research Development Center, Yusipang. Twenty-one days old seedlings were transplanted without maintaining plant to plant distance but keeping a row to row distance of 15 cm.


Figure 5.2. Manually transplanting 21 days old seedlings and a few weeks after transplanting

Water managementThree days after transplanting when the seedlings have rooted, water was introduced and maintained at 5 cm level throughout the growing season. The water was drained out only a week before harvesting the rice.

Figure 5.3. Water pumped in from the earthen channel using a water pump.

Pests and diseasesNo pesticide was applied since no pests and diseases affected the rice plants.

Experimental layout and designThe Randomized Complete Block Design (RCBD) with 4 replications was used in the experiment. The experiment consisted of 4 treatments as given below:Treatment 1 = Butachlor was applied at 12 kg/acTreatment 2 = Ethoxysulfuron was broadcast at 50 g/ac Treatment 3 = hand weeding twice, 25 and 40 days after transplantingTreatment 4 = Control (weedy check)The main experimental area was 402.93 (33.3 m x 12.1m) m2. The plot size for


each treatment was 18.09 (7.95m x 2.275m) m2sq.m. Replicates were separated by one meter spacing, and treatments within a replicate were separated by 0.5m spacing (Figure 5.4).

.5m .5m .5m

7.95m 2.275m

12.1m

1m

1m

1m

33.3 m

Figure 5.4. Layout of the experimental area.

Data collection and sample preparationData was collected using a 1m x 1m quadrat. From each plot, two quadrats were collected. Weeds were washed free of soil, sorted by species and oven dried at 60°C for 72 hours. Dry weight was taken by using a digital weighing balance.

Figure 5.5. Sampling the plots and sample preparation in the laboratory

Statistical analysisFor statistical analysis, the Statistical Procedures for Agricultural Research by Gomez & Gomez (1984) was refereed and was computed using Office Excel ® 2007 (12.0.4518.1014). Only the dry weight was analyzed.


4.1.3 Results

In the experimental plots, these weeds were found: Potamogeton distinctus, Monochoria vaginalis, Schoenoplectus juncoides, Echinochloa spp., Biden stripartita, Ischaemum rugosum and Cynodon dactylon. Statistical analyses (Table 5.1) showed that there was no significant difference in the treatments.

Table 5.1. Analysis of variance using dry weight of weeds sampled from different treatment plots.

Analysis of Variance (RCB) of Dry Weight of WeedsSource of Variation

Degree of Freedom

Sum of Squares

Mean Square Computed F Tabular F

5% 1%Replication 3 69653 23218

Treatment 3 12358 4119 0.37ns 3.86 6.99

Error 9 99512 11057

Total 15 181523 38394

Coefficient of variation = 34%;

ns = Not significant

DiscussionBecause the computed F value of 0.37 is smaller than the Tabular F value at the 5 % level of significance, it is concluded that the experiment failed to show any significant difference among the 4 treatments.

The failure of the experiment to show any significant difference in the 4 treatments may be due to the failure to control water and the sandy nature of the soil. Water was not available during the critical crop growth periods. During the rainy season, the plots were flooded with excess water and overflowed from one plot to another despite the large bunds, which may have caused herbicides to flow. In addition, water from terraces above the experimental plots poured in and could not be avoided.

Seepage was another problem. Despite strong bunds built to prevent seepage, due to sandy nature of the soil, seepage could not be controlled. This was especially true underground, where water seeped profusely.


4.1.4 Conclusion

The experiment could not determine any significant difference among the 4 treatments. Difficulty in water management and sandy nature of soil may have caused the experiment to fail.

The continuation of the experiment is recommended. There is a need for a totally isolated experimental area with a dedicated water source.

References

PPD. 2016. RNR Statistics 2016. Policy and Planning Division, Ministry of Agriculture and Forest, Thimphu, Bhutan.

Gomez K, Gomez A. 1984. Statistical Procedures for Agricultural Research. Second Edition. A Wiley-Interscience Publication, John Wiley & Sons.

Dorji S, Lhamo K, Chophyll K Tobgye K. 2013. Weeds of transplanted rice in Bhutan. Journal of Renewable Natural Resources Bhutan 9 (1).

Sangay T, Sindel BM, Mahesh G, Chauhan BS. 2016. Weed management challenges in rice (Oryza sativa L.) for food security in Bhutan: a review. Crop Protection: 90117-124. doi:10.1016/j.cropro.2016.08.031.


4.2 Training on the Global Positioning System to Agriculture Officials of wangduephodrang dzongkhag to Collect wildlife Crop damages Information

4.2.1 Introduction

A two-day training on the Global Positioning System (GPS) was organized for the agricultural officials of the Wangduephodrang Dzongkhag from 15 – 16 December 2016. The training was organized by the National Plant Protection Centre (NPPC) at the College of Natural Resources, Lobesa, Wangduephodrang. The training was one of the activities of the Project on “Human-wildlife conflict management and improving food security in Bhutan” implemented by the NPPC with technical and financial support from the WWF. The project pilots the Safe System approach of the WWF, which is founded on the idea of holism that considers the needs of both humans and the wildlife and their co-existence in any landscape. Participants included those who already had some theoretical background from their college education and those who did not know anything about the GPS.

Mr. Sonam Dargay, GIS and Landscape Analyst from the WWF-Bhutan provided the training. The training was organized with the objective to provide hands-on training on the use of GPS to collect data on crop losses to wildlife, which is severely lacking in the country today.

Figure 5.6. In the classroom and in the field. The training included topics on field applications of GPS, data collection methods, saving the data, creating maps using Google Earth Pro and sending to the NPPC for database development, analysis and annual reporting. The training also included a


practical session wherein participants were made to collect points and line/polygon data using the GPS device, and were made to import the data using Google Earth Pro and creating kml/kmz file for sending to the NPPC.

Figure 5.7. Participants introduced to GPS device and doing practical

4.2.2 Training outcome and future work

Participants found the training highly relevant and useful for data collection. They said the GPS could be used not only for collecting data on crop losses to wildlife but also for reporting on crop damages by natural disasters.

The participants expressed that without a proper assessment method for crop damages by wildlife, they had to rely on eye estimation or damages reported by the farmers. Such methods, they found, were not accurate and erroneous but was the only option available to them in the absence of standard assessment method. Now, with the training on the GPS, participants felt data collection should not be a problem and timely reporting will be ensured.

The project supported eight numbers of Garmin Etrex device to the Wangduephodrang Dzongkhag thus, making it the pilot dzongkhag for the use of GPS in collecting data on wildlife crop damages and reporting. Mr. Sangay Dorji of NPPC informed the participants that provision of GPS to the agriculture staffs for collecting data on crop damages by the wildlife is the first of its kind in the country. He said data on crop damages by wildlife is very critical in the country to understand the severity and to map hotspot areas. The dzongkhag requested provision of another seven sets of GPS to cover all the gewogs in the dzongkhag.

The NPPC as an apex agency for addressing crop losses to wildlife in the country has always found lack of data as the main limitation in mapping the hotspot areas in the country to target intervention measures. Hotspot mapping is also one of the strategies


of Safe System approach implemented by the NPPC. The NPPC now expects, with the training on the GPS and equipping the Dzongkhag with the GPS device, to receive accurate crop losses data from the Wangduephodrang Dzongkhag. The Centre aims, with the success of data collection using GPS, to cover other dzongkhags through the future projects.


Ann

ex 2

a: T

ypes

and

qua

ntity

of h

erbi

cide

s, ro

dent

icid

e, tr

ee sp

ray

oil (

TSO

), an

d st

icke

rs d

istr

ibut

ed fr

om Ju

ne 2

016

to

July

201

7.

Dzo

ngkh

agbu

tach

lor 5

GG

lyph

osat

e 41

SL

met

ribu

zim

70

wP

Zinc

pho

sphi

de

80 w

PTo

tal

herb

icid

e pe

r dz

ongk

hag

TSO

Tota

l TS

O p

er

dzon

gkha

g

Stic

ker

Tota

l st

icke

r

Jan-

Jun

Jul-D

ecJa

n-Ju

nJu

l-Dec

Jan-

Jun

Jul-D

ecJa

n-Ju

nJu

l-Dec

Jan-

Jun

Jul-d

ecJa

n-Ju

nJu

l-dec

Bum

than

g0

04

049

3.3

00.

380

497.

6810

010

00

0C

hhuk

ha52

000

243

198.

30

00

5425

.30

00

00

0D

agan

a50

000

76.5

60

00.

520

5083

.02

140

140.

50

0.5

Gas

a0

00

00

00

00

00

00

00

Haa

5000

013

10

154.

20

2.03

052

87.2

328

50

285

20

2Lh

unts

e50

000

0.5

00

00

050

00.5

00

00

00

Mon

ggar

6000

013

10

50

1.5

061

37.5

2030

505

05

Puna

kha

6500

00

23.5

3.5

0.5

02.

460.

365

030.

260

00

00

0Pa

ro13

7000

039

312

339

7.8

00.

150.

413

7914

.35

3132

130

3262

34.5

034

.5Pe

mag

atse

l0

00

00

00

0.28

0.28

00

00

00

Sam

tse

5000

03

00

00

050

030

00

00

0Sa

mdr

up

Jong

khar

00

10

00

00

10

00

00

0

Sarp

ang

1500

00

107.

50.

53.

80

0.53

0.2

1511

2.53

1010

2010

010

Tsira

ng90

000

310.

520

7.5

00

00.

695

18.6

00

00

00

Tron

gsa

1500

00

150

4075

00

015

265

00

00

00

Tras

higa

ng0

00

00

00

00

00

00

00

Tras

hi Y

angt

se44

000

00

00

00

044

000

00

00

00

Thim

phu

2201

00

259

5319

9.5

00.

10.

3222

521.

9232

7193

542

0677

.50

77.5

Wan

gdue

pho-

dran

g46

050

040

4312

1772

.60

4.32

0.1

5188

2.02

00

019

00

190

Zhem

gang

00

00

00

00

00

00

0TO

TAL

3842

600

5657

.544

8.5

3300

11

.99

2.2

3936

80.1

967

4211

0578

4731

9.5

031

9.5


Ann

ex 2

b: T

ypes

and

qua

ntiti

es o

f fun

gici

des d

istr

ibut

ed to

diff

eren

t dzo

ngkh

ag fr

om Ju

ne 2

016-

July

201

7.

dzo

ngkh

agC

apta

n50

wP

Car

bend

azim

50

wP

Cop

per

oxyc

hlor

ide

50 w

P

hea

xcon

azol

e 5

ECm

anco

zeb

75

wP

met

alax

ly

8wP

Sulp

hur 8

0 w

PTr

icyc

lazo

le

5EC

Tot

al p

er

dzon

gkha

gJa

n- Jun

Jul-

Dec

Jan-

Jun

Jul-

Dec

Jan- Jun

Jul-

Dec

Jan- Jun

Jul-

Dec

Jan-

Jun

Jul-

Dec

Jan- Jun

Jul-

Dec

Jan- Jun

Jul-

Dec

Jan- Jun

Jul-

Dec

Bum

than

g0

012

.75

00

00

015

5.5

00

00

00

016

8.25

Chh

ukha

00

12

107

00

50

00

00

00

25D

agan

a0

00.

50

3.7

00

00

00

00

011

015

.2G

asa

00

00

00

00

00

00

00

00

0H

aa23

.50

590

0.2

037

.80

111

00

00

00

023

1.5

Lhun

tse

00

10

10

00

10

00

00

00

3M

ongg

ar0

010

039

.10

00

100

00

00

50

64.1

Puna

kha

00

2.5

05.

60.

20.

50

00

01.

32.

50

19.8

4.3

36.7

Paro

22.5

11.5

271.

57

210

00

476.

2535

46.8

010

04

090

5.55

Pem

agat

sel

00

00

0.7

00

00

00

00

00

00.

7Sa

mts

e0

08

010

00

00

10

00

00

019

Sam

drup

Jo

ngkh

ar0

00

00

00

00

00

00

00

00

Sarp

ang

00

100

6.7

00

010

800

027

00.

70

134.

4Ts

irang

00

0.5

00

24.6

00

00

80

00

00

33.1

Tron

gsa

00

00

50

00

200

200

00

1.5

147

.5Tr

ashi

gang

00

00

00

00

00

00

00

80

8Tr

ashi

Yan

gtse

00

00

4.5

00

00

03.

50

00

00

8Th

imph

u11

62

232.

51.

7528

.61.

329

.70

415.

7555

.516

0.8

0.5

00

090

0.4

Wan

gdue

pho-

dran

g0

00

01.

60

00

1797

.75

063

1.1

00

00

024

30.4

5

Zhem

gang

00

00

0.5

00

00

10

00

00

01.

5To

tal

162

13.5

609.

2510

.75

138.

233

.168

030

02.2

517

2.5

725.

42.

140

050

5.3

5032

.35


Ann

ex 2

c: T

ypes

and

qua

ntiti

es o

f ins

ectic

ides

supp

lied

to d

iffer

ent d

zong

khag

from

June

201

6-Ju

ly 2

017.

dzo

ngkh

agC

hlor

pyri

fos 2

0 EC

(kg/

lts)

Cyp

erm

ethr

in10

EC

(kg/

lts)

dim

etho

ate

30

EC (k

g/lts

)Fe

nvel

erat

e 0.

4dA

lpha

cype

rmet

hrin

10

SL

Aza

dira

chtin

0.

3%To

tal p

er

dzon

gkha

g Ja

n-Ju

nJu

l-Dec

Jan-

Jun

Jul-D

ecJa

n-Ju

nJu

l-Dec

Jan-

Jun

Jul-D

ecJa

n-Ju

nJu

l-Dec

Jan-

Jun

Jul-D

ecBu

mth

ang

00

10.4

00

00

00

200

030

.4C

hhuk

ha0

00

09.

50

302

00

00

41.5

Dag

ana

00

13.5

06.

62.

620

20

052

096

.7G

asa

00

00

00

00

00

00

0H

aa0

0.5

73.1

4.5

29.6

022

40

00

00

331.

7Lh

unts

e0

00.

50

0.5

00

00

00

01

Mon

ggar

42.5

069

.80

47.5

030

00

00

200

479.

8Pu

nakh

a0

014

2.1

10.5

2.5

862

25

00

80

798.

1Pa

ro12

7.3

40.1

864.

924

5.7

40.5

11.6

256

270

00

016

13.1

Pem

agat

sel

00

014

.30

00

750

00

089

.3Sa

mts

e0

00

00

010

00

00

010

Sam

drup

Jong

khar

00

00

00

00

00

00

0Sa

rpan

g14

074

.80.

481

03

440

07

022

4.2

Tsira

ng0

00.

30

100

2729

00

7.5

073

.8Tr

ongs

a9

060

03

00

00

00

072

Tras

higa

ng0

040

00

040

00

00

00

440

Tras

hi Y

angt

se0

010

00

00

00

00

010

Thim

phu

80.7

466

0.8

31.2

59.1

7.5

513

4314

40

00.

515

43.8

Wan

gdue

phod

rang

20

200.

60

20

01

00

00

205.

6Zh

emga

ng0

025

00

00

00

00

025

TOTA

L27

5.5

44.6

2245

.830

6.6

291.

829

.724

0522

814

420

93.5

0.5

6085

Documents

རྒྱལ༌ཡོངས༌སོ་ཤིང༌སྲུང༌སྐོབས༌ལྟེ༌བ། སོ་ནམ་ལས་ཁུངས། སོ་ནམ་དང ... · viii