Project Progress Report:" Investigation of rice kernel cracking and its control in the field and during post-harvest processes in the Mekong Delta of Vietnam - MS12 " pot

1 Ministry of Agriculture & Rural Development Project Progress Report 026/05VIE Investigation of rice kernel cracking and its control in the field and during post-harvest processes in the Mekong Delta of Vietnam MS12 : VALIDATION OF IMPROVED HARVESTING, DRYING AND MILLING METHODS Cooperative demonstrations detailing the physical and financial benefits of implementation of optimal harvest methods, optimal drying conditions and improved performance of milling plants. (Output 31. and 3.2) July 2009 2 NONG LAM UNIVERSITY Table of Contents 1.  Institute Information__________________________________________________ 1 2. Project abstract ______________________________________________________ 2 3. Executive summary ___________________________________________________ 2 4. Demonstration of benefit of harvesting practices ___________________________ 3 5. Demonstration of benefits of flat bed and fluidised bed drying:_______________ 4 6. Milling experiments to demonstrate the benefit of roller milling as against stone milling___________________________________________________________________ 5  7. Survey results________________________________________________________ 6 7.1 Harvesting time__________________________________________________________ 7 7.2 Harvesting methods ______________________________________________________ 7 7.3 Rice drying______________________________________________________________ 7 7.4 Training program and extension activities ___________________________________ 8 7.5 Cooperatives ____________________________________________________________ 9 7.6 The impact of this project to smallholder farmers ____________________________ 10 8. Training activities ___________________________________________________ 10 8.1 Training of farmers _____________________________________________________ 10 8.2 Study tours for farmers and service providers _______________________________ 14 8.3 Demonstrations _________________________________________________________ 15 8.4 Mill installation and training of mill owners/operators ________________________ 17 9. Physical and Financial Benefits ________________________________________ 20 9.1 Integrated data on harvest and post-harvest losses of rice and information on the use of harvesters and dryers ________________________________________________________ 21 9.2 Assessment of benefits gained by Tan Phat A cooperative region. _______________ 24 9.3 Benefits from improvement of harvesting methods:___________________________ 24 9.4 Benefits from improvement of drying methods: ______________________________ 26 9.5 Summary on the benefits gained by Tan Phat A cooperative from the project_____ 28 9.6 Assessment of overall benefits to a province or MRD _________________________ 31 10. Conclusion _________________________________________________________ 32 11. Appendix___________________________________________________________ 33 1 1. Institute Information Project Name Investigation of rice kernel cracking and its control in the field and during post-harvest processes in the Mekong Delta of Vietnam Vietnamese Institution Nong Lam University HCMC Vietnamese Project Team Leader Assoc. Prof. Dr. Vinh Truong Australian Organisation The University of Queensland Australian Personnel Professor Bhesh Bhandari Professor Shu Fukai Date commenced April 2006 Completion date (original) March 2009 Completion date (revised) April 2009 Reporting period 6 months Contact Officer(s) In Australia: Team Leader Name: Bhesh Bhandari Telephone: +61733469192 Position: Professor Fax:+61733651177 Organisation: The University of Queensland Email:b.bhandari@uq.edu.au In Australia: Administrative contact Name: Mr Kerry Johnston Telephone: +61 7 3365 7493 Position: Research support officer Fax: +61 7 33658383 Organisation: The University of Queensland Email: k.johnston@research.uq.edu.au In Vietnam Name: Vinh Truong Telephone: 84-8-37242527 Position: Head, Department of Chemical Engineering Fax: 84-8-37245030 Organisation: Nong Lam University Email: tv@hcmuaf.edu.vn 2 2. Project abstract 3. Executive summary This report presents the validation of improved harvesting, drying and milling methods since the project started in 2006. The deliverables of the project are cooperative demonstrations detailing the physical and financial benefits of implementation of optimal harvest methods, optimal drying conditions and improved performance of milling plants addressing the outputs 31. and 3.2 (logframe reference) as explained in the original proposal. During the last three years, this CARD project has carried out abundant activities to enhance harvesting, drying and milling methods by both strengthening the knowledge of smallholder farmers and demonstrating the methods of implementation of optimal harvesting, drying and milling practices. At first, the data collection was carried out in terms of milling losses in various milling plants. Experimental works were then undertaken to test the hypothesis of rice cracking during harvest and post-harvest periods and to find out the optimal harvesting time, harvesting methods, drying conditions and milling performance. The systematically data collection and experimental results were prepared in the forms of training manuals and leaflets and distributed to stakeholders, particularly smallholder farmers via training workshops and study tours. To date (since the project commencement) 2312 farmers and 300 extension workers participated in the training. Demonstrations were also performed to stakeholders through equipment such as reapers, combined harvesters and driers provided by this CARD project. According to the results obtained from the farmers’ survey carried out in March 2009, the integrated approach implemented in this project improved the awareness of farming practices of smallholder farmers. Reduced whole rice grain yield due to cracking is one of the major issues that directly reduce income and availability of staple food to the farmers in the Mekong River Delta. The cracking or partial fissuring of rice kernels may occur right in the paddy field due to incorrect harvesting time/practice, improper post-harvest drying conditions and inappropriate milling operations. This project aims to improve the quality and value of the rice, through an integrated approach which encompasses farmers, millers, service providers and extension workers and education institution. A key objective of this project is to improve the knowledge of smallholder farmers by organizing workshops and demonstration for farmer cooperatives in the region so that appropriate harvesting and subsequent grain handling techniques are observed to improve rice grain quality. Similarly there will be demonstration and workshops for small millers to encourage them to install driers and/or provide them technical knowledge to practice optimum drying conditions. Improvement of the capacity of the extension workers by providing updated knowledge is another objective. The theory of grain drying will be advanced that would improve designs of future dryers. The education institutions involved in the project will work together for capacity building of their staff members in the Nong Lam University. 3 The data of milling losses in two provinces Tien Giang and Kien Giang were collected in 2007. To evaluate the current milling performance and investigate a new approach for better milling performance, two milling experiments were undertaken in Can Tho University (Aug 2008) and Kien Giang province (March 2009). A rice milling workshop was also successfully organised in Tan Hiep district, Kien Giang province to make local authorities, service providers, millers, extension workers and farmers’ representatives aware of using appropriate milling technology. The estimation of physical and financial benefits of this project showed that Tan Phat A cooperative will gain USD 50,326 every year from the improvement of harvesting and drying practices without further installation of the equipments. If the benefits from service of harvesting and drying are included, the cooperative will gain USD 125,826 every year. Under the circumstances if the advanced system is applied to MRD in rice production, i.e. correct harvesting, combined-harvesting cutting, mechanical drying, milling using modified dehusker, MRD may reduce 13% total losses which are equivalent to USD 190 million per annum . 4. Demonstration of benefit of harvesting practices Timely harvesting plays an important role in controlling rice cracking. Reduced whole rice grain yield due to cracking causes the value loss and reduces the farmers’ income. Field experiments were carried out to study the effect of harvesting time around crop maturity on rice cracking and head rice yield for seven common rice varieties (OM1490, OM2718, OM2517, OM4498, AG24, IR50404 and Jasmine) in three different locations, namely Seed Centre (An Giang Province), Tan Phat A Cooperative (Kien Giang Province) and Tan Thoi 1 Cooperative (Can Tho City) in four consecutive harvesting seasons during two years (2006- 2008). The results showed that the rice cracking was strongly influenced by both the variety and time of harvesting around maturity. There was a general trend of increase in percentage of cracked rice with late harvesting in relation to estimated grain maturity date. The head rice yield also followed the same trend in response to delayed harvesting. A delay of 4-6 days reduced the head rice yield by 11.3 % an average and up to 50 %. Similar trends were observed in both wet and dry seasons. The large varietal difference in percentage of cracked grain (0.9 to 60.5%) on 6 days after maturity date indicated that the level of rice cracking caused by late harvesting time can be minimized by the selection of suitable varieties. The detailed report about effects of harvesting time around grain maturity on rice cracking and head rice yield in MRD is presented in Appendix 1. Consecutive field experiments showed that a few days early harvesting (before maturity) is better than late harvesting by 4 to 6 days because late harvesting will make the grain more sensitive to cracking. The unavailability of harvesting machines or the shortage of harvesting labours will make the situation more severe because any delay or longer harvesting time can cause more losses, as is often the case of harvesting by hand. Therefore, using appropriate 4 harvesting methods such as combine-harvesters to prevent late harvesting is necessary. In addition to prevent grain losses caused by late harvesting, mechanization of harvesting methods using combine-harvesters can reduce 1.5% grain losses owing to threshing is not applicable after mechanical harvesting. 5. Demonstration of benefits of flat bed and fluidised bed drying: Rice drying became an issue in Mekong Delta in early 1980’s when a second crop was promoted, of which the harvest fell into the rainy season. Mechanical drying not only reduces grain losses caused by germination and spoilage but also be an utmost intervention opportunity to minimize rice grain cracking after drying or during milling stage. The project activities carried out rice drying experiments in both actual and laboratory conditions in order to improve drying efficiency and promote the mechanical drying, i.e. flat-bed and fluidised bed rice drying. The study, including experiments and survey on the flat-bed dryer, focused on the cracking of paddy grains, and on comparing the air reversal mode. Results showed that, in both the 8- ton production-scale dryer and the 20-kg laboratory dryer, the effect of air reversal was very apparent in reducing the final moisture differential; however, its effect on the drying time or the drying rate was not statistically significant. Mechanical drying, whether with or without air reversal, was superior to sun drying in terms of reducing rice crack. However, compared to shade control drying, drying (with or without air reversal) did decrease the head rice recovery and increase the crack. The decrease in head rice recovery was inconsistent, slightly lower or higher in each specific pair of experiments with and without air reversal; this was not expected in line with data on the final moisture differential. Testing of a 4-ton dryer at Long-An equipped with the solar collector as supplementary heat source resulted with good grain quality and confirmed the good economic potential. The actual drying time involved with the use of flat bed driers ranges from 8-10 h for wet paddy, if farmers want to reduce the grain moisture content to a safe level (14% wet basis). If the paddy needs to be dried to 15-16% moisture, the fluidized bed drying system can be used as a compact drier. In this project, Response Surface Method (RSM) experiment for optimum drying condition was determined in terms of HRY using a high temperature fluidised bed dryer. The drying air temperature and time in the first pass of RSM experiments (75-87 o C and 2.5 mins) were used effectively to determine the drying rate and HRY. At optimum condition, the head rice yield (HRY) was found almost similar to the controlled sample. However, sensory experiment showed that the whiteness of optimum sample was lower than that of the controlled sample. This reduced the sensory score of the optimum sample. Statistical analysis also indicated that first drying pass affected remarkably on the colour of the samples. The detailed methodology, brief results and discussion of this experiment are presented in the Appendix 2. 5 6. Milling experiments to demonstrate the benefit of roller milling as against stone milling Due to the current post-harvest system in the Mekong River Delta the mechanical drying can cover only 30% of the total wet paddy. Most of the rice is processed by sun drying. In addition, the price of paddy between 14% and 17-18% moisture is not differentiated clearly by the traders. Thus, the farmers prefer to sun-dry the paddy to final moisture content of 17- 18%. A large amount of high moisture paddy (17-18%) is demanded for milling. Thus, the milling operators have used the stone-dehusker for husking of paddy to suit this high moisture content paddy. This system has reduced HRY and needed to be investigated. Two milling experiments were undertaken using medium and large capacities of milling plants (1-ton/hour and 7-ton/hour, respectively). The main purposes of milling experiment were (i) to evaluate the current milling performance and find out a new approach for better milling performance; (ii) to propose a strategy how to upgrade from current milling system to a better performance system with less investment; (iii) to propose an integrated rice management model from harvesting to milling for a better rice quality and higher farmers’ income. The first milling experiment was carried out with 1-ton milling system (RS10P – SINCO) at Can Tho province. The purpose of this experiment was to determine the effect of paddy moisture content on the HRY while using rubber-roll dehusker. The paddy variety was OM1490 and paddy samples with three moisture levels (14, 15 and 16%) were compared. It was found that HRY was not significantly different between 14% and 15% paddy moisture contents. However, when the moisture content of paddy increased to 16%, the HRY reduced significantly from 46.7% to 37%. This reduction is quite high and implies the importance of moisture content level regarding milling performance. The complete result is submitted in MS11 report. The second experiment was carried out with 7-ton milling system for two varieties (OM6561 and IR50404) at two moisture levels (14% and 17-18%) using two milling techniques, i.e., stone and rubber roll dehusking. Currently, in MRD, in a milling system, 70% and 30% of paddy are processed by stone and rubber roll dehusking, respectively. The modified milling technique processes 0-30% and 70-100% of paddy by stone and rubber roll dehusking, respectively. In this experiment, the modified milling system with 30% husking by stone dehusker and 70% husking by rubber-roll dehusker is called modified 70% rubber-roll dehusker and denoted by M70RD. Similarly, the modified system with 100% rubber-roll husking is denoted by M100RD. The traditional system is therefore denoted by M30RD (only 30% of paddy processed by rubber-roll dehusker). The Hung Loi milling plant at Tan Hiep district, Kien Giang province was used for this experiment. In this experiment, the following results were obtained: 6 A. First experiment (March 2009): 1) For moisture content of paddy of 17-18%, the recovery of rice containing 15% broken rice (it is called “rice grade 15”) for M70RD system was 2.44% higher than that from M30RD system. 2) For the same M70RD system, the recovery of (rice grade 15) was 3.25% higher at 14.5% moisture than at 17-18% moisture. The above results indicated that M70RD system for rice moisture of 14% improved the HRY of the rice. B. Second experiment (August 2009): The results of this experiment are shown in following Table 1. Table 1. Total recovery and head rice yield (HRY) No Brown rice White rice 1 2 1 70 % CD + 30% CS (sun drying) (M30RD) 82,66% 40,71% 2 30 % CD + 70% CS (sun drying) (M70RD) 84,53% 35,89% 3 30 % CD + 70% CS (Dryer) (M70RD) 86,43% 53,36% 4 70 % CD + 30% CS (Dryer) (M30RD) 85,00% 49,28% CD: stone dehusker; CS: rubber-roll dehusker Results showed that: + For sun drying rice (moisture = 17%): HRY of 70% stone dehusker (M30RD) was higher than that of 30% stone dehusker (40,71% - 35,89%). + For mechanical drying rice (moisture = 14-15%): HRY of 70% stone dehusker (M30RD) was lower than that of 30% stone dehusker ( 49,28% - 53,36%). + HRY of mechanical drying rice was higher than that of sun drying rice about 13-14%. Therefore, dehusking using rubber roll will improve HRY only when the paddy is dried correctly up to moisture content of 14-15%. The Appendix 3 presents the technical report of these milling experiments. 7. Survey results Farmer survey was carried out in Tan Phat A cooperative, Tan Hiep district, Kien Giang province in early March 2009. The objective of this survey is to determine the likely impact of CARD 026/VIE-05 since the project started in September 2006. Thirty-one specific questions containing knowledge, attitude and practice questions were designed to address at various aspects of the project activities in changes of KAS (Knowledge, Attitudes, Skills) of System Product 7 smallholder farmers. A total number of respondents for the survey in dry season 2009 were 162 included CARD-trainees (41%, 66 out of total 162 respondents). The survey approach was one-to-one interview. Survey results are listed as followings: 7.1 Harvesting time Correct harvesting time is the first intervention opportunity in the field to reduce grain loss after harvesting. Field experiments undertaken during CARD project implementation period from 2006 to 2008 showed that late harvesting for 4-6 days after grain maturity (varied for each rice variety) caused the reduction of head rice by 9-50%. Among 162 respondents, 95.1% were aware of the negative impact of delayed harvesting compared to the awareness of recommended harvesting time for each rice variety. Training activities jointly organised by CARD project and extension centre provided this knowledge for 49.35% respondents in addition to the initiation of smallholder farmers through their self- learning (Figure 1). Despite the awareness of almost all respondents on the consequences of late harvesting, 45.34% smallholder farmers still delayed their paddy harvesting. The major problems identified were the shortages of harvesting labours (65.82%) and harvesters (25.32%). This implies that not only the extension propaganda of correct harvesting time is important but also the facilitation of harvesting equipment availability for harvesting mechanisation. 7.2 Harvesting methods Figure 2 represents the percentage of respondents who used different harvesting methods in 2006 (before this project started) and 2009. There were 83.65% respondents who pointed out that they harvested rice manually three years ago. After three years, the number of respondents using manual harvesting practice decreased remarkably by approximately 70%. Alternatively, the percentage of respondents employing harvesters went up significantly from 6.29% in 2006 to 63.35% three years later. Almost all respondents in this survey obtained knowledge of appropriate rice harvesting method. For instance, there were 80% of respondents who knew paddy threshing should be done immediately after harvesting. 7.3 Rice drying Drying is considered as an utmost intervention opportunity to minimize rice grain cracking after drying or during milling stage. According to the field experiments carried out in this project, it is estimated that the average percentage of grain loss caused by sun drying and field drying was about 8.7% for Winter-Spring crop. This number will be higher in wet season due to the fluctuation of weather and rains. As shown in Figure 3, there was a decrease in the percentage of respondents who used sun drying (from 79.5% in 2006 to 39.75% in 2009) and the number of respondents using dryers increased by 40% (8.70% to 47.83% during three years 2006-2009). The unavailability of dryers and the high cost of mechanical drying as compared to sun drying were two reasons that caused 12% respondents not being able to apply mechanical drying. Though over 80% of respondents thought the mechanical drying is better than sun drying and reduces grain cracking during milling (92.5%), there were only 53% respondents who knew mechanical 8 drying improved rice quality. The remaining respondents pointed out that mechanical drying is energy-consuming (21.12%) and they had no idea about mechanical drying (26.09%). About 63.3% respondents stated that CARD project and local extension centres were the providers of these drying knowledge and information (Figure 4). Figure 1. Three information sources of harvesting knowledge gained by respondents. Figure 2. Comparisons of various harvesting methods used by respondents in 2006 and 2009. Figure 3. Trends of using sun drying and mechanical drying among respondents in 2006 and 2009. Figure 4. Three information sources of rice drying knowledge obtained by respondents. 7.4 Training program and extension activities Among 162 respondents, the percentage of respondents who took part in the training program of CARD project was 41% (66 respondents). The effectiveness of these training workshops and study tours was highly appreciated by 98.5% respondents, but there were only 1.52% respondents who said that they had a prior knowledge of all the information provided during the training. Figure 5 describes the comparison between the percentage of respondents attending CARD training activities (41%, 66 out of total 162 respondents) and the number of respondents (out of 162 respondents including CARD-trainee-based [...]... system 33 APPENDIX 1 Influence of harvesting time around grain maturity on rice cracking and head rice yield in the Mekong River Delta of Vietnam ABSTRACT Timely harvesting plays an important role in controlling rice cracking Reduced whole rice grain yield due to cracking causes the value loss and reduces the farmers’ income Field experiments were carried out to study the effect of harvesting time around... CARD026/VIE05 project for experiments and training activities were the three of four leading provinces in relation to percentage of harvesting mechanization in the MRD in 2009 (Table 5) These provinces have increased the number of combined-harvesters dramatically in three years from 2006 to 2009 Consequently, the number of combineharvesters in the MRD has increased from 33 units in 2006 to 2300 units in 2009 These... maturity on rice cracking and head rice yield for seven common rice varieties (OM1490, OM2718, OM2517, OM4498, AG24, IR50404 and Jasmine) in three different locations during two cropping years (200 6-2 008) in the Mekong River Delta, Vietnam The results showed that the rice cracking was strongly influenced by both the variety and time of harvesting around maturity There was a general trend of increase in percentage... 70% of rice field in which 35% was harvested by reapers The average rice field cut by machine in Long An was 180ha/machine/year which is equivalent to machine capacity of 4ha/day The data of Long An is reasonable and close to the actual capacity of standard combine-harvester (SCH = 4ha/day) currently used in the MRD and was selected for estimation of the percentage of rice field cut by machine in the. .. date indicated that the level of rice cracking caused by late harvesting time can be minimized by the selection of suitable varieties 1 INTRODUCTION Head rice yield, which is defined as the weight percentage of rough rice that remains as head rice (the kernels that are at least ¾ of the original kernel length) after milling, is considered as the main quality indicator because the broken rice has often... extension officers have been trained on cracking issues for controlling of rice quality during harvest and post-harvest operations (Table 2) It is clear that 10 the target of training 1800 farmers and extension workers in this project (520 farmers/year and 39 extension officers/year) has been quite achieved The content of training session comprised of three lessons on harvesting time, harvesting methods and. .. competency to win the farmers’ confidence Figure 5 Comparison between the percentage of respondents attending CARD training activities (41%, 66 out of total 162 respondents) and the number of respondents (out of 162 respondents including CARD-trainee-based and non CARD trainee-based) who had correct answers in terms of harvesting time, harvesting method and rice drying 9 7.6 The impact of this project to... non-CARD-trainees) Two groups were compared into two categories: information line and rice knowledge based on their answers in the farming survey The statistical analysis showed that there is no significant difference in ‘information line’ between CARDtrainees and non-CARD-trainees groups (P>0.05) Analysis of percentage of correct answers for rice knowledge questions in the survey given by CARD-trainees... imply the impact of this project on mechanization of rice harvesting Beside CARD project, other programs such as “competition of combined-harvester” organised yearly by MARD since 2007 might have also contributed to the increased number of combineharvesters in MRD Therefore, it is hard to estimate how much is the impact of CARD project on the mechanization of harvest and post-harvest of rice in MRD... only the CARD project was involved with demonstrating the farmers the cracking issues (value losses) caused by late harvesting, sun drying and incorrect mechanical drying Kien Giang is a province where CARD project organised more than 10 training sessions in all the districts Over 1200 farmers have been trained In Kien Giang, the number of reapers in 2006 was only 16 units and there were no combine-harvesters . 1 1. Institute Information Project Name Investigation of rice kernel cracking and its control in the field and during post-harvest processes in the Mekong Delta of Vietnam Vietnamese Institution. Ministry of Agriculture & Rural Development Project Progress Report 026/05VIE Investigation of rice kernel cracking and its control in the field and during post-harvest processes. losses in various milling plants. Experimental works were then undertaken to test the hypothesis of rice cracking during harvest and post-harvest periods and to find out the optimal harvesting