Yield-contributing Parameters Research Articles

Effects of Different Irrigation Regimes and Genotypes on Yield Contributing Parameters of Potato (Solanum Tuberosum L.) Under Chhattisgarh, India

The field experiment was conducted at the Horticultural Research Farm, College of Agriculture, Indira Gandhi Krishi Vishwavidyalaya, Raipur, Chhattisgarh, India during Rabi 2018-19 in Split plot Design with four level of irrigation regimes and four potato genotypes. The irrigation treatments were allotted in the main plot while, potato genotypes allotted in the sub-plots. At 75 days after planting (DAP) and 90 days after planting (DAP), the various yield contributing parameters were affected significantly by the different irrigation regimes except the plant emergence and number of shoots/plant. The number of shoots/plant, number of total leaves/plant, fresh weight of tubers/plant (g), total number of tuber/plant and harvest index (%) were significantly affected by the different irrigation regimes and potato genotypes. The plant with irrigation at 25 mm cumulative pan evaporation (CPE) produced the maximum plant height, number of shoots/plant, number of total leaves/plant, number of tubers/plant, fresh weight/plant and harvest index at 75 DAP and 90 DAP, respectively. The potato genotype AICRP-P-38 gave the highest fresh weight of tuber/ plant, number of tubers/plant and harvest index at 75 DAP and 90 DAP, respectively. Bangladesh J. Bot. 52(1): 211-216, 2023 (March)

Foliar application of gibberellic acid in combination with cowdung enhances growth and yield attributes of okra(Abelmoschus esculentus)

A field experiment was conducted at the Horticulture Farm of Bangladesh Agricultural University, Mymensingh during March to July 2020 to investigate the results of various amount of cowdung and gibberellic acid (GA3) on okra growth and production. The experiment comprised of Factor A: three doses of cowdung such as C0= 0 ton (Control), C1= 5 t ha-1, C2= 10 t ha-1and Factor B: four variable concentrations of GA3such as G0= Control (with no gibberellic acid), G1= 50 ppm gibberellic acid, G2= 100 ppm gibberellic acid and G3= 150 ppm gibberellic acid. Three replications ofthe experiment were set up using a Randomized Complete Block Design (RCBD). Most of the developmental and yield-contributing parameters of the okra tested significantly varied when various quantities of cowdung and varying amounts of gibberellic acid wereused. The 10 t ha-1cowdung (C2) had the maximum yield (11.34 t/ha) as well as the amount of green pods(13.77)per plant. From a 0 t ha-1cowdung (C0) treatment, the fewest green pods (14.18), and lowest green pod production (5.98 t/ha), were produced. On the other hand, gibberellic acid with 100 ppm (G2) showed the best performance on number of green pods (13.77), green pod output (10.51 t/ha) and the lowest performance on number of green pods (10.05), green pod produce (6.47 t/ha) from control (G0) treatment (without gibberellin). Okra's development and yield-contributing characteristics were greatly impacted by the interaction of cowdung and gibberellic acid. The integration of 10 t ha-1 cowdung (C2) and 100 ppm gibberellic acid performed the best on the number of green pods (15.91), green pod yield (13.47 t/ha) tremendously non-identical from the combination of treatment of 0 t ha-1(C0) with no gibberellic acid applied plants in the same parameters viz. number of green pods (7.72), green pod yield (4.13 t/ha). The finding of this study suggested that application of 10 tons cowdung per hectare combine with 100 ppm gibberellic acid to be recommended for okra cultivation.

Aerobic rice (Oryza sativa) cultivation under drip irrigation and fertigation system

A field experiment was conducted during the summer of 2019 and 2020 at the research field of (All Indian Coordinated Research Project on Water Management), Agricultural College and Research Institute, Madurai, Tamil Nadu, to assess the effect of drip irrigation and fertigation on aerobic rice (Oryza sativa L.) cultivation. The experiment was laid out in strip-plot design, replicated thrice. The irrigation was scheduled once in 3 days at 120, 100, and 80% pan Evaporation (PE), and the fertigation of 100, 75 and 50% recommended Dose of Fertilizer (RDF) was given weekly intervals from 15 days after sowing (DAS) to 70 DAS and the control of surface irrigation at an irrigation water: cumulative evaporation (IW : CPE) 1.25 with soil application of RDF (150 : 50 : 50 kg/NPK/ha) was separately maintained. The results of different irrigation and fertigation practices showed that, 120% PE × 100% RDF along with associated crop management had a significant effect on crop growth, yield and yield-contributing parameters and their values were significantly higher than all the other drip irrigation regimes and fertigation levels. This was mainly owing to continued availability of soil moisture and nutrients throughout the life period of aerobic rice, which led increased growth and yield parameters at the maximum level. Thus, 120% PE drip regimes and 100% RDF fertigation level proved better option in aerobic rice cultivation under drip irrigation and fertigation system in respect of yield and water saving.

Evaluation and Identification of Stable Chickpea Lines for Yield-Contributing Traits from an Association Mapping Panel

An association mapping panel consisting of 380 genotypes of chickpea was evaluated for three different years, including 2014–2015, 2015–2016 and 2016–2017, for yield-contributing parameters, including the seed number and seed weight. The AMMI analysis presented mainly concentrated on the seed weight and seed number, which are the two most important yield-contributing traits. The genotypes contributed 93.08% of the total variance, while the interaction effect was comparatively low, with 4.1% for the two traits. AMMI biplot analysis identified IG5986, IG5982, ILC6025 and ICCV14307 as desirable genotypes for the seed weight and IG5893, ILC6891 and IG5856 for the seed number. Identifying stable genotypes would help in strategic planning for yield improvement through component trait breeding.

Sulfur Sources Mediated the Growth, Productivity, and Nutrient Acquisition Ability of Pearlmillet–Mustard Cropping Systems

Globally, excess soil nutrient mining is a serious challenge to sustainable agricultural production. The task is more daunting in the semi-arid region of the globe. In addition to the primary nutrient deficiency over the mining of secondary nutrients, especially sulfur is an emerging challenge in contemporary crop production systems. Hence, there is a dire need to devise an appropriate sulfur management protocol by searching for efficient and sustainable sulfur sources. Therefore, the efficacy of new sulfur molecules was evaluated on the performance and nutrient acquisition potential of the pearl millet–mustard system at the research farm of the Indian Agricultural Research Institute in New Delhi, India, for two years. The flexibility of urea–ES technology allows customized sulfur-enhanced urea formulations that suit unique crop needs, offering an all-in-one nitrogen and sulfur fertilizer solution. Hence, the study hypothesized that new sulfur molecules like sulfonated urea (SEU) will have a positive impact on crop growth, yield, and nutrient acquisition in the pearl millet–mustard system. The results revealed that the application of 50% sulfur (S) (15 kg/ha) as a base and 50% (15 kg/ha) as a topdressing (SEU 10-0-0-75) produced better growth, yield-contributing parameters, and economic productivity of the pearl millet–mustard system. However, both compositions of SEU (40-0-0-13 and 10-0-0-75) were significantly better than the recommended dose of fertilizer (RDF) and the RDF along with other S sources like single super phosphate and bentonite in enhancing crop growth and productivity. The agronomic efficiency of nitrogen (AEn) and S (Aes) of SEU (40-0-0-13 and 10-0-0-75) were 9.1 and 10.3 kg seed yield/kg N and 51.2 and 28.9 kg seed/kg, respectively. The agronomic nitrogen use efficiency of SEU (40-0-0-13) and SEU (10-0-0-75) is significantly higher than those of nitrogen, phosphorus, and potassium (NPK) alone. Thus, the findings inferred that splitting S (50% as a base and 50% as topdressing) through SEU is a practically feasible and economically robust S option for profitable and sustainable production of the pearl millet–mustard production model in the semi-arid region.

Effect of Plant Spacings on Growth, Physiology, Yield and Fiber Quality Attributes of Cotton Genotypes under Nitrogen Fertilization

Cotton is a major cash crop of Pakistan that provides high foreign exchange and plays an important role in agriculture, industry, and economic development. The plant population is important in achieving high cotton yield and fiber quality attributes in irrigated conditions. Most farmers maintain plant spacing according to their local tradition, and often ignore the varietal characteristics in Pakistan that cause low yield and poor quality of products. Therefore, standardization of plant spacings according to varietal characteristics is important to achieve higher yield and fiber quality. A field experiment was carried out at the Agronomic Research Area, Muhammad Nawaz Shareef University of Agriculture, Multan, Pakistan in 2017, in order to evaluate the performance of four cotton cultivars (MNH-1016, FH-Lalazar, NIAB-878, and Cyto-124) under five plant spacings (15.0, 22.5, 30.0, 37.5, and 45.0 cm), comparing them with and without nitrogen application. Nitrogen fertilization was applied at the rate of 197 kg ha−1. The experiment was replicated thrice, as per Randomized Complete Block Design with factorial arrangements. The results showed that nitrogen application of 197 kg ha−1 showed a positive impact on all crop parameters compared to plots where no nitrogen fertilizer was applied. The wider plant spacing (45 cm) increased the values of many cotton parameters compared with other plant spacings (22.5, 30.0, 37.5 and 45.0 cm), but the seed cotton yield was found to be higher in the narrow plant spacing (15 cm). However, fiber quality parameters such as GOT, staple strength, and micronaire showed higher values under wider plant spacing (45.0 cm). The varieties showed a mixed effect on cotton productivity and fiber quality. The MNH-1016 significantly impacted yield-contributing parameters such as bolls plant−1, boll weight and seed cotton yield. The NIAB-878 showed a higher photosynthetic rate and stomatal conductance compared to other varieties. Therefore, the wider plant spacing with nitrogen application could be a better strategy to increase cotton growth, yield, physiology, and fiber quality. However, long-term studies under different climatic conditions are suggested for wider plant spacing with nitrogen fertilizers.

Exogenous Sodium Nitroprusside Mitigates Salt Stress in Lentil (Lens culinaris Medik.) by Affecting the Growth, Yield, and Biochemical Properties.

Soil salinity disrupts the physiological and biochemical processes of crop plants and ultimately leads to compromising future food security. Sodium nitroprusside (SNP), a contributor to nitric oxide (NO), holds the potential to alleviate abiotic stress effects and boost tolerance in plants, whereas less information is available on its role in salt-stressed lentils. We examined the effect of exogenously applied SNP on salt-stressed lentil plants by monitoring plant growth and yield-related attributes, biochemistry of enzymes (superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD)) amassing of leaf malondialdehyde (MDA) and hydrogen peroxide (H2O2). Salinity stress was induced by NaCl application at concentrations of 50 mM (moderate salinity) and 100 mM (severe salinity), while it was alleviated by SNP application at concentrations of 50 µM and 100 µM. Salinity stress severely inhibited the length of roots and shoots, the relative water content, and the chlorophyll content of the leaves, the number of branches, pods, seeds, seed yield, and biomass per plant. In addition, MDA, H2O2 as well as SOD, CAT, and POD activities were increased with increasing salinity levels. Plants supplemented with SNP (100 µM) showed a significant improvement in the growth- and yield-contributing parameters, especially in plants grown under moderate salinity (50 mM NaCl). Essentially, the application of 100 µM SNP remained effective to rescue lentil plants under moderate salinity by regulating plant growth and biochemical pathways. Thus, the exogenous application of SNP could be developed as a useful strategy for improving the performance of lentil plants in salinity-prone environments.

ASSOCIATION STUDY OF ASSORTEDYIELD LINKED COMPONENTS IN WHEAT CROSSES BY INVOLVING EXOTIC GENOTYPES

In the world, Wheat is produced in an area of about two hundred million hectares. The 80% population is growing wheat in Pakistan. The top wheat producing countries Pakistan stands in 10th number. Biotic and abiotic factors, adverse environmental conditions and decline in cultivation area the wheat production decreasing day by day in Pakistan. For increasing the yield, there is a need to develop new wheat lines. For that motive, the present experiment was planned. F1 generation nine cross combinations (XJ-22×XJ-24, XJ-22×XJ-25, XJ-22×XJ-23, XJ-24×XJ-22, XJ-24×XJ-23, XJ-23×XJ-22, XJ-23×XJ-25, XJ-25×XJ-22, and XJ-25 × XJ-23) were used. The F1 hybrids compared with the local wheat varieties (Faisalabad 2008, Ujala 2016 and Johar 2016). The selected material was grown with three replications under randomized complete block design during typical sowing date in the field zone of Plant Breeding and Genetics in University of Agriculture, Faisalabad. From the genotypes, yield and yield-related traits were collected, and data was analyzed for yield and yield-contributing parameters using variance analysis and correlation. Among crosses difference was detected by analysis of variance. Study of correlation showed that positive correlation between crosses grains per spike and all yielding features such as grain yield per spike, plant height, peduncle length, spike length, spikelets per spike, thousand grain weight, and tillers per plant and yield per plant except for spike density. The superior crosses and wheat lines can be further used to develop new high yielding wheat varieties in order to obtain high wheat production.

Bioefficacy of Some Aqueous Phytoextracts Against Clavibacter Michiganensis Subsp. Michiganensis (Smith), the Cause of Bacterial Canker of Tomato

The ability of some medicinal plants was explored to control bacterial canker of tomato caused by Clavibacter michiganensis subsp. michiganensis. The plants tested included Peganum harmala, Allium sativum, Withania somnifera, Melia azedarach, Calotropis procera, Mentha piperita and Nerium oleander. Aqueous extracts of P. harmala and M. piperita proved to be very effective under in vitro conditions against Clavibacter michiganensis subsp. michiganensis. In in vivo studies, the highest dose of dried powder of P. harmala and M. piperita kg−1 of soil decreased disease severity significantly. Other yield-contributing parameters were also enhanced by the application of dried powder and no phytotoxicity was observed at given concentrations. Alkaloids, tannins, glycosides, flavonoids and saponins were detected in aqueous extracts of P. harmala, W. somnifera, M. azedarach, C. procera and M. piperita. Dried powders of P. harmala and M. piperita could be incorporated as an integral part in the integrated disease management programs against Clavibacter michiganensis subsp. michiganensis.

Impact of salt-induced toxicity on growth and yield-potential of local wheat cultivars: oxidative stress and ion toxicity are among the major determinants of salt-tolerant capacity

High salinity is a major constraint for wheat productivity in many countries, including Bangladesh. Here, we examined the effects of salt-induced toxicity on growth and production of 10 local wheat cultivars by analyzing physiological, biochemical and agronomical responses to identify the salt-tolerant attributes among the contrasting genotypes. Results of cluster analyses based on salt tolerance indices of plant growth-related and yield-contributing parameters, ionic balance (Na+, K+ and Na+/K+ ratio), and stress indicators (SPAD values and proline) revealed Gourab and Shatabdi as salt-sensitive, BARI Gom 27 and 28 as salt-tolerant and the other six examined varieties as moderately salt-tolerant cultivars. Hierarchical clustering and principle component analyses also demonstrated BARI Gom 27 and 28 as the highest salt-tolerant cultivars, especially in terms of Na+/K+ ratio and proline level. Additionally, lower accumulations of hydrogen peroxide and malondialdehyde, and higher activities of antioxidant enzymes catalase, peroxidase and ascorbate peroxidase in the salt-tolerant BARI Gom 28 than in the salt-sensitive Gourab indicated reduced oxidative damage in BARI Gom 28 relative to that in Gourab. Collectively, our findings suggest that the optimum growth and yield of salt-tolerant cultivars are associated with decreased Na+/K+ ratio, increased proline level and reduced oxidative stress. Furthermore, BARI Gom 27 and 28 could be suggested as suitable cultivars for cultivation in salt-affected areas, and the contrasting salt-responsive genotypes can be used as valuable genetic resources in breeding and dissection of molecular mechanisms underlying wheat adaptation to high salinity.

Exogenous Glutathione Modulates Salinity Tolerance of Soybean [Glycine max (L.) Merrill] at Reproductive Stage

In this study, we evaluated salt stress responses of 11 soybean genotypes and explored the protective roles of exogenous glutathione (GSH) against salt toxicity by assessing various biochemical and yield-attributing parameters. Exposure of the soybean genotypes to salt stress at the reproductive (R1) stage significantly decreased their yields by down-regulating the yield-contributing parameters as compared with unstressed controls. The highest decrease was found in number of seeds plant−1, yield plant−1, and number of pods plant−1, whereas the lowest decrease was recorded in number of seeds pod−1. Exogenous GSH was found to be effective in improving salinity tolerance, and the highest positive effects of GSH were recorded in terms of yield plant−1, number of seeds plant−1 and number of pods plant−1, whereas its lowest effect was observed with respect to the 100-seed weight. Cluster analysis of the genotypes based on yield-contributing and yield data revealed different levels of salt tolerance. Notably, BINA-01 and -02, and BINA-04 were recognized as the highest and lowest salt-tolerant genotypes, respectively. Furthermore, exogenous GSH alleviated oxidative stress in the representative contrasting genotypes at the vegetative (V3) stage by decreasing salt-induced accumulation of malondialdehyde and hydrogen peroxide. Taken together, our findings revealed that exogenous GSH application can minimize oxidative stress and contribute to the improvement of yield-contributing parameters, leading to improved yield in soybean genotypes under salt stress. Further investigations on molecular aspects will enable us to gain an in-depth understanding of how exogenous GSH can improve salinity tolerance in soybean, particularly at reproductive stage, to discover relevant pathways for biotechnological manipulation.

Evaluation of Orange Fleshed Sweet Potato (Ipomoea batatas L.) Varieties for Yield and Yield Contributing Parameters in the Humid Tropics of Southwestern Ethiopia

Evaluation of Orange Fleshed Sweet Potato (Ipomoea batatas L.) Varieties for Yield and Yield Contributing Parameters in the Humid Tropics of Southwestern Ethiopia

Agronomic indices, growth, yield-contributing traits, and yield of dry-seeded rice under varying herbicides

Dry-seeded rice (DSR) is an emerging resource-conserving technology in many Asian countries, but weeds remain the major threat to the production of DSR systems. A field study was conducted in 2012 and 2013 at the International Rice Research Institute (IRRI), Los Baños, Philippines, to evaluate the performance of sole and sequential applications of preemergence (oxadiazon and pendimethalin), early postemergence (butachlor+propanil and thiobencarb+2,4-D), and late postemergence herbicides (bispyribac-sodium and fenoxaprop+ethoxysulfuron) with different modes of action in comparison to manual weeding in DSR. The sequential applications of all preemergence and postemergence herbicides reduced weed density and biomass by 80–100% compared to the nontreated plots. The sole application of postemergence herbicides reduced weed density by only 44–54% and weed biomass by 51–61%, whereas oxadiazon alone reduced weed density and biomass by 96–100%. All herbicide treatments and manual weeding significantly affected tiller number, biomass, crop growth rate, agronomic indices, yield-contributing parameters (panicle density and filled grains), and yield (biological and grain) of rice. The highest grain yield was obtained in the manually weeded plots (5.9–6.1tha−1) and the plots treated with oxadiazon alone (5.4–5.6tha−1) and oxadiazon followed by postemergence herbicides (5.2–5.8tha−1). The lowest paddy yield (0.22tha−1) was achieved in the nontreated plots followed by the plots treated with the sole application of bispyribac-sodium and fenoxaprop+ethoxysulfuron. The results suggest that oxadiazon is the best broad-spectrum and economically effective herbicide when applied alone or in combination with other effective postemergence herbicides with different modes of action, depending on the weed species present in the field.

Mild to prolonged stress increased rice tillering and source-to-sink nutrient translocation under SRI management

System of rice intensification (SRI) is a water-saving agro-technique being popularized in Southern Asia including India. A particular key practice in SRI, reduced water application (no continuous flooding), needs to be more farmer-friendly for its mass adoption under traditional and non-traditional cultivation. A field experiment was conducted maintaining different water regimes throughout the crop season (vegetative as well as reproductive stages) by scheduling irrigation applications at 1, 3, or 5 days after disappearance of ponded water (DADPW), using two different plant spacings and two different varieties. With an increase in the period of water stress, tiller production was increased significantly (P ≤ 0.05) and found to be maximum under prolonged stress, i.e., 5 days after disappearance of ponded water (5 DADPW). Increased tiller production did not result in yield increments, but yield-contributing parameters (panicle weight, grain weight per panicle, filled grain percentage, and test weight) were confirmed as critical determinants of yield. Plant nutrient (NPK) uptake was reduced under stress conditions, but the translocation of phosphorus and potassium from sources to sink was increased significantly in this study. Nutrient utilization efficiency was also enhanced under mild (3 DADPW) to prolonged (5 DADPW) water stress conditions. No significant reduction in yield was recorded under mild water stress, and this resulted in increased water productivity; however, significant yield loss was observed under prolonged water stress (5 DADPW).

Crop performance and water- and nitrogen-use efficiencies in dry-seeded rice in response to irrigation and fertilizer amounts in northwest India

Because of increasing constraints of labor and water availability, dry-seeded rice (DSR) is now considered to be a new and emerging rice production system in the northwest Indo-Gangetic Plains of India. However, limited information is available on optimizing nutrient and water management in DSR to produce high yields. The effects of four amounts of N (0, 60, 120, and 180kgha−1) applied with or without P and K fertilizers under two irrigation regimes (10 and 20kPa; irrigated when soil water potential at 15-cm soil depth reached 10 and 20kPa, respectively) were studied on rice yield, and N- and water-use efficiencies. Grain yield with irrigation threshold increasing from 10 to 20kPa did not decrease with the application of P and K fertilizers at 120kgNha−1, leading to substantial savings in irrigation water. At the soil moisture potential of 20kPa, application of P and K fertilizers along with 120kgNha−1 resulted in a 14% increase in rice vis-à-vis when P and K fertilizers were not applied. However, this effect was not observed at the soil moisture potential of 10kPa. Applying P and K fertilizers along with N at 20kPa compared with 10kPa resulted in higher water- and N-use efficiencies. Water-use efficiency was significantly correlated with yield-contributing parameters when P and K were supplied along with N; whereas, without P and K application, water-use efficiency was not correlated with any yield-contributing parameters. It was concluded that, in DSR, the addition of P and K along with N could compensate for the yield loss under water-stress conditions. Our study suggests that there is a need to study the effects of applying different amounts of P and K along with N under a range of water regimes on dry matter partitioning and soil characteristics to understand the mechanism of yield loss in DSR.

Response of Sugarcane to Calcium Silicate on Yield, Gas Exchange Characteristics, Leaf Nutrient Concentrations, and Soil Properties in Two Different Soils

Silicon (Si), applied as calcium silicate (Ca-silicate), was evaluated for effects on yield; yield-contributing parameters in sugarcane, such as chlorophyll content, gas exchange characteristics, moisture content, and leaf nutrient concentrations; and soil fertility in the greenhouse in two different soil types. Seven levels of Si (0 20, 40, 60, 80, 120, and 150 g pot–1) were tested by applying them with traditional fertilizers. Gas exchange characteristics such as photosynthesis, transpiration, and stomatal conductance were significantly greater with the plants fertilized with silicate over unamended control for both soils. Silicate fertilization increased chlorophyll and moisture contents in the top visible dewlap (TVD) leaf tissues, but results were not significantly better in both soils when compared with unamended control. In our 12-month study, we found that the Si content reached up to 2.64% and 1.86% per dry mass in TVD leaf tissues when amended with Ca-silicate fertilizer in soils 1 and 2, respectively. Results showed that as compared to unamended control, Si-amended treatments significantly increased maximum dry matter and cane yield by 77% and 66% in soil 1 and 41% and 15% in soil 2, respectively. With increasing silicate application, iron, copper, zinc, and manganese contents significantly decreased in leaf tissues and soil contents in both soils. Soil pH, Si contents, available sulfur, exchangeable Ca and magnesium, and cation exchange capacity were increased significantly more or less, whereas aluminum contents of soil decreased dramatically in both soils when amended with Ca-silicate. Our results indicate that different soil fertility status and rates of Si application are important factors influencing the yield, growth parameters, chlorophyll, and nutrient contents of sugarcane leaf as well as soil properties.

Effect of cucumber mosaic virus infection on morphology, yield and phenolic contents of tomato

Ten tomato genotypes were screened for their resistance against cucumber mosaic virus (CMV) and its vector Myzus persicae under natural infection in field, using aphids M. persicae under net-house and mechanical inoculation under greenhouse. Large differences were observed among genotypes for infection percentage (IP) and severity index (SI) among the testing methods used. All genotypes showing tolerance to CMV in the field or through aphid inoculation, however, become susceptible and highly susceptible after mechanical inoculation. All the test genotypes also showed susceptibility to the aphid M. persicae population. Plants inoculated with CMV showed substantial decrease in yield and yield-contributing parameters which varied with cultivars that probably depended upon its genetic make up. All the test genotypes exhibited 0.97–30.19% decrease in plant height, 11.47–52.65% decrease in root length, 46.56–95.56% decrease in fresh plant weight, 65.78–92.84% decrease in root fresh weight, 19.97–87.65% decrease in the dry weight of plants, 75.63–95.43% decrease in dry root weight, 69.51–95.65% reduction in the number of fruits and 89.04–99.89% decrease in yield per plants. After 15 days of inoculation, the quantitative analysis using double beam spectrophotometer showed an increase in total phenolics in CMV-inoculated plants as compared to un-inoculated plants among genotypes. Similarly the thin layer chromatography (TLC) on silica gel G indicated that the number of phenolic compounds was increased in most of the inoculated genotypes while in others they were either decreased or remained same.

Estimation of the effect of Tomato spotted wilt virus (TSWV) infection on some yield components of tomato

The effects of Tomato spotted wilt virus (TSWV) on yield and quality of tomato fruits were studied from May through November of 2004 at the Experimental Field of the Agricultural Faculty of Ondokuz Mayis University, in Samsun province, Turkey. TSWV caused 42.1% and 95.5% reduction in yield and marketable value of tomato, respectively. TSWV infection in tomato crop caused significant (P < 0.05) reductions in weight, total number, width and length of the fruits in infected plants. Reductions in yield-contributing parameters were 26.61% in weight, 20.18% in number, 10.94% in width and 11.93% in length of fruits. It is difficult to estimate the actual yield loss and influence levels of TSWV in the field. Economic data are scarce, but in the present study it was estimated that the yield loss due to TSWV in tomatoes was approximately $0.9 million in Samsun, Turkey.

Rice root growth and physiological responses to SRI water management and implications for crop productivity

This paper reports on several research findings on rice root responses, in terms of growth and physiology, manifested when applying System of Rice Intensification water management principles under semi-field and field conditions, in conjunction with variations in plant density and microbial density in the soil. The research aimed to learn about causal relationships, if any, between rice root and shoot growth at different growth stages of the rice plant’s development and their cumulative effect on yield, which is affected by both biotic and abiotic influences. It was seen that greater root length density and a higher rate of root activity affected the yield-contributing parameters in all of the trials, whether conducted under semi-field or field conditions. At the same time, both root parameters were significantly affected by the water regime, soil microbial density, and planting pattern, the three main factors considered. The most important finding observed under semi-field conditions was that enhanced microbial density in the soil improved the sink capacity of the rice plants under all water regimes evaluated. Positive correlations were found between the chlorophyll content of the flag leaf and the duration of grain filling, between the chlorophyll content of plants’ lower leaves and their roots’ oxidizing activity rate, and the roots’ oxidizing activity rate at later growth stage and the available soil nitrogen. These relationships can significantly improve rice plants’ physiological efficiency and hence grain yield, provided that soil nutrients are not a limiting factor and when source–sink demand is maintained simultaneously. To realize the highest crop yield per hectare, both planting pattern and spacing are factors that need to be optimized. This paper in its conclusion considers the relevance of exploiting roots’ potential for plasticity to enhance crop productivity in the context of impending water constraints and climate-change effects.

Effect of Indole Acetic Acid (IAA) on Yield and Yield Contributing Parameters of Soybean

Effect of Indole Acetic Acid (IAA) on Yield and Yield Contributing Parameters of Soybean