Maximum Total Dry Weight Research Articles

The Use of Bamboo Biochar as a Soil Improver on the Growth and Yield of Mustard Plants

This study aims to obtain the right dose of biochar in mustard plants. The design used was a completely randomized design with a one-factor pattern. The biochar treatment was studied at four dose levels and one control. The application of biochar significantly affected plant height, total fresh weight, and total dry weight, except for the number of leaves which was not significant. The highest total dry weight yield was achieved at 9 t ha-1 biochar with a weight of 10.80 g or an increase of 60% compared to 6.75 g without biochar. From the regression analysis, the effect of biochar on total dry weight was found on the quadratic regression line with the equation: Ŷ = 6.717 + 0.8217 X - 0.04381 X2 (R2 = 91.80%), biochar with an optimal dose of 9.38 t ha -1 and a maximum total dry weight of 10.70 g.

Response of tomato growth to continuous elevated CO2 concentration under controlled environment

CO2 fumigation has been extensively used in greenhouses cultivation to enhance crop yield. The effects under the precise level of elevated CO2 (e[CO2]) on crop morphology, yield, and fruit quality remain largely elusive yet. To explore the response of plant growth to the continuous RCPs (Representative Concentration Pathways) projected CO2 concentration [CO2], tomato (Hezuo 908) plants were grown under ambient CO2 (a[CO2], 462 µmol/mol) and e[CO2] (550, 700, 850 and 1000 µmol/mol): named as EC550, EC700, EC850, and EC1000, respectively, under uniform environmental condition for two planting seasons. Collective growth of tomato plants (plant height, stem diameter, and leaf area index) was significantly enhanced under EC700 and showed a slightly negative response under EC850. The optimum yield was stimulated under EC700 by 74.05% and 55.91%, while maximum total dry weight (DWt) was enhanced under EC1000 by 58.23% and 39.78% during autumn-winter and spring-summer planting seasons, respectively, as compared to a[CO2]. The greatest yield and least DWt stimulated under EC700 for both seasons indicated that EC700 improved the ability of the tomato plants to translocate carbohydrates to fruits. Optimum water use efficiency related to yield (WUEy) was enhanced by 55.91-210.87% under EC700 compared to a[CO2]. The titratable acid (TA) was improved by 19.94% (EC700), 29.17% (EC850), and 97.92% (EC1000), and the lycopene (Lp) was increased by 2.22% (EC700) and reduced by 2.28% (EC1000). Thus, the overall optimum impact on tomato growth was explored under EC700. Super e[CO2] did not positively influence the tomato growth process and yield under adequate water and fertilizer conditions. The present study results are beneficial for greenhouse crop production and might be used as a reference to validate the climate change influence modeling. Keywords: elevated CO2, tomato plant, yield, water use efficiency, fruit quality DOI: 10.25165/j.ijabe.20221506.7418 Citation: Akhlaq M, Zhang C, Yan H F, Ou M X, Zhang W C, Liang S W, et al. Response of tomato growth to continuous elevated CO2 concentration under controlled environment. Int J Agric & Biol Eng, 2022; 15(6): 51–59.

Effect of Gamma Rays on the Growth Performance of Bangladesh Clone Tea

The experiment was carried out to investigate the effects of gamma radiation on the early growth performance and physiological traits of BT2 clone tea, the most promising cultivar released by Bangladesh Tea Research Institute. The fresh shoot cuttings were irradiated with seven different levels of gamma radiation such as 0, 10, 20, 30, 40, 50 and 60 Gy from Cobalt 60Co source (Dept. of PlantBreeding, Bangladesh Institute of Nuclear Agriculture). Thereafter, the irradiated shoot cuttings were planted in polythene bags and kept under natural conditions. It was observed that callusing was initiated from 8th weeks after placement of tea shoot cuttings in the polythene bags and completed by 12th weeks. The morphological growth of tea shoot cuttings were recorded under varying levels of gamma radiation and growth stages. It was observed that the number of leaves, number of primary branches, base diameter, root length and total leaf area per plant significantly increased with the progress of time and increasing levels of gamma radiation, however, the plant height showed decreasing trend with the increasing levels of gamma radiation, which could be due to the change in chromosomal structure and genetic makeup. After 56 weeks of planting, the plant height, the number of leaves and primary branches per plant, base diameter, root length and total leaf area per plant recorded were 65.70 cm, 30.67, 7.33, 1.48 cm, 23.50 cm, and 1250.67 cm2 per plant respectively under the radiation level 60 Gy, whereas the corresponding figures of the above parameters at the control treatment were 76.21 cm, 18.33, 3.67, 0.92 cm, 17.75 cm and 778.33 cm2 per plant, respectively. A significant relationship was observed among the physiological growth parameters with the increasing levels of gamma radiation. The total dry matter gain, leaf area index, absolute growth rate and relative growth rate were significantly influenced with the rising levels of gamma radiation (up to 60 Gy), whereas the net assimilation rate of individual tea plant non-significantly responded as compared to those of control treatment. Finally after 56 weeks of planting, the maximum total dry weight gain, leaf area index, absolute growth rate, relative growth rate and net assimilation rate recorded under 60 Gay radiation level were 40.25 g/plant/week, 4.25, 1.18 g/week, 0.0621g/g/week and 17.07 g/m2/week respectively.

Growth and flowering responses of Canna generalis to nitrogen supplied to the growing medium via top- or sub-irrigation

SummaryEffects of nitrogen concentration on growth and flowering were studied in Canna generalis L. H. Bailey ‘Tropical Rose’ and ‘Tropical Red’ grown with irrigation supplied either to the top (top-irrigation) or the bottom surface (subirrigation) of the growing medium. For ‘Tropical Rose’, maximum total dry weights occurred at 4 mM N for both irrigation methods, but growth was greater with subirrigation compared to top-irrigation. For ‘Tropical Red’, maximum total dry weight occurred at 4 mM N under subirrigation, and 8 mM N under top-irrigation. Growth was reduced in all treatments when growing media EC exceeded 1.25 dS m–1. Shoot dry weight increased as leaf N content increased from 0.6% to 1.4 %. Plants under top-irrigation took longer to flower than did those under subirrigation. At 4 to 32 mM N, regardless of irrigation method, plants flowered after 9–10 leaves had been formed. Plants grown at 0 mM N did not flower after treatment for 145 d. Maximum spike length and floret number were observed at 4 mM N in both irrigation treatments.

Nitrogen Nutrition of Spathiphyllum 'Sensation' Grown in Sphagnum Peat- and Coir-based Media with Two Irrigation Methods

Effects of nitrogen application on growth, stomatal conductance, transpiration, and chlorophyll content were studied in Spathiphyllum Schott 'Sensation' grown in sphagnum peat (SP)- and coir dust (CD)-based media with top-irrigation or subirrigation. Maximum shoot dry weight occurred at 8 mM N in plants grown in SP-based medium under top-irrigation and subirrigation, and in CD-based medium under subirrigation. For plants in CD-based medium under top-irrigation, maximum shoot dry weight was obtained at 16 mm N. In SP- or CD-based medium, shoot dry weight was greater at 4 and 8 mm N under subirrigation than under top-irrigation. Stomatal conductance and transpiration were reduced by nitrogen deficiency (0 N), greatly enhanced by 4 mm N, and decreased gradually at higher N levels. Chlorophyll content increased with increasing N concentration up to 8 mm. The percentage of maximum total dry weight increased quadratically as leaf N content increased from 1.5% to 3.5%. Nitrogen at 16 and 32 mm increased the number of leaves with marginal necrosis. Reduced growth and more leaves with marginal necrosis occurred in SP- or CD-based media with EC > 1.25 dS·m-1 in the middle and bottom layers.

The effect of growth temperature, level of ammonium nitrate, and light intensity on the growth and nodulation of cowpea (Vigna sinensis endl. ex hassk.)

The nodulation and growth of cowpea plants (Vigna sinensis Endl. ex Hassk. var. Poona), grown in the CERES phytotron glasshouses, were examined. The plants were grown under six controlled temperature regimes (21, 24, 27, 30, 33, or 36°C day temperature) with ammonium nitrate (NH4N03) additions of 0, 10, 30, and 90 mg nitrogen per pot of six plants; and were grown either under natural daylight or under natural daylight reduced in intensity by one-third by mesh screens. Primary root nodulation was significantly affected by temperature, NH4NO3 level, and light intensity, with an optimum temperature of 24°C. Secondary root nodulation was also affected by light intensity and temperature, but the nodulation pattern (with an optimum temperature of 33°) was almost the inverse of the primary root pattern. Temperature significantly influenced the fresh weight of nodules per plant and the nodule size, with a lesser effect of the NH4NO3 level. Plant dry weight production (tops and roots) was governed by the temperature, NH4NO3 level, and light intensity, the maximum total dry weight being produced at 27°C. Temperature, light intensity, and NH4NO3 level all influenced the plant combined- nitrogen uptake. The nodule leghaemoglobin concentration was significantly reduced at the two extreme temperatures 21° and 36°C. Temperature also markedly affected the nodule structure – particularly the distribution of starch within the nodule.