Full Pod Stage Research Articles

Optimizing Nitrogen Input Increased Yield and Efficiency in Maize-Soybean Strip Intercropping System

Optimizing nitrogen (N) fertilizer combination is a crucial measure to maximize yield and production efficiency in a maize-soybean strip intercropping system (MSSI). In this field experiment, six maize/soybean N input combinations (0 kg ha−1, F0; 255/30 kg ha−1, F1; 255/45 kg ha−1, F2; 255/60 kg ha−1, F3; 210/45 kg ha−1, F4; 300/45 kg ha−1, F5) were set in 2022 and 2023. The results indicated that optimizing N combination (maize/soybean, 255/45 kg ha−1) could synergistically increase yield and economic benefits. Path analysis results showed that the grain numbers in maize and soybean emerged as the most critical yield-affecting factors. Compared with F0, F5 showed the highest grain yield during the 2-year experiment, and the net return increased by 86.1% (F1), 133.3% (F2), 87.4% (F3), 104.7% (F4), and 128.3% (F5), respectively. Optimizing N input under F2 and F5 notably enhanced the leaf area index (LAI) of maize at the milk stage (R3) and soybean at the full pod stage (R4). Additionally, optimization of N distribution in maize stems at the tassel stage (VT) and soybean leaves at the initial flowering stage (R1) facilitated increased dry matter and N accumulation at the maturity stage, resulting in final land equivalent ratios (LER) of 1.44 and 1.55, respectively. Our results provide a more valuable field N combination for summer maize planting areas (sandy soil areas) in Huang-Huai-Hai and southern China, thus promoting the wider application of MSSI.

Effects of Different Harvest Stages on Forage Yield and Quality of Soybean Cultivars Grown as Second Crops

In this study, the effect of three different harvesting stages [full bloom stage (R2), full pod stage (R4), and full seed stage (R6)] on forage yield and quality of three soybean (Glycine max (L.) Merr.) cultivars (Adasoy, Derry and Yeşilsoy) were evaluated under Mediterranean climate conditions in Adana, Türkiye in second crop seasons. Plant height, green herbage yield, dry matter yield, crude protein (CP), crude protein yield (CPY), leaf and stem ratio, dry matter intake (DMI), acid detergent fiber (ADF), neutral detergent fiber (NDF), digestible dry matter (DDM) and relative feed value (RFV) were determined. The results showed that the average plant height of three soybean cultivars was 106.5-203.5 cm and green herbage yield was 190 42-603 50 kg ha-1. The highest values were obtained from cv. Derry at R4 and R6 harvest stages. In both years, the highest CPY values were determined from the R6 harvest stages. Obtained ADF, NDF, DMI, DDM, and RFV values were found to be between 32.8-47.1%, 41.1-59.3%, 2.0-3.6%, 52.1-63.3%, 83.0-180.2%, respectively, and the best results were obtained from the R6 harvest stage of cv. Yeşilsoy. According to these results, in second crop conditions, while cv. Derry came to the fore of soybean yield, cv. Yeşilsoy stands out in terms of quality. As a result, it is thought that it is appropriate to harvest soybean in the R6 harvest period, the use of soybean as a green herbage should be expanded and its addition to feed rations can provide positive contributions.

Effects of waterlogging time on growth, physiology and yield of peanut cultivar L14 (Arachis hypogaea)

This study was conducted to evaluate the effects of waterlogging time on growth, physiology and yield of L14 peanut cultivar in the grasshouse of Faculty of Agronomy (Vietnam National University of Agriculture, Ha Noi) in Spring 2020. The experiment was designed as a randomized block design with 2 factors. Factor 1 was irigation regime including CT1: normal irrigation and CT2: waterlogging for 10 weeks and then drainage (soil moisture: 70 - 80%); Factor 2 was the time of waterlogging, including waterlogging at the seedling (3 leaves stage), flowering (25 days after begining of flowering), and full pod stages (65 days after begining of flowering). The results showed that waterlogging reduced both growth and physiological parameters, such as plant height, primary branch length, number of leaves/plant, fresh weight and dry matter, and nodule formation, soil plant analysis development index, and chlorophyll fluorescence efficiency. Only the increased ion leakage indicated the level of waterlogging stress. However, waterlogging at the seedling stage had a great impact on the number of pod per plant, and the pod set rate resulted in a 60.3% reduction in the individual yield of the cultivar L14 compared to the control. Meanwhile, waterlogging at the flowering and full pod stages caused a similar decrease in yield of peanut cultivar L14 ( 31%). Thus, waterlogging at the seedling stage for 10 weeks had the greatest effect on the yield of peanut variety L14.

Effects of Biochar With Inorganic and Organic Fertilizers on Agronomic Traits and Nutrient Absorption of Soybean and Fertility and Microbes in Purple Soil.

Biochar is a kind of organic matter that can be added into the soil as a soil amendment to improve its quality. What are the effects of using biochar on purple soil and soybeans? Can the use of biochar reduce the use of fertilizers? This is our concern. Therefore, we carried out this study. The objectives of our study were to evaluate the effects of biochar, inorganic and organic fertilizer application on plant growth, chlorophyll content, photosynthetic gas exchange, and yield of soybean as well as fertility and microbial community in purple soil, and to appraise the possible reduction rate of inorganic fertilizer under the biochar application. A pot experiment was conducted with three levels of biochar, two levels of inorganic fertilizer, and two levels of organic fertilizer in a randomized complete block. The results indicated that the low rate of biochar together with half rate of inorganic fertilizer and organic fertilizer increased the plant growth of soybean. Meanwhile, the chlorophyll content, root growth, and yield of soybean were increased by 16.61, 197.73, and 96.7%, respectively, with biochar compared with no biochar. The high rate of biochar with half rate of inorganic fertilizer and organic fertilizer can promote the exchange of photosynthetic gas in soybean, and the photosynthetic rate increased by 45.25% compared with the blank control. At the full pod stage, the nitrogen content, phosphorus content, and potassium content of the whole plant under the high rate of biochar were 28.35, 13.65, and 28.78%, respectively, higher than that of the blank control. The application of biochar increased nitrogen, phosphorus, and potassium uptake of soybean. The high rate of biochar with half rate of inorganic fertilizer and organic fertilizer can improve soil nutrient content and soil microbial community. Compared with no biochar treatments, total organic carbon (TOC) increased by 740.28%, and cation exchange capacity (CEC) increased by 54.17%. Phospholipid fatty acid (PLFA) increased by 65.22%, and all kinds of soil microorganisms increased to varying degrees. In conclusion, the application of biochar can reduce the use of organic and inorganic fertilizers, improve the agronomic traits and yield of soybean, and play a positive role in soil nutrients and soil microorganisms.

Grain Yield in Mungbean (Vigna radiata) is Associated with Spatial Distribution of Root Dry Weight and Volume

Root system is an important plant organ affecting yield and the degree of influence of roots on yield in different spatial locations in the soil is different. The aim of this study was to research the spatial distribution characteristics of mung bean root and to analyze the correlation between spatial distribution of root and yield. The roots of mung bean in 0 - 5, 5 - 10, 10 - 15, 15 - 20 and 20 - 25 cm horizontal soil layers and in 0 - 20, 20 - 40, 40 - 60, 60 - 80 and 80 - 100 cm vertical soil layers were collected to analyze spatial distribution characteristics of root volume and root dry weight at full flowering stage and full pod stage. Yield and yield components were measured at maturity. Our study showed that approximately 48.4% - 65.2% of the mung bean root were in 0 - 5 cm horizontal soil layer and about 73.2% - 82.3% were in 0 - 20 cm vertical soil layer. Yield of mung bean exhibited significantly positive correlation with number of pods per plant. The root volume density of mung bean in 20 - 25 cm horizontal soil layer at full flowering stage exhibited significantly positive correlation with yield. These findings could be used to provide scientific basis for cultivating high-yield mung bean varieties with excellent root system.

Responses of Soybean Dry Matter Production, Phosphorus Accumulation, and Seed Yield to Sowing Time under Relay Intercropping with Maize

Soybean production under maize–soybean relay-intercropping system (MSICS) is vulnerable to shading. A study was initiated to investigate the effects of three sowing-times: ST1, 90; ST2, 70; and ST3, 50 days of co-growth period and two phosphorus-rates: P0, 0; and P60, 60 kg P ha−1 on soybean under MSICS. Results revealed that ST3 significantly increased the photosynthetically active radiations, leaf area index, and photosynthetic rate by 72% and 58%, and 61% and 38%, and 6% and 8%, respectively, at full-flowering and full-pod stage of soybean than ST1. Treatment ST3, increased the total dry-matter (TDM) and the highest TDM was reached at full-seed (R6) stage. Similarly, ST3 considerably increased the dry-matter partitioning to pods and seeds, relative to ST1, soybean under ST3 at R6 had 35% and 30% higher pod and seed dry-matter, respectively. Moreover, ST3 exhibited the maximum seed-yield (mean 1829.5 kg ha−1) for both years of this study. Soybean under ST3 with P60 accumulated 38% higher P, and increased the P content in pods and seeds by 36% and 33%, respectively at R6 than ST1. These results imply that by selecting the appropriate sowing-time and phosphorus-rate for soybean, we can increase the TDM and seed-yield of soybean under MSICS.

The Effect of Oregano and Cinnamon Essential Oils on Fermentation Quality and Aerobic Stability of Field Pea Silages.

This study was performed to determine the effect of field pea silages which were the organic acid (OA) alternative of oregano and cinnamon essential oils on fermentation quality and aerobic stability. Whole crop pea was harvested at full pod stage and wilted in the laboratory at the 48 h. The chopped pea was mixed and divided into equal portions allocated to five groups: CON (non-treated), distilled water, denoted as control group; OA group, a mixture of 60% formic acid, 20% sodium formate and 20% water applied at a rate of 5 g/kg fresh forage (Silofarm Liquid, Farmavet); origanum (ORE) group, Origanum onites essential oil at 400 mg/kg fresh forage; cinnamon (CIN) group, cinnamon essential oil at 400 mg/kg fresh forage; origanum+cinnamon (ORECIN) group, a mixture of ORE and CIN applied at an equal rate of 400 mg/kg fresh forage. Cinnamon decreased acetic acid (AA), ammonia nitrogen (NH3-N) and weight loss (WL) at the end of 60 days silage. Crude protein (CP) and dry matter (DM) increased by cinnamon essential oil. Yeasts were not detected in any treatments, including the control, after 7 days of air exposure. The CO2 amount decreased and the formation mold was inhibited in the aerobic period by the addition of cinnamon oil. Oregano did not show a similar effect, but when it was used with cinnamon, it showed synergic effect on AA and during aerobic period, it showed antagonistic effect on mold formation and DM losses. It was found in this study that cinnamon can be an alternative to organic acids.

Timing of N Application Affects Net Primary Production of Soybean with Different Planting Densities

Understanding the relationship between the timing of N fertilizer applications and crop primary production is crucial for achieving high yield and N use efficiency in agriculture. This study investigated the effects of starting-N plus topdressing N applications (as compared to the common practice of all basal application) on soybean photosynthetic capacity under different planting densities. A field experiment was conducted in two growing seasons (2011 and 2012), and the soybean (Glycine max L. Merrill) cultivar was Dongnong 52, three planting densities (20, 25 and 30 plants m−2), and four N fertilizer application patterns (all N fertilizer of 6 g N m−2 as basal fertilizer, all N fertilizer as topdressing at beginning pod stage (R3), 1.8 g N m−2 as basal fertilizer and 4.2 g N m−2 as topdressing at stage R3 and full pod stage (R4), respectively). The results indicated that under the same planting density, compared to applying all N as basal fertilizer, the application of starter-N plus topdressing N substantially reduced the rate of pod abscission, and enhanced leaf area index (LAI) significantly at beginning seed stage (R5) (P<0.05), net assimilation rate (NAR) during stages R4-full seed stage (R6) (P<0.05), contribution rate of post-seed filling assimilate to seed (CPA) (P<0.05), and yield (P<0.05). Applying topdressing N at stage R4 resulted in higher net primary production and yield than applying topdressing N at stage R3. When applying starter-N plus topdressing N at planting density of 25 plants m−2, LAI after stage R5 and NAR after stage R4 were increased by 5.92-16.3% (P<0.05) and 13.7–26.6% (P<0.05) with the planting density of 20 plants m−2, respectively, and yield was 8.46–14.0% (P<0.05) higher than that under 20 plants m−2. When planting density increased to 30 plants m−2, only LAI during stages R4-R5 and NAR during stages R4-R5 increased by applying starter-N plus topdressing N, while the other indexes declined. Overall, results of this study demonstrated that applying starter-N plus topdressing N could significantly enhance soybean photosynthetic capacity after stage R5 at planting density of 25 plants m−2.

Effect of Rhizobium Inoculants and Reproductive Growth Stages on Shoot Biomass and Yield of Soybean (Glycine max (L.) Merril)

The experiment was conducted during the 2012 farming season in the agricultural experimental field of the University for Development Studies, Nyankpala in the Northern Region of Ghana. The objective of the study was to determine the influence of Rhizobium inoculants and growth stages on shoot dry matter and grain yield of soybean. Two levels of inoculation regimes (inoculation (+In) and uninoculation (-In)) were combined with four sampling developmental stages (vegetative stage, flowering stage, pod stage and physiological maturity stage). The experimental design was a 2 x 4 factorial laid out in a Randomized Complete Block Design with eight treatments at four replications. Plants inoculated with Rhizobium and harvested at flowering stage recorded significantly higher fresh and dry shoot matter of 74.2 g and 23.57 g per plant, respectively as compared to plants that were not inoculated and harvested at the physiological maturity stage. The latter recorded the lowest fresh and dry shoot weights of 45.2 g and 15.5 g per plant, respectively. Rhizobium inoculation significantly increased grain yield (1262 kg/ha) compared to the yield obtained in the uninoculated treatments (1044 kg/ha). Grain yield positively correlated with plant height, plant stand, canopy spread, number and weight of nodules, number and weight of pods. From the results, it is recommended that soybean seeds should be inoculated with Rhizobium before planting in order to obtain higher grain yields. It is also recommended that for higher nodule numbers, which can be a good indication of higher N2 fixation if the nodules are effective, and higher shoot biomass which is required for effective green manuring, soybean should be harvested at full pod stage.

Evaluation of Forage Yield and Quality in Wild Soybeans (Glycine soja Sieb. and Zucc.)

Wild soybeans (Glycine soja Sieb. & Zucc.) are generally higher in protein and lower in oil with potential advantages as forage than cultivated soybeans. This study was conducted to evaluate forage yield and quality of wild soybeans. Three wild soybeans were compared to three cultivated soybeans for forage yield and quality at the full bloom stage, full pod stage, and full seed stage (R6) of development. The wild soybeans had significantly lower forage yield than cultivated soybeans at R6 which was determined to be the best stage to harvest based on forage quantity and quality. Wild soybean also had lower crude fat (2.0%) and crude protein (17.7%) concentration than cultivated soybean (5.7 and 21.3%, respectively) at the R6 stage. There were no significant differences for neutral detergent fiber, acid detergent fiber and relative feed value among growth stages between cultivated and wild soybean. The neutral detergent fiber was 40.2 and 40.4%, acid detergent fiber was 26.1% and 27.5%, and relative feed value was 161 and 158 at R6 stage for cultivated and wild soybean, respectively. Wild soybean had less forage yield at harvest time but had similar forage quality comparable to cultivated soybean. However, wild soybeans have smaller and softer stems for potentially improved palatability and feed intake than cultivated soybeans. Therefore, it will be a good genetic source to improve forage characteristics of soybean.

Screening and diversity of plant growth promoting endophytic bacteria from peanut

In order to study potential abilities to promote the growth of the plants and population diversity of endophytic bacteria in peanut plant at four different growth stages, 94 endophytic bacteria strains were isolated. Result indicate that numbers of endophytic bacteria of different growth stages ranged from 2.6 to 7.1×104 cfu/g FW with the maximum presented at the full pod stage. Based on 16S- restriction fragment length polymorphism (RFLP) and 16S rDNA sequences, these 94 strains were identified as 14 genera among which Bacillus and Pantoea were the dominant genera. The genus of the endophytic bacteria varied tremendously during annual growth period with the highest species richness at the full pod stage. Of the 15 antibacterial strains for the five phytopathogenic fungi, 12 strains were known to express antimicrobial activity againstFusarium solani, Colletotrichum gloeosporioides, Botrytis cinerea Pers andPseudoperonospora cubensis, but only three against Sclerotium rolfsii. Bacillus was dominant of these antibacterial strains. Among the 48 indole acetic acid (IAA) producing strains, Pantoea agglomerans, Bacillus megaterium and Enterobacter asburiae were remarkable for their high levels of IAA production and only three siderophore-producing bacteria were isolated which belong to Pseudomonas spp. At the same time, growth-promoting effects of three strains (Y21, F10 and H2) were proved by treatment of peanut seedling with bacterial supernatants. This study revealed the diversity of endophytic bacteria in peanuts at different growth stages. The obtained isolates have potential applications as inoculants that can adapt to poor soils and peanut. Basis is also provided for the manufacture of a multifunction bacterium agent. Key words: Peanut, endophytic bacteria, growth-promoting, antifungal activity

Planting Soybean With A Grain Drill Inconsistently Increases Yield And Profit

Growers can plant soybean [Glycine max (L.) Merr.] with a grain drill or row crop planter, which can affect seed and weed control costs and yield. Farmers planted soybean with a drill in 0.19‐m rows and row crop planter in 0.38‐ and 0.76‐m rows at two seeding rates (420,000 and 321,000 seeds ha−1) in two field‐scale studies in New York to obtain agronomic information and conduct partial budget analyses to aid in future planter selection and purchase decisions. Soybean intercepted more light at flowering in 0.19 (65–70%) compared with 0.76‐m rows (50–55%), despite lower early plant establishment (∼70 and ∼85%, respectively) at both locations. At a no‐till location, 0.76‐m rows compared with narrower rows had greater weed density at full pod stage (19.7 vs. 6.3 and 5.1 weeds m−2) and weed biomass at harvest (13.7 vs. 6.6 and 7.3 g m−2, respectively) but similar yield (∼3.30 Mg ha−1). At a chisel tillage location, soybean in 0.19‐m rows at the recommended 420,000 seeds ha−1 yielded 4% more (4.27 Mg ha−1) than in 0.76‐m rows at the recommended 321,000 seeds ha−1 (4.11 Mg ha−1). Partial budget analyses indicated that soybean in 0.19‐m rows at 420,000 seeds ha−1 had ∼$30 ha−1 greater profit compared with 0.76‐m rows at 321,000 seeds ha−1. Partial budget analyses indicated that at present prices the 4% yield advantage offset purchasing and owning costs of a new drill and added seed costs, if planting 250 and 500 ha of soybean.

Seasonal allocation of photosynthetically fixed carbon to the soybean-grown Mollisols in Northeast China

The knowledge of the contribution of carbon (C) released by growing roots to soil is essential to better understand the terrestrial C cycling and optimally manage soil organic matter in ecosystems. However, little information has been gained on quantifying the distribution of photosynthetically fixed C in the plant–soil system and its contribution to soil C over a growing season in soybean-grown Mollisols, the main soil type in Northeast China. In a pulse-chase labelling experiment, soybean plants grown in Mollisols were labelled with 13CO2 at various growth stages. More than 3/4 of fixed 13C was observed in shoots at Day 0 after labelling, and then the fixed 13C was continually exported from shoots, showing that 7.5% of 13C fixed at V4 (fourth node) and 71.1% at R6 (full seed stage) remained in shoots by the end of the growing season. The 13C recovery in roots decreased over the same period, while soil 13C was significantly increased. The allocation of 13C fixed at different growth stages to underground (roots and soil) varied at the end of the growing season, showing that 13C retained in roots and soil was 6.0 and 12.4% of the net assimilation at V4, compared with 1.4 and 2.1% of that at R6, respectively. Nodules, however, had the highest demand for C at R4 (full pod stage). The contribution of shoot C assimilation to the soil C pool was similar at the growth stages up to R5 before a sharp decrease at R6, and the cumulative contribution reached 93% at R5. Over the whole growing season, it was estimated that ~210 kg of photosynthetically fixed C per ha was accumulated in soil. This indicates that the C flow from soybean plants to soil during growth is a non-negligible source of C pool in Mollisols, and the majority of the C efflux occurs during V4–R5.

Effects of Feeding Forage Soybean Silage on Milk Production, Nutrient Digestion, and Ruminal Fermentation of Lactating Dairy Cows

The objective of this study was to determine the feeding value of forage soybean silage (SS) for dairy cows relative to a fourth-cut alfalfa silage (AS). Forage soybean was harvested at full pod stage. Two isonitrogenous diets were formulated with a 48:52 forage:concentrate ratio. Soybean silage and AS constituted 72% of the forage in each diet, with corn silage constituting the remaining 28%. Twenty Holsteins cows in early lactation were used in a switchback design. Four lactating Holsteins cows fitted with ruminal cannulas were used to determine the effects of dietary treatments on ruminal fermentation parameters and in vivo total tract nutrient utilization. Relative to AS, SS contained 15, 28, and 25% more neutral detergent fiber, acid detergent fiber, and crude protein, respectively. Dry matter intake (23.5 vs. 25.1 kg/d) and milk yield (35.5 vs. 37.2 kg/d) were lower for cows fed SS than for those fed AS. However, energy-corrected milk and milk efficiency were similar for both dietary treatments. Milk protein, lactose, and total solids concentrations were not influenced by dietary treatments (average 3.0, 4.7, and 12.6%, respectively). However, cows fed SS produced milk with greater milk fat (3.8 vs. 3.6%) and milk urea nitrogen concentrations (15.6 vs. 14.3 mg/dL) compared with cows fed AS. Ruminal pH was lower, whereas ruminal NH3-N concentration was greater in cows fed SS than in cows fed AS. Total tract digestibilities of dry matter, crude protein, and neutral detergent fiber were not influenced by silage type. We concluded that forage SS, when compared with AS, had a negative impact on feed intake and milk yield, whereas energy-corrected milk, milk efficiency, and total tract nutrient digestion were similar.

Short communication. Harvest stage effects on forage yield and quality for rape and turnip genotypes

The effects of two different harvest stages (full flowering and full podding) on forage yield and quality of ten forage rape (Brassica napus L. var. oleifera) and three turnip (Brassica rapa L. var. rapa) cultivars were evaluated under rainfed conditions in a Mediterranean type climate at Bursa, Turkey, during the 2002/2003 and 2003/2004 growing seasons. Plant height, branches per plant, leaf length and width, plant part components, and dry matter (DM) and crude protein (CP) yield were measured. Significant differences were observed for the main effects cultivar and harvest stage on DM and protein yields. The CP content of the whole plant and vegetative parts of the Brassica genotypes decreased as plant maturity progressed. In general, turnip cultivars showed better performance in DM yield. Fall sown turnip produced 9.10 and 12.1 Mg/ha DM yield, with 15.1 and 9.10% CP concentrations, at full flowering and at podding stage, respectively. Significant differences were noted among cultivars for these two parameters. Protein content decreased dramatically in stem parts when maturity advanced from full flower to full pod stages. High leaf percentage and high protein content at full flowering suggest that this should be the preferred forage harvest stage for rape and turnip cultivars.

Phosphorus Application Affects the Soybean Root Response to Water Deficit at the Initial Flowering and Full Pod Stages

Application of phosphorus (P) fertilizer is an important factor for improving the tolerance to water deficit in many plants. A pot experiment was conducted to identify the effects of P application on soybean adaptability to water deficit at the R1 (initial flowering) and R4 (full pod) stages through the investigation of root morphological traits, plant P uptake and resultant yield in two soybean (Glycine max L. Merrill) cultivars (Dongnong 46 and Heisheng 101). The four levels of P application were 0, 7.3, 14.6 and 29.2 mg kg−2, respectively. The three water treatments were (1) 65–75% of field water capacity (FWC) as a well-watered control, (2) 30–40% of FWC at the R1 stage, and (3) 30–40% of FWC at the R4 stage. Root traits, plant uptake of P and yield were significantly reduced by water deficiency at different growth stages, especially at the R4 stage. Application of P enabled to alleviate the adverse effects of water deficit, to increase the root dry weight, root length and root surface area, and to slow root senescence after the R5 (initial pod filling) stage. The response of soybean genotypes to both water and P deficit was different. In the absence of P application, Dongnong 46 showed relatively low adaptability to water deficit at the R4 stage, whereas Heisheng 101 showed a lower reduction of root traits and yield. The beneficial effects of P application for Dongnong 46 were more pronounced than those for Heisheng 101. Based on this experiment, we suggested that P fertilizer application to soybean may be justified in low-rainfall years because of its ability to enhance the soybean adaptability to water deficit stress by improving the root morphology, P uptake and consequently yield.

Field Response of Soybean to Nodulation by a Rhizobitoxine‐Producing Strain of Bradyrhizobium

AbstractNodulation by rhizobitoxine‐producing (RT+) strains of Bradyrhizobium japonicum has been shown to decrease shoot growth of green‐house‐grown soybeans. The potential impact of nodulation by a RT+ strain on the productivity of field‐grown soybeans has not been determined. Therefore, a field experiment was conducted for 2 yr on a Matapeake silt loam (fine‐silty, mixed, mesic Typic Hapludults) to determine the response of soybean cv. ‘Forrest’ to nodulation by one RT+ strain (USDA 94). Inoculation treatments were (i) USDA 94, (ii) a mixture of bradyrhizobia indigenous to the field site (Control), and (iii) a combination of Treatments 1 and 2 (USDA 94/Soil). Inoculation treatments were applied to the seed and the seedlings were grown for about 21 d under greenhouse conditions. Pre‐nodulated seedlings were transplanted to 1.8‐m2 field microplots. Inoculation with USDA 94 reduced plant N derived from fixation (as measured by isotope dilution) by 43% relative to the Control (2‐yr mean). Inoculation with USDA 94 decreased seed yield by 38%. Yield reductions were associated with reductions in pod number. The USDA 94 inoculation decreased vegetative growth, delayed the onset of full pod, beginning seed and full seed stages, and doubled the interval between beginning pod and full pod stages. For most of the parameters measured, USDA 94 and USDA 94/Soil treatments produced similar results. This research demonstrated that nodulation by USDA 94 can significantly alter shoot growth and reduce seed yield of field‐grown soybeans.

Comparative yield and chemical composition of soybean and fababean grown on chernozemic soils on the Canadian prairies

Abstract Soybean (Glycine max (L.) Merrill) and fababean (Vicar faba (L.)) were grown under field conditions on six Orthic Black Chernozemic soils over three years at two levels of fertility. At flowering, full pod and maturity the yield and N, P, K and S composition of harvested plant materials were compared. Application of fertilizer (P, K and S) increased dry matter and seed yields of both crops. At all, growth stages fababeans produced more dry matter than soybean, and at maturity produced higher yields of seed, hull and stalk. However, the ratio of seed: hull: stalk for both crops was similar and constant at 3.8: 1: 4.7 on all soils and at both levels of soil fertility. At the high level of soil fertility, at the flowering and full pod stages, the concentration of N, P, and K in fababean was higher than that in soybean, but both crops had a similar concentration of S. At low fertility both crops had similar concentrations of P, K and S. At maturity, soybean seed had the higher concentrations of the f...

Heliothis virescens y Etiella zinckenella capturados en trampas lumínicas en gandulares

En 1934, 1985 y 1986 se hicieron estudios con trampas lumínicas para establecer preliminarmente si había Heliothis virescens y Etiella zinckenella en las diferentes etapas de desarrollo del gandúl (floración y formación de la vaina). Se sembraron las variedades Kaki y 2B-Bushy. Los resultados indican que H. virescens es más predominante que E. zinckenella. Aunque ambas especies se detectaron en la etapa de florecida, H. virescens se capturó en mayor número durante las etapas de floración y formación de la vaina. Los adultos de E. zinckenella se capturaron en mayor número cuando las vainas estaban ya maduras alcanzando su número máximo durante la etapa de vainas secas. Ambas especies de barrenadores se capturaron en gran número durante la época de cosecha (vainas verdes). Se sugiere una posible sobreposición de generaciones de ambas especies coincidiendo con una mayor abundancia en la cosecha y una sincronía de los ciclos de vida de estos insectos con la fenología del cultivo.

Effects of Crop Maturity, Weather Conditions and Cutting Height on Yield, Harvesting Losses and Nutritive Value of Cereal–Legume Mixtures Grown for Hay Production

SUMMARYThe introduction of forage or hay crops into fallow land represents a means of increasing feed supplies for small ruminants in north Africa and west Asia. Such fallows lie between zones planted with food crops and traditional grazing areas. Mixtures of vetch with barley, oats or triticale, and peas with barley, were cut at the 10% flowering, 100% flowering (100F) and full pod (FP) stages of the legume component. Effects of crop maturity, weather conditions and cutting height on yield, the chemical composition of the standing crop and re-growth were measured. Barley–vetch mixtures yielded 8147 kg dry matter ha−1 of standing crop at the FP stage in 1983 but only 2283 kg dry matter ha−1 in 1984 under drought conditions. Hay yields were 4377 and 1640 kg dry matter ha−1, respectively. The highest yielding mixture, grown in 1983, was oat–vetch which yielded 8670 kg dry matter ha−1 of standing crop and 4285 kg dry matter ha−1 of hay at the FP stage. Cutting at the 100F or FP stage maximized dry matter yield and minimized the risk of rainfall prolonging hay making. Rain caused slight damage to some hays cut at early stages of maturity. Voluntary intakes and digestibilities of field-cured hays were determined. The voluntary intakes of triticale–vetch hay at the FP stage and all barley–pea hays were low compared with other hays. Hays contained sufficient estimated metabolizable energy (ME) for use in sheep diets during pregnancy and middle or late lactation. ME values averaged 9.2 megajoules per kg dry matter in both 1983 and 1984.