ผลของการใส่ปุ๋ยโบรอนต่อการดูดใช้โบรอนและการสร้างผลผลิตในข้าวพันธุ์สันป่าตอง 1 ที่ปลูกใน 2 พื้นที่

Abstract

Boron is an essential nutrient for plant growth and development. It plays the important roles in pollen development and fertility resulting in increasing the number of fertile grains and yield. It has been reported that boron deficiency in the soil causes the low production in several crops across 80 countries. Therefore, applying boron would be a promising way to reduce the loss of yield caused by boron deficiency in soils. The limited information on the efficacy of boron fertilizer in the economical crops, particularly in rice is reported in comparison to the other crops. Therefore, the objective of this study was to evaluate the effects of boron fertilizer on boron uptake and yield productivity of the Sanpatong 1 rice variety.

This study was carried out in two experiments as in the following details. Experiment 1 was to evaluate the effects of boron fertilization application on boron uptake and yield production in Sanpatong 1 rice variety grown at two different locations in comparison between the research station, Chiang Mai University, and farmer's field at San Sai District, Chiang Mai Province. Each experimental site was carried out under the same experimental design and management. The experiment was arranged in a randomized complete block design (RCBD) with four replications. Eight different treatments of boron fertilizer were applied in Sanpatong 1 rice variety. The treatments of soil applications were applied from one to seven at seven days before planting, while the eighth treatment was the foliar application of boron, two times at flowering and early milky stages. The results showed the rice plants grown in the San Sai location had a higher grain yield than plants grown at Chiang Mai University. It was not found the difference among the treatments of boron applications on grain yield at both locations. Applying Etidot-67 increased straw dry weight and percentage of filled grain at Chiang Mai University, but no effect on grain yield was found, which contrasted with the San Sai location as the reduction of straw dry weight was observed. On the other hand, it was found that applying Granular Boraks Pentahydrate and Granular Colemanite increased the straw dry weight of plants grown at Chiang Mai University from the increasing of numbers of tillers and panicles per hill compared to the control. In addition, filled grain was increased when applied with Boric Acid at Chiang Mai University, whereas, the numbers of tillers panicles per hill and percentage of filled grain were increased when applied with foliar of Etidot-67 as compared to the control.

Application of boron fertilizer had affected boron concentration in plant tissues. It was found that applying boron fertilizer as in Borax Pentahydrate power resulted in the highest boron concentration in stem without the significant effect of location at Chiang Mai University, while the application of Granular Colemanite resulted in the highest concentration of boron accumulation in leave and flag leaf. On the other hand, the highest boron concentrations in leave and flag leaf were observed when applied with the Borax Pentahydrate power at San Sai location. According to the results, applying boron fertilizers as in Borax Pentahydrate power, Boric Acid and Granular Colemanite increased the straw dry weight, numbers of tillers and panicles per hill and percentage of filled grain, which might be due to the enhance in boron concentration in plant tissues. However, the increased boron concentration in the tissues was not significantly increased the grain yield. The result showed that total boron uptake by Sanpatong 1 at San Sai location was 5.3 mg/m2, which was 1.2 times higher than at Chiang Mai University location. In addition, there was significantly different in the total boron uptake among boron treatments. Applying boron fertilizers as in Borax Pentahydrate power, Boric Acid and Granular Colemanite increased the total boron uptake ranging from 5.4-6.0 mg/m2, which was higher than no boron application at 4.1 mg/m2 . This study indicated that the variations in boron uptake and accumulation in rice plants could be varied depending on the soil environmental factors, especially the soil fertility.

The experiment 2 was to evaluate the effects of lime and boron fertilization application on boron uptake and yield production in Sanpatong 1 rice variety. A pot experiment was conducted at the research station, Chiang Mai University. The experimental design was arranged in the factorial in completely randomized design (CRD) with three replications comprising of two factors, lime (non-lime application and lime application at the rate of 12 g/pot (2 t/ha) and boron fertilizer application (non-boron, soil boron, foliar boron, and soil boron + foliar boron fertilizer). The results showed that soil boron + foliar boron fertilizer applications increased grain yield of Sanpatong 1 grown under soil lime application. While, applying soil and foliar boron fertilizer increased the number of tillers and panicle per plant compared to non-boron fertilizer in the soil without lime application. The harvest index and 1,000 grain weight were decreased when applied with soil boron + foliar boron fertilizer in non-lime soil condition, but it increased the percentage of filled grain in plants grown under lime soil condition. The applications of all boron fertilizer treatments increased the percentage of fully developed grain compared to non-boron fertilizer which was observed in both with and without soil lime condition. This indicates that applying lime and boron fertilizer improved rice grain yield. Considering the concentration of boron in different parts, it was found that the rice plants grown under non-lime soil application, foliar boron fertilization increased stem and flag leaf boron concentrations. Applying soil boron alone and soil boron + foliar boron fertilization increased leaves and flag leaf boron concentration. Under the lime soil application, soil boron increased leaves boron concentrations compared with no boron applied. The applications of foliar boron and soil boron + foliar boron treatments increased leaves, flag leaf, and grain boron concentration compared to non-boron fertilizer. These results showed that rice grown under lime soil condition, boron application effectively increased tissues boron concentration as well as grain yield in comparison to the soil without lime application. For boron content, foliar boron fertilizer increased stem and flag leaf boron content in rice grown under non-lime soil application, while the application of soil boron and soil boron + foliar fertilizer treatments increased leaves and flag leaf boron content compared to non-boron fertilizer. Under lime soil application, it was found that applying soil boron fertilizer increased boron content in leaves, while foliar boron increased leaves, flag leaf, and grain boron content. Grain boron concentration was enhanced by soil boron + foliar fertilizer application. These results indicated that lime application into the soil would help to promote the effectiveness of boron fertilizer due to the improvement of nutrient availability in the soil. The positive correlation between grain yield and percentage of filled grain was observed, indicating that applying lime and boron fertilizer could positively enhance the development of pollen at grain filling, increasing fertility inflorescences, grain filling, and total grain yield. However, the mechanism and response of rice under lime application and boron fertilization application are still unknown. Further experiment with various rice varieties and growing conditions are necessary to be confirmed for the beneficial use of boron fertilizer on yield improvement for farmers' practice.