Higher LAI Research Articles

Influence of Foliar Nutrition for Maximising the Growth and Yield of Black Gram (Vigna mungo L.) under Irrigated Condition

Background: A field experiment was conducted at the Central farm of Imayam Institute of Agriculture and Technology, Thuraiyur, during Thaipattam (Jan.- Feb.) 2019 to study the influence of foliar nutrients for maximizing the yield of blackgram (Vigna mungo L.) under irrigated condition. Methods: The experiment was laid out in a randomized block design and replicated thrice. The treatments comprised six different foliar nutrients viz.,T1 - Control (RDF alone - 25:50:25 kg NPK ha-1), T2 - RDF + foliar spray of 1% TNAU Pulse wonder, T3 - RDF + foliar spray of 1% (19:19:19), T4 - RDF + foliar spray of 1% KCl, T5 - RDF + foliar spray of 2% DAP, T6 - RDF + foliar spray of Salicylic acid 100 ppm, T7 - RDF+ foliar spray of PPFM @ 500 ml ha-1. The variety used VBN(Bg) 5. The foliar nutrients were sprayed on 30 and 45 DAS. Result: The results revealed that among the different foliar nutrients, foliar application of 1% pulse wonder resulted in higher LAI and DMP, closely followed by 2% DAP spray. Similar to the yield parameters, foliar application of 1% TNAU pulse wonder produced more pod clusters plant-1, number of pods plant-1 and number of seeds pod-1,and it, however, was on par with 2% DAP spray. Foliar spray of 1% TNAU pulse wonder produced a higher grain yield of 918 kg ha-1, comparable with a grain yield of 2% DAP (896 kg ha-1). The highest gross return (` 50,490 ha-1), net return (` 26,000 ha-1) and BCR (2.03) were obtained with foliar spray of 1% pulse wonder followed by 2% DAP spray, Hence, it is concluded that raising blackgram with foliar spray of pulse wonder spray @ 1% twice at 30 and 45 DAS is the viable package for getting higher yield and higher income.

Optimizing Establishment Methods and Weed Management Practices on Growth, Yield and Economics of Maize under Irrigated Condition

To study the performance of different crop establishment techniques and weed management practices on growth, yield attributes, yield and economics of maize hybrid, field experiment was conducted during Summer 2023 season.The treatment comprised of different sowing methods viz., pneumatic precision planter, manual rotary dibbler and manual dibbling and these treatments were compared with varied weed management practices such as pre-emergence (PE) application with atrazine 50 % WP @ 0.75 kg ha-1 at 3 DAS + power weeding at 20 and 40 DAS, pre-emergence (PE) application with atrazine 50 % WP @ 0.75 kgha-1 at 3 DAS + hand weeding at 20 and 40 DAS and pre-emergence (PE) application with atrazine 50 % WP @ 0.75 kg ha-1 at 3 DAS + early post-emergence (EPoE) application with topramezone 33.6 % SC @ 25.2 g ha-1 at 20 DAS. The results revealed that manual dibbling under conventional levelled ridges and furrows and pre-emergence application of atrazine 50 % WP @ 0.75 kg ha-1 at 3 DAS through drone followed by power weeding at 20 and 40 DAS recorded the highest vigour index, root length, volume and biomass. Early field emergence was noticed with manual dibbling under ridges and furrows which wasfollowed by pneumatic precision planter. However, higher LAI was recorded under manual rotary dibbler followed by pneumatic precision planter. Pre-emergence application of atrazine 50 % WP @ 0.75 kgha-1 at 3 DAS + hand weeding at 20 and 40 DAS had significantly less weed density and dry weight and the next best treatment was pre-emergence application with atrazine 50 % WP @ 0.75 kg ha-1 at 3 DAS + power weeding at 20 and 40 DAS. Significantly higher grain and stover yieldwas obtained under manual rotary dibbler treatment which was at par with pneumatic precision planter. Highest net returns and benefit cost ratio were observed with manual rotary dibbler followed by atrazine 50 % WP @ 0.75 kg ha-1 at 3 DAS + power weeding at 20 and 40 DAS.

Performance of Wheat (Triticum aestivum L.) Influenced by the Application of Nano-fertilizers

An experiment into the "Performance of wheat (Triticum aestivum L.) on application of nano-fertilizers" was conducted on well-drained sandy soil in response to concerns about food and nutritional security as well as second-generation post-green revolution problems, such as increasing input use with declining efficiency trends, deteriorating soil health, depleting water resources, pollution and narrowing farmer profits. On the wheat variety DBW187 in RBD with three replications, 12 twelve treatments containing control, basal administrations of the required 100% NPK (150:60:40), 75% NPK (112.5:45:30), and Nano N and Nano P in various combinations were tried. The study's findings showed that wheat sprayed with 75% NPK + Nano N and Nano P at 30 and 45 days of growth experienced significantly better growth as evidenced by taller plants (91.23 cm), more tillers per square metre (322.5), higher LAI (0.83), and higher dry matter accumulation per square metre (1532.7), all of which were measured at harvest.

Effect of grafting and number of stems on plant growth, yield and fruit quality of soilless tomatoes

Vegetable grafting has grown considerably and has been a management alternative to overcome adverse soil cultivation conditions. However, many growers have used grafted tomato plants in substrate cultivation, claiming greater plant vigor, fruit yield, and longevity. Thus, the work objective is to evaluate the effect of grafting and the number of stems on plant growth, fruit yield, and quality of the Italian tomato, cultivated in a system of troughs filled with raw rice husk substrate. The experiments were conducted in southern Brazil, in the 2017/18 (long cycle) and 2019/20 (short cycle) crop seasons. The cleft grafting was used. The analyzed variables were the number of leaves, leaf area index, vegetative and fruit dry matter production, plant total dry matter, number of fruits, fruit yield, mean fruit weight, and total soluble solids content (ºBrix). The grafted plants had higher LAI, fruit dry matter production, fruit number, and yield (17 and 19%, respectively, in the first and second crop seasons). The quality of the fruits, concerning the concentration of sugars, was not affected by grafting, and the mean fruit size was increased by 7.9 and 8.1 grams (long and short cycle, respectively). In a long cycle, both for grafted and non-grafted plants, single-stem plant cultivation promotes 13.54% more plant growth and is 4.86% more fruit yield than double-stem plants. In a short cycle, from the point of view of reproductive growth and fruit yield, for both types of plants, cultivation with two stems is like that of single-stem plants.

Transparent and Black Film Mulching Improve Photosynthesis and Yield of Summer Maize in North China Plain

In order to clarify the influences of drip irrigation under different mulch materials on crop yield, field experiments were carried out in the North China Plain for two seasons in 2020 and 2021. The changes in field microenvironment, photosynthetic capacity, leaf biological factors, and maize growth indexes were analyzed under drip irrigation with transparent film (W), black film (B), and straw mulching (S), with a nonmulching field as control (CK). The results showed that compared with CK, the yield of W and B increased by 7.2–9.9% and 7.1–12.4%, and the yield of S did not change significantly. The increase in yield was related to the improvement of the field microenvironment and photosynthetic capacity and higher LAI. Compared with CK, the soil water content 0–40 cm below the soil surface of W, B, and S increased by 13.6%, 9.1%, and 4.6%, respectively, and the 5 cm effective accumulated soil temperature of W and B increased by 7.9–10.2% and 4.1–4.7%, respectively. The maximum carboxylation rate (Vmax) of W, B, and S at the jointing stage was significantly increased by 3.5–17.3%, 12.7–17.6%, and 10.1–12.7% compared with CK. There was a significant linear correlation between Vmax and Nmass, and the correlation was affected by mulching treatments. At the jointing stage, compared with the CK, the LAI of W and B significantly increased by 8.6–66.5% and 7.2–56.0%, but there was no significant difference between S and CK. In conclusion, the increase in yield of W and B resulted from the combined effect of increasing LAI, Vmax, and soil water content and temperature.

Crop attributes explaining current grain yield dominance of maize over sorghum

Yield genetic gains have been significantly higher for maize ( Zea mays L.) than for sorghum ( Sorghum bicolor L. Moench ). Today there is questioning under which environments sorghum is a better option than maize, since maize has increased its tolerance to water and N limitations. For this we conducted eleven rainfed experiments at different sites around the central region of Argentina, using representative commercial genotypes of each crop. Experiments involved different sowing dates and N fertilization treatments, generating a total of 21 growing conditions where both crops were simultaneously compared. Measured traits included yield, phenology, leaf area development, light interception, and biomass accumulation. Explored growing conditions yielded from 1.8 to 11.7 Mg ha −1 for maize, and from 1.4 to 9.9 Mg ha −1 for sorghum. Crops yield difference (maize minus sorghum) ranged from − 0.3 to 4.8 Mg ha −1 , and this difference significantly favoured maize in all growing conditions except one. As expected, the yield difference in favor to maize increased in magnitude in the environments with more positive water balance (r: 0.54; p < 0.01) and higher N levels (r: 0.43; p < 0.05). When compared to maize, sorghum always showed a longer time to anthesis and a shorter grain-filling duration, higher LAI, lower post-anthesis biomass accumulation, and similar total biomass at physiological maturity. Maize harvest index was higher and less variable than the sorghum one (0.44 to 0.56 and 0.28 to 0.45, for maize and sorghum, respectively). A comparison with previous literature showed that the cut-off yield (i.e., maize yield below which sorghum has better yield performance) is significantly lower than expected. Results reinforce previous evidences highlighting that the differential research investment in the two crops is limiting the capacity of sorghum to out-yield maize across environments. • Maize and sorghum were simultaneously grown across a wide environmental range. • Maize out-yielded sorghum in mostly all growing environments. • The yield where maize was out-yielded by sorghum was 1.8 Mg ha −1 only. • Maize has a shorter vegetative period, a higher post-flowering growth, and a higher harvest index.

Effect of planting time and plant growth habits on phenological, physiological traits and associated with seed yield in African sarson (Brassica carinata)

An experiment was conducted during two consecutive years to study the effect of planting times (15 October, 5 November and 25 November) and cultivars differing for growth habits (BJC-13-1, BJC-13-2, BJC-13-3, BJC-13-4) newly developed determinate type and (PC-5 indeterminate variety) on phenology and physiological traits of African sarson (Brassica carinata A. Braun). The experiment was laid out in split plot design with three replications keeping planting times in main plot and genotypes in sub-plots. Planting time had a significant influence on both phenology and physiological traits of African sarson. The early sown crop took less number of days (66) for flowering while late sown crop took more number of days (79). There was drastic reduction in flowering period (20.8days), siliquing duration (23.3days) and reproductive phase(27.2days). Early planted (15 October) cultivars intercepted more PAR, higher LAI and SPAD-chlorophyll values resulting in higher yield. The interactive effects of planting dates and the cultivars were significant (p &lt; 0.05) for most of the features, which showed variable trends for the changes in the cultivars in response to planting dates. In all the cultivars, there was considerable deterioration in most of the studied traits due to delayed planting. Seed yield had positive association with siliquae duration (0.436), reproductive phase (0.426), SPAD (0.540*) and LAI (0.701**) with first planting (15 October) whereas with late planting (5 November) correlation existed between seed yield and LAI (0.073) and PAR interception (0.086) while with only flowering duration (0.772**) with 25 November sowing.

Effect of residue and nutrient management on productivity, nutrient uptake, economics and greenhouse gas emission of rice in intensified rice-based cropping systems

A long-term field experiment was conducted at Institute research farm, ICAR-National Rice Research Institute, Cuttack, Odisha since 2012-13. The experiment was conducted in a split plot design involving two cropping systems i.e., rice-maize-cowpea (R-M-C) and rice-groundnut-cowpea (R-G-C) covering three crops in three seasons i.e., kharif, rabi and summer, respectively in main plots and five nutrient management treatments i.e., control control - control (C-C-C), RDF-RDF - RDF (R-R-R), Residue Incorporation (RI) +75% of RDF-RDF - RDF (RI+R75-R-R), RI+ 75 % of RDF-Straw Mulching (SM) + RDF - RDF (RI+R75-SM+R-R) and RI+75 % of RDF - SM+RDF - 50 % of RDF (RI+R75-SM+R-R50) in sub-plots; where control indicates no fertilizer application to each crop of the system, RDF indicates recommended dose of fertilizers for respective crops, RI indicates cowpea residue incorporation in succeeding rice crop before transplanting and SM indicates rice straw mulching @ 6 t ha-1 in succeeding groundnut and maize. Significant improvement in growth parameters of rice i.e., plant height, tillers plant-1, leaf area index, dry matter accumulation, yield i.e., grain yield, straw yield, harvest index, nutrient uptake, economic gain i.e., gross return, net return and B:C ratio, CH4 flux in cowpea residue incorporated treatments than the residue removal treatments. Cowpea residue incorporation with 75% of recommended dose of fertilizer to rice followed by straw mulching with recommended dose of fertilizer to rabi season crops i.e., maize and groundnut and recommended dose of fertilizer to summer season crops i.e., RI+R75-SM+R-R recorded 10.2% higher number of tillers hill-1, 17.1% higher LAI, 10.9% higher DMA, 8.5% higher panicles m-2 and 8.8% higher filled grains panicle-1 than recommended dose of fertilization to each crop i.e., R-R-R. RI+R75-SM + R-R also recorded 11.3% higher grain yield, 9.7% higher straw yield, 13.7% higher N uptake, 15.8% higher P uptake, 11.9% higher K uptake, 11.3% higher gross return, 15.1% higher net return and 25.6% less N2O emission than recommended dose of fertilization to each crop i.e., R-R-R. Cowpea residue incorporation with 25% reduction in RDF, straw mulching with RDF to rabi season crops i.e., maize and groundnut and RDF to summer season crops (RI+R75-SM+R-R) however recorded at par growth, yield, nutrient uptake and economic return to that of RI+R75-SM+R-R50. Thus, RI+R75-SM+R-R50 could be useful in achieving higher productivity and profitability from rice in an intensified rice-based cropping system.

Effect of Water Regimes on the Growth of and Yield of Rabi / Summer Groundnut Genotypes in Northern Transition Zone of Karnataka

Background: Groundnut crop grown during Rabi / summer experiences moisture stress, thus irrigation is must. However, water for irrigation gets scarce during summer month hence it becomes important to choose stress tolerant varieties and optimize irrigation schedule without compromising the yield.Methods: A field experiment with four rabi / summer groundnut genotypes (G1: Dh-86, G2: Dh-101, G3: K-9 and G4: G2-52) exposed to four irrigation regimes (I1: 7 irrigations at 15 days interval from sowing to 105 DAS as control, I2: withdrawal of one irrigation between 45 - 60 DAS i.e., pegging stage, I3: withdrawal of two irrigations between 45-75 DAS i.e., at pegging and pod filling stage, I4: withdrawal of four irrigations from 45-105 DAS i.e., at pegging, pod filling and kernel development stage) was carried out from December to April of 2016-17 on black cotton soils at AICRP on Groundnut UAS, Dharwad.Result: Among the genotypes tested, Dh-86 recorded significantly higher pod yield (2,376 kg ha-1) followed by Dh-101 (2,215 kg ha-1) and K-9 (2,048 kg ha-1), whereas G2-52 gave the lowest yield (1,880kg ha-1) and all of them performed well at I1 and I2 irrigation regimes. Among different water regimes, I1 (i.e., control) recorded significantly taller plants, higher LAI, more branches and higher dry matter at harvest as compared to other irrigation regimes, hence it also recorded significantly higher pod yield and haulm yield (2,870 and 4,691 kg ha-1, respectively), but was found at par with I2, i.e., crop stressed only at pegging stage (2,858 and 4,648 kg ha-1, respectively). This suggests that, at the most, one irrigation can be skipped at pegging stage without compromising on yield.

Shade and Irrigation Effects on Growth, Flowering, Pod Yields and Cacao Tree Survival Following 5 Years of Continuous Dry Season Irrigation

The effects of plantain shade and dry season irrigation on the growth, field survival, flowering and pod production of cacao was investigated. Treatments were a 2 by 2 factorial combinations of shade regimes (Unshaded/open sun and shaded) and irrigation intervals (5-day and 10-day intervals) arranged in a split-plot design. There was an unirrigated but shaded control. The shade regimes constituted the main plot while irrigation intervals were the sub-plot treatments. The growth, dry season survival, flowering and pod/bean yield characters of cacao were enhanced in the unshaded (open sun) compared with the shaded plants. The open sun treatment combined with 5-day irrigation produced the largest canopy development, flowering and pod production compared with shading-irrigation combinations. The shade-irrigation ameliorated microclimate and enhanced growth and development, flowering and uniform fruiting/pod production and total bean yield and reduced dry season mortality (whole tree death, branch and twig dieback). For the non-irrigated but shaded cacao, about 30% dry season mortality (branch and twig dieback) were obtained. Air temperatures within the cacao field were highest for open sun cacao followed by moderate and dense shade respectively. Flowers were more profuse for unshaded (open sun) cocoa compared with the shaded while the yield and yield components of cacao for each harvest dates and total pod and bean yields were significantly different between the unshaded and shaded cacao regimes. Trees that were irrigated at 5-day intervals produced significantly (P &lt; 0.05) higher LAI, branching, flowers and pods compared with those irrigated at 10-day intervals. The 5-day irrigation interval significantly increased percentage of trees bearing flowers and pods, and produced larger number, and heavier pods and beans compared with the 10-day interval. The drip irrigation strategy adopted ameliorated dry season terminal drought (hydrothermal stresses) in cacao. This is a veritable tool to scale up growth, survival, establishment and flower/pod production.

Suitable genotype and optimization of seed rate for late sown wheat

A field experiment was conducted to identify suitable genotype and seed rate of wheat under late sown conditions during Rabi season of 2017-18 at Research Farm of CCS Haryana Agricultural University, Hisar. Experiment was laid out in split plot design with four replications. The experiment was comprised of three wheat genotypes viz. WH 1124, HD 3059 and DBW 90 as main plot treatments and five seed rates viz. 100.0, 112.5, 125.0, 137.5 and 150.0 kg/ha as sub plot treatments. Among genotypes, WH 1124 was found most suitable wheat genotype for late sown condition, produced significantly tallest plant (98.2 cm), highest dry matter accumulation/mrl (153.4 g), higher LAI at 90 DAS (4.54), lowest leaf senescence score at 30 DAA (9.09), higher total tillers/mrl (88.6), highest effective tillers per mrl (85.2), grains per spike (53.5), spikelets per spike (18.3), test weight (38.7) resulted in highest grain (4,843 kg/ha), straw (7,015 kg/ha) and biological yield (11,858 kg/ha). While among different seed rates, seed rate of 150 kg/ha was found optimum to obtain higher yield of late sown wheat produced significantly tallest plant (98.4 cm), highest dry matter accumulation/mrl (153.6 g), higher LAI at 90 DAS (4.50), higher total number of tillers/mrl (91.3), highest effective tillers (86.5), grains per spike (50.5), highest grain yield (4,909 kg/ha), straw yield (6,991 kg/ha) and biological yield (11,900 kg/ha). However,, spike length, number of spikelets per spike was not affected significantly by various seed rates. Among genotypes, maximum days to attain 50 per cent heading (75.6 days) and 50 per cent anthesis (79.1 days) was taken by HD 3059 and maximum duration (109 days) to achieve maturity was observed in DBW 90. Phenological stages of wheat were not affected significantly by different seed rates. Highest gross returns (₹ 30,562/ha), net returns (₹ 52,735/ha) and B: C (1.68) were obtained with WH 1124. Among different seed rates inspite of having highest cost of cultivation (₹ 78,353/ha), highest gross returns (₹ 131,259/ha), net returns (₹ 52,906/ha) and B: C (1.68) was obtained in wheat sown at seed rate of 150.0 kg/ha.

Functional Crown Architecture of Five Temperate Broadleaf Tree Species: Vertical Gradients in Leaf Morphology, Leaf Angle, and Leaf Area Density

The morphology, inclination, and spatial distribution of leaves in different parts of tree crowns are important determinants of the radiation, momentum, and gas exchange between the canopy and the atmosphere. However, it is not well known how these foliage-related traits vary among species differing in successional status. We measured leaf size, leaf mass area (LMA), leaf inclination (angle to the horizontal), leaf area density (LAD), total leaf area (leaf area index, LAI), and leaf area distribution across the crown in adult trees of five common, early to late-successional tree species (Betula pendula Roth, Quercus petraea (Matt.) Liebl., Carpinus betulus L., Tilia cordata Mill., and Fagus sylvatica L.) using different canopy access techniques and the harvest of foliated trees (29 trees in total). Leaf size increased continuously with crown depth in B. pendula and T. cordata but peaked at mid-crown in Q. petraea, C. betulus, and F. sylvatica to decrease toward the shade crown. By contrast, LMA and leaf angle decreased continuously with crown depth in all species, but the pattern of vertical change varied. The mid/late- and late-successional species had higher LAI, lower shade-leaf LMA, lower leaf angles (shade and sun crown), and higher LAD in the uppermost sun crown in comparison to early successional B. pendula. We assume that the most peripheral sun leaf layer is partly acting as a shield against excess radiation, with foliage properties depending on the structure of the shade crown. We conclude that the vertical change in leaf morphology, inclination, and spatial distribution in tree crowns is highly species specific, with partial dependence on the species’ position in succession.

Growth, crop phenology and PAR interception in kharif maize (Zea mays L.) as influenced by planting methods and nitrogen levels

A field experiment was conducted at Punjab Agricultural University, Ludhiana during kharif 2015 to study the influence of three planting methods (flat, ridge and bed planting) and five nitrogen levels (0, 90, 120, 150 and 180 kg N/ha) on the growth, phenology and PAR interception in kharif maize. Bed planting method produced significantly higher LAI, DMA, leaf chlorophyll content, cob length, cob girth, number of rows per cob and grain yield of maize as compared to flat sowing method but was statistically at par with ridge planting method. Maximum PAR interception of 78.2% was registered at 90 DAS when the crop was raised on beds. Tasselling, silking and physiological maturity were enhanced by 2.3 to 2.5, 3.3 to 3.7 and 2.2 to 2.6 days, respectively, under bed and ridge planting methods as compared to flat sowing method. Application of 150 kg N/ha recorded significantly higher LAI, DMA, leaf chlorophyll content, PAR interception, cob length, cob girth, number of rows per cob and grain yield over 120, 90 and control but at par with 180 kg N/ha. Maximum PAR interception of 82.8% was observed with application of 180 kg N/ha at 90 DAS which was significantly higher than 0, 90 and 120 kg N/ha but was at par with 150 kg N/ha. Nitrogen application enhanced the tasselling and silking stages but delayed the physiological maturity stage.

Influence of some environmental factors on maize productivity in Osun state, Nigeria

Temperature, humidity and direction of the prevailing wind are parts of significant environmental factors, which have greater impact on crop productivity, especially with the recent global climate change. These were researched into on maize seeds planted at three different furrow orientations on the field; Or. 900, Or. 600 and Or. 300 to direction of the prevailing wind on the same plot of land at three replicates A, B and C each. Temperature and humidity were measured at 8.00hr, 10.00hr for morning; 14.00h and 16.00h for afternoon each day. Temperature-Humidity Index-THI was calculated using THI equation. Leaf development was measured in terms of broadness, stem girth, length and number of leaves. Harvest Index, HI and Leaf Area Index, LAI were also calculated. The result shows that at significant level (p &lt; 0.05), effect of Or. was observed on THI values in the afternoon period, but in the morning, significant (p &gt; 0.05) effect of orientation on THI was not observed. The Or. 900 had highest HI of maize and better growth. The LAI values show that Or. 900 had higher LAI (0.775), than that of Or. 600 of value (0.770), between 40th and 70th days. It was found out that orientation of furrow of maize crops to direction of the prevailing is a function of the environmental parameters such as temperature, humidity, and the closer the orientation of furrow slice for crop leaves is towards the 900 wind direction, the better its growth and yield. Key Words: Crop productivity, Leaf Area Index, Temperature-Humidity Index, orientation, Osun State

Contribution of Arbuscular Mycorrhiza to Productivity of Barley on Contrasting Cropping Systems, in Central Greece

The objective of this study was to evaluate the effect of Arbuscular Mycorrhizal fungi inoculation on productivity of barley, under different levels of fertilization on organic or conventional agricultural systems. In addition, the mycorrhizal dependency of each system was studied for all fertilization levels. Experimental field was settled in central Greece, on clayey soil and experiments were conducted under real field conditions, in a split plot design. Two mycorrhizal treatments were combined with five fertilization treatments, in three replications. Growth parameters (e.g. plant height, total biomass production, seed yield, Leaf Area Index, Harvest Index) were monitored throughout cultivation period. Percentage of root AM colonization and mycorrhizal dependency were also measured for each treatment. Results indicated that AM inoculation had a positive effect on growth parameters and final productivity of barley. Plants of inoculated plots reached higher final height, higher LAI, and higher seed yield. Inorganic fertilization suppressed AM root colonization, especially when higher rates of inorganic fertilizers were applied. In contrast, organic fertilization did not suppressed AM colonization, especially in the case of AM inoculation. Mycorrhizal dependency was higher for the low-input cropping systems. In the present research work, we demonstrated that AM inoculation can positively affect growth and productivity of barley, in both organic and conventional cultivation.

Canopy Apparent Photosynthetic Characteristics and Yield of Two Spike-Type Wheat Cultivars in Response to Row Spacing under High Plant Density.

In northern China, large-spike wheat (Triticum aestivum L) is considered to have significant potential for increasing yields due to its greater single-plant productivity despite its lower percentage of effective tillers, and increasing the plant density is an effective means of achieving a higher grain yield. However, with increases in plant density, the amount of solar radiation intercepted by lower strata leaves is decreased and the rate of leaf senescence is accelerated. Row spacing can be manipulated to optimize the plant spatial distribution under high plant density, therefore improving light conditions within the canopy. Consequently, field experiments were conducted from 2010 to 2012 to investigate whether changes in row spacing under high plant density led to differences in canopy apparent photosynthesis (CAP), individual leaf photosynthesis and grain yield. Two different spike-type winter wheat cultivars, Jimai22 (a small-spike cultivar as a control cultivar) and Wennong6 (a large-spike cultivar), were grown at a constant plant density of 3,600,000 plants ha–1 (a relatively higher plant density) over a wide range of row spacing as follows: 5-cm row spacing (R0), 15-cm row spacing (R1), 25-cm conventional row spacing (R2), and 35-cm row spacing (R3). The two-year investigations revealed that increased row spacing exhibited a significantly higher light transmission ratio (LT), which improved light conditions within the canopy; however, excessive light leakage losses in R2 and R3 treatments were not favorable to improved irradiation energy utilization efficiency. Aboveground biomass accumulation was influenced by row spacing. Two spike-type wheat accumulated greater biomass under 15-cm row spacing compared to other row spacing treatments, although a markedly improved photosynthetic rate (PN), effective quantum yield of photosystem II (ΦPSII) and maximal efficiency of photosystem II photochemistry (Fv/Fm) in the penultimate and third leaves were observed in R2 and R3 treatments. At the same time, a longer duration of CAP and green leaf area was maintained in R1 during grain filling. Compared with conventional row spacing, Wennong6 in R1 treatment obtained 21.0% and 19.1% higher grain yield in 2011 and 2012, respectively, while for Jimai22 it increased by 11.3% and 11.4%, respectively. A close association of yield with CAP and LAI at mid-grain filling was observed. In conclusion, for the tested growing conditions, decreasing the row spacing to an optimal distance (15 cm) maintained a longer duration of LAI and CAP during grain filling, made a better coordination of group and individual leaf photosynthesis, and accumulated higher aboveground biomass, leading to a greater grain yield. In addition, Wennong6 had a more rational canopy architecture than Jimai22 (improved LT and higher LAI) and CAP under 15-cm row spacing, leading to a higher grain yield, which indicated that the large-spike type cultivar has the potential to obtain higher yields by increasing plant density through optimum row spacing allocation (15 cm).

Responses of Gibberelic Acid (GA3) on Growth and Yield of Cowpea cv. BARI Falon-1 (Vigna unguiculata L.)

An experiment was carried out at the research farm of Patuakhali Science and Technology University (PSTU) during the period from November 2010 to April 2011 to study on growth and yield performance of cowpea cv. BARI Falon-1 under different treatment of GA3 as foliar spray to investigate the responses and most optimum level of gibberelic acid regarding growth and yield of Falon that are suitable to cultivate in coastal region of Bangladesh. Among the GA3 treatments, 33.33 ppm GA3 produced significantly the tallest plant (61.07 cm), maximum leaves and branches plant–1 (28.50 and 19.73, respectively), higher LAI (1.10) and higher TDM plant–1 (81.95 g) comparatively than that of other GA3 levels while control had lower on the above characters. Growth characters such as CGR, RGR and NAR had also higher (0.99 and 1.65 gm–2 day-1 for CGR, 0.43 and 0.72 gm–2 day–1 for RGR and 0.027 and 1.275 mg cm2 day–1 for NAR) in 33.33 ppm GA3 at the stage between 30 to 60 DAS and 60 to 90 DAS, respectively Yield contributing characters Among other observation of yield and yield contributing characters, 33.33 ppm GA3 further registered the maximum pods plant–1 (11.50), longest pod (17.05 cm), higher weight fresh (3.78 g) and dry pod (1.99 g), higher weight of 100–seed (12.25), seed yield (18.57 g plant–1 and 2986.72 kg ha–1) and higher HI (22.45%). These results also showed that GA3 up to 33.33 ppm signifciantly developmend morpho–physiological, growth, yield and yield contributing characters and thereafter all the data decreased due to its destructive effect of higher GA3 levels. So, considering the above observation it could be suggested that GA3 @ 33.3 ppm would be appropriate doses of GA3 for obtaining the better produciton of BARI Falon-1 under resion.DOI: http://dx.doi.org/10.3329/jesnr.v7i2.22196 J. Environ. Sci. &amp; Natural Resources, 7(2): 7-12 2014

Relationship between Growth and Photosynthetic Efficiency of Soybean(Glycine maxL. Merrill) Genotypes under variable Photoperiods

Photosynthetic rate and leaf area index are the most important traits for determining the yield of soybean. LAI, photosynthetic rate and growth efficiency during the different growth and developmental stages of soybean were strongly influenced by variable photoperiods. The objective was to investigate the alteration of source-sink of different maturity group soybean genotypes under variable photoperiods (longer and shorter) and to examine the dynamics of LAI, photosynthetic rate and growth efficiency (CGR and RGR) at the different growth and develop-ment stages. Fifteen soybean genotypes of three maturity groups were grown under variable pho-toperiods at Punjab Agricultural University, Lu-dhiana, India in a Randomized Block Design along with three replications. LAI and photosyn-thetic rate were recorded at vegetative, flowering and pod initiation stages of each photoperiod. Growth efficiency was measured at two intervals i.e. 30–45 DAS and 45–60 DAS. Significant varia-tions were found for LAI, photosynthetic rate, growth efficiency, duration from R1 to R8 period and yield contributing traits within each maturity groups. Late maturity group genotypes had higher LAI, Photosynthetic rate, CGR, RGR and yield attributes traits than medium and early ones under both the photoperiodic conditions. A strong positive relation was found for LAI, photo-synthetic rate and crop growth rate with grain yield per plant in late maturity group genotypes. The confirmation obtained in the present studies further proved that photoperiods influence the whole life cycle of soybean crop.

High Yield Formation and Its Eco-Physiological Characteristics of Cast-Trans¬planting Rice

Cast-Transplanting rice has a low cost, easy operation, high and stable yield potential advantage, Depth study of the seedings throwing is very important to develop the light and simple cultivation of rice. The purpose of this study is to explore the high yield formation and its eco-physiological characteristics of cast-transplanting rice. Under the rice-wheat cropping systems, conventional japonica cultivar Nanjing 44 and japonica hybrid rice cultivar Yongyou 8 were used to investigate the characteristics of high yield formation including tillering dynamic, LAI, photosynthetic potential, dry matter production and the eco-physiological basis, such as post-root activity, photosynthetic characteristics, material accumulation and translocation, with three cast-transplanting methods of transplanted seedlings (TS), pointed seedlings (PS), and broadcasted seedlings (BS) in contrast with the manually transplanting of seedlings with roots washed beforehand (MTS), which could provide the theoretical and practical basis for the high and stable yield of the cast-transplanting rice. The results showed that the yields of three methods were 21.9%, 18.3%, and 13.2% higher than MTS for Yongyou 8, and 18.3%, 14.1%, and 9.87% higher than MTS for Nanjing 44, respectively. The yields of two cultivars both showed the trend of TS PS BS MTS. Although the filled-grain percentage and 1000-grain weight of cast-transplanting rice were significantly or very significantly lower than those of MTS, the total number of spikelets of cast-transplanting rice was conformably higher than that of MTS at a significant or very significant degree. The increased yield was mainly due to the higher total spikelet number. Compared to MTS, the cast-transplanting rice had more peak seedling tillers, higher or equivalent ratios of productive tillers to total tillers, an enough number of ultimate effective panicles, higher LAI and LAD, and thus a more robust population quality. According to these results, we could give the conclusion of the eco-physiological basis of high and stable yield of cast-transplanting rice. After transplantation, there were earlier tillering, more leaf tillering positions, stronger tillering capability, and higher quality and enough quantity of tillering. At the heading stage, they had suitable plant height, stouter stems and sheaths, efficient leaf configurations, preferable air ventilation and light transmission conditions, higher biomass accumulation, a more coordinated sink-source relationship, and hence a higher yield potential. In the late growth period, the cast-transplanting rice had stronger roots, slower senescence of leaves, more powerful photosynthesis, more coordinated dry matter accumulation and translocation of stem and sheath, higher filling ratios, being more conducive to the higher yield. TS and PS have evident advantages than MTS, and are more favorable in achieving higher yield.

Effect of BARI Wheat Varieties on Seed Germination, Growth and Yield under Patuakhali District

A pot experiment was carried at Patuakhali Science and Technology University to study the performance of some BARI wheat varieties under the coastal area of Patuakhali. Four wheat varieties viz. BARI ghom-23, BARI ghom-24, BARI ghom-25 and BARI ghom-26 were planted in the field to evaluate their comparative performance in respect of germination percentage, growth, yield and yield attributing characters. Among the four varieties, BARI ghom-26 showed superior performance irrespective of all parameters studied except total dry matter content (TDM) and yield reduction percentage. Among the BARI varieties, BARI ghom-26 produced greater germination (61.00%) at 13 days judge against to other varieties. The taller plant (47.91 cm), higher LAI (1.84), maximum TDM (17.37 g plant-1) and effective tillers hill-1 (18.08) were also obtained with the similar variety. BARI ghom-26 was also most effective to produce the maximum grains spike-1 (38.52), higher weight of 1000-grains (49.38 g), higher grain (3.35 t ha-1) and straw (8.50 g plant-1) yield and greater HI (4.03%). So, the variety BARI ghom-26 produced the outstanding superiority among the varieties.DOI: http://dx.doi.org/10.3329/jesnr.v5i2.14816 J. Environ. Sci. &amp; Natural Resources, 5(2): 209-212 2012