Enhancement Of Seed Yield Research Articles

Biochar application affected biochemical properties, yield and nutrient content of safflower under water stress

A two-year field trial was set up to investigate the effects of applying 3 tons ha-1 of wheat (3WB) and cotton biochar (3CB) alone or in combination with chemical nitrogen (N) and phosphorus (P) fertilizers on biochemical properties, yield and nutrient content of safflower under normal irrigation and water stress (irrigation cut-off at flowering stage) conditions. The total water applied in the chemical treatments [150 kg ha−1 N + 50 kg ha−1 P (100% of the recommended dose) and 112.5N + 37.5P (75% of the recommended dose)] under water stress, was significantly higher than other treatments. Application of 112.5N + 37.5P + 3CB increased RWC from 57.5 to 59.4% and the total chlorophyll content from 80.7 to 128.1%, compared to the control. The carotenoid content, catalase and peroxidase in 112.5N + 37.5P + 3CB were lower than chemical fertilizers. Under water stress, the seed yield of 112.5N + 37.5P + 3CB was 10.2–12.6% higher than 112.5N + 37.5P + 3WB. The higher chlorophyll content, RWC, remobilization efficiency and nutrient content in 112.5N + 37.5P + 3CB compared to other treatments was associated with seed yield enhancement. The findings indicate that the combination of CB with 75% recommended dosage of N and P, may be the optimal approach for enhancing safflower production under water stress conditions.

Role of Entomophily and Artificial Pollination in Enhancing Quality and Yield of Seed Onion (Allium cepa L.) in Indian Himalayas

Abstract Onion (Allium cepa L.) is a highly cross pollinated crop that needs insect pollination (entomophily) for optimum seed set. In the present study, more than 120 insect species were noted to visit onion flowers, out of which fifty-nine species were collected through in-situ sampling technique and identified up to species level. The Indian bee (Apis cerana indica) was the most abundant insect pollinator visiting onion flowers in the study location. The pollination behaviour and foraging activity of A. c. indica were assessed, and the pollen foragers were observed to be swift flyers visiting a significantly higher number of flowers per minute during the peak flowering period and spending less time per flower (3 seconds) to collect nectar from deep seated nectaries of the flowers. The seed yield enhancement assessed through entomophily and artificial pollination methods showed that the open pollinated flowers recorded the highest yield statistically, followed by A. c. indica and A. mellifera pollinated flowers. However in artificial pollination treatments, sponge puff pollinated flowers recorded significantly high seed yield per hectare and percentage seed set per umbel, followed by camel brush, hand gloves (cloth) and hand gloves (rubber). In conclusion, all the cross pollination treatments were statistically significant on the closed pollination treatment concerning to the entire yield parameters calculated.

Role of heterosis for photosynthetic traits and sink organs in seed yield enhancement in safflower

Abstract Genetic basis of heterosis has been exploited for yield improvement in safflower (Carthamus tinctorius L.) but little is known about physiological basis of heterosis for yield. The objective of this study was to quantify the physiological basis of heterosis for seed yield in safflower by examining 19 safflower hybrids and their parents for photosynthetic traits, and yield and its components. The results showed that heterosis for yield and its components was high and positive but was low and negative for photosynthetic traits in most of the hybrids studied. There were weak and non-significant relations between photosynthetic traits and yield and its components. Hybrids were more efficient in translocating photoassimilates to two major sink organs viz., number of seeds and number of capitula despite having low net photosynthesis than parents. Seed yield increase in safflower is more sink-than source-limited and was necessary through heterosis for sink organs. Heterosis breeding for larger sink size with parallel increase in effectiveness of sink organs in translocation of photo-assimilates is suggested for yield improvement in safflower.

Mitigating moisture stress in Brassica juncea through deficit irrigation scheduling and hydrogel in ustocherpts soils of semi-arid India

A field experiment was conducted to study the effect of irrigation scheduling and use of superabsorbent polymers on growth, seed and water productivity, soil moisture dynamics in Indian mustard under semi-arid conditions. During the first year of the study, the increase in the mustard seed yield with irrigations applied at IW/CPE (Irrigation water, mm/Cumulative Pan Evaporation, mm (CPU) ratios 0.8, 0.6, 0.4 and no-irrigation (rainfed) with hydrogel application (+HG) was 18.6, 17.9, 14.4 and 28.3%, respectively, over no hydrogel (-HG). The seed yield enhancement by hydrogel application during the second year varied from 3% under sufficient irrigation to 24.9% under rainfed conditions. The pooled data indicated that the production indices and economics with hydrogel use improved significantly (P ≤ 0.05) under limited irrigation or rainfed condition. A net increase of 38, 27.7, and 10.7%, in production efficiency (PE), the net return, and profitability of mustard respectively was observed due to the use of hydrogel improved under the rainfed condition. Under limited irrigation (single irrigation at IW/CPE 0.4), a net increase of 24.2 and 31.8%, in the marginal and gross water productivity of mustard respectively, was recorded with hydrogel use. Similarly, in rainfed conditions, hydrogel increased gross water productivity by 22.6%. The energy intensity under irrigations scheduled at IW/CPE 0.8, 0.6, 0.4, and rainfed condition, was enhanced by 4.9, 5.9, 6.7, and 10.5%, respectively, due to hydrogel application. Thus, the use of hydrogel both under the rainfed condition and deficit irrigation has the potential to enhance productivity, profitability, and bio-energy output of Indian mustard in semi-arid agro-ecologies.

Growth and Nutritional Responses of Bean and Soybean Genotypes to Elevated CO2 in a Controlled Environment.

In the current situation of a constant increase in the atmospheric CO2 concentration, there is a potential risk of decreased nutritional value and food crop quality. Therefore, selecting strong-responsive varieties to elevated CO2 (eCO2) conditions in terms of yield and nutritional quality is an important decision for improving crop productivity under future CO2 conditions. Using bean and soybean varieties of contrasting responses to eCO2 and different origins, we assessed the effects of eCO2 (800 ppm) in a controlled environment on the yield performance and the concentration of protein, fat, and mineral elements in seeds. The range of seed yield responses to eCO2 was −11.0 to 32.7% (average change of 5%) in beans and −23.8 to 39.6% (average change of 7.1%) in soybeans. There was a significant correlation between seed yield enhancement and aboveground biomass, seed number, and pod number per plant. At maturity, eCO2 increased seed protein concentration in beans, while it did not affect soybean. Lipid concentration was not affected by eCO2 in either legume species. Compared with ambient CO2 (aCO2), the concentrations of manganese (Mn), iron (Fe), and potassium (K) decreased significantly, magnesium (Mg) increased, while zinc (Zn), phosphorus (P), and calcium (Ca) were not changed under eCO2 in bean seeds. However, in soybean, Mn and K concentrations decreased significantly, Ca increased, and Zn, Fe, P, and Mg concentrations were not significantly affected by eCO2 conditions. Our results suggest that intraspecific variation in seed yield improvement and reduced sensitivity to mineral losses might be suitable parameters for breeders to begin selecting lines that maximize yield and nutrition under eCO2.

تاثیر سطوح آبیاری، تراکم بوته و نیتروژن بر عملکرد و اجزای عملکرد منداب (Eruca sativa Mill.)

تاثیر سطوح آبیاری، تراکم بوته و نیتروژن بر عملکرد و اجزای عملکرد منداب (Eruca sativa Mill.)

Physio-biochemical basis of iron-sulfide nanoparticle induced growth and seed yield enhancement in B. juncea

Metal nanoparticles have been reported to influence plant growth and productivity. However, the molecular mechanisms underlying the effects have not been completely understood yet. Current work describes the physio-biochemical basis of iron sulfide nanoparticle induced growth and yield enhancement in Brassica juncea. Iron sulfide nanoparticles (0, 2, 4, 6, 8 and 10 ppm) were used for foliar treatment of B. juncea at 30, 45 and 60 days after sowing, under field conditions. Foliar treatment of 4 ppm iron sulfide nanoparticle solution at 30 days after sowing brought maximal enhancement in agronomic attributes of the treated plants. Results of assays i.e. total chlorophyll, electrolyte leakage, Malondialdehyde (MDA), proline, H2O2 and antioxidant enzyme activities indicated the benign effect of iron sulfide nanoparticles on plants. Consequently, improved redox status of the treated plants, enabled them to assimilate higher photosynthate. The augmentation in growth and seed yield in iron sulfide nanoparticle treated plants was amply supported by activation of RUBISCO small subunit (rubisco S), RUBISCO large subunit (rubisco L), glutamine synthetase (gs) and glutamate synthase (gogat) genes. Thus, iron sulfide nanoparticle induced growth and yield enhancement is proposed to be mediated through activation of carbon and nitrogen assimilatory pathways at specific growth stage. The iron content in the leaves and root tissues of the treated plants was also significantly improved.

Wheat Brassinosteroid-Insensitive1 (TaBRI1) Interacts with Members of TaSERK Gene Family and Cause Early Flowering and Seed Yield Enhancement in Arabidopsis.

Brassinosteroids (BRs) hormones are important for plant growth, development and immune responses. They are sensed by the transmembrane receptor kinase Brassinosteroid-Insensitive 1 (BRI1) when they bind to its extracellular Leu-rich repeat (LRR) domain. We cloned and characterized the TaBRI1 from T. aestivum and raised overexpression transgenics in Arabidopsis to decipher its functional role. TaBRI1 protein consists of a putative signal peptide followed by 25 leucine rich repeats (LRR), a transmembrane domain and a C-terminal kinase domain. The analysis determined the interaction of TaBRI1 with five members of the wheat Somatic Embryogenesis Receptor Kinase (TaSERKs) gene family (TaSERK1, TaSERK2, TaSERK3, TaSERK4 and TaSERK5), at the plasma membrane. Furthermore, overexpression of TaBRI1 in Arabidopsis leads to the early flowering, increased silique size and seed yield. Root growth analysis of TaBRI1 overexpressing transgenic plants showed hypersensitivity to epi-brassinolide (epi-BL) hormone in a dose-dependent manner. Interestingly, transgenic Arabidopsis plants show thermotolerance phenotype at the seedling stages as revealed by chlorophyll content, photosystem II activity and membrane stability. The transcriptome profiling on the basis of microarray analysis indicates up-regulation of several genes related to brassinosteroid signaling pathway, abiotic stress response, defense response and transcription factors. These studies predict the possible role of TaBRI1 gene in plant growth and development imparting tolerance to thermal stress.

Crop establishment techniques affect productivity, sustainability, and soil health under mustard-based cropping systems of Indian semi-arid regions

Indian mustard [Brassica juncea (L.) Czern & Coss] is the predominant oilseed crop in semi-arid India, conventionally grown by repeated plowings during the rainy seasons to conserve soil moisture in fallow fields. To evaluate the effect of establishment methods on productivity, soil health and economics of mustard under various cropping systems, a field experiment was conducted for four years from 2009–2010 to 2012–2013 at the Directorate of Rapeseed-Mustard Research, Bharatpur, India. Conventional tillage (CT), reduced tillage (RT), zero tillage (ZT), and permanent furrow irrigated raised beds (FIRB) treatments were evaluated for five mustard-based cropping systems, viz., fallow–mustard, green manure–mustard, brown manure–mustard, cluster bean–mustard, and pearl millet–mustard, in split-plot design with three replications. The variable tillage practices significantly affected seed, stover, and biological yields, production efficiency, and the economics of mustard along with the bulk density and soil organic carbon dynamics. After four years of the experimentation, the highest mustard seed yield was obtained under FIRB (2765kgha−1) which was 23.6% higher over CT. The seed yield obtained under ZT (2533kgha−1) was 17.5% higher over CT. The seed yield recorded under RT was found similar with ZT, but significantly higher over CT due to higher dry matter accumulation, higher translocation efficiency, and greater sink/source potential at the seed filling stage. Among the cropping systems, highest yield was obtained under the green manure-mustard system followed by the cluster bean–mustard system. The seed yield enhancement with the green manure–mustard cropping system was 13.9% over the fallow-mustard system. The highest assimilate supply (0.33gsiliqua−1) was recorded under ZT. Sustainability parameters, including harvest index (0.29), sustainability yield index (0.85), and production efficiency (16.1kgha−1day−1) were also found highest under ZT after four years of the experiment. Soil organic carbon increased to 0.39% and 0.36% in ZT and FIRB, respectively, from 0.26% in CT. A higher mass of soil organic carbon and carbon sequestration potential rate was recorded under ZT. The bulk density under ZT and FIRB decreased over CT. The soil organic carbon, the mass of soil organic carbon, and the carbon sequestration potential rate were highest in the green manure–mustard system. These parameters were similar between the pearl millet–mustard system and fallow-mustard system, indicating that an additional pearl millet crop can be successfully grown without exhausting the soil organic carbon. The net returns, profitability, and the benefit-cost ratio were highest under FIRB, followed by ZT.

Trinexapac‐Ethyl Effects on Red Clover Seed Crops in Diverse Production Environments

Trinexapac‐ethyl (TE) plant growth regulator (PGR) effects on diploid red clover (Trifolium pratense L.) seed production were investigated in two diverse environments, Canterbury (CA), New Zealand (NZ), and Willamette Valley, Oregon (OR). Five TE rate (250 and 500 g a.i. ha−1) and timing [Biologische Bundesanstalt, Bundessortenamt, and CHemische Industrie (BBCH) growth stages 32, 51, 32 + 51] treatments and an untreated control were examined at six on‐farm sites in OR and one experimental site in CA in 2011 and 2012. Seed yield was increased across CA and OR production environments with 500 g ha−1 TE applied at BBCH 32 (15%, CA‐2011; 9%, OR‐2011; 13%, OR‐2012). Split applications of 500 g ha−1 TE (BBCH 32 + 51) improved seed yield by up to 13% in OR but had no effect in CA. Seed weight was generally inversely related to yield; TE treatments that produced the highest yield also had the lowest seed weight and thus did not contribute to TE‐induced yield improvement. Increases in inflorescences m−2 with TE ranged from 26 to 62% in all environments. Coupled with other measured effects of TE on flowering and stem production, these may have been contributing factors to seed yield enhancement by TE. Crop height was consistently reduced by TE across CA and OR environments but aboveground crop biomass was not affected by TE. The timely use of TE PGR is a practice that has broad applicability in red clover seed production across CA and OR environments.

Trinexapac-ethyl rate and application timing effects on seed yield and yield components in tall fescue

Trinexapac-ethyl (TE) has been used for lodging control and seed yield enhancement in several grass seed crop species but little is known about how this plant growth regulator (PGR) performs in tall fescue [Schedonorus arundinaceus (Shreb.) Dumort.]. The objective of this study was to determine how TE application rate and timing influences seed productivity over six diverse lodging environments in Oregon's Willamette Valley. Three field trials were conducted to examine TE effects on seed yield and yield components. Stem length, a key factor in lodging control, was reduced incrementally with increasing TE rate from 17% reduction at 200gTEha−1 to a maximum of 39% reduction at 600gTEha−1. Lodging was consistently reduced by TE but had no effect on above-ground biomass and paniclesm−2. Over environments, TE increased seed yield by an average 40% over the untreated control. However, TE rate or application timing did not differentially affect seed yield across environments. Increases in tall fescue seed yield attributable to TE were the result of increased seed numberm−2 and improved harvest index (HI), but not seed weight. A better understanding of TE-induced seed yield increases will aid in improving use efficiency and economy of this important PGR.

Seed Yield Component Identification and Analysis for Exploiting Recombinative Heterosis in Bottle Gourd

Bottle gourd [Lagenaria siceraria (Molina) Standley] is an important African vegetable, but its production is low due to lack of high-yield varieties. This study was conducted to select parameters on which efforts should be concentrated to improve its performance. Path analysis was performed on 52 open-pollinated accessions of bottle gourd grown in a field experiment to determine how per plant seed yield was directly and indirectly affected by: number of days from sowing to emergence (TE) and to first fruit maturity (FM); number of branches (NB); plant length (PL); number of fruit per plant (NF); fruit weight (FW); number of seed per fruit (NS); 100-seed weight (100-SW); sex ratio (SR); and harvest index (HI). All traits except TE and FM were highly variable (CV ≥ 30%) and suitable for exploiting recombinative heterosis in L. siceraria. Five traits exhibiting high CV were correlated with seed yield and NS, FW, and 100-SW had relatively strong direct effects on seed yield enhancement. Stepwise multiple regression analysis indicated that 89.4% of total variation in per plant seed yield could be explained by variation in NS, FW, and 100-SW; 70.5% could be attributed to variation in NS. About 19% of total variation in seed yield could be explained by variation in FW and 100-SW. Residual effects were relatively high (mean combined value = 0.302), indicating that substantial variation was accounted for by components of SY not analyzed. Path analysis identified fruit weight number of seed per fruit, and 100-seed weight as having the greatest effect on seed yield. The accessions showing the highest values for these parameters (NI106; NI266; NI273; NI283; NI354; NI421) and lowest values (NI180; NI202; NI212; NI215; NI248) should be used as parental genotypes to investigate recombinative heterosis for use in breeding.

Spring‐Applied Nitrogen and Trinexapac‐ethyl Effects on Seed Yield in Perennial Ryegrass and Tall Fescue

Trinexapac‐ethyl (TE) [4‐(cyclopropyl‐α‐hydroxymethylene)‐3,5‐dioxo‐cyclohexanecarboxylic acid ethylester] is a widely used plant growth regulator (PGR) for lodging control and seed yield enhancement in perennial ryegrass (Lolium perenne L.) and tall fescue [Schedonorus phoenix (Scop.) Holub], but little information is available on interaction of this PGR with spring‐applied N. The objective of this study was to determine how spring‐applied N and TE influenced seed production in perennial ryegrass (180 kg N ha−1) and tall fescue (135 kg N ha−1). Field trials were conducted over three harvest years in both crops. Interaction of spring‐applied N and TE were evident for seed yield in all 3 yr in perennial ryegrass and in 2 yr in tall fescue. The combination of spring‐applied N and TE produced the greatest yields among the treatments tested. Averaged over years, the combination of spring‐applied N and TE PGR increased yield over the untreated control (no spring‐applied N and no TE) by 859 kg ha−1 (126%) in perennial ryegrass and by 538 kg ha−1 (75%) in tall fescue. Responses of other seed production characteristics to spring‐applied N and TE were independent of one another. Spring‐applied N consistently increased aboveground dry weight and seed weight of both seed crops. Other characteristics were inconsistently affected or not affected by N or by TE. Spring‐applied N × TE interaction effects in increasing yield were best explained by an increase in seed number per unit area. Perennial ryegrass and tall fescue seed yield is best enhanced by the lodging control agent TE with recommended rates of spring‐applied N.

Influence of Daily Carbon Dioxide Exposure Duration and Root Environment on Soybean Response to Elevated Carbon Dioxide

AbstractLittle is known about effects of daily CO2 enrichment duration and root environment on plant response to elevated CO2. Two experiments were performed with Essex soybean (Glycine max L. Merr.) in open‐top field chambers to address these questions. In one experiment, effects of 12 and 24 h d−1 exposures to double‐ambient CO2 were compared for plants grown in 14 L pots that were either insulated to moderate soil temperature or not insulated. Although never significant statistically, trends at some growth stages suggested that nighttime CO2 enrichment contributed to growth and yield. Plants grew and yielded more in insulated than noninsulated pots, but there were no significant CO2 enrichment × insulation interactions. In the second experiment, response to approximately 1.3, 1.6, and 1.9 times ambient CO2 was compared for plants grown in the ground or 14 L pots. Enhancement of photosynthesis, growth, and yield by CO2 enrichment was similar in pots and in the ground. Linear responses to different CO2 concentrations were significant for all yield components in both root environments, whereas quadratic responses were significant for plants in pots but not for plants in the ground. Tests of proportionality of response for yield components showed no evidence of significant differences between plants in pots and in the ground except weight per 100 seeds. Seed yield enhancement at 1.9 times ambient CO2 was 36% for plants in pots and 33% for plants in the ground. Overall, proportional response of soybean to CO2 enrichment was relatively uniform in spite of large differences in baseline growth and yield.

Irrigation of Soybean Genotypes During Reproductive Ontogeny. I. Agronomic Responses1

Successful irrigation management for soybeans [Glycine max (L.) Merr.] requires a knowledge of the effect of irrigations applied during specific stages of reproductive ontogeny. Eight soybean cultivars, varying in stem growth habit and maturity, were subjected to a factorial set of eight irrigation treatments involving either no irrigation or one irrigation applied at three reproductive stages: R1 to R2 flowering (F), R3 to R5 pod elongation (P), or R5 to R6 seed enlargement (S). The experiment was conducted for 3 years on a Sharpsburg silty clay loam (Typic Argiudoll). An F irrigation had little effect on ultimate seed yield (+20 kg/ha) and for some cultivars actually depressed yield below that of the nonirrigated check. A P irrigation consistently increased seed yield (+379 kg/ha), irrespective of cultivar or year. An S irrigation also enhanced seed yield (+ 384 kg/ha), but the degree of enhancement was inconsistent across years, being influenced by the amount of natural rainfall occurring during the seed enlargement stage. Although a dual F‐P irrigation treatment enhanced seed yield above that for both the nonirrigated check and single F irrigation treatment, the seed yield increase was significantly smaller (+166 kg/ha) than that achieved with a single P irrigation treatment. Soybean maturity was delayed 2 to 6 days with irrigation but the delay was greatest when irrigation was applied late in reproductive ontogeny. This senescence delay lengthened the seed‐fill period and was responsible in part for the seed yield enhancement effected by irrigation. Increases in soybean plant height and lodging were greatest with an F irrigation, intermediate with a P irrigation, and minimal with an S irrigation. Although irrigation effects on seed quality were variable depending on the cnltivar, there was an overall tendency for a P irrigation to improve and an S irrigation to worsen seed quality. An F irrigation had no effect on seed quality. Of the eight cultlvars evaluated, the determinate ‘Elf’ was the most yield responsive to irrigation and was relatively resistant to changes induced by irrigation in plant height, lodging, and seed quality. Based on these data, optimal yield enhancement in irrigated soybean culture can be achieved with the use of short‐stature or lodging‐resistant cultivars irrigated during pod elongation (R3 to R4) and seed enlargement (R5 to R6).