Research on identifying new varieties and cultivated techniques protocol to improve productivity and economic efficiency in tomato production in red river delta

sulting in 18.7 – 34.1% bebefit increaments. -5- Introduce some protential hybrid tomato varieties in some province: Hai Duong, Hung Yen, Vinh Phuc, Hanoi… which are widely accepted by tomato growers. In 2012, production area of 2 varieties Savior and TAT072672 is up to 1382.4 ha and 328.3 ha. Variety TAT062659 was introduced into production in 2013. 6. Sructure of the Thesis Thesis consists of 127 page including: introduction (5 pages), Chapter 1: Summary of references and sciencific basic of the thesis (36 pages); Chapter 2: Material and method (12 pages); Chapter 3: Results and discussions (72 pages); Conclusion and proposals (2 pages). There are 161 references used, including 58 Vietnamese ones and 102 English ones in the thesis. There are 55 data tables, 4 ficgures, 10 expendixes, 4 declared studies. -6- CHAPTER 1 Literature review There are 58 Vietnamese ones and 102 English ones in the thesis regarding to: 1. Introduction of tomao; 2. Status of tomato production in the world and in Vietnam; 3. Status of research on tomato in the world and in Vietnam. Origin of Tomato Solanum lycopersicum is from Andean region including Colombia, Ecuador, Peru, Bolivia and Chile (Jaime Prohens and Fernando Nuez, 2008). Tomato is a fruit vegetable with nutritional value, high medicinal value and is one of the vegetable with high economic efficiency, is a good of export in many countries worldwide. Area of tomato production in the world continues increasing but it is not stable. In 2011, area of tomato production was 4,734,350 ha, productivity was 34.59 tons/ha and yield 159,023 million tons (FAOSTAT Database, 2011). In Vietnam, tomato has been cultivated for over 100 years, which is well-developed in many regions in the country. In 2011, area was 23,083 ha, evarage productivity was 25.55 tons/ha and yield was 589.83 million tons (Tổng Cục thống kê, 2012). Methods of tomato breeding are still traditional methods, including: sexual hybrid and selecting generated populations, sexual hybrid and … Recently, with applications of bio-technology, especially genetic engineering in tomato breeding has been strongly developed in some countries and international organizations. Beside achievements of genetic engineering, applications of heterosis effects in tomato are also well-developed in the 20th century (Singh and Checma (1989); Thomas and Umesh (1989), Pichet and Anon (1996)AVRDC (2003), AVRDC reports (2005, Foolad et al., (2012), Easlon H M, (2009), Nasar Virk et al., (2012). Recent years, there is a diversity of materials for tomato breeding including both cultivated cultivals and wilt cultuvals. Tomato breeding, especially heterosis selections of high yield, good quality, resistance with diseases such as bacterials wilt, yellow curly leaf, late blight, ring spot, tematodes, suitable for fresh tomato and processing is taken place and achieved a lot of successes in USA, India, France, Bulgaria, Thailand, Phillipine… and the AVRDC(Gaikwad et al., 2010; Wessel Beaver et al., 1992; Lin and Lai,1989; Anbinder et al.,2009; Vidavski F. et al.,2008, Dagan et al.,2012; AVRDC Report, 2004; 2005 và 2008a; Chunwongse J. et al., 2002; Min-Jea Kim et al., 2005; R.Chaerani và cộng sự, 2007; Chaerani et al., 2007. Technology of molecular marker is used successfully in tomato breeding of adaption with unfavorable to conditions such hot climate, high humidity, salt tolerance, drought tolerance (AVRDC, 2000; Easlon H M, 2009; Nasar Virk et al., 2012) Alica -7- et al, (2001), Denoyes and Anais (1989); Denoyes and Rhino, (1999), Tiwari and Choudhury, (1993). Worldwide, applications of high technology, greenhouse technology in tomato production brough revulitionary results for tomato production in term of productivity and control of harvesting time as well ( Valerie et al., 2010; Asit Baran Mondal at el., 2011;, Sanchez et al., 2011; Liu et al., 2012; Choudhary et al., 2010; Manson et al., 2010; ….). Studies in many countries regarding to crop densit, fertilizers, cultivation habitat, pest management improved countable productivity and quality, decrease disease infection in production, resulting in improvement of economic efficiency of production (Tran Khac Thi, Ngo Thu Ha, 2010). Studies on rootstock eggplant, Hawai variety in tomato production have been carried out soon and brough remarkable results such as high productivity, good quality, tolerance to disease and unfavorable conditions (Nina, 2004; Khah et al., 2006; Francisco et al., (2010), Dimitrios Savvas et al., (2009),.. Studing and breeding of tomato in Vietnam focus on good growth, high yield, firm fruit, thick flesh, high crack resistance, good tolerance to pest, heat tolerance, short life cycle, long shelf life, good color, good quality for fresh market and food processing. In recent years, universities and research institutes introduced a number of hybrid tomato varieties with high quality and good disiese tolerance such as HT7, HT42, HT160, FM20, FM29, lai số 9, HPT 10, VT3, VT4… contributing development of tomato production in Red River delta (Nguyen Minh Hong, Kieu Thi Nhu et al, 2006ab, 2011a, 2011b; Le Thi Thuy et al, 2010; Duong Kim Thoa et al, 2012). However, the number of tomato varieties is limited, account for small area and slowly introduced in practice production. In practice production, there is lack of varieties with high productivity and good tolerance, suitable for production in off- season. In parallel to breeding, studies and application of innovations (crop season, density, fertilizer program, grafted tomato with rootstock of egg plant…) provide potential results, contributing increased productivity and production efficiency in main crop season as well as in off-season (Ta Thu Cuc, 2007; Dao Xuan Thang el all 2005; Duong Kim Thoa et al 2006, Nguyen Thi Mao, 2008; Tran Van Lai et al, 2002; Vu Thanh Hai, 2011; Tran Thi Ba et all., 2010; Tran Khac Thi et all.,2011)… Althought there is improvement in research and applicatinon of hybrid tomato as well as cultivation techniques in tomato production… -8- CHAPTER 2 MATERIAL, OBJECTIVE AND RESEARCH METHODOLOGY 2.1. Research Materials 2.1.1. Varieties materials Group of 80 hybrid combinations of semideterminate tomato and 62 hybrid combination of determinate tomato mported from Thailand and India and 4 popular varieties of check Grandeva, DV269, HT42, VL2004. 10 potential varieties are introduced to evaluate including 5 semideterminate varieties (TAT072672, Savior, TAI786, TAT08-1072, TAT08-1336) and 5 determinate varieties (TAT071001, TAT071004, TAT062659, TAT08-1266 và TAT08-1336). Technical guidelines for cultivation in Red River delta of 3 potential varieties Savior, TAT072672 (Hồng ngọc), TAT062659 were completed. 3 varieties of rootstock Egg Plant EG203, Hawaii 7996 and Cà Gai were evaluated efficacy of rootstock with scion variety Savior in off-season in Red River delta. 2.1.2. Others materials - Organic fertilizer: Composted fertilizer - Inorganic fertilizers: Ure 46.6% N, super phosphorous fertilizer 16,5% P2O5, KCL 60% K2O, NPK đầu trâu 13-13-13+TE fertilizer. 2.2. Research Objectives 2.2.1.Evaluation of status and propose technical solutions for improvement of productivity and efficiency of tomato production in Red River delta. 2.2.2. Evaluate and select tomato varieties that are suitable for production in Red River delta 2.2.3. Complete technical guildeline for cultivation of potential varieties. 2.2.4. Complete technical guideline of tomato grafting and evaluate production efficiency of grafted tomato Savior in Red River delta. 2.3. Place and Period implementation 2.3.1. Research Place: Evaluated status of tomato production in 7 provinces Vinh Phuc, Ha Noi, Bac Ninh, Hung Yen, Hai Duong, and Nam Dinh. Trials of variety selecting and research on farming technical were carried out in farming co-operative Song Phuong, Hoai Duc district, Ha Noi. Trials of production were carried out in Vinh Phuc, Ha Noi, Hai Duong and Nam Dinh. Trial of grafted tomato were carried out in Tam Dao, Vinh Tuong of Vinh Phuc province, Hoai Duc, Ha Noi; Nam Sach, Hai Duong province; Tien Lang, Hai Phong province. -9- 2.3.2. Implementation period: from 2008-2013 2.4. Research Methodology 2.4.1. Survey methodology about tomato production status in RRD - Data was collected from relevant national and local divisions, departments. - Farmers interview by method RRA, PRA, KIP, Group interview; analysis of strength, weakness, opportunities and difficulties 2.4.2. Setting up field trials methodology 2.4.2.1. Evaluation and Selection varieties trials Trial 1: Evaluate group of varieties using sequential method, no replication, 2 varieties of check for every 10 evaluated varieties. Plot size is 12.0 m2 (20 plants/plot) Trial 2: Evaluate farming and efficiency of potential varieties in 3 different seasons: autumn – winter, Winter and Spring – Summer in Red River delta to determine suitable varieties for each crops season. Trial was designed as Randomly Completed Block Design (CRBD) with 3 replications, plot size 20m2. Density is 28500 plants/ha of semi-determinate varieties; 35700 plants/ha of determinate varieties. Fertilizers per ha were: 25 tons composted fertilizer, 1385 kg lime, NPK: 150 kg N+180 kg P2O5+200kg K2O. 2.4.2.2. Techniques research trials Trial 3: Effect crop seasons: There were 12 treatments of crop season from July 20, 2009 to February 20, 2010: 2 treatments in Summer-Autumn, 3 treatments in Autumn-Winter; 3 treatments in Winter and 4 treatments in Spring-Summer. Trial was designed as RCBD with 3 replications, plot size 12.0 m2. Crop interval is 70 x 50 cm. Fertilizers per ha were: 25 tons composted fertilizer, 1385 kg lime, NPK: 150 kg N+180 kg P2O5+200kg K2O. Trial 4: Effect of crop density on growth, development, productivity and pest infection of variety TAT072672 in Spring-Summer and Autumn-Winter. Trial was designed as RCBD with 3 replications, plot size 12.0 m2 and 5 treatment of crop density with crop intervals 35cm, 40cm, 45cm, 50cm và 55cm, and crop row interval 70cm. Trial 5: Effect of inorganic fertilizer on growth, development, productivity and pest infection of variety TAT072672 in Spring-Summer and Autumn-Winter. There were 6 treatments of fertilizer of N:P: K as treatment 1: 120:150:150; treatment 2: 120:180:180; treatment 3: 150:180:200; treatment 4: 150:200:200; treatment 5: 180:180:180; treatment 6: 180:200:200. Trial was designed as RCBD with 3 replications, plot size 12.0 m2, crop row interval 70 x 50 cm. Basic fertilizer per ha were 25 tons composted fertilizer, 1385 kg lime. -10- Trial 6: effect of density on growth, development, productivity and pest infection of variety TAT072672 in Winter season. There were 5 treatments of 70 x 35cm, 70x40cm, 70x45cm, 70x50cm và 70x55cm. Trial was designed as RCBD with 3 replications, plot size 12.0 m2. Fertilizer per ha were 25 tons composted fertilizer, 1385 kg lime +150kgN + 180kg P2O5 + 200kg K2O. Trial 7: Effect of fertilizer on growth, development, productivity and pest infection of variety TAT072672 in Winter season. There were 6 treatments of fertilizer of N:P: K as treatment 1: 120:150:150; treatment 2: 120:180:180; treatment 3: 150:180:200; treatment 4: 150:200:200; treatment 5: 180:180:180; treatment 6: 180:200:200.. Basic fertilizer per ha were 25 tons composted fertilizer, 1385 kg lime. Trial was designed as RCBD with 3 replications, plot size 12.0 m2, crop row interval 70 x 40 cm Trial 8: Evaluate rootstock, specifications of rootstock and time of grafting for Sarvior variety to complete technical guideline for grafting of commercial Savior tomato. 3 varieties for rootstock were eggplant, Hawaii tomato, cà gai. Trial 9: Evaluation Bacterial wilt of Savior and Rootstock Hawaii7996 by infecsion Trial 10: Evaluate growth, development, adaptation and productivity off grafted Savior tomato with different rootstock and in Summer-Autumn season and Spring- Summer season in Red River delta. Trial was designed as RCBD with 3 replications, plot size 20.0 m2 (50 plants/plot) and crop interval 70 x 50 cm.. Fertilizer per ha were 25 tons composted fertilizer, 1385 kg lime +150kgN + 180kg P2O5 + 200kg K2O. Number of observed plant: 10 plants/plot. Trials were according to experimental regulation of farming and efficacy of tomato 10 TCN-2004. Observed criteria of growth, development, pest were according to regulation TCN. Data was analyzed by excel and IRRISTAT. 2.4.3. Collection evaluation methods Apply standard methodology from “Crop breeding” book (2005) and national standard on DUS testing - 10TCN 667-2002 to evaluated and separate varieties group by special characters, using evaluation appearant characteristic method, yield components, fruit quality chacracters… . Base traits to select good variety are: Good growth ability, short to medium growth duration, tolerant to TYLCV, Late blight and high yield. 2.4.4. Method on cultivation testing and building demonstration 2.4.4.1. Cultivated testing of some selected varieties There were 2 production trials of 02 semi-determinate varieties Sarvior and TAT072672 and 01 determinate variety TAT062659 in some locals in Red River delta with scale of 360m2 with different soil. Technical guideline of growing was -11- experimental regulation VCU of Ministry of Agriculture and Rural Development 10 TCN-2004. 2.4.4.2. Demostration for selected varieties Base on researching results from density and fertilizer trials to set up demonstration at multi locations across RRD. 2.4.4.3. Demostration of grafted tomato plant Demostration of grafted tomato plant from Savior scion had been implemented at 5 locations in Summer-Autumn season 2012 (started from 15-20/7/2012). Non- grafted plant had been used as check plot on Demos, Demos area was around 0,3- 1,0ha/location. Caculation economic efficiency as fommular Gross Return (GR) = Yield x selling price - Total variation Cost (TVC) = Material cost + Labor cost - Benefit = GR –TVC. CHATER III: RESULTS AND DISCUSSION 3.1. Current status of tomato production in RRD 3.1.1. Weather condition in RRD period 2008-2012 The Weather condition in RRD allow to develop tomato production from at many seasons as Summer-Auturm, Auturm-Winter, Winter and Spring-summer. In which Winter season is the best suitable for different tomato type, Summer-Auturm season can be develop good heat tolerant, TYLCV tolerant, Bacterial wilt, in Spring-summer season require varieties with heat tolerant, late blight and TYLCV tolerant … 3.1.2. Cultivated season and tomato varieties partern in RRD in period 2008-2012 In RRD condition, tomato cultivated season started from middle of July to end of Jannuary. The early season starts sowing from middle of july to end of August with the varieties as heat tolerant, TYLCV tolerant. Some provinces with high area in this season as Haiduong, Namdinh, the popular varieties as Monggan, at Haiphong, Bacninh with Savior, HT160… The main tomato season (sowing at early of Sep to end of Oct) have been growing at the 2 rice seasons area and irrigated area. The provinces with high contrentation area as Namdinh, Hungyen, Hanoi, Vinhphuc… the popular varieties as VL2000, BM199, Grandeva, VL3500, HT160. The Spring- summer season and Summer season have been growth on high and irrigated area, the required traits for these season are heat tolerant, good to medium late blight tolerant, the popular varieties as Savior, Grandeva, DV2962... , The provinces have larges area in this season are Bắc Ninh (140 ha), Hưng Yên (80 ha), Hải Dương (120 ha), Hải Phòng( 125 ha), Hà Nội (90ha), Vĩnh Phúc (85 ha)…, -12- RRD area are diversity on cultivated tophography. The higher soil area with 40% where tomato have been grwown at early season, main season and late season. The popular varieties are semi determinate type as Savior, Grandeva, VL3500…Continuous by 2 rice seasons area with 55% area, main crop partern here is winter season, the varieties in this segment are short growth duration, concentrated harvesting as BM199, DV178, Perfect 89 and Savior. A small area of soil nearby river (5%) in Vinhphuc and Hanoi … have been growth at early season, the popular varieties as VL2004, VL2000, Perfect 89… 3.1.3. Variation tomato variety quatity through periods Have variation on number of tomato variaties through period. It was from 32 varieties in 2000-2005 to 27 varieties at 2006-2008 and 2009-2011. The local varieties, inbred varieties had been replaced by hybrids one (from incountry and import from outside). The current production has high demand of high yield, high quality, tolerant to some important diseases due to existing 16 kind of insects and 16 kind of diseses with different effected level. The pressure of the late blight, TYLCV and bacterial wilt have been increasing and more serious at recent years that big effected to tomato production in RRD. 3.1.5. Economy efficiency of tomato production at RRD by season and by location It is high variation economic efficiency by growing seasons. The highest efficiency from Summer-Auturm season with profit from 70,7 – 92,7 mio VND/ha, Continuous by Spring-Summer season from 44,6-51,6 mio VND/ha, in Winter season with suitable condition for tomato production but the price always at low level so that benefit at low level also. 3.1.7. The limitation and difficulties of tomato production in RRD. The high pressure of late blight in Winter-spring and Spring-Summer are biggest problem (76,6% - 94,5% surveyed people); Leaf miner is second worries pest with 62,5% - 93,3%; The pressure of Bacterial wilt is thirth with (51,6% - 61,4% surveyed people). The pressure of diseases as late blight, bacterial wilt have been developing fast and strong expanding in RRD while the high yield, better diseases tolerant varieties still gap. Problem from flooding/ heavy rain in Summer-Auturm season also effected to tomato production. The Social -economic factors as unstable price, lack of technicial knowledge are limit to tomato production also. 3.1.8. Research orientation to reduce limitation and difficulties on production. Develop new varieties with high yield, good diseases tolerant and completed cultivated techniques protocol to support. -13- Deeply research on breeding variety with heat tolerant, TYLCV and late blight tolerant traits to support for tomato production on Summer-Auturm and Spring- Summer season that can bring higher benefit for tomato growers. Research and quickly apply the improved cultivated techniques protocol on prevent late blight, bacterial wilt disease on tomato production, especial on off season production in RRD. 3.2. RESEARCH ON SELECTING NEW VARIETIES FOR RRD AREA. 3.2.1. Testing imported collection In the 146 varieties were tested in Winter-Spring season in RRD, many of them have good characters as good fruit setting (61,5%), good fruit shape (93,2%), high plant yield with >2kg/plant (30,8%); good late blight tolerant (46,6%) and leaf spot (63%). These are very good material to select good varities for production. Based on targeted criteria, we selected variety groups with good agronomic characters, good tolerant to diseases and higher yield. There were 5 varieties in semiditerminate type as TAT072672, TAI786, Savior, TAT081072, TAT081119 and 5 varieties in determinate type as TAT062659, TAT071001, TAT071004, TAT081266 and TAT081336. 3.2.2. Evaluating selected varieties 3.2.2.1. Agronomy characters of tomato varieties The varieties belong to semi determinate type had growth duration from 113 days (TAI786 – Autumn-Winter season) to 145 days (Savior, Winter season), harvesting time from from 40 days (TAI786, Grandeva – Spring-Summer) to 65 days (Savior – winter season). The growth duration of determinate varieties were shorter as 95 days (TAT081266 – Autumn-winter) to 120 days (TAT071101 – winter season). The harvesting time were shoter than semiditerminate varieties, the variation from 32 days (TAT071101 –Spring-summer season) to 40 days (TAT062659, winter season). These characters are basement to set up cropping partern on different area in RRD. In Spring-summer season, the plant height is highest, in Auturnm-Winter season, the growth ability were stronger at early stage and in Winter season the plant height shorter due to growth duration in the reducing temperature period make limit the heigh. It was variation on trait as plant height from bottom to first node between seasons; Number of node from bottom to first fruit bunch had no variation between seasons. In the determinate varieties, the plant height similar between seasons, numbers of node from bottom to first fruit bunch have small variation between seasons. -14- 3.2.2.2. The yield components and yield Table 3.16. Yielding of tomato varieties in different season in Hoaiduc, Hanoi, 2009-2010 Characters Varieties Plant yield (kg/plant) Potential yield (ton/ha) Acual yield (ton/ha) Aut- Win Winter Spr- Sum Aut- Win Winter Spr-Sum Aut-Win Winter Spr-Sum TAT072672 2,29ab 3,17a 2,53ab 63,4ab 79,2a 70,2ab 53,1a 64,1a 50,3ab TAI786 2,33a 3,42a 2,70a 64,5a 85,5a 74,8a 53,1a 68,7a 52,4ab Savior 2,33a 3,19a 2,60a 65,5a 79,8a 72,0ab 53,8a 64,7a 54,6a TAT08-1072 2,28ab 3,20b 2,48b 63,2ab 79,9b 68,8b 52,1ab 64,2a 48,2cd TAT08-1119 2,11c 3,22ab 2,47b 58,4c 80,5ab 68,3b 48,1c 64,6a 47,9cd Grandeva (đc1) 2,26b 3,19a 2,47b 62,5b 79,7a 68,3b 50,0bc 64,5a 46,3d CV(%) (BHH) 1,5 3,5 3,6 1,5 3,5 3,6 2,6 5,7 3,5 LSD0,05(BHH) 0,06 0,21 0,17 1,7 5,1 4,6 2,5 6,8 3,2 TAT062659 1,68a 2,10a 1,75ab 49,8a 62,2a 51,8ab 39,6a 50,3a 39,5ab TAT071101 1,63a 1,91bc 1,67b 49,5a 56,4bc 49,3b 39,4a 45,1bc 38,0b TAT071104 1,68a 2,02abc 1,64b 48,3a 59,8abc 48,6b 36,9b 47,4abc 36,2b TAT08-1266 1,66a 2,01abc 1,63b 49,1a 59,5abc 48,3b 39,1a 48,2abc 36,8b TAT08-1336 1,68a 2,04ab 1,83a 49,8a 60,3ab 54,1a 39,6a 48,8ab 41,2a HT42 (đc2) 1,62a 1,87c 1,63b 48,0a 55,3c 48,4b 35,9b 43,9c 36,6b CV(%) (HH) 2,7 4,0 5,0 2,7 4,0 5,0 2,6 5,2 4,4 LSD0,05(HH) 0,08 0,14 0,15 2,4 4,3 4,5 1,8 4,5 3,0 3.2.2.4. Fruit quality The Savior and TAT072672 have splended characters better than check variety at main and off season as good mature fruit colour, less cracking shoulder, high rind percentage (79,5-85,3%), firmness and less hard seed. The determinate varities as TAT062659 had better on fruit quality and uniform fruit between harvesting time than HT42 at different cultivated seasons as good mature fruit colour, high rind percentage 80,5-82,8%, no cracking shoulder in winter condition ( score 9), slightly cracking in Summer-Autumn and Spring-Summer condition (Score 7). It was different on brix level between varieties, that was from 2,54 % (TAI786) to 3,18% (TAT072672). The brix level at most semi determinate varieties were higher than check Grandeva, the higest grade in TAI786 at 5,95%. The brix level at most determinate varieties were similar than check HT42. -15- 3.2.2.5. Diseases tolerant The Savior and TAT072672 varieties had good presented on high tolerant to TYLCV with very low effected rate at Autunm – Winter season (0,7%) but at low rate and no effected at Winter and Spring-summer seasons. In Winter and Spring – Summer seasons, the varieties Savior, TAT081072 and TAT081119 were lighter effected late blight than others at both seasons (Score 1-2), The variety TAT072672 had better tolerant than check. The determinate varieties tolerant TYLCV than check HT42 in three seasons, The HT42 was effected TYLCV the highest as 16,7% effected plant in Autunm – Winter season. In Summary: After 3 tested trial across seasons show that: in semideterminate varieties, the variety TAT072672 and Savior have many splendid traits better than check as good growth abilities, good fruit shape, uniform fruit, high fruit setting abilities at both main and off seasons. High tolerant to TYLCV, light effected to bacterial wilt and medium tolerant to late blight. In determinate varieties, the variety TAT062659 better than check in growth ability at different seasons, achieved highest yield in winter season, good fruit shape, unifrm fruit, high tolerant to TYLCV, BW and light effected late blight. 3.2.3. Cultivated testing of selected varieties in Winter season in RRD. 2 semi determinate varieties as Savior and TAT072672 were tested at multi locations as Vĩnh Phúc, Hải Dương, Hà Nội, Nam Định on different tophograhy. The results showed that: both of them had very good on stable growth ability, the achieved yield higher than check Grandeva. The Savior achieved 64,9-68,0 tons/ha, the growth duration from 158 – 165 days and harvesting duration as 62-67 days accordingly. They have good tolerant to TYLCV, medium tolerant to late blight. The variety TAT072672 has variation growth duration from 156 - 165 days and harvesting duration was 60 days, good tolerant to TYLCV. The 2 diterminate varieties TAT071001 and TAT062659 were tested in Hanoi and Namdinh. The variety TAT062659 had good performance at Winter season on 2 rice seasons area with growth duration 145 days, concented harvesting on 45 days, good late blight tolerant at score 0-1 and good tolerant to TYLCV as effected rate from 0,0-4,0%, the yied achieved from 49,1 – 52,0 tons/ha. Since 2010, the Savior had been set to main varieties collection to develop at off season at many locations in RRD. Currently at 7 provinces of RRD, Savior and TAT072672 (Hồng Ngọc) have been cultivated as 1382ha and 328,3ha arccordingly. -16- Table 3.22. Production area of Savior and TAT072672 In RRD from 2010 to 2012 (ha) Location 2010 (ha) 2011 (ha) 2012 (ha) Savior variety Vĩnh Phúc 216,0 259,2 302,4 Hà Nội 103,7 129,6 172,8 Bắc Ninh 86,4 172,8 216,0 Hưng Yên 129,6 129,6 129,6 Hải Dương 259,2 259,2 259,2 Nam Định 129,6 172,8 86,4 Hải Phòng 129,6 216,0 216,0 Total (ha) 1054,1 1339,2 1382,4 TAT072672 variety Hà Nội 43,2 43,2 43,2 Bắc Ninh 34,6 43,2 43,2 Hưng Yên 43,2 43,2 69,1 Hải Dương 25,9 25,9 51,8 Nam Định 34,6 34,6 69,1 Hải Phòng 34,6 43,2 51,8 Total (ha) 216,0 233,3 328,3 3.3. RESEARCH ON IDENTIFYING TECHNIQUED METHODS TO INCREASE YIELD AND ECONIMIC EFFICIENCY FROM SELECTED VARIETIES In parallel develop these varieties to production, the cultivated techniques had implemented to support achieve maximum potential yield. The research on suitable season, density and fertilizer rate had been done. The Savior was research on seasons adaptation, the TAT072672 and TAT062659 were research on density and fertilizer rate to complete techniques protocol. 3.3.1. Effected from growing season to growth alility, yielding and diseases effected of Savior. The data from table 3.24 show that, Savior is good heat tolerant variety as able to start sowing from 10/8. In main season, Savior had very good performance at growth ability and potential yield. This one can be very good development in Spring- Summer season till 20/2. In both main and off seasons, Savior had well toerant to TYLCV, light effected late blight and BW and yellow leave diseases at Spring- -17- summer season. The yield achived >65 tons/ha in main season and >46 tons/ha at off season. These results were really bring high benefit for tomato growers in RRD. Table 3.24. Yied componants and yield of Savior in different seasons (Hanoi, 2009-2010) Characters Formular Fruit setting at 5 first bunches (%) Nuber of fruit bunch/p lant (bunch) Fruit number/ plant( fruit) Fruit weight (g) Plant yield (kg/plant) potential yield (tons/ha) Actual yield (tons/ha) The sum-aut TV1(20/7) 40,5g 8,4f 26,6e 106,3d 1,6d 39,2d 34,3g TV2 (30/7) 44,3f 8,9ef 28,3de 107,3d 1,7d 41,7d 36,7f TV3 (10/8) 50,6de 9,4de 30,0cd 111,2c 2,1c 53,3c 46,4e TV4 (20/8) 53,2cd 9,5cd 29,5cd 113,3abc 2,3c 56,7c 48,5cde TV5 (30/8) 54,4c 10,0bc 32,3b 113,9abc 2,5b 61,7b 51,0bc The winter TV6 (5/10) 67,0a 11,8a 44,5a 115,7a 3,2a 80,0a 67,9a TV7 (15/10) 66,2a 12,1a 44,6a 116,2a 3,1a 77,5a 68,6a TV8 (25/1) 66,5a 12,1a 45,2a 116,0a 3,2a 80,0a 67,2a The Spr.-Su TV9 (15/1) 58,2b 10,4b 32,6b 114,7ab 2,5b 63,3b 51,6b TV10 (25/1) 55,3c 10,3b 31,1bc 111,7bc 2,2c 55,0c 49,2bcd TV11(5/2) 54,3c 9,9bcd 30,0cd 112,0bc 2,2c 55,0c 47,7de TV12 (20/2) 50,1de 8,2c 26,3d 113,0abc 2,1c 52,5c 42,5e CV (%) 2,9 2,9 3,1 1,5 4,5 4,5 2,8 LSD0,05 2,7 0,5 1,8 2,9 0,2 4,6 2,4 3.3.2. Identifying suitable density and fertilizer rate for TAT072672 (Hongngoc) at offseason condition in RRD. 3.3.2.1. Identifying suitable density in Spring-summer season and Autumn-winter seasons In Spring-summer season had different yield between density rate from M1, M2 versus others, variation between rate from 47,0-51,3 tons/ha and get highest yield at M5 (51,3 tons/ha). In Summer-autumn season, the yield of this variety variation from 44,8-55,9 tons/ha, the highest benefit also reached at M5 with 88,7 miovnd/ha in Spring-summer season. The yield in Autumn-winter season get highest at M4 as 105,7 mio vnd/ha. Conclusion that, the Hongngoc variety need optimum density suitable as 70x55 cm or 26,0k plants/ha in Spring-summer season. In Summer- autumn season need optimum density as 70x50 cm or 28,6k plants/ha. -18- Table 3.29. Effecting from density to yield and investment effectiveness of Hongngoc variety in offseason, 2010 in RRD. Characters Rates Potential yield (tons/ha) Actual yield (tons/ha) Benefit (mio vndđ/ha) Spr-Sum Aut-Win Spr-Sum Aut- Win Spr-Sum Aut- Win M1 (40,8) 63,9b 61,7ab 47,0b 44,8c 64,6 50,1 M1 (35,7) 67,3a 55,9c 50,2a 51,4b 81,5 82,6 M3 (31,7) 66,0a 57,4bc 48,5b 54,8ab 73,7 99,4 M4 (28,6) 66,3a 65,1a 50,3a 55,9a 82,9 105,7 M5 (26,0) 66,7a 63,5a 51,3a 53,6ab 88,7 94,9 CV(%) 4,7 4,7 4,6 4,2 LSD0,05 2,1 5,4 1,5 4,1 3.3.2.2. Identifying suitable fertilizer rate for Hongngoc variety at Spring-Summer and Autumn-winter season in RRD. Table 3.32. Effecting from fertilizer rates to yield and investment cost of Hongngoc variety in offseason, in RRD, 2010 Characters Rates Potential yield (tons/ha) Actual yield (tons/ha) Benefit (mio vnd/ha) Spr- Sum Aut- Win Spr-Sum Aut-Win Spr- Sum Aut- Win CT1. 120:150:150 58,6c 61,5c 42,3c 45,2c 52,3 60,1 CT2. 120:180:180 62,5b 70,2b 46,1b 51,6b 65,3 89,2 CT3. 150:180:200 67,4a 78,3a 52,4a 57,6a 95,7 116,7 CT4. 150:200:200 68,9a 79,7a 53,6a 58,6a 100,9 121,0 CT5.180:180:180 68,4a 77,2a 53,2a 56,8a 99,2 112,7 CT6.180:200:200 68,6a 78,0a 53,5a 57,3a 85,6 114,3 CV (%) 3,8 4,7 3,6 4,2 LSD0,05 4,5 5,4 4,4 4,1 The yield of any variety at different fertilizer rate displays potential yield at optimum condition as well as identifying effectiveness of fertilizer rate to production effectiveness. The trial results showed clearly role of elements N, P, K to variety Hồng Ngọc. In order to Hồng Ngọc variety achieve highest potential yield and fruit -19- quality adapt to market required at off season need fertilizer rate as 150-180 kg N/ha, 180-200 kg P2O5/ha and 200 kg K2O, In case of short supply or un balance NPK are effected to yield and fruit quality as well as some diseases effection. 3.3.3. Identifying suitable density and fertilizer rate for the TAT062659 in main season in RRD. In RRD, the determinate variety was grown mainly in winter season in 2 rice seasons area. To confirm developing the variety TAT062659 in this area, The trialed had been implemented to identify suitable density and fertilizer rate in the winter condition. 3.3.3.1. Identify suitable density for the TAT062659 in Winter season 05 density rate were seted up to evaluate growth ability, yield comonents and fruit quality of the variety TAT062659 showed that: the best density for this is 70x40 cm (35,7k plants /ha), and achieved yield was 51,6 tons/ha and get highest benefit as 60,4 mio vnd/ha. Table 3.36. Effected on density to yield and investment effectiveness from TAT062659 in Winter season, in 2010, in RRD Characters Density Fruit setting ratio (%) Fruits/plan t (fruit) Fruit weight (g) Potential yield (tons/ha) Actual yield (tons/ha) Net profit (miođ/ha) M1 (40,8) 49,7b 26,3b 93,2b 79,7a 50,2ab 54,7 M2 (35,7) 54,0a 32,4a 97,7a 69,1b 51,6a 60,4 M3 (31,7) 55,5a 32,0a 98,3a 65,4b 48,1bc 48,9 M4 (28,6) 55,8a 33,0a 98,6a 60,3c 45,7cd 41,3 M5 (26,0) 55,6a 32,7a 98,1a 55,6d 42,8d 31,6 CV(%) 2,7 2,5 1,0 3,6 3,5 LSD0,05 2,7 1,6 1,8 4,5 3,2 3.3.3.2. Identifying suitable fertilizer rate to TAT062659 in Winter season Beside suitable density, fertilizer rate also strong contribute to build yield and quality of agriculture products. Evaluating result from fertilizer rate to growth ability, diseases tolerant and yield of the TAT062659 showed that:the best fertilizer rate was: 50N:180P2O5:200K2O và 150N:200 P2O5:200 K2O on the base of 25 organic fertilizer + 500 kg lime, the yield achieved to 54,0-54,2 tons/ha with benefit at 69,5 and 68,4 mio VND/ha. -20- Table 3.38. Effected from differenr fertilizer rate to yield and investment effectiveness from variety TAT062659 in Winter season, 2010, in RRD Characters Fertilizer rate Fruit setting ratio (%) Fruits/pl ant (fruit) Fruit weight (g) Potential yield (tons/ha) Actual yield (tons/ha) Net profit (miođ/ ha) Charac ters Density CT1. 120:150:150 51,8b 26,7b 97,3b 57,7c 48,4b 4,6 52,1 CT2. 120:180:180 52,5ab 30,0a 97,7b 60,4ab 50,9ab 4,8 59,2 CT3. 150:180:200 54,5a 31,0a 99,7a 64,6a 54,2a 5,0 69,5 CT4. 150:200:200 53,6ab 30,7a 99,3a 64,3a 54,0a 5,1 68,4 CT5.180:180:180 52,3ab 30,6a 99,7a 63,5a 52,0a 5,0 66,2 CT6.180:200:200 52,6ab 30,4a 99,3a 61,9ab 53,3a 5,0 60,5 CV (%) 2,6 2,2 0,7 2,9 2,9 LSD0,05 2,4 1,2 1,2 3,2 2,7 Base on trial results, we was established full cultivated techniques protocol for 3 selected varieties. 3.3.5. Implementing production Demos of the Hongngoc and the TAT062659 varieties in RRD. 3.3.5.1. Demos of the Hongngoc variety The researched results from density and fertilizer trials had been applied to demos in RRD. In Spring-summer season demos with planting distant 70 x 55 cm and fertilizer rate as 150N:200P2O5:200K2O at 5 locations as Vĩnh Tường, Vĩnh Phúc; Hoài Đức, Hà Nội; Bồ Sơn, Bắc Ninh; Nam Sách, Hải Dương; Hải Hậu, Nam Định. In Autumn-winter season with planting distant as 70x50 cm, on fertilizer rate as 150N:200P2O5:200K2O at 5 locations as Vĩnh Tường, Vĩnh Phúc; Mê Linh, Hà Nội; Bồ Sơn, Bắc Ninh; Yên Phú, Hưng Yên và Hải Hậu, Nam Định. The demos results in Spring-summer season showed that yielding of Hongngoc variety were stable between locations, variation from 54,5 – 55,7 tons/ha, the benefit achieved 60,5 - 87,2 mio VND/ha, that higher than normal production from 1,2 - 6,4%. Conclusions from local people were: Hongngoc have many traits better than current varieties and they accept to expanding in production accordingly. 3.3.5.2. Demos of the TAT062659 variety The TAT062659 variety had been position at winter season on 2 rices area in RRD. This variety has some good traits as concentrated harvesting, medium plant height that suitable to build cropping pattern at these area. Demos of TAT062659 -21- variety in winter season with density 70 x 40 cm on fertilizer rate as 150:180:200 in Vĩnh Yên, Vĩnh Phúc; Hoài Đức, Hà Nội; Lạng Giang, Bắc Giang và Hải Hậu, Nam Định. The demos results showed that: The yield of TAT062659 variety reached to 51,6 - 55,3 tons/ha across location, the benefit achieved 46,9 - 62,5 mio vnd/ha. The yield from Demos were hogher than normal field from 9,0-14,5%. The variety TAT062659 had good fruit shape, firmness fruit, good appearance that made attractive by collectors. Most of growers who implemented Demos were accept to continuous to growth this one at comming year. 3.4. IMPROVING GRAFTED PROTOCOL AND EVALUATING BENEFIT OF GRAFTED SAVIOR PLANT IN RED RIVER DELTA 3.4.1. Identifying suitable rootstock variety to grafte on Savior scion variety Many trials have been implemented to complete grafted protocol and evaluating benefit of using Savior scion to grafte on rootstock EG203, Hawai7996 and Cagai . Thess results were support for producing grafted seedling at Summer-Autumn season in RRD. To grafte Savior scion on rootstock EG203 need to sow EG203 before Savior 19 days. Do grafting when rootstock have 3-4 real leaves, seedling heigh is 18,0-20,0 cm, stem diameter 0,26-0,28 cm. The grafted plant need 4 days after grafted in cool condition and 13 days in normal condition to recover before transplanting. To grafte Savior on rootstock Hawaii 7996 need to sow rootstock before Savior 1-2 days, do grafting when rootstock 3-4 real leaves, seedling heigh is 18,0 - 20,0 cm, stem diameter is 0,28 cm, The grafted plant need 4 days after grafted in cool condition and 12-13 days in normal condition to recover before transplanting. To grafte Savior on rootstock Cagai need to sow rootstock before Savior at least 24 days, do grafting when rootstock 3-4 real leaves, stem diameter is 0,25 cm, The grafted plant need 5 days after grafted in cool condition and 15 days in normal condition to recover before transplanting. The grafted survival rate reach to 85,6-92,1% by these protocol and these results were adapt to production required. By bacterial ioculation and evaluation results showed that rootstock Hawaii7996 variety had high tolerant to Bacterial wilt that can be used as good rootstock to grafte on tomato variety to a voice BW pressure. 3.4.2. Growth ability, adaptation ability and yielding potential of grafted tomato plant from Savior scion on different rootstocks varieties in Summer-Auturm and Spring-Summer seasons. Trials of grafted tomato plant evaluation from savior scion had been carried out in 2 locations at 2 seasons as Summer-Autumn (early season) and Spring-Summer season (late season) in Vinhphuc and Hanoi sites. -22- 3.4.2.1. In Summer-Autumn season Have variation on growth duration between grafted and non grafted plants. Grafted tomato plant has flowering time later than non grafted one 4-9 days but duration from flowering to first harvesting earlier non grafted one 4-6 days. Grafted plant had better growth ability vs non grafted one as greener and maintain longer, harvesting time longer than non grafted plants 5-17 days vs non grafted one, especialty Savior scion grafted on EG203 rootstock have longest harvesting period from 15 -17 days vs non grafted at different trialing locations. In 3 trialed rootstock varieties, EG203 have better performance compare to others as longer harvesting time, shorter period from transplanting to flowering, this was a good trait for grafted tomato in Norhhern part condition. Table 3.46. Yielding and yield characters of grafted savior scion on different rootstocks plant at Summer-Autunm season, 2011 Chacraters Combinations Fruit bunch number (bunche s) No of fruits/pl ant (fruit) Fruit settin g perce ntage (%) Plant yield (kg/pla nt) Plot yield (kg/plot) Actual yield (ton/ha) Increas e vs check (%) Vĩnh Tường, Vĩnh Phúc Savior/EG203 10,8a 46,9a 56,7 2,8a 142,7a 71,3a 36,6 Savior/Hawaii 10,6a 39,5b 58,7 2,7b 138,3a 69,1a 32,4 Savior/Cà gai 8,1b 30,4c 53,0 2,5c 121,2b 60,6b 16,1 Savior non grafted(ch) 9,1b 31,5c 56,3 2,2d 100,4c 52,2c CV(%) 6,0 2,9 7,7 1,8 3,2 2,6 LSD 0,05 1,2 2,1 0,1 0,1 8,1 3,3 Hoài Đức, Hà Nội Savior/EG203 11,3a 46,2a 57,8 2,8a 144,7a 72,4a 40,3 Savior/Hawaii 10,3ab 39,7b 58,5 2,8a 130,7b 65,4b 26,7 Savior/Cà gai 9,6b 33,2c 54,6 2,4b 130,1b 65,1b 26,2 Savior non grafted(ch) 10,0b 36,7bc 56,5 2,3c 103,2c 51,6c CV(%) 6,4 5,0 4,7 1,0 1,8 1,8 LSD 0,05 1,3 3,9 0,1 0,1 4,6 2,3 About Yielding: The highest yield achieved at Savior/EG203 plot with 71,3- 72,9 tons/ha, higher vs check 36,6-40,3%, following by Savior/Hawwai7996 achieved as -23- 65,4-69,1 tons/ha, over vs check was 26,7-32,4%. Savior/Cagai had yield over than check 16,1-26,2%. About qualitative characters show that fruit from non-grafted plant was non significant different than grafted fruits on fruit weight, rind thickness… but have different on colour of mature fruit, fruit uniformity, firmness fruit and cracking shoulder level. In Summer-Autumn season, Bacterial wilt pressure is high, Level of this diseases tolerant is different between grafted and non grafted plant. Evaluating results showed that Savior non-grafted plants were effected BW . 15,8-25,6% but in grafted with EG203 were no effected plant, grafted with Hawaii7996 effected from 0-5%, grafted with Cagai also have low effected rate. In both grafted and non-grated plants were non effected by TYLCV mean that Savior variety high tolerant with TYLCV. About leaves spot, have non significant different between grafted and non-grafted at Hoaiduc but non-grafted population in Vinhtuong were effected higher than grafted. 3.4.2.2.In Spring-Summer season Table 3.51. Yielding and yield components of grafted scion Savior on differents rootstock varieties in Spring-Summer season, 2012 in RRD Characters Combination Fruit bunch number (bunche s) No of fruits/ plant (fruit) Fruit setting percent age (%) Plant yield (kg/pla nt) Plot yield (kg/plot) Actual yield (ton/ha ) Increas e vs check (%) Vĩnh Tường, Vĩnh Phúc Savior/ EG 203 10,1a 38,3a 113,8a 3,0a 132,9a 66,4a 24,0 Savior/Hawaii7996 9,6b 37,1a 112,0a 2,9b 126,1b 63,1b 18,9 Savior non grafted(ch) 9,8ab 37,5a 108,6b 2,7c 106,6c 53,3c CV(%) 1,6 2,8 2,0 1,9 1,6 1,6 LSD 0,05 0,5 2,4 5,2 0,1 4,3 2,2 Hoài Đức, Hà Nội Savior/ EG 203 9,8a 38,0a 113,4a 2,9a 127,6a 63,8a 25,0 Savior/Hawaii7996 9,8a 37,5a 111,7a 3,0a 131,1a 65,6a 28,4 Savior non grafted(ch) 9,3b 34,4b 107,8a 2,7b 102,1b 51,1b CV(%) 1,8 4,7 3,0 2,4 2,6 2,6 LSD 0,05 0,4 1,4 7,4 0,2 7,0 3,5 -24- In this season, the duration time from transplant to flowering in grafted plants were higher than non grafted plants but no significant different on duration from flowering to first harvesting between grafted and non-grafted plants. 3.4.4. Benefit from demonstrations of grafted Savior plants in RRD The grafted Savior plants from Savior/EG203 and Savior/Hawaii7996 had been demonstrated in many locations in RRD. The results show that yielding from Savior grafted on EG203 and Hawaii rootstocks have stable yield in summer-autunm season in 2012, variation between locations 59,3 - 65,8 tons/ha. The production cost of graftedplants were higher than non grafted due to cost of Hawaii higher than EG203. Benefit from grafted plants in summer-autumn season were 104,5 – 137,6 mio VND/ha, it was higher than normal production from 18,7 – 34,1% in value . Table 3.53. Yielding and benefit from demostrations of grafted Savior plants in summer-autumn season, 2012 in RRD Characters Locations Rootstock Demo area (ha) Average yield (ton/ha) Total income (miovn d/ha) Invest ment cost (mio vnd/ha) Benefit (mio vnd/ha) Increas e vs normal (%) Vĩnh Tường, Vĩnh Phúc EG203 0,5 63,2 322,3 195,1 127,2 28,2 Vĩnh Tường, Vĩnh Phúc Hawaii 0,3 59,3 302,4 197,9 104,5 18,7 Hoài Đức, Hà Nội Hawaii 0,5 63,0 324,4 197,9 126,5 29,2 Nam sách, Hải Dương EG203 1,0 64,9 334,2 196,6 137,6 31,7 Tiên Lãng, Hải Phòng EG203 0,5 65,8 329,0 196,6 132,4 34,1 -25- IV. CONCLUSIONS AND RECOMENDATIONS 4.1 Conclusions 1. Cureent status of tomato cultivation in RRD such as: - RRD area is good condition to cultivate tomato in Spring-Summer and Summer Autunm to get high benefit. - Have big variation on varieties collection and type of tomato during period 2000-2011 in RRD. The variation forwarding to growth hybrid varieties as semideterminate type. - Some limitation effected to tomato cultivation as: higher pressure of pest and diseaeses; lack update improved technology and products, over use crop protection chemical; unstable fresh fruit price. 2. To select and identify 1 determinate variety TAT062659 and 2 semi determinate varieties as Savior and Hồng Ngọc (TAT072672) to introduce to production in RRD. Variety TAT062659 have high yield and highest benefit in Winter season at multi location, yield variation from 49,1 – 52,0 ton/ha, round fruit shape, deep red colour at mature stage, less cracking shoulder, high rind ration (80,5-82,8%), good tolerant to late blight (score 0-1), suitable to growth on 2 rice season area. Fresh fruit suitable for both fresh consumption and processing. This variety had started introduce to cultivation since 2013. Varieties Savior and Hồng Ngọc are suitable for both fresh consumption and processing, good adapted at both main and off season in RRD, Savior yielding variation from 53,8 - 64,7 ton/ha, yielding of variety Hồng Ngọc variation from 50,3 - 64,1 tons/ha. Both varieties had high and stable yield at different locations across RRD, cultivated area have been increasing year by year. Till 2012, cultivated area of these varieties reach to 1382,4 ha and 328,3 ha accordingly. 3. Identifyied suitable growing season for Savior, completing cultivated protocol for Hongngoc and TAT062659 with different technicial about seasoning, plant density, fertilizer dose as: Savior variety with large adaptation, could be growth in Summer-Autumn season from 10/8 till Spring-Summer season, the latest transplanting is 20/2. Hongngoc variety should be plant with 28,6 thousand plants/ha in Summer- Autumn season and 26,0 thousand plants/ha in Spring-Summer season. The suitable fertilizer rate per ha is 25 tons of manual + 1385 kg lime + 150N: 200P2O5: 200K2O. The achieved yield on Spring-Summer demostrations were 54,5 – 55,7 tons/ha, in Autumn-Winter were 54,3 – 59,1 tons/ha. -26- Variety TAT062659 growth at main season with suitable density is 35,7 thousands plants/ha and suitable fertilizer rate per ha is 25 tons manual + 1385 kg lime + 150N:180P2O5:200K2O, The achieved yield on demostrations were 51,6 – 55,3 tons/ha. 4. Confirming effectiveness of grafted Savior scion on EG203 rootstock and introduced 2 suitable rootstock varieties to grafte to Savior are Hawaii 7996 variety – from AVRDC and Ca gai – wild eggplant was collected in Vietnam. Survival percentage from grafting protocol was 85,6 - 92,1%. Confirming rootstock variety Hawaii7996 tolerant to Bacterial wilt. In Summer-Autunm, grafted plant from Savior had better growth ability and yielding than non-grafted plant from 16,1 – 43,6%. Fruit from grafted plant has quality higher than non grafted as fruit colour at mature stage, firmness and cracking shoulder traits. Grafted plants higher tolerant to bacterial wilt significantly with yield higher 15,8 – 25,6%. In Spring-Summer, grafted Savior plant tolerant to yellow leaves disease better in Spring –Summer season, yielding different between grafted and non grafted was 18,9 – 28,4 %. 5. Demostrations of grafted Savior plant at different locations showed as: higher yield and benefit versus check (non grafted) was 18,7-34,1% in Summer-Autunm in RRD and have been required to expanding in RRD. 4.2 Recommendations 1. Continuing expand cultivated area of new vaieties in RRD as Hồng Ngọc, Savior, and TAT062659 to diverfify varieties collection in production area. 2. Countinuing research implementation on tolerant to bacterial wilt, over water, drough condition of rootstock varieties Hawaii7996 and Ca gai in Summer – Autumn season in Northern part to have direction development grafted plant on these rootstock varieties. 3. Expanding cultivated area of grafted Savior /EG203 plant in RRD, especialy at off season (Sumer-Autumn, Spring-Summer) to help tomato growers achieve higher income. -27- THE DECLARED STUDY LIST RELATED TO THESIS 1 Đặng Văn Niên, Nguyễn Thị Ngọc Huệ (2008), “Giống cà chua lai chịu nhiệt và kháng bệnh xoăn vàng lá Savior”, Tạp chí khoa học và công nghệ Việt Nam, Viện KHNNVN, số 3 (2008), tr.8-13 2 Đặng Văn Niên, Nguyễn Thị Ngọc Huệ, Trần Ngọc Hùng (2013), “Nghiên cứu mức độ thích ứng và hiệu quả sản xuất cà chua Savior ghép ở Đồng bằng sông Hồng trong điều kiện trái vụ”, Tạp chí Nông nghiệp và Phát triển nông thôn”: Chuyên đề giống cây trồng – vật nuôi, Tập 1, Bộ Nông nghiệp và Phát triển nông thôn, tháng 6/2013, tr.88-93 3 Đặng Văn Niên, Nguyễn Thị Ngọc Huệ, Trần Ngọc Hùng (2013), “Thực trạng và giải pháp kỹ thuật nâng cao hiệu quả sản xuất cà chua ở Đồng bằng sông Hồng ”, Tạp chí Nông nghiệp và Phát triển nông thôn”: Bộ Nông nghiệp và Phát triển nông thôn, số 219 năm 2013, tr.24-31. 4 Đặng Văn Niên, Nguyễn Thị Ngọc Huệ, Trần Ngọc Hùng (2013), “Nghiên cứu ảnh hưởng của thời vụ trồng đến năng suất, chất lượng và khả năng chống chịu bệnh của giống Savior tại Đồng bằng sông Hồng, Tạp chí Nông nghiệp và Phát triển nông thôn”: Bộ Nông nghiệp và Phát triển nông thôn, số 225 năm 2013, tr. 24-30.