Increase In Number Of Pods Research Articles

Effect of phosphorus, organic and biological fertilizer on yield of mungbean (Vigna radiata) under two cropping patterns

Abstract. Suryantini. 2016. Effect of phosphorus, organic and biological fertilizer on yield of mungbean (Vigna radiata) under two cropping patterns. Nusantara Bioscience 8: 273-277. The research investigated the effect of phosphorus rates, organic and biological fertilizer on productivity of mungbean grown after rice (cropping pattern: rice-rice-mungbean) and after soybean (cropping pattern: rice-soybean-mungbean). Treatment was arranged in a split plot design with three replications. The main plots were (i) without organic and biological fertilizer, (ii) organic soil treatment (OST) and (iii) phosphate solubilizing biofertilizer (PSB). The subplots were phosphorus (P) fertilizer rates: 0, 100, 150 and 200 kg SP36/ha. The results revealed that the grain yield of mungbean grown after soybean was not affected by the application of OST or PSB, but it was increased by fertilizer P at 200 kg SP36/ha with an increase of 68%, from 0.60 t/ha (control) to 1.01 t/ha. Conversely, the grain yield of mungbean grown after rice was significantly affected by the interaction between fertilizer P and OST or PSB. The highest yield was obtained from the combination treatments of 150 kg SP36/ha + PSB and 150 kg SP36/ha + OST with an increase of 78% and 71% over control respectively. Increased grain yield was supported by the increase in number of pods, 100 seeds weight, and plant P uptake.

Canopy application of film antitranspirants over the reproductive phase enhances yield and yield-related physiological traits of water-stressed oilseed rape (Brassica napus)

Oilseed rape (Brassica napus L.) yield is strongly decreased by water deficit, and crop-management solutions are urgently required considering the emerging difficulties in breeding for drought-tolerant varieties. Film-forming antitranspirants (polymers) are agrochemicals that, applied to the crop canopy, mechanically block the stomata and decrease canopy transpiration. In this study, the drought-protection efficacy of an adaxial-surface application at the flowering stage of two film-forming treatments (poly-1-p-menthene and di-1-p-menthene) was investigated in pot-grown, droughted oilseed rape over two glasshouse experiments. Over the drought period, the two compounds reduced leaf stomatal conductance (P < 0.001), and as the soil moisture deficit increased, they sustained carbon assimilation and improved water-use efficiency with differing efficacy. Following the antitranspirant treatments, ABA concentration in leaves and reproductive organs was severely reduced and this was accompanied by significant improvements in leaf and flower–pod water potential. Drought significantly decreased the seed dry matter production of oilseed rape plants, by 39% on average. The treatments significantly increased seed dry matter by 13% (poly-1-p-menthene) and 17% (di-1-p-menthene), on average, compared with the unsprayed droughted plants, as a result of a significant increase in number of pods per plant, by 11% and 13%, respectively. The results suggest that film-forming compounds may be a useful crop-management tool to avoid severe drought-induced yield losses in oilseed rape by improving water-use efficiency and plant water status, thus alleviating ABA signalling under water deficit.

Soybean fruit development and set at the node level under combined photoperiod and radiation conditions.

In soybean, long days during post-flowering increase seed number. This positive photoperiodic effect on seed number has been previously associated with increments in the amount of radiation accumulated during the crop cycle because long days extend the duration of the crop cycle. However, evidence of intra-nodal processes independent of the availability of assimilates suggests that photoperiodic effects at the node level might also contribute to pod set. This work aims to identify the main mechanisms responsible for the increase in pod number per node in response to long days; including the dynamics of flowering, pod development, growth and set at the node level. Long days increased pods per node on the main stems, by increasing pods on lateral racemes (usually dominated positions) at some main stem nodes. Long days lengthened the flowering period and thereby increased the number of opened flowers on lateral racemes. The flowering period was prolonged under long days because effective seed filling was delayed on primary racemes (dominant positions). Long days also delayed the development of flowers into pods with filling seeds, delaying the initiation of pod elongation without modifying pod elongation rate. The embryo development matched the external pod length irrespective of the pod's chronological age. These results suggest that long days during post-flowering enhance pod number per node through a relief of the competition between pods of different hierarchy within the node. The photoperiodic effect on the development of dominant pods, delaying their elongation and therefore postponing their active growth, extends flowering and allows pod set at positions that are usually dominated.

不同生育时期断根对花生光合特性及产量的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 不同生育时期断根对花生光合特性及产量的影响 DOI: 10.5846/stxb201305131035 作者: 作者单位: 青岛农业大学农学与植物保护学院/山东省旱作农业技术重点实验室,青岛农业大学农学与植物保护学院/山东省旱作农业技术重点实验室,青岛农业大学农学与植物保护学院/山东省旱作农业技术重点实验室,青岛农业大学农学与植物保护学院/山东省旱作农业技术重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目(31271657); 国家科技支撑计划项目(2009BADA8B03); 国家花生产业技术体系建设专项(CARS-14-东北区栽培); 山东省"泰山学者"建设项目; 山东省农业重大应用技术创新项目; 山东省花生产业技术体系建设项目. Effects of root cutting at different growth stages on photosynthetic characteristics and yield of peanut Arachis hypogaea L. Author: Affiliation: Qingdao Agricultural University, Shandong Provincial Key Laboratory of Dry Farming Techniques,,,Qingdao Agricultural University, Shandong Provincial Key Laboratory of Dry Farming Techniques Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:在田间试验条件下,以青花5号花生品种为材料,研究了不同生育时期断根对花生功能叶片光合特性及产量的影响。结果表明:适期断根(花后20d)可促进花生叶片生长,显著提高叶面积指数,且维持较高的叶面积指数和叶绿素含量的时间较长;植株功能叶片的净光合速率、气孔导度和蒸腾速率较高,胞间CO2浓度较低,光合效率显著提高;可增加花生结果数量和果重,提高单株生产力,显著提高荚果产量和经济系数。过早断根(花后5d至10d)叶面积增长慢、峰值低、后期下降快,叶绿素含量低;功能叶片净光合速率、气孔导度、蒸腾速率峰值低且峰值过后下降速度快,而胞间CO2浓度一直维持在较高水平;断根时间越早,产量越低。过晚(花后25d)断根不利于叶面积指数的发展和较高叶绿素含量的维持,基本不影响花生叶片各光合性能指标,对产量影响较少。研究认为,开花后20d断根可作为花生栽培中的一项技术措施。 Abstract:The aim of the present paper is to investigate the effects of root cutting on leaf photosynthetic characteristics and yield of peanut, which can provide the theoretical basis for root cutting applied to peanut production as an agronomic technology. Under the field condtions with Arachis hypogaea L. cv. ‘Qinghua 5’ as the experimental materials in 2011 and 2012, the experiments was conducted to study the effects of root cutting at different growth stages on functional leaf photosynthetic characteristics and yield of peanut. The experiments were subjected to five treatments at different growth stage: root cutting on the fifth day after the first flowering date(T1), the tenth day after the first flowering date(T2), the fiftieth day after the first flowering date(T3), the twentieth day after the first flowering date(T4), and the twenty-fifth day after the first flowering date(T5), while the intact plants without root cutting were taken as the control treament(CK). The results showed that root cutting (T4) at the suitable stage promoted the leaf growth, significantly improved the leaf area index (LAI) and functional leaf chlorophyll content, moreover, maintained a longer time of higher LAI and chlorophyll content until later growth stage, compared with CK and other treatments, .Root cutting (T1, T2) at the early stages caused low growth speed and LAI peak value. LAI decreased rapidly at the late growth stage. The chlorophyll content in the functional leaf of T1 and T2 treatment was higher than that of CK, but significantly lower than that of T4 treament. Root cutting (T5) at the later stage was unfavorable to the development of LAI and maintaining high chlorophyll content. under By root cutting at the optimum stage, the net photosynthetic rate, stomatal conductance, and transpiration rate of functional leaves were higher, and the intercellular CO2 was lower compared to the other treatments, which significantly improved the photosynthetic efficiency of functional leaves. Under root cutting too early, there were low peak values of the net photosynthetic rate, stomatal conductance, and transpiration rate of functional leaves. At the same time, these photosynthetic characteristics of functional leaves dropped fast after the peak value, and decreasd to lower level at the late stage, except the intercellular CO2 maintaining at a high level all the time. Root cutting too late did not affect the leaf photosynthetic characteristics of peanut. Root cutting at the optimum stage increased pod number and weight per plant, and improved the productivity per plant, with the high pod yield and economic coefficient of peanut. The pod yield under the T4 treatment reached 4148 kg/hm2, which improved by 9.1% compared to CK. Pod number and weight per plant improved by 7.1% and 3.3% compared to CK, respectively. Root cutting at the early stages reduced the yield, moreover, the earlier root was cut the lower yield peanut reduced. Pod yield of peanut under T1 treatment reduced by 10.3%. Root cutting too late has the less influence on pod yield of peanut. It was concluded that root cutting on the twentieth day after the first flowering date can be used as a management practice of peanut cultivation. 参考文献 相似文献 引证文献

Melatonin enhances plant growth and abiotic stress tolerance in soybean plants.

Melatonin is a well-known agent that plays multiple roles in animals. Its possible function in plants is less clear. In the present study, we tested the effect of melatonin (N-acetyl-5-methoxytryptamine) on soybean growth and development. Coating seeds with melatonin significantly promoted soybean growth as judged from leaf size and plant height. This enhancement was also observed in soybean production and their fatty acid content. Melatonin increased pod number and seed number, but not 100-seed weight. Melatonin also improved soybean tolerance to salt and drought stresses. Transcriptome analysis revealed that salt stress inhibited expressions of genes related to binding, oxidoreductase activity/process, and secondary metabolic processes. Melatonin up-regulated expressions of the genes inhibited by salt stress, and hence alleviated the inhibitory effects of salt stress on gene expressions. Further detailed analysis of the affected pathways documents that melatonin probably achieved its promotional roles in soybean through enhancement of genes involved in cell division, photosynthesis, carbohydrate metabolism, fatty acid biosynthesis, and ascorbate metabolism. Our results demonstrate that melatonin has significant potential for improvement of soybean growth and seed production. Further study should uncover more about the molecular mechanisms of melatonin's function in soybeans and other crops.

Performance of Some Promising Genotypes of Fine-flavour Cocoa Selected at Penataran Estate, East Java

Prelimanary selection at Panataran Estate, East Java found five genotypes of promising fine flavor cocoa (PNT 12, PT 16, PNT 17, PNT 18, and PNT 33B) which had high yielding potency and estimated tolerant to VSD valuation of superior characters in each accession was important as base to be developed in multilocation test. The research was conducted in Penataran Estate, PTPN XII using single plot design and consisted of five fine flavor cocoa genotypes (PNT 12, PNT 16, PNT 17, PNT 18, and PNT 33B) and two genotypes as control (DR 2 and DRC 16). Each genotype consisted 33 plants (seven years old). Yield potential, score of VSD resistance, yield quality and morphology of stomata characters were observed. The analysis results showed that PNT 16 and PNT 12 had the highest of yield potential (1.46 and 1.10 kg/plant/year) respectively. PNT 16 also showed VSD scoring value low and stable on two years observation (2012-2013). Increasing pod number in 2013 was caused by recovery of the plant from VSD attack. Number of stomata on young leaf (flush) on PNT 16, PNT 17, PNT 18, and PNT 33B was lower than DR 2. Size of stomata qualitatively was different in each number. Characters of yield quality as pod lengh, pod weight, and pod girth on five promising clones were not as significantly different compared to control. Five fine flavor cocoa promising genotypes had white bean percentage more than 80 percent. Character of dry weight per bean on five fine flavour cocoa promising genotypes showed smaller than DR 2 but were not significantly different compared to DRC 16.

Separate and combined application of herbicide in bean weeds control and its yield

Prevalent presence of weeds in bean fields means that it is necessary that new herbicide adopt for weed control in this crop. In order to evaluate the effects of gallant (hexafop methyl) Treflan (trifluralin) bentazone herbicides on bean and its weeds an experiment was conducted in 2013 using Randomized Complete Blocks Design with three replications. Seven herbicide treatments included: 1) gallant, 2) treflan, 3)bentazone, 4) gallant + treflan, 5) gallant+ bentazone, 6) bentazone+ treflan, 8) gallant+ treflan+ bentazone and 9) weedy check were used in the experiment. The results showed that combined application of herbicides had a better effect on weed control compared to separate application of each of them. Combined application of three herbicides significantly increased pod number (12.14 pod per plant) and seeds per pod (6 seeds) the lowest weeds density and dry weight also obtained in treatment of gallant+ treflan+ bentazone. In conclusion the results showed that the use of combined application had better performance in bean weed control and can be recommended as an alternate application instead of separate application of herbicides in similar conditions.

Source-sink manipulation of Camelina sativa L. related to grain yield under stressful environment of Hokkaido, Japan

Five cultivars of camelina species (Camelina sativa L.) were grown in the field at two levels of nitrogen (N) under the climate conditions of Hokkaido Island, Japan. N nutrition as well as the genetic difference between cultivars influenced biomass and grain production. Three cultivars responded positively to N application, but not the other two. Increase in grain yield was associated more with grain number than grain size. The plants accommodated the extra grains by increasing pod number. Irrespective of the N level in the soil, α linolenic acid concentration of the grain was very high at 31% of the total fatty acids. In cultivar Calena, lower leaves on the main stem were excised to find the effect of reduced source area on yield. Defoliation of lower leaves did not affect grain yield, indicating that these leaves do not contribute to source capacity of the plant during grain filling. However, removal of all leaves decreased grain yield to 70% relative to the control plant. In contrast to defoliation, shading of the whole panicle consisting of the pod shell and rachis was more effective in reducing grain yield. Shading of the panicle prior to the grain filling period at the levels of 33 and 6% irradiance relative to control decreased grain yield to 39 and 26%, respectively. These results suggested that the pod shell and rachis are more important source organs for photosynthetic carbon supply to grains than the upper leaves, and they can sustain grain filling in exigency. The presence of attributes like extended source area for grain filling and high α-linolenic acid content of leaves is an indicator for successful adaptation of Camelina in the stress-prone environment of Hokkaido Island.

Pea aphid promotes amino acid metabolism both in Medicago truncatula and bacteriocytes to favor aphid population growth under elevated CO2

Rising atmospheric CO(2) levels can dilute the nitrogen (N) resource in plant tissue, which is disadvantageous to many herbivorous insects. Aphids appear to be an exception that warrants further study. The effects of elevated CO(2) (750 ppm vs. 390 ppm) were evaluated on N assimilation and transamination by two Medicago truncatula genotypes, a N-fixing-deficient mutant (dnf1) and its wild-type control (Jemalong), with and without pea aphid (Acyrthosiphon pisum) infestation. Elevated CO(2) increased population abundance and feeding efficiency of aphids fed on Jemalong, but reduced those on dnf1. Without aphid infestation, elevated CO(2) increased photosynthetic rate, chlorophyll content, nodule number, biomass, and pod number for Jemalong, but only increased pod number and chlorophyll content for dnf1. Furthermore, aphid infested Jemalong plants had enhanced activities of N assimilation-related enzymes (glutamine synthetase, Glutamate synthase) and transamination-related enzymes (glutamate oxalate transaminase, glutamine phenylpyruvate transaminase), which presumably increased amino acid concentration in leaves and phloem sap under elevated CO(2). In contrast, aphid infested dnf1 plants had decreased activities of N assimilation-related enzymes and transmination-related enzymes and amino acid concentrations under elevated CO(2). Furthermore, elevated CO(2) up-regulated expression of genes relevant to amino acid metabolism in bacteriocytes of aphids associated with Jemalong, but down-regulated those associated with dnf1. Our results suggest that pea aphids actively elicit host responses that promote amino acid metabolism in both the host plant and in its bacteriocytes to favor the population growth of the aphid under elevated CO(2).

A NEW MUTATNT SPRING FORAGE VETCH LINE (VICIA SATIVA SSP. SATIVA L.) WITH INCREASED POD NUMBER PER FERTILE NODE

A new mutant spring forage vetch line with increased pod number (3-4) per fertile node, obtained by applying of chemical mutagenesis in variety Obrazetz 666, was studied. For estimate the degree of heritability of the mutation was determined the genotypic variance (S 2 g) according to the traits number of pods per plant, mean number of pods per fertile node and number of seeds per plant between the mutant and the initial genotype of mean sample of 10 plants by ANOVA model 3. Significant genotypic difference between the mutant line and the initial variety with regard to the traits mean number of pods per fertile node, number of pods and number of seeds per plant was established. A very high coefficient of heritability (H 2 = 99%) was observed for the trait mean number of pods per fertile node and was reason to be considered that its phenotypic performance in the mutant line was entirely genetically determined. The genotypic variance for the traits number of pods and seeds per plant was significantly superior to the ecological one and can be considered that in the newly-selected line will be actual increase in the grain yield because of the higher values of these elements structuring it. The introduction into practice of this line, which has higher propagating coefficient, respectively higher seed yield, can contribute to the wider use of forage vetch as crop for green manure and cover crop.

Effects of fully open-air [CO<sub>2</sub>] elevation on leaf ultrastructure, photosynthesis, and yield of two soybean cultivars

The objective of this study was to investigate the effect of elevated (550 ± 17 μmol mol−1) CO2 concentration ([CO2]) on leaf ultrastructure, leaf photosynthesis and seed yield of two soybean cultivars [Glycine max (L.) Merr. cv. Zhonghuang 13 and cv. Zhonghuang 35] at the Free-Air Carbon dioxide Enrichment (FACE) experimental facility in North China. Photosynthetic acclimation occurred in soybean plants exposed to long-term elevated [CO2] and varied with cultivars and developmental stages. Photosynthetic acclimation occurred at the beginning bloom (R1) stage for both cultivars, but at the beginning seed (R5) stage only for Zhonghuang 13. No photosynthetic acclimation occurred at the beginning pod (R3) stage for either cultivar. Elevated [CO2] increased the number and size of starch grains in chloroplasts of the two cultivars. Soybean leaf senescence was accelerated under elevated [CO2], determined by unclear chloroplast membrane and blurred grana layer at the beginning bloom (R1) stage. The different photosynthesis response to elevated [CO2] between cultivars at the beginning seed (R5) contributed to the yield difference under elevated [CO2]. Elevated [CO2] significantly increased the yield of Zhonghuang 35 by 26% with the increased pod number of 31%, but not for Zhonghuang 13 without changes of pod number. We conclude that the occurrence of photosynthetic acclimation at the beginning seed (R5) stage for Zhonghuang 13 restricted the development of extra C sink under elevated [CO2], thereby limiting the response to elevated [CO2] for the seed yield of this cultivar.

Introducing a sustainable soil fertility system for chickpea ( Cicer arietinum L.)

In order to introduce a sustainable soil fertility system for chickpea, field experiments were carried out in 2007 and 2008 growing seasons. Experiments were arranged in split-split plot arrangements with three replications. Main plots consisted of (G 1 ): establishing a mixed vegetation of vetch and barley, (G 2 ): without green manure. Also, five strategies for obtaining the base fertilizer requirement including (N 1 ): farm manure; (N 2 ): compost; (N 3 ): triple super phosphate; (N 4 ): farm manure + compost and (N 5 ): farm manure + compost + triple super phosphate. Four levels of biofertilizers consisted of (B 1 ): Phosphate solubilizing bacteria; (B 2 ): Trichoderma harzianum ; (B 3 ): Phosphate solubilizing bacteria + T. harzianum ; and (B 4 ): without biofertilizers were arranged in sub-sub plots. Results showed that green manure increased pod number and number of fertile pods per plant. Integrating biofertilizers (B 3 ) and green manure (G 1 ) produced the highest pod number per plant and grain yield. The highest amounts of yield and yield components were obtained in G 1 N 5 treatment. Comparison of 3-way interactions showed that G 1 N 5 B 3 was the best treatment. Significant increase of N, P, K, Fe and Mg content in leaves and grains emphasized on superiority of mentioned treatment because each one of these nutrients has an approved role in chlorophyll synthesis and photosynthesis ability of the crop. The N 5 treatment in addition to having the highest yield had the best grain quality due to high protein, starch and total sugar contents, low crude fiber and reduced cooking time. Key words : Biofertilizer, chickpea, compost, farm manure, soil fertility system.

Germplasm evaluation and enhancement for the development of cowpea (Vigna unguiculata (L.) Walp) dual-purpose F2 genotypes.

Cowpea is an important grain legume as well as fodder crop, especially in the dry regions of South Africa. The production of this crop has been below average because of low genetic variation and cultivation of poor-yielding varieties which have not been improved. The potentials of cowpea F2 generation arising from crosses made from 55 exotic parental lines, introduced into South Africa were determined. F1 lines derived from the crosses were advanced to F2 lines in the glass-house, and the segregating F2 families were further evaluated in the field with their parental lines. The following data were collected from the progeny: number of pods per plant, 100 seed-weights, fodder yield, grain yield and harvest index. Results showed that F2 lines exhibited significant differences on all the parameters studied thus indicating the presence of genetic variability among the segregating progeny. Number of pods per plant, 100 seed-weight and harvest index showed higher significant differences. The F2 lines obtained a significant increase in number of pods per plant as compared to their parents, thus indicating the potentials of progeny for higher pod production. Harvest index for F2 lines varied between 0.16 and 0.60 (dual-purpose type), and are mostly medium cowpea types with dual purpose characteristics for producing grain for human consumption and fodder for livestock. These parameters should therefore receive highest priority in developing high yielding dual-purpose varieties. There are several promising F2 progenies which performed exceedingly well over the parents, so further screening is essential until their full potential is attained. Key words: Vigna unguiculata, germplasm, harvest index, dual-purpose, 100 seed-weights, segregating population.

English

Field studies were conducted during the 2008 - 2009 cropping season to determine the minimal insecticide application which can reduce cowpea yield losses on the field due to insect pest infestations in the Transkei region of South Africa. Treatments consisted of five cowpea varieties and four regimes of insecticide spray which were laid out with a split-plot experimental design with four replications. Observations were taken on the incidence of major insect pests, cowpea pod and seed damage by insects as well as growth and yield parameters of the cowpea varieties. Results showed that spray regimes had significant effects on insect population counts, pod and seed damage and consequently on cowpea yield parameters. Application of insecticide once each at flower budding and early podding significantly reduced pod borers and pod-sucking bugs infestations by 44 and 56%, respectively, compared to the untreated control. Application of insecticide, once at flower budding, early podding and pod filling significantly reduced pod and seed damage, resulting in substantial increase in number of pods, pod weight and seed weight per plant, and also number of seeds per pod of cowpea compared to the untreated control. This study provides information on the incidence of major insect pests of cowpea as well as the minimum insecticide control intervention necessary for effectively reducing cowpea yield losses on the field. Two insecticide spray regimes (once at flowering and podding) significantly reduced insect population and damage of cowpea.

Responses of soybean yield and yield components to light enrichment and planting density

Light intensity intercepted by the soybean canopy during the reproductive period is an important environmental factor determining soybean yield components and grain yield. A 2-year field experiment was conducted to investigate the effects of light enrichment and its interaction with planting density on yield formation of soybean cultivars. Light enrichment increased seed yield per plant and yield per unit area dramatically ranging from 26-94% (P<0.05) regardless of density and cultivars at lower and moderate density however the yield increase effect was not observed in H339 and HN35 at the high density in 2007. Seed yield and pod number per plant declined with the increased density in 2007 for all cultivars but remained unchanged in 2008 for KN18. There was significant light enrichment-by-density (P<0.05) on yield per plant and pod number per plant, but not on seed number per pod and seed size across the two years. Yield sensitivity to light enrichment differed among soybean cultivars. Adjustments to light enrichment imposed at the early flowering R1 stage increased pod number. Pod number per plant increased 20-119% over the two-years. Seed size in this study was unchanged or reduced slightly by light enrichment. Our data suggest that clarification of mechanisms induced the greatest yields in high population as demonstrated under light enriched conditions may provide insights for crop management and phenotypic improvement.

Effect of elevated atmospheric CO&lt;sub&gt;2&lt;/sub&gt; concentrations on growth and yield of blackgram (Vigna mungo L. Hepper) - a rainfed pulse crop

The response of blackgram (&lt;i&gt;Vigna mungo&lt;/i&gt; L. Hepper) to two levels of elevated carbon dioxide (550 and 700 ppm) in terms of growth and yield was investigated and compared with ambient CO&lt;sub&gt;2&lt;/sub&gt; level (365 ppm) using open-top chambers. The growth parameters viz., length and weight of root and shoot, root:shoot ratio, leaf area and weight significantly increased at 700 ppm CO2 when compared with 550 ppm. The percentage increase in total biomass at 700 and 550 ppm CO&lt;sub&gt;2&lt;/sub&gt; was 65.4% and 39%, respectively compared to the ambient (chamber) control. The increase in total seed yield at 700 ppm (129%) was due to an increase in number of pods per plant and 100 seed weight, whereas at 550 ppm (88.7%) it was due to an increased number of pods/plant and seeds/pod. The results indicate variable responsive effects at different levels of CO&lt;sub&gt;2&lt;/sub&gt; emphasizing the pertinence of research on elevated CO&lt;sub&gt;2&lt;/sub&gt; in various agroecological inhabitations all over the world. The indication of higher responses for root and leaf at initial growth stages at the higher elevated level of CO&lt;sub&gt;2&lt;/sub&gt; (700 ppm), which leads to better root establishment, achieving early photosynthetic efficiency and also better biomass production, and its improved partitioning can be reckoned as a positive aspect of increasing concentrations of CO&lt;sub&gt;2&lt;/sub&gt; in atmosphere. The harvest index increased significantly to 35.7 and 38.4% at 550 and 700 ppm, respectively; it is a very important phenomenon in pulses for breaking the yield barrier.

Yield and yield components responses of old and new soybean cultivars to source-sink manipulation under light enrichment

Limited information is available regarding the source-sink alterations on soybean yield under whole plant light enriched conditions. The differential responses of yield components for two old and two new cultivars were investigated. The yield sensitivity of the old cultivars to the changes in source strength and light enriched conditions was much greater than that of the two new cultivars. The yield of the new cultivars was more likely sink-limited, and source-limited for the old cultivars. The increased yield by light enrichment was in part due to an increased branch contribution. Pod number per plant was more responsive than seed number per pod. The reduction in pod number by source-sink manipulation was more severe in the old cultivars. Light enrichment increased pod number in the two old cultivars but not in the two new cultivars. Seed size was responsive to changes in the source-sink ratio and changes in the environment. Both pod number or seed size may be increased or decreased if environmental conditions for seed filling are altered.

Foliar nitrogen applications increase the seed yield and protein content in chickpea (Cicer arietinum L.) subject to terminal drought

The effect of foliar application of isotopically labelled nitrogen (15N-urea) at 4 stages during flowering and podding on the uptake and utilisation of nitrogen by chickpea (Cicer arietinum L.) under conditions of terminal drought was investigated in a glasshouse study. Five treatments were used to investigate the effect of timing of foliar application of urea, equivalent to 30 kg N/ha, on the uptake and utilisation of nitrogen for biomass, yield, seed protein content, and seed size: foliar application at (i) first flower, (ii) 50% flowering, (iii) 50% pod set, and (iv) the end of podding, and (v) an unsprayed control treatment. Terminal drought was induced from pod set onward, resulting in a rapid development of plant water deficits (–0.14 MPa/day) and a decrease in leaf photosynthesis irrespective of the timing of foliar urea application. Foliar applications of urea at first flower and at 50% flowering, before terminal drought was induced, increased yield and seed protein content. The increase in yield resulted from an increase in the number of pods with more than one seed rather than from increased pod number per plant or increased seed size, indicating greater seed survival under terminal drought. Also, the increase in the seed protein content resulted from increased nitrogen availability for seed filling. Foliar application of urea during flowering, before terminal drought was induced, resulted in 20% more biomass at maturity, suggesting that growth prior to the development of water shortage increased the carbon resources for sustained seed filling under conditions of terminal drought. Foliar applications of urea at 50% pod set and at the end of podding did not affect the yield or seed protein content, primarily because the uptake of nitrogen was limited by the leaf senescence that occurred with the development of terminal drought. The results indicate the potential to increase yields of chickpea by application of foliar nitrogen near flowering in environments in which terminal droughts reduce yield.

Effects of Source/Sink Ratio and Cytokinin Application on Pod Set in Soybean

A large proportion of soybean flowers abort during development. Pod set is significantly affected by the availability of assimilate and cytokinin in the flowers, but their synergistic effects on pod set remain unclear. The objective of this study was to examine whether pod set at specific nodes of a plant is enhanced by increasing the source-sink ratio and applying cytokinin to the nodes. The source-sink ratio was manipulated by removing floral buds excluding the specific nodes. As the ratio increased, the number of pods per node of control plants increased curvilinearly, reaching a plateau at high source/sink ratios. By contrast, in the cytokinin-applied plants, the number of pods per node increased without the plateau with increasing source/sink ratio, either by increasing the number of flowers or by increasing the pod-set percentage depending on the year. The results indicated that cytokinin plays a promotive role in increasing pod number in the plants with high levels of assimilate availability.

Impact of 2,4-DP and BAP upon pod set and seed yield in soybean treated at reproductive stages

A large number of soybean (Glycine max L. Merr.)flowers and young pods abscise rather than develop into mature pods. Flower andpod drop or abortion accounts for the majority of total reproductive abscissionand influences potential soybean yield. The objectives of this study were todetermine the patterns of flower, pod and seed development under treatmentswiththe growth regulators, 2-(2,4-dichlorophenoxy) propanoic acid (2,4-DP) and6-benzylaminopurine (BAP), applied at the early reproductive stages, and toexamine the association of reproductive abscission with growth characteristicsand agronomic traits, including seed yield and seed weight. Small seeded [cvPungsan (11.1 ± 0.4 g100-seed−1)] and large seeded [cv Manlee(21.0 ± 0.5 g 100-seed−1)]genotypes were separately planted in the greenhouse and field, and treated witheither 2,4-DP or BAP. 2,4-DP (a synthetic auxin) and BAP (a syntheticcytokinin)were each applied at three concentrations (i.e. high, intermediate or low):0.12mM, 0.08 mM, 0.04 mM, and 1.5mM, 1 mM, 0.5 mM respectively. High andlow concentrations were employed for greenhouse experiments to examine thenumber of flowers per plant in pots. With the exception of low BAP (0.5mM) treatment in Pungsan, all treatments increased total podnumberwith various numbers of seeds per pod. Low 2,4-DP (0.04 mM) inbothgenotypes or BAP (0.5 mM) in Manlee significantly reduced flowerabortion and delayed abscission of pods in both genotypes, resulting inincreased pod setting rates. Under field conditions using intermediateconcentrations, 1 mM BAP significantly increased 100-seed weightto22.3 g at R1 in Manlee and 11.9 g at R3 in Pungsan.BAP (1 mM) at R3 in Pungsan significantly improved seed yield(40.1g plant−1). Maturity was not significantlyaffected by either application in Manlee, but was significantly affected by BAPin Pungsan. In Pungsan, 2,4-DP increased pod number, plant height and nodenumber, but decreased 100-seed weight in Pungsan treated at R1, causing nosignificant change of seed yield. This study suggested that exogenousregulatorssignificantly influenced reproductive and growth characteristics, andconsequently seed yield, but increase of pod number was not always beneficialfor seed yield.