Effect of Phosphate Fertilizers on Growth and Manganese Uptake of Rubber Seedlings

Since the concentrations of manganese (Mn) in soils and leaves in most rubber plantations in Thailand are higher than optimum level. To reduce Mn uptake becomes necessary. It is well known that application of phosphate (P) fertilizer is able to reduce Mn toxicity symptoms in some plants and also solve the P deficiency in acid soil. This experiment aimed to investigate the effect of P fertilizers on growth and Mn uptake in rubber. The rubber seedlings (RRIM 600) were grown in a greenhouse using completely randomized block design with 5 treatments and 5 replicates. The 5 treatments consisted of without P fertilizer (control) and 40 mg kg-1 P2O5 in the forms of diammonium phosphate (DAP), triple super phosphate (TSP), rock phosphate (RP) (as avai. P) and RP (as total P). The result showed that addition of P fertilizer increased plant growth in terms of stem diameter, leaf number, trunk height and dry weight. Both of the RP treatments gave the highest growth followed by TSP and DAP. Moreover, adding P fertilizers decreased Mn concentrations in leaf, petiole, stem, tap root and lateral root compared with the control. This finding proves that P fertilizers play an important role in rubber gown in acid soils containing low P and high Mn and reduce Mn uptake.

Effect of fertilizer and dolomite applications on growth and yield of tapping rubber trees

Tropical acid soil used for rubber planting has usually low fertility due to continuous loss of plant nutrient elements by crop removal and leaching. Thus, proper soil improvement in tapping rubber is very essential. This study aimed to measure the growth and yield of 17-year-old rubber trees, chemical properties of soil, and plant nutrient status in the leaf and latex after two years of soil improvement. A randomized complete block of seven treatments: No fertilizer (Control treatment), Chemical fertilizer based on soil analysis according to the recommendation of the Rubber Research Institute (Ch.F), Ch.F+ Dolomite to raise pH up to 6.0 (D), 3 kg per plant of compost (C), Ch.F+C, ½ Ch.F+C and ½ Ch.F+C+D, with three replicates was designed. After two years of giving treatments, it was found that adding full rate of chemical fertilizer based on soil test together with compost or dolomite increased the tree girth increment from the first year to the second year. Rubber yield after soil improvements tended to increase from the beginning to the end of the year, especially with compost application. Increasing of soil fertility was found after soil improvement treatments. However, total N, available P and available K were still lower than optimum levels as well as leaf N and K. Nitrogen in rubber latex after soil improvement treatments was higher than those in the control treatment, which contrasted to those of Ca and Mg. However, fertilizer and dolomite effect on micronutrient elements in rubber leaf and latex were not clear. Thus, fertilizer should be continuously applied at least with the full rate of chemical fertilizer based on soil analysis, and organic fertilizer should be applied to gain some trace elements. Dolomite could also be applied in a very strong acid soil

Alleviation of plant boron toxicity by using water to leach boron from soil contaminated by wastewater from rubber wood factories

ABSTRACT: Wastewater from rubber wood furniture factories contains large amounts of boron (B) which contaminates the soil and causes unusual symptoms in plants in the area. We aim to establish the toxicity effects in tomato seedlings planted in Kho Hong (Kh) soil series irrigated with wastewater and compare them with seedlings grown in the same soil series but receiving tap-water containing B, S, Ca, or Na at the same concentrations as found in the wastewater. Then, we study B leaching from B-contaminated soil in a column by applying distilled water at different rates. We alleviate the B contamination in the Kh soil series by using water to leach out the B, then planting tomato seedlings. The results showed that in plants subjected to the wastewater or B treatments, growth was reduced and the plants showed tip and marginal chlorosis and necrosis of mature leaves at high B concentrations. The boron in B-contaminated soil was decreased to a greater degree by the application of a larger amounts of leaching water. Using 167.5 mm (field capacity) of water leached the B in the topsoil (0-15 cm) from a concentration of 11.11 mg/kg down to 2.83 mg/kg, a nontoxic level (< 3 mg/kg), and the leached B accumulated in the subsoil (15-30 and 30-50 cm). However, using 1000, 2000, or 4000 mm of water leached the B from the soil to below a toxic level with only a slight accumulation in the subsoil. This indicates that applying water to leach B from soil decreased the extractable B to below a toxic level, resulting in a decrease in plant B uptake. As a result, the tomato seedlings showed better growth in terms of height, leaf number, and plant dry weight than those of the control treatment

Growth of immature rubber trees planted in abandoned paddy field and upland areas in relation to soil properties and leaf nutrients

Although lowland area is not suitable for rubber production, rubber trees are currently extended into abandoned paddy fields. This study investigated rubber growth, soil properties and leaf nutrients of immature rubber trees planted in lowland and upland plantations. Nine soils (0-30 cm depth) in both poor and good productive lowland and upland plots from three districts in Songkhla province were sampled for some physical and chemical analysis and leaf samples were also performed for nutrient analysis. Growth of rubber trees was recorded. Results showed that soil in the lowland had finer texture compared with the upland soil, resulting in tendency of higher organic matter, total N and CEC. In addition, high DTPA Mn and soil mottles are generally found in a profile of the lowland soil. However, immature rubber trees planted in the good productive lowland plot grew as similar as in the upland soil. Whereas, in the poor productive plot, rubber growth was limited and concentrations of leaf N, P and K tended to be lower than those in the upland soil, in contrast to leaf Mn. These findings revealed that soil mottles within 0-30 cm are markedly indicator of limitation of the lowland for rubber cultivation

Alleviation of plant boron toxicity by using water to leach boron from soil contaminated by wastewater from rubber wood factories

ABSTRACT: Wastewater from rubber wood furniture factories contains large amounts of boron (B) which contaminates the soil and causes unusual symptoms in plants in the area. We aim to establish the toxicity effects in tomato seedlings planted in Kho Hong (Kh) soil series irrigated with wastewater and compare them with seedlings grown in the same soil series but receiving tap-water containing B, S, Ca, or Na at the same concentrations as found in the wastewater. Then, we study B leaching from B-contaminated soil in a column by applying distilled water at different rates. We alleviate the B contamination in the Kh soil series by using water to leach out the B, then planting tomato seedlings. The results showed that in plants subjected to the wastewater or B treatments, growth was reduced and the plants showed tip and marginal chlorosis and necrosis of mature leaves at high B concentrations. The boron in B-contaminated soil was decreased to a greater degree by the application of a larger amounts of leaching water. Using 167.5 mm (field capacity) of water leached the B in the topsoil (0-15 cm) from a concentration of 11.11 mg/kg down to 2.83 mg/kg, a nontoxic level (< 3 mg/kg), and the leached B accumulated in the subsoil (15-30 and 30-50 cm). However, using 1000, 2000, or 4000 mm of water leached the B from the soil to below a toxic level with only a slight accumulation in the subsoil. This indicates that applying water to leach B from soil decreased the extractable B to below a toxic level, resulting in a decrease in plant B uptake. As a result, the tomato seedlings showed better growth in terms of height, leaf number, and plant dry weight than those of the control treatment

Beneficial Effects of Silicon Fertilizer on Growth and Physiological Responses in Oil Palm

Vigorous and well-established nursery seedlings are an important component of sustainable oil palm production. We postulated that Si fertilization at the seedling stage could help to achieve improved performance of oil palm seedlings leading to healthy and vigorous nursery establishment. In this study, we evaluated the growth and physiological responses of oil palm Tenera hybrid seedlings under three Si fertilization treatments and a control including (i) 0 g Ca2SiO4 (T0), (ii) 0.5 g Ca2SiO4 (T1), (iii) 3.5 g Ca2SiO4 (T2), and (iv) 7.0 g Ca2SiO4 (T3) per plant per month. Ca2SiO4 was used as the Si fertilizer source and was applied for four consecutive months. Nondestructive data including stem diameter, plant height, leaf length, photosynthetic rate, leaf angle, and leaf thickness and destructive data including leaf, stem, and root fresh weight and dry weight, as well as chlorophyll a, Si, and nitrogen contents, were recorded before treatment (0 DAT), as well as 60 (60 DAT) and 120 days after treatment (120 DAT). Results indicated that Si fertilization enhanced Si accumulation in oil palm seedlings, and maximum accumulation was observed in the aerial parts especially the leaves with the highest accumulation of 0.89 % dry weight at T3. Higher Si accumulation stimulated the growth of seedlings; a total fresh weight of 834.28 g and a total dry weight of 194.34 g were observed at T3. Chlorophyll a content (0.83 gm−2) and net photosynthetic rate (4.98 µM CO2·m−2·s−1) were also observed at T3. Leaf morphology was not significantly influenced under Si fertilization, whereas the nitrogen content of seedlings was significantly increased. Correlation analysis revealed a highly significant and positive association among Si accumulation, chlorophyll a content, photosynthetic rate, total fresh weight, total dry weight, and nitrogen content of seedlings, indicating that Si fertilization enhanced the performance of these attributes. On the basis of the research evidence, it was concluded that Si fertilization should be considered for improved nutrient management for oil palm seedling and nursery production

Beneficial Effects of Silicon Fertilizer on Growth and Physiological Responses in Oil Palm

Vigorous and well-established nursery seedlings are an important component of sustainable oil palm production. We postulated that Si fertilization at the seedling stage could help to achieve improved performance of oil palm seedlings leading to healthy and vigorous nursery establishment. In this study, we evaluated the growth and physiological responses of oil palm Tenera hybrid seedlings under three Si fertilization treatments and a control including (i) 0 g Ca2SiO4 (T0), (ii) 0.5 g Ca2SiO4 (T1), (iii) 3.5 g Ca2SiO4 (T2), and (iv) 7.0 g Ca2SiO4 (T3) per plant per month. Ca2SiO4 was used as the Si fertilizer source and was applied for four consecutive months. Nondestructive data including stem diameter, plant height, leaf length, photosynthetic rate, leaf angle, and leaf thickness and destructive data including leaf, stem, and root fresh weight and dry weight, as well as chlorophyll a, Si, and nitrogen contents, were recorded before treatment (0 DAT), as well as 60 (60 DAT) and 120 days after treatment (120 DAT). Results indicated that Si fertilization enhanced Si accumulation in oil palm seedlings, and maximum accumulation was observed in the aerial parts especially the leaves with the highest accumulation of 0.89 % dry weight at T3. Higher Si accumulation stimulated the growth of seedlings; a total fresh weight of 834.28 g and a total dry weight of 194.34 g were observed at T3. Chlorophyll a content (0.83 gm−2) and net photosynthetic rate (4.98 µM CO2·m−2·s−1) were also observed at T3. Leaf morphology was not significantly influenced under Si fertilization, whereas the nitrogen content of seedlings was significantly increased. Correlation analysis revealed a highly significant and positive association among Si accumulation, chlorophyll a content, photosynthetic rate, total fresh weight, total dry weight, and nitrogen content of seedlings, indicating that Si fertilization enhanced the performance of these attributes. On the basis of the research evidence, it was concluded that Si fertilization should be considered for improved nutrient management for oil palm seedling and nursery production