Average Leaf Width Research Articles

Effect of Different Monomers on Water Retention Properties of Slow Release Fertilizer Hydrogel

The combination of hydrogel and fertilizer as slow release fertilizer hydrogel (SRFH) has become one of the promising materials to overcome the shortcomings of conventional fertilizer by decreasing fertilizer loss rate, supplying nutrients sustainably, and lowering frequency of irrigation. A comparative study on water retention and plant growth performances of SRFH made from three hydrophilic monomers; acrylic acid (AA), acrylamide (AAm) and AA-co-AAm was executed. PAA SRFH has smaller swelling rate constant, k as it required only 166.67minutes to absorb 0.63 of its equilibrium capacity of swelling, followed by P(AA-co-AAm) SRFH and PAAm SRFH. Although PAAm SRFH has the lowest swelling rate constant, it has the most excellent water retention ability in soil followed by P(AA-co-AAm) SRFH. Additionally, the presence of PAA SRFH in soil has enhanced the plant growth performances of model plant (capsicum annum) in term of its average leaf width and plant height. The synergistic effects of acrylic acid and acrylamide in P(AA-co-AAm) SRFH could be utilized to produce hydrogel used in agriculture.

THE EFFECT OF FERTILIZER ON GROWTH OF STAGHORN FERN AT SEEDLING STAGE

The effects of two fertilizer types with 3 concentrations on growth of staghorn fern (Platycerium coronarium) were studied. This experiment was conducted at the nursery of Division of Crop Production, Faculty of Agricultural Technology, Rajamangala University of Technology Thanyaburi, during October and December 2013. It was laid out in a RCBD with 4 replications and consisted of seven treatments. The treatments were application of: water, a 21-21-21 fertilizer with the concentration of 0.5 g/l, 1.5 g/l, 3g/l, Bio-fertilizer with the concentration of 1 ml/l, 2 ml/l and 3 ml/l of water. Leaf length, leaf width and canopy width of the ferns were measured. The data were subjected to ANOVA, followed by Duncan’s Multiple Range Test at 5% level of significance. No significant difference among treatments was found. However, the water showed the best result. It gave 108.79 mm average canopy width, 3.13 mm average leaf length and 89.67 mm average leaf width.

Seasonal Variations on Quality Parameters of Pak Choi (Brassica rapa L. subsp. chinensis L.)

The aim of this study is to determine the changes in quality of pak choi in successive growing seasons. Experiments were carried out in a PE covered cold greenhouse in late autumn-early winter and late winter-early spring growing period in Turkey (41°11’ N, 27°49’ E). Results showed that morphological features, the leaf area (73.82 mm2), leaf length (31.21 mm), average leaf width (2.70 mm), maximum leaf width (3.92 mm), mass (95.27 g) and moisture content values of leaves (0.90% w.b.) were higher in late autumn-early winter period but leaf thickness (0.33 mm) contents were higher in late winter-early spring period. Yield characteristics investigated were affected by season and were found relatively higher in late autumn-early winter than late winter-early spring growing period. And it was 5713 kg ha-1 in late autumn-early winter growing period and 5034 kg ha-1 in late winter-early spring growing period. In point of the dry matter content investigated were affected by season, and were higher in late autumn-early winter than late winter-early spring growing period. It was 12.4% in late autumn-early winter growing period and 10.25% in late winter-early spring growing period. Account of total protein of plants grown in late autumn-early winter (25.16%) was higher than in late winter-early spring (22.45%) growing period. Sowing time did affect ascorbic acid content significantly. It was 44.21 mg.100-1 g in late autumn-early winter growing period and was recorded as 38.02 mg.100-1 g in late winter-early spring growing period. Color parametres L, a, b values were measured as 27.92; -6.98 and 8.53 in late autumn-early winter and as 21.64; -5.48; 7.49 late winter-early spring. Sowing time did affect color parameters content significantly. Late autumn-early winter growing time result was higher than in late winter-early spring growing time. With regard to mineral content N (4.67%), P (0.65%), Cu (9.32 ppm), Fe (879.6 ppm) and Zn (49.13 ppm) values were higher in plants grown in late autumn-early winter in comparison with plants grown in late winter-early spring as K (4.45%), Ca (2.36%), Mg (0.41%) and Mn (62.25 ppm) values of plants were higher in late winter-early spring growing period. Results of the study indicated that different weather conditions influenced the pak choi yield and the chemical composition of the leaf as well. Pak choi with its relatively short cultivating period, easy growing, and dietary value can be a good alternative crop for late autumn-early winter growing period in cold greenhouses.

QTL Analysis of Major Agronomic Traits in Soybean

Soybean is a main crop, and most agronomic traits of soybean are quantitative; therefore, there is very important studying and applying value to locating these traits. A F 2:10 RIL population containing 154 lines, derived from the cross between Charleston as female and Dongnong 594 as male parent, were used in this experiment. A genetic linkage map was constructed with 164 SSR primers, which were screened with the two parents and amplified on the 154 lines. 12 agronomic traits different between the two parents were investigated, and QTLs of all the traits were analyzed using the software Windows QTL Cartographer V2.0. The agronomic traits included quality traits: protein content, oil content, and content of protein and oil; yield traits: pods per plant, seed weight per plant, and 100 seeds weight; and other agronomic traits: plant height, days to maturity, branches, nod number in main stem, average leaf length, and average leaf width. The results showed that 68 QTLs in total were found for the 12 agronomic traits. The number of QTLs per trait varied from 3 for the average leaf width to 11 for 100 seeds weight and plant height, and was 5.8 on average. Good accordance was seen in many QTLs between the results of this study and the results obtained by other similar studies; therefore, these QTLs may be valuable for molecular marker assistant selection in soybean. In this study, 68 major QTLs of 12 important traits of soybean were analyzed.

Test of an extended mathematical approach to calculate maize leaf area index and leaf angle distribution

Accurate estimates of leaf area index (LAI) and leaf angle distribution (LAD) are important for estimating the exchange of energy and gases in vegetative canopies. Direct estimates of LAI and LAD are laborious, time consuming and often times destructive. Stewart and Dwyer [Agric. For. Meteorol. 66 (1993) 247] introduced a mathematical method to calculate LAI and LAD of maize canopies based on descriptions of leaf width and leaf curvature. However, the method is limited in its application. The objectives of this research are to: (1) extend the method to account for leaves with maximum curvature height at the leaf tip (i.e., straight leaves, which commonly occurs with leaves at the top of maize canopies), so that the method provides a general application to maize canopies, and (2) test the performance of the extended model. LAI and LAD simulated using the mathematical method were tested against observed LAI and LAD values. Average leaf width coefficients, determined from all leaf positions, were used in the leaf area calculation. Leaf area simulations agreed overall within 2% (51 cm 2) of observed leaf area values. Estimated LAD agreed within 5% of the field observed LAD. The method offers a straightforward, reliable means of estimating LAI and LAD, when the appropriate coefficients are known, without requirements for special instrumentation or other conditions. The method also offers a means of checking the performance or reliability of other methods of characterizing canopy structure.