Tentative standard concentration values of iron, manganese, zinc, copper and boron in Longkong (Aglaia dookkoo Griff.) Leaf

The standard concentration values are important for evaluation of plant nutrient status, classified into low, sufficient and high, which leads to the optimum nutrient management. However, the standardconcentration values of iron (Fe), manganese (Mn), zinc (Zn), copper (Cu) and boron (B) in longkong leaf (Aglaia dookkoo Griff.) have not been reported even though micronutrient deficiency symptom in someorchards was found. The objective of this research was to establish standard concentration values of Fe, Mn, Zn, Cu and B in longkong leaf. The leaf sampling was collected from middle leaflet of the 2nd compound leaf(5-month-old leaf) at the post harvest stage during 2003-2005 from 7 orchards in Songkhla province and 3 orchards in Narathiwat province, 10 trees per orchard. Yield of individual tree was recorded and used for establishment of nutrient standard concentration values by the high-yield-tree method (>70 kg tree-1) and theboundary-line method. The results revealed that the sufficient ranges of Fe, Mn, Zn, Cu and B established by high-yield-tree method were 74-88, 81-107, 16-19, 7-9 and 32-38 mg kg-1, respectively and the sufficientranges of Fe, Mn, Zn, Cu and B estimated by boundary-line method were 61-66, 49-58, 18-20, 7-8 and 27-30 mg kg-1, respectively. The standard concentration values by the high-yield-tree method were higher thanthose of the boundary-line method. However, the values estimated by the boundary-line method, which was calculated from the linear regression of yield and individual nutrient, did not include nutrient luxuryconsumption, and the values from this method can classify nutrients into deficient, low, sufficient and excess ranges. Therefore, the nutrient standard concentration values estimated by the boundary-line methodshould be used as the standard values for evaluation of Fe, Mn, Zn, Cu and B in longkong leaf

Effect of cattle manure and dolomite on soil properties and plant growth in acid upland soils

One of the major plant growth limiting factors has been associated with soil acidity. In general, lime is used for pH raising in acid soils. However, it is also well known that manure can be used for acid soil reclamation for a better cultivation. A greenhouse experiment was conducted to study the effect of lime (dolomite) and cattle manure on soil properties and plant growth in Kho Hong soil series (coarse loamy, siliceous; Typic Paleudults) which was considered to be a low fertility acid upland soil (pH 5.07, OM 1.04%, avai.P 4.12 mg kg-1, exch.K 0.02 cmol(+)kg-1, exch.Al 0.48 cmol(+)kg-1). The experiment design was a randomized complete block design with 4 replications and 8 treatments as follows: unamended (control), application of dolomite at the half rate of lime requirement at pH 5.5 (1/2L), application of cattle manure at the rate to raise soil organic matter to be 2.0%, 2.5%, 3.0% by volume, application of dolomite at the half rate of lime requirement at pH 5.5 together with cattle manure to make soil organic matter to be 2.0%, 2.5%, 3.0% by volume, respectively. It was found that shoot and root dry weights of corn were increased in all amended treatments, but no significant difference (P<0.01) was observed among them. Dry matter weight of corn was increased according to the increasing rate of manure application either with or without addition of dolomite.The maximum yield (7.96 g bag-1) was obtained in treatment of 3% soil organic matter plus dolomite andthe yield was significantly (P<0.01) higher than that of control (1.14 g bag-1) and dolomite applied alone (3.13g bag-1). It was also found that application of manure in all treatments increased the amount of N, P, K, Ca,Mg and S in corn. Higher uptake of N, P, K at the amount of 231.40, 38.68 and 487.11 mg bag-1, respectivelywere obtained in the treatment of 3% organic matter plus dolomite when compared to low uptake of N, P, Kat the amount of 42.08, 3.01 and 50.77 mg bag-1, respectively in the unamended treatment. Application of manure could increase soil pH, organic matter, P, K, Ca, Mg and S but significantly (p<0.01) decreased exchangeable acidity and aluminum of soil. Application of manure at the rate to elevate soil organic matter up to 3% could decrease exchangeable aluminum to the amount of less than 0.01 cmol (+) kg-1

Effect of lime, gypsum and potassium chloride on growth and nutrient uptake of longkong (Aglaia dookkoo Griff.) seedlings

Application of lime and gypsum for alleviation of aluminum toxicity in acid soil, including potassium (K) fertilization, may interfere with the nutrient uptake of longkong (Aglaia dookkoo Griff.) trees. Threeexperiments were conducted to explore the possible problem of longkong soil. 1) Effect of lime and gypsum on growth and nutrient uptake of longkong seedling. 2) Effect of lime and potassium chloride on potassiumand magnesium uptake of longkong. 3) Relationship between potassium, calcium and magnesium in longkong leaves. The results showed that exchangeable aluminum in the soil decreased with the increase of Ca(OH)2 treatment and the application of lime was more effective than that of the gypsum treatment. Theapplication of lime and gypsum tended to increase nutrient concentration in longkong, but did not affect the growth of longkong seedlings. The lime application on nutrient uptake of longkong seedlings decreased Kuptake; no lime and lime treatments were 863 and 720 mg tree-1, while without K applied the per tree uptakes were 579 and 356 mg tree-1 respectively. Besides the K application treatment reduced Ca and Mg uptake.Negative correlations between K and Ca (r = -0.532**) and between K and Mg (r = -0.663**) in leaves of 60 longkong trees in a farmer's orchard were found

Some properties of longkong growing soils in Songkhla and Narathiwat province and management

The major problems of longkong (Aglaia dookkoo Griff.) production in Thailand are poor quality and low quantity of yield, which may be caused by the imbalance or deficiency of essential nutrients in soils.The objective of this study was to investigate soil properties and land suitability for longkong growth in southern Thailand. Ten private longkong orchards in Songkhla and Narathiwat province were selected asthe experimental sites. The soil samples were taken at 2 depths; 0-15 and 15-30 cm, around the middle of the longkong canopy and outer longkong canopy at the pre-flowering period, then analyzed for some importantchemical and physical properties. Results indicated that longkong soils in the study areas were suitable for longkong plantation. However, some study still had limitation on slope factors especially those located onthe low terrace areas. All of the longkong soils (0-30 cm, inner and outer canopy) were the extremely acid to slightly acid soil (soil pH = 3.72-6.16; soil: water = 1: 5), with medium soil organic matter level (6.25-30.28 g kg-1) and very low soil electrical conductivity level (0.041-0.081 dS m-1). The inner canopy soils (0-15 cm)were of medium fertility level (237.80 mg kg-1 of available P and 0.23, 2.33, 0.70 and 0.12 cmolc kg-1 of exchangeable K, Ca, Mg and Na, respectively) when compared to the medium to low fertility level (26.77 mgkg-1 of available P and 0.13, 1.46, 0.22, and 0.08 cmolc kg-1 of exchangeable K, Ca, Mg and Na, respectively) in the outer canopy soils. However, longkong soils contained a large amount of available P

Standard sampling method of Longkong leaf for evaluation of plant nutrient status

Leaf analysis is a tool for effective fertilizer recommendations in fruit trees. To achieve this goal, suitable leaf sampling method is a very important step. This study aimed to investigate leaf age, leaflet from different compound leaf positions and number of trees to be sampled as a representative sample for plant nutrient status of Longkong (Aglaia dookkoo Griff.) tree. The middle pair of leaflets from the 1st, 2nd, 3rd, and 4th compound leaves from growing twigs at the lower canopy of Longkong trees were separately sampled and the following nutrients were determined: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg). The effect of soil fertility management and leaf age collected from twigs flushed at flowering and post harvest stages on nutrient concentration was investigated. Results showed that concentrations of plant nutrients in leaflets collected from different compound leaf positions were not significantly different. The leaf nutrient concentration depended on soil fertility management, higher fertilizer input resulting in higher leaf nutrient concentration. As leaf age increased, concentrations of N, P and K tended to decrease. In contrast, concentrations of Ca and Mg increased with leaf age. However, concentrations of most nutrients showed minimum variation with leaf aged 3-6 months. It is, thus, suggested that the middle pair leaflet of the 2nd compound leaf position aged 3-6 months of the lower twig should be sampled at post harvest stage from 25-35 trees to be used as a composite sample for plant nutrient analysis