 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Effect of Seed Quality on Field Emergence and Seedling Performance of Rubber (Hevea brasiliensis)) ผู้เขียน: Vichai Wongvarodom, Wipharat Duang-iat, Wullop Santipracha, Sayan Sdoodee สื่อสิ่งพิมพ์:pdf AbstractThe effect of seed quality on the emergence and seedling growth performance of rubber (Hevea brasiliensis) was studied. Seven seed samples of various initial quality levels of the RRIM 600 clone were collected from various rubber plantations in Nakhon Si Thammarat, Phatthalung and Songkhla provinces, southern Thailand in 2012 and 2013. The seeds were tested for quality and filed sown to investigate the emergence and growth potential of seedlings using the seedling stem diameter, seedling height and leaf number at 6 mth after germination. The results showed that rubber seeds with germination of 85.50% gave a field emergence of 60.50%, whereas the lower quality seeds (50.50–72.50% germination) had field emergence levels of only 27.00–40.00%. The high quality seeds provided the best growth potential under field conditions based on the seedling stem diameter, seedling height and leaf number at 6 mth after planting with values of 1.17 cm, 118.90 cm and 13.10 leaves, respectively. A comparison among the different quality seeds revealed significant reductions in the performance of seedling characteristics such as seedling stem diameter, seedling height and leaf number, respectively. Therefore, high quality seeds with over 85% germination were recommended for rootstock production and to ensure high seedling performance under field conditions. However, using lower 70% germination rubber seeds resulted in a lower plant population by 20–30% and slower growth than from the high quality seeds. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Prediction of Sweet Corn Seeds Field Emergence under Wet Soil Condition) ผู้เขียน:Vichai Wongvarodom, Wikanate Rangsikansong สื่อสิ่งพิมพ์:pdf AbstractField emergence prediction of sweet corn seeds under wet soil conditions was studied using three different quality seeds of Hawaiian Sugar Super Sweet and Super Sweet Argo Extra MT varieties. The seeds were subjected to germinate in sand at room temperature. Germination was evaluated for 7 days after planting (DAP). Flooded germination was done by planting the seeds in 1000 g of clay soil in a plastic basket, flooding at 1 cm above soil level for 5 hours and evaluating at 7 DAP. Field emergence was studied under daily watering, three times a day, to simulate wet planting soil condition. Field emergence evaluation was performed at 7 DAP. Results showed that the sweet corn seeds with 79.50- 91.00% germination of Hawaiian Sugar Super Sweet and Super Sweet Argo Extra MT varieties had field emergence of 61-79% under wet soil condition. The lower quality seed had the field emergence of lower than 60%. Sand germination and flooded germination in clay soil did not correspond to field emergence under wet soil condition. The field emergence under wet soil condition of sweet corn seeds could be predicted by the polynomial equations which gave better results than sand germination test. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Physiological Quality and Desiccation Sensitivity of Rubber (Hevea brasiliensis) Seeds during Fruit Maturation) ผู้เขียน:Wipharat Duang-iat, Vichai Wongvarodom, Wullop Santipracha, Sayan Sdoodee สื่อสิ่งพิมพ์:pdf AbstractThe physiological quality and desiccation of rubber seeds were investigated during development. Fruits of rubber clone RRIM 600 at different stages of development were collected from a plantation in Nakhon Sri Thammarat province, southern Thailand, during July–August 2012. Seeds of deep green fruit, yellowish-green fruit, brown fruit and from the naturally shedding stage were tested for their weight, moisture content, germination, mean germination time, seedling shoot height, seedling shoot dry weight, electrical conductivity and desiccation tolerance during dry storage. Rubber seeds with high germination ranging from 86.67 to 95.00% were obtained from the yellowish-green fruit, brown fruit and naturally shedding stages. However, the seeds reached physiological maturity at the brown fruit stage with values for seed dry weight, moisture content and germination of 2.93 g per seed, 34.54% and 95.00%, respectively. At the shedding stage, the seeds had a moisture content and a high germination of 22.17% and 91.66%, respectively. The critical moisture content of the seeds was 15% and at this level, they were very short lived (3–7 d in dry conditions). The seeds with a moisture content of about 15% and from 11 to 12% had germination of 58.33–63.34% and 1.67–8.34%, respectively. Therefore, the early collection of the shed seed is recommended to ensure high quality seed is obtained. Such information may be helpful for improving the seed collection or transport procedures and ensuring high seed performance in the seedbed for successful rootstock production. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Responses of Bambara Groundnut Seed to Accelerated Aging) ผู้เขียน:Vichai Wongvarodom, Suteera Naulkong สื่อสิ่งพิมพ์:pdf AbstractBambara groundnut seeds of Songkhla 1 and landrace variety were subjected to accelerated aging at temperatures of 40, 43, 46, 49, 52, and 55?C for 48, 72, and 96 hours in order to determine the response of variety and seed quality to accelerated aging conditions. The non-aged and aged seeds were subjected to tests of their quality including moisture content, standard germination, speed of germination, and seedling growth rate. Results indicated that responses of bambara groundnut seeds to accelerated aging differed with varieties and seed quality characteristics. The Songkhla 1 seed was more sensitive to accelerated aging than landrace variety. High quality seeds of both varieties with germination of 86.50- 88.00% had a reduction of viability and vigor after accelerated aging at 40?C for 96 hours and at 43?C for 48-72 hours with germination of 75.50-62.25%. These aging regimes provided seed vigor separation between varieties with germination differences of about 10% while a greater separation (around 20%) occurred after aging at 46?C for 48 hours. Germination and speed of germination index showed a greater response to accelerated aging. Seedling growth rate in terms of shoot length, root length, and seedling dry weight could not be used to evaluate the deterioration of the acceleratingly aged seed. |