This study was conducted to analyze the productivity and economic feasibility of truss-limited tomatoes (Lycopersicon esculentum L.) grown at a high density in Cambodia during the rainy season. During the rainy season in Cambodia, due to excessive rain and very high temperature, tomatoes cannot grow well in an open field, leading to a greatly reduced yield. High density truss-limited cultivation (HDTLC) of tomatoes can shorten the growing season and increase yields. In conventional cultivation (control), tomatoes were transplanted at a spacing of 70×40 cm and harvested up to the 4th fruit cluster. In HDTLC, tomatoes were transplanted at a spacing of 20×20 cm or 25×25 cm and harvested up to the 2nd fruit cluster. Plant heights in HDTLC were higher than those in the control at 22 days after transplanting (DAT). At 39 DAT, plant heights did not differ between 25×25 cm and control. At 60 DAT, plant height, stem diameter, leaf length, and leaf width of the HDTLC were lower than those of the control. Fruit length and width were also lower in HDTLC compared to those of the control. However, sugar content was more than 19% higher in HDTLC compared to that in the control. Yield per plant of the control was the highest, but yields per ha in HDTLCs were 99% (20×20 cm) and 38% (25×25 cm) higher, respectively, compared to that of the control. No pesticides were used for disease control in this experiment. However, to ensure yield, it is recommended to observe the disease status of plants and spray pesticides at the appropriate time. The disease index (1: disease-free; 5: all leaves were disease-infected) of late blight (Phytophthora indestans) was significantly higher for 20×20 cm (4.5) and 25×25 cm (3.6) groups compared to the control (2.0). Income with 20×20 cm (5,668 thousand KRW) and 25×25 cm (1,863 thousand KRW) were 4.9 and 1.6 times higher, respectively, compared to that with the control (1,149 thousand KRW). So, we want to spread the HDTLC technology, which transplanting of tomato seedlings at 20×20 cm intervals and harvests up to 2nd fruit cluster, to Cambodian farmers.

In 2006, Cambodian Agriculture Research and Development Institute (CARDI) bred a high-quality tomato ‘Neang Pich’ variety. Since ‘Neang Pich’ is susceptible to Sclerotium rolfsii (S. rolfsii), it is severely affected the production major tomato growing regions. This study was conducted to evaluate the effect of seven S. rolfsii tolerant rootstocks on growth and yield in graft cultivation of ‘Neang Pich’ tomato. ‘Neang Pich’ seedlings were used as scion and non-grafted control. Six eggplant genotypes (‘2017053’, ‘2017062’, ‘17CJVC2’, ‘No. 80’, ‘VI041979A’, ‘VI041996’) and a commercial tomato variety (‘Hulk’) were used as rootstock. The grafted and non-grafted tomatoes were grown in a plastic greenhouse and open field. The survival rate of plants did not differ between plastic greenhouse (80.2%) and open field (79.5%). The top and root fresh weight of plants grown in a plastic greenhouse increased by 77% and 11% compared to the open field and the dry weight increased by 48% and 10%, respectively. The top (309 g) and root (18.9 g) fresh weight, and the top (90.5 g) and root (6.39 g) dry weight depending on rootstock were the highest in plants grafted onto ‘2017062’. The yield of tomatoes in a plastic greenhouse (19.5 MT/ha) was 65% higher than that of open field (11.8 MT/ha). The yield of tomatoes depending on rootstock were the highest in ‘2017062’ (17.8 MT/ha). The effect of cultivation practice and grafting on pH and sugar content (oBrix) of the fruit was non-significant difference (p0.05). The scion diameter, top fresh weight, fruit weight and yield (MT/ha) were significant difference (p0.05) in the interaction effect between tomato cultivation practices (plastic greenhouse and open field) and rootstock.

양파의 웅성불임을 이용한 고랭지 지역 재배에 적합한 장일형 일대잡종 품종, ‘대관황’을 2007년 고령지농업연구센터에서 육성하였다. ‘대관황’은 ‘만추황’의 웅성불임친을 모친으로, ‘NIHA-5001’을 부친으로 하여 2001년 교배하여 육성하였다. 교배 후 ‘고시가-1호’로 명명 후 2003년에 생산력검정 예비시험을 거쳐 2004년부터 2006년까지 생산력 검정 본시험을 고랭지 3개 지역에서 실시하였다. ‘대관황’의 초형은 직립이며 숙기는 중만생형이다. ‘대관황’의 구중은 시판품종인 ‘히구마’와 비슷하며 구형은 원형이며 구피색은 황갈색으로 ‘히구마’ 보다 저장성이 뛰어난 특성을 가지고 있다. ‘대관황’은 ‘히구마’에 비해 가용성 고형분이 높고, 건물중은 비슷하여 저장성이 뛰어나 고랭지 지역 재배에 적합한 품종으로 판단된다. 그러나 고랭지지역은 해발 600 m부터 800 m의 다양한 지역에 위치하고 있어 다양한 환경 변이가 있으므로 대면적 재배 전 지역적응성을 검토하는 것이 좋을 것으로 판단된다.