Thai Agricultural Research Journal

A High Sugar-yielding Sugarcane Variety “DOA Nakhon Sawan1”

2025-05-19T17:28:27+07:00

The demand for high-yielding and high-sugar-content sugarcane varieties has been rising. Nakhon Sawan Field Crops Research Center developed a sugarcane variety, DOA Nakhon Sawan1, derived from a cross between Q76 and CP63-588 in the year 2010. From crossing, the NSUT10-266 clone was selected and evaluated between the years 2011-2021. This clone exhibited a high commercial cane sugar (CCS) content of 15.77, which was 10 and 7% higher than those of the LK92-11 and DOA Khon Kaen3 varieties, respectively. The cane yield of NSUT10-266 was 18.0 tons/rai, which was not different from those of the LK92-11 and DOA Khon Kaen3 varieties, but its sugar yield reached 17.6 tons CCS/rai, which was higher than that of LK92-11 by 18% but was comparable to DOA Khon Kaen3. Additionally, this sugarcane clone demonstrated moderate resistance to red rot wilt diseases and strong adaptability. The Department of Agriculture approved this sugarcane clone as the DOA Nakhon Sawan1 variety on July 12, 2022. This variety exhibited high-yield and high-sugar content and was suitable for planting on loamy, clay loam, and clay soils in rainfed areas. From the years 2022-2025, this variety has been promoted to farmers, associations, and sugar factories, and it was mostly accepted due to its fast growth, high yield, and high sugar content. DOA Nakhon Sawan1 was considered a high-potential variety and valuable alternative for increasing farmers' income.

Speed Breeding for Rapid Plant Variety Development

2026-01-29T15:55:19+07:00

Speed breeding is a technique that employs controlled environmental conditions to accelerate the plant life cycle from vegetative growth to reproductive development. This approach involves the management of key factors such as extended photoperiods, regulated temperature and humidity, increased carbon dioxide concentration, and high plant density cultivation. In certain systems, additional physiological management, including the use of plant growth regulators, may be applied to promote early flowering and rapid seed production. Consequently, this technique enables an increased number of generations per year and reduces the time required for plant breeding programs. Furthermore, the integration of this strategy with advanced technologies, such as high-throughput phenotyping and genotyping, marker-assisted selection, and genome editing, can enhance accuracy and shorten the duration of selecting or developing crop varieties with desirable traits. Therefore, it has emerged as an important strategy to address global food security challenges associated with climate change and population growth. To date, protocols for this technique have been developed for several major economic crops, including rice, maize, and soybean.

A New Hybrid Oil Palm Variety: DOA Surat Thani9

2025-12-08T18:28:59+07:00

The hybrid oil palm DOA Surat Thani9 was developed under the oil palm breeding program, phase 2, using the modified reciprocal recurrent selection method. The elite maternal and paternal parents were selected to generate 69 hybrid combinations. Subsequently, extensive progeny testing was done to identify crosses with fresh fruit bunch (FFB) yield, crude palm oil (CPO) yield, and bunch components exceeding the DOA’s standards at the Surat Thani Oil Palm Research Center between 2001 and 2017. Five crosses of oil palm were evaluated with DOA Surat Thani3 as the standard cross using a randomized complete block design with 4 replications. The results demonstrated that the DOA Surat Thani9, a cross between the maternal parent 68/374D (Deli Dura group) and the paternal parent 125/154T (AVROS group), was the superior performer with an average FFB yield of 3,773 kg/rai/year during the age period of 3-10 years, surpassing the standard cross by 31.4%. Specifically, the early productive phase (age of 3–4 years) gave an average FFB yield of 1,908 kg/rai/year, while the full maturity phase (age of 6–10 years) gave a higher yield of 4,634 kg/rai/year. These high yields were attributed to an average of 13.5 bunches/palm/year, an average bunch weight of 12.8 kg/bunch, and a high CPO yield averaging 817.8 kg/rai/year because of a high mesocarp content and oil-to-bunch ratio. Yield components analysis of DOA Surat Thani9 revealed that fresh mesocarp/fruit, shell/fruit, kernel/fruit, and oil-to-bunch were 86.0, 7.5, 6.6 and 25.5%, respectively. It has been determined as the recommended variety of the Department of Agriculture under the name of Surat Thani9. This variety can contribute to decreasing the country's reliance on imported oil palm seeds for planting.

Uthai Thani Native Small-ear Waxy Corn Improvement

2025-05-08T14:53:24+07:00

Native waxy corn varieties widely cultivated in Uthai Thani Province are Tein Yao and Tein Kareing. As open-pollination, these varieties have apparent genetic deterioration due to contamination from cross-pollinated, leading to variations in yield and quality. This study aimed to collect, select, and improve the native small-ear waxy corn of Uthai Thani to enhance varietal uniformity, prolific ear formation, and yield potential. From 2018 to 2023, the populations were improved through three cycles S₁NRS. Each selection cycle consisted of three steps: 1) self-pollination of population, 2) bulk half-sib pollination in population, and 3) randomly open pollination in population. Selection progress was evaluated in two growing seasons. Selection progress of Tein Yao improved population (YC3) and Tein Kareing improved population (KRC3) was compared to the base population, intermediate cycles, and commercial varieties. Results indicated that YC3 showed consistent positive responses to selection. Unhusked and husked yields increased by 169.1 and 116.2 kg/rai/cycle, respectively. The study also found that the total ear number and first ear number increased by 1,414 and 916 ears/rai, respectively, with high coefficients of determination. In contrast, KRC3 exhibited limited response to selection, with unhusked and husked yields of 61.4 and 39.6 kg/rai/cycle, although relatively high coefficients of determination were observed. Three cycles of S₁NRS was effective for improving Tein Yao and Tein Kareing populations with enhanced uniformity, prolific ear production, and high yield. The improved populations can be utilized as open-pollinated varieties and as valuable genetic resources for additional breeding programs focused on waxy corn.

Design Development and Performance Evaluation of a Sugarcane Leaf Trash Shredder

2026-02-02T15:44:40+07:00

Sugarcane leaf trash management is a critical challenge in mechanized farming, often leading to open burning and environmental pollution. This study aimed to develop a prototype sugarcane shredder designed to improve shredding efficiency, evaluated by the reduction in residue size and field-tested for engineering economic viability. The machine utilizes a dual-shaft mechanism: shaft A employs C-shape 24 blades for initial cutting, while shaft B features 12 sets of Y-shape flail blades operating at high linear speed of 16.7 m/s (800 rpm) for fine shredding. The performance was evaluated under varying blade linear speeds for shaft A (7.4, 9.6, and 11.7 m/s) and forward speeds (0.5 and 1.2 km/h). Statistical analysis indicated that the optimal condition was a blade linear speed of 11.7 m/s combined with a forward speed of 1.2 km/h. This configuration significantly reduced residue size, with the average width decreasing by 78.6% (to 0.7 cm) and the average length by 77.7% (to 28 cm). Economic analysis revealed a field capacity of 1.1 rai/h, with a break-even point of approximately 114.6 rai/year. This developed sugarcane shredder offers an efficient mechanical solution to support zero burn policies, enhancing biomass incorporation into the soil while remaining commercially viable for farmers.

Response to Nitrogen and Potash Fertilizer of Advanced Cassava Varieties for High Yield in Loamy Sand, Huai Pong Soil Series

2025-08-04T18:19:18+07:00

Cassava varieties differ in their responses to soil nutrient availability. Most cassava growing areas are dominated by sandy loam and sandy soils. This study aimed to determine an appropriate chemical fertilizer rate for advanced cassava varieties grown on Huai Pong soil series, a representative sandy loam soil, in order to develop recommendations for this soil type. The experiment was conducted during 2024/2025 growing season at Rayong Field Crops Research Center. Two experiments were arranged in a split plot design with 3 replications. In both experiments, the main plot consisted of four cassava varieties/genotypes: DOA Rayong9, CMR56-71-68, CMR58-75-110 and CMR59-55-202. The first experiment evaluated the response to nitrogen fertilizer. The subplot consisted of 5 nitrogen application rates: 0, 8, 16, 24 and 32 kg N/rai. All treatments received phosphate and potash fertilizers according to soil analysis recommendations (2–16 kg P₂O-K₂O /rai). The second experiment evaluated the response of potash fertilizer using the same experiment design. The subplot consisted of 5 potash application rates: 0, 8, 16, 24 and 32 kg K₂O/rai. All treatments received nitrogen and phosphate fertilizers based on soil analysis recommendations (16–2 kg N–P₂O₅/rai). Results showed that CMR59-55-202 produced the highest fresh root yield of 6,423 kg/rai in the nitrogen experiment, with the application of 16 kg N/rai providing the highest net profit of 14,343 baht/rai. In the potash experiment, CMR59-55-202 also achieved the highest fresh root yield and starch yield, reaching 6,250 and 1,760 kg/rai, respectively. The application of 16 kg K₂O/rai provided the highest net profit of 13,461 baht/rai. Overall, CMR59-55-202 exhibited greater yield potential than the standard variety DOA Rayong9. The optimum fertilizer rates for this variety under a Huai Pong soil series were 16 kg N/rai and 16 kg K₂O/rai, which provided the highest fresh root yield, starch yield, and economic return.

Testing Quality Management Technology for Producing Fresh Pineapple cv. MD2 in the Areas of Phetchaburi Province

2025-04-27T14:23:36+07:00

Fresh pineapple production in Phetchaburi Province is constrained by inconsistent yields, short shelf life, and browning of the core upon arrival at the market, which are partly attributed to land preparation and soil and fertilizer management practices. This research aims to evaluate planting, soil preparation and fertilizer management technologies to enhance the quality of MD2 pineapples under local growing conditions. The study was conducted in 10 pineapple growers' fields in Nong Ya Plong, Phetchaburi Province, during 2022-2024, tested practices were compared with farmers’ practices. The tested practice consisted of raised-beds planting in a single-row system with a spacing of 30 x 70 cm, fertilizer application based on soil analysis at 3 and 6 months after planting, foliar applications of calcium-boron at the early of flowering stage and at 1 and 2 months after flowering, and foliar application of 2.0 mM salicylic acid at 20 and 10 days before harvest. The results showed that the tested practice produced an average yield of 9,368 kg/rai, which was 32.5% higher than that obtained under farmer's practice. Fruit sweetness averaged 19.3° Brix, which was also higher than that of the farmers’ practice. After storage at -14°C for 1 month, fruit produced under the tested practice exhibited a delayed onset of internal browning compared with those from farmers’ practice. In addition, raised- bed planting reduced the incidence of root and stem rot disease. Although the tested practice increased the average production cost to 118,442 baht/rai, representing a 22.1% increase over the farmers’ practice, it generated a net income of 113,770 baht/rai, which was 58.7% higher, resulting in a higher average return on investment ratio of 2.0. Furthermore, 90% of participating farmers expressed the highest level of satisfaction with the improved practice, that met market quality standards, and one model farmer was successfully developed as a learning center for the dissemination of MD2 pineapple production technology to other farmers in the area.

Production of Abscisic Acid from Botrytis cinerea for Promoting Growth of Tomato under Water Stress Condition

2025-04-21T13:53:56+07:00

Abscisic acid (ABA) is a phytohormone that regulates plant adaptation to survive in unsuitable environments. This study aimed to develop ABA production from microbes for promoting plant growth under drought stress. For producing ABA, 35 isolates of Botrytis spp. were collected and selected by morphology and tannic acid oxidation. The isolate with the greatest ability to produce ABA was BRDO-23. This isolation was identified as Botrytis cinerea by ITS region sequencing. The examination of the optimum growth conditions for the production of ABA by BRDO-23 showed that blue light and 25% tomato mixed juice can promote ABA production. With these favored growth conditions, BRDO-23 had the ability to produce ABA up to 76.2±11.7 mg/L at 3L spinner flask fermentation. The ethyl acetate phase separation method demonstrated a 74.6% ABA recovery rate, with the final ABA product being a dry powder. In a laboratory efficacy test, the ABA product at 2 µM was found to be the most effective for growth promotion of young tomato plants under drought stress. In the greenhouse test, adding a 3 µM ABA product can enhance the tolerance of fruiting-stage tomatoes under drought stress. Overall, these findings suggest that ABA biosynthesized by Botrytis cinerea holds promise as a phytohormone for improving the resilience of tomatoes under drought conditions.

Development of Tetra-primer ARMS-PCR Technique for High Amylose Selection in Cassava Breeding

2025-05-08T14:37:11+07:00

Amylose starch in cassava (Manihot esculenta Crantz) can be widely used in many industries. Rapid selection of cassava varieties with high amylose starch content can be done using advanced techniques. This study aimed to develop molecular markers associated with high amylose content by designing primers for single nucleotide polymorphism (SNP) markers. The results revealed that the SNP marker S2_25293441 on chromosome 2 was significantly associated with high amylose content. Optimal conditions for tetra-primer amplification refractory mutation system polymerase chain reaction (tetra-primer ARMS-PCR) were achieved at an annealing temperature of 60°C. In heterozygous (CT) genotypes, DNA bands of 339, 229, and 166 bp were observed, while homozygous (CC) genotypes produced bands of 339 and 229 bp. Genotypes exhibiting the CT genotype demonstrated phenotypes with high amylose content. In testing with cassava varieties containing amylose content exceeding 18%, the developed SNP marker achieved an accuracy rate of 75.90% in selecting high amylose varieties. The use of this molecular marker reduced the number of plants required for field selection, enabled screening with fairly high accuracy, and shortened the time for selecting cassava varieties with high amylose content.