Seed longevity and fire: post‐germination responses of Rumex acetosella L. in northwest Patagonian grasslands (Argentina)

The cosmopolitan herb Rumex acetosella forms persistent soil seed banks and increases in cover after fire. We investigated how the interaction between seed age and fire affects seedling growth by exposing different‐aged seeds to heat, smoke, charcoal, and ash treatments. We measured growth of germinated seedlings that were transplanted and allowed to grow for 65 days in a greenhouse. Seedlings from seeds >8 years old did not reach an appropriate radicle length for transplantation. Seedling growth decreased with increasing temperature of the heat treatment. As seed age increased, growth decreased with smoke and charcoal, and increased with ash treatment. Height was negatively correlated with seed age. Our results suggest that fire and seed age could affect demographic responses of R. acetosella seedling populations. Post‐fire recruitment could be partially favored by the positive effect of nutrient input from ash on seedling growth. High fire intensities, however, would be detrimental to seedling vigor.     

The Effect of Bamboo Charcoal Application on Soil Nutrients and Heavy Metals in Rice

Soil heavy metal pollution is becoming more and more serious. Biomass charcoal application can play an important role in alleviating the toxicity of heavy metals in soils. Compared with other biochar, bamboo charcoal has more unique properties and may have a unique effect on heavy metal pollution. Zhejiang Province of Southeastern China is rich in bamboo resources. However, few studies related to bamboo charcoal application for heavy metal remediation in farmland were reported. In this study, four treatments with different amounts of bamboo charcoal application were set up through a field experiment, namely BC0 (no bamboo charcoal application), BC1 (2500 kg⋅ha⁻¹), BC2 (5000 kg⋅ha⁻¹), and BC3 (10000 kg⋅ha⁻¹), and each treatment was replicated three times. The results showed that (1) The application of bamboo charcoal significantly increased the soil pH and organic matter content. Compared with BC0, the pH and organic content of BC3 increased by 7.4% and 17.4% (P < 0.05) respectively. (2) The HCl-extractable Cd content of paddy soil in the BC1 treatment was significantly lower than other treatments (P < 0.05), and decreased by 15.3%, compared with BC0. The soil HCl-extractable Zn and Cu content did not differ significantly between treatments (P > 0.05). (3) With the increase of bamboo charcoal application, the Cd content in rice gradually decreased, the BC3 treatment significantly decreased by 39.0% (P < 0.05), and the Zn and Cu contents in rice did not differ significantly between treatments (P > 0.05), compared with BC0. (4) Soil pH, organic matter and Cd in rice seeds were significantly negatively correlated (P < 0.01). The heavy metal content in rice does not change with the change of heavy metal content with HCl-extractable state in soil. It means bamboo charcoal does not reduce heavy metal content in rice by simply declining the heavy metal content with HCl-extractable state. The mechanism of action is relatively complicated, and further study is needed.     

Seed germination and seedling physiology of Larix kaempferi and Pinus densiflora in seedbeds with charcoal and elevated CO2

We investigated the effect of ectomycorrhizal colonization, charcoal and CO₂ levels on the germination of seeds of Larix kaempferi and Pinus densiflora, and also their subsequent physiological activity and growth. The seeds were sown in brown forest soil or brown forest soil mixed with charcoal, at ambient CO₂ (360 μmol mol⁻¹) or elevated CO₂ (720 μmol mol⁻¹), with or without ectomycorrhiza. The proportions of both conifer seeds that germinated in forest soil mixed with charcoal were significantly greater than for seeds sown in forest soil grown at each CO₂ level (P < 0.05; t-test). However, the ectomycorrhizal colonization rate of each species grown in brown forest soil mixed with charcoal was significantly lower than in forest soil at each CO₂ treatment [CO₂] (P < 0.01; t-test). The phosphorus concentrations in needles of each seedling colonized with ectomycorrhiza and grown in forest soil were greater than in nonectomycorrhizal seedlings at each CO₂ level, especially for L. kaempferi seedlings (P < 0.05; t-test), but the concentrations in seedlings grown in brown forest soil mixed with charcoal were not increased at any CO₂ level. Moreover, the maximum net photosynthetic rate of each seedling for light and CO₂ saturation (P _max) increased when the seedlings were grown with ectomycorrhiza at 720 μmol mol⁻¹ [CO₂]. Ectomycorrhizal colonization led to an increase in the stem diameter of each species grown in each soil treatment at each CO₂ level. However, charcoal slowed the initial growth of both species of seedling, constraining ectomycorrhizal development. These results indicate that charcoal strongly assists seed germination and physiological activity.     

Aggregation and mortality of Agriotes obscurus (Coleoptera: Elateridae) at insecticide-treated trap crops of wheat

Agriotes obscurus (L.) wireworms assembled in increasing numbers at rows of treated (Agrox DL Plus seed treatment) and untreated wheat, Triticum aestivum L., planted at increasing densities (0, 0.15, 0.30, and 0.60 seeds/cm). In treated wheat plots at all planting densities, no wireworm damage to seedlings was apparent, and total wireworms taken in core samples in wheat rows increased according to the asymptotic equation y = B0(1 -e(-Blx)), where B0 is the asymptote, B1 is the slope of the initial rise, and x is the seeding density. The number of dead wireworms in treated plots increased linearly and intercepted the asymptotic models (theoretical point at which 100% mortality of assembled population occurs) at 0.95 seeds/cm on 11 June and 1.14 seeds/cm on 18 June 1996. Untreated wheat at all densities planted had severe wireworm damage and significantly reduced stand. Populations that had assembled at the surviving untreated wheat were fewer than in the treated wheat plots, and although increasing with seeding density, did not follow the asymptotic model. The data suggest that A. obscurus populations can be assembled and killed in fallowed fields in large numbers at treated trap crops of wheat over a 19-d period when planted in rows spaced 1 m apart at a linear seeding density of 1.5 seeds/cm.     

The effect of water potential on soil-borne diseases of wheat seedlings

Under glasshouse conditions, Fusarium culmorum caused more injury to wheat seedlings in soil at 33% saturation (approximately – 1 bar) than at 66% (–0·1 bar). The same effect occurred with inoculated seeds raised on soil moisture tension tables at –0·1 and –0·5 bar, at 20° and at 15°C. In controls, spontaneous infection by soil-borne F. culmorum was unaffected by soil water potential. Inoculated F. nivale, at 127deg; and at 15°C, showed a similar, but smaller, effect to that with inoculated F. culmorum. Water potential in this range did not affect disease incidence with inoculated Gaeumannomyces graminis, but disease was more severe in the drier soil. On tension tables, seedlings did not consistently develop faster under wetter conditions, and factors other than host growth rate probably played a part in limiting fungal attack.     

Consumption of wheat seed reserves during germination and early growth as affected by soil water potential

Seed size and weight are important criteria for determining seedling vigour and stand establishment. Evolution of seed dry weight of wheat (Triticum aestivum L.) during germination and early growth was examined because poor stands are often associated with the depletion and exhaustion of seed reserves. Two laboratory experiments were conducted on filter paper and in soil at three water potentials using wheat seeds. Seed, root, and shoot dry weights were recorded at approximately one-day intervals. Coleoptile and first leaf lengths were also measured at all sampling periods. Wheat seedlings grown on filter paper in the dark grew to a length of 90 to 100 mm with 50% of the initial seed weight remaining after eight days when the experiment was terminated. In soil, wheat seedlings grew 15 mm with 25% of the initial seed weight remaining. Seed reserves were depleted more quickly when the soil was wet because seedlings grew more quickly. There were significant and similar negative relationships between seed weight and coleoptile length of wheat seedlings grown on filter paper and in soil. There was no effect of soil water potential on the relationship between seed weight and shoot length. Therefore, it was concluded that poor wheat stands are not likely to occur due to depletion of seed reserves under field conditions without mechanical obstacles.     

Wheat bulb fly, Leptohylemyia coarctata Fall., and its effect on the growth and yield of wheat

In two experiments done in successive years to compare the growth and yield of Cappelle wheat either protected from or exposed to attacks by larvae of wheat bulb fly, the plots were previously fallowed, but egg laying was prevented on half of each plot by using Polythene soil covers. In the first season wheat was sown at the end of October, November and December and in the second season in late October and in early January, when there were two sowings, one with and one without a spring application of herbicide. The infestation rate was 1·1-1·7 million eggs per acre, typical of a moderate attack. Larvae had little effect on the yield of October-sown wheat as the plants had two shoots each when first attacked and few were killed. On plots sown late, yield was decreased by up to 22%, as plants had only a single shoot when attacked and many were killed. The main effect of wheat bulb fly was to reduce the number of ear-bearing shoots by killing plants and restricting the production of new shoots. Surviving plants partially compensated by producing more ear-bearing shoots with heavier ears and slightly heavier seeds than normal. Killed plants were not distributed uniformly but were often in patches several feet across. Wheat on the attacked plots ripened more slowly and unevenly than on the unattacked plots. Weather affects the growth of the plants and activity of the larvae and thus partly determines percentage shoot survival.     

镁、锰、活性炭和石灰及其交互作用对小麦镉吸收的影响

采用盆栽试验,研究了在镉污染土壤上施用石灰、硫酸镁、硫酸锰和活性炭不同用量以及交互作用对小麦生长和吸收重金属镉的影响.研究结果表明,在试验条件下施用适量的硫酸镁、硫酸锰或与石灰配合能明显提高小麦籽粒产量,单施石灰或与活性炭配合施用降低了小麦籽粒产量;与对照(CK)相比,所有处理秸秆产量均下降.施用硫酸镁能显著降低小麦籽粒和秸秆中Cd浓度,且随用量的增加两增大.低量硫酸锰能有效降低小麦籽粒和秸秆中Cd浓度,高量反而增加小麦对Cd的吸收.石灰、活性炭单独施用或配合施用都能明显减少小麦对Cd的吸收,但籽/杆中Cd比却随石灰用量的增加呈明显的上升趋势.叶面喷施硫酸镁对降低小麦吸收镉的效果与土施相当,但叶面喷施硫酸锰却比土施硫酸锰显著降低了小麦籽粒中的镉浓度与吸收量.硫酸镁与硫酸锰,或石灰、硫酸镁和硫酸锰3种物质配合施用,对小麦籽粒镉浓度和吸收量的降低表现出明显的正交互作用,对抑制小麦体内镉从秸秆向籽粒的转移具有显著效果.     

Seed longevity and fire: germination responses of an exotic perennial herb in NW Patagonian grasslands (Argentina)

Fire affects grassland composition by selectively influencing recruitment. Some exotic species can increase their abundance as a consequence of fire-stimulated seed germination, but response may depend on seed age. Rumex acetosella L. (Polygonaceae, sheep's sorrel) is a cosmopolitan herb that has invaded NW Patagonia's grasslands. This species forms persistent soil seed banks and increases after disturbances, particularly fire. We studied how fire and seed longevity influence R. acetosella germination. In 2008, we conducted laboratory experiments where we exposed different-aged seeds (up to 19 years old) to heat, smoke, charcoal, ash and control treatments. Total percentage germination and mean germination time depended on both seed age and fire treatment. Germination of younger seeds decreased with increasing temperature. There was no general pattern in germination responses of different-aged seeds to smoke, charcoal and ash. While smoke improved the germination of fresh seeds, charcoal decreased germination. Germination of untreated seeds was negatively correlated with seed age, and mean germination time increased with seed age. In most treatments, fresh seeds had lower germination than 1-5-year-old seeds, indicating an after-ripening requirement. Smoke stimulates R. acetosella germination, causing successful recruitment during post-fire conditions. Fresh seeds are particularly responsive to fire factors, possibly because they have not experienced physical degradation and are more receptive to environmental stimuli. Knowing the colonisation potential from the soil seed bank of this species during post-fire conditions will allow us to predict their impact on native communities.     

The root activity of cereals and peas when grown in pure stands and mixtures

Lithium was used as a non-radioactive tracer to investigate the root activity of two cereals (wheat and barley), and of two contrasting cultivars of pea (leafy and semi-leafless), both in pure stands and in mixtures. The mixtures included combinations of each cereal with each pea cultivar in single rows, alternative rows and cross-drilled. Total lithium uptake (mg m^-2) was higher for wheat than for barley, and higher for semi-leafless pea than for leafy peas. Growing cereals with peas reduced the total lithium uptake by peas, compared with pure stands, especially in alternate-row mixtures. Growing peas with cereals only reduced the total Li uptake by cereals when they were cross-drilled. The Li uptake by wheat, barley and peas generally decreased with soil depth in a similar manner; however, semi-leafless peas absorbed proportionately more Li from close to the soil surface than did leafy peas. Both pea cultivars absorbed more Li at 10–20 cm depth when grown in intimate mixtures with cereals, compared with less intimate mixtures or pure stands. The potential of lithium as a non-radioactive tracer in mixed-cropping studies is briefly discussed.     

The parasitism of Striga hermonthica Benth. on Sorghum spp. under irrigation: I. Preliminary results and the effect of heavy and light irrigation on Striga attack

Investigations were carried out at the Gezira Research Farm in the Anglo-Egyptian Sudan. The greater majority of the seeds of Striga hermonthica can only be germinated by excretions from roots of certain plants not all of which can act as hosts for this parasite. Unless it becomes attached to a host plant, the Striga seedling dies. The growing of those plants whose roots can stimulate the germination of Striga seed but cannot be parasitized by it, may be a means of ridding infested land of this parasite. Green ovaries picked from flowering plants produce viable seeds if left to dry. Sorghum is sown in the field during the rainy season, viz. June to October: the earlier the sowing date within this period the greater is the Striga attack. In the field Striga seeds are distributed in the soil to a depth of at least 15 in. When Striga seeds are evenly distributed through the soil, the number of Striga seedlings attached to a sorghum root is proportional to the root's development. Size of sorghum seed has no effect on the root size of a sorghum plant and consequently no effect on the degree of parasitism. The effect of severe Striga attack on the sorghum plant is to produce a reduction of about 60% in leaf and root weight. No reduction of Striga attack is obtained when various micro-elements are coated on sorghum seeds before sowing. Field and laboratory experiments show that light irrigation of the sorghum crop during the normal sowing period increases the Striga attack and heavy irrigation decreases it. This result was not obtained in laboratory experiments when sorghum was sown out of season. Striga attack is lessened when conditions favouring growth of the sorghum crop are improved.     

Persistence and distribution of insecticidal seed-dressings for control of the wheat bulb fly, Leptohylemyia coarctata

Samples of plants and soil from two experimental sites, one clay loam and one peaty loam, were analysed chemically to try to explain differing results with γ-BHC and dieldrin seed-dressings applied to control wheat bulb fly on different soil types, and to suggest reasons for patchy plant stands and occasional failure to control the pest. Seed dressed with dieldrin yielded more than untreated seed on both sites, whereas seed treated with γ-BHC yielded as much as seed treated with dieldrin on the clay site, but it yielded less than untreated seed on peat. The chemical analyses showed that the poor performance of γ-BHC on the peat site could not be explained by its failure to persist, because the soil still contained considerable quantities of γ-BHC at the time of insect attack. Possible reasons may be sorption of the poison by organic matter making it less available, and deeper sowing, permitting larvae to reach the plants without prolonged contact with the insecticide. Bayer 38156 (O-ethyl S-p-tolyl ethyl phosphonodithioate) and trichloro-nate (O-ethyl O-2,4,5-trichlorophenyl ethyl phosphonothionate) persisted in soil long enough and were sufficiently toxic to wheat bulb fly to suggest that organophosphorus compounds might provide alternatives to chlorinated hydrocarbon insecticides for control of the fly. Analyses made on seeds dressed at the laboratory for the experiment showed that the amounts of insecticide on seeds were smaller than expected and that the amounts on individual seeds differed greatly. Of ten samples of seeds dressed commercially with y-BHC, three carried very little insecticide, and the variations in the other seven samples were greater than with experimentally applied dressings.     

Increased Resistance to Penicillium Seed Rot in Transgenic Wheat Over‐expressing Puroindolines

Puroindolines (PINs) are the main components of the wheat grain hardness locus (Ha) and have in vitro antimicrobial activity against bacteria and fungi. Here, we examined the effect of variation in PINA and/or PINB content upon Penicillium sp. seed fungal growth inhibition. The Penicillium sp. assays were germination assays performed after incubating seeds in Penicillium sp. contaminated soil. The first set of wheat genotypes consisted of two sets of transgenic isolines created in the varieties ‘Bobwhite’ and ‘Hi‐Line’ having over‐expression of PINA and/or PINB. The second set of genotypes consisted of near‐isogenic lines (NILs) varying for mutations in PINA or PINB created in the varieties ‘Explorer’ and ‘Hank’. After incubation in Penicillium sp.‐infected soil, transgenic wheat seeds over‐expressing PINA in both ‘Hi‐Line’ and ‘Bobwhite’ and both PINs in ‘Hi‐Line’ exhibited significantly reduced fungal infection and increased germination. No significant differences in Penicillium sp. infection or germination rates were observed in seeds of the NILs. The results indicate that puroindolines native role in seeds is to increase seed viability and that when over‐expressed as transgenes, the puroindolines are effective antifungal proteins.     

Effect of Introduced Pseudomonas fluorescens Strains on Soil Nematode and Protozoan Populations in the Rhizosphere of Wheat and Pea

Abstract Previous studies have shown that inoculation of pea seeds with Pseudomonas fluorescens strains F113lacZY or F113G22 increased mineralization of organic nitrogen in the rhizosphere. In contrast, inoculation of the same strains onto wheat seeds reduced mineralization of N from organic residues incorporated into soil. In the present study, we report on a likely explanation of this phenomenon, which appears to be governed by the effect of plant-microbe interactions on bacterial-feeding nematodes and protozoa. In soil microcosm tests, inoculation of pea seeds with Pseudomonas fluorescens strains F113lacZY or F113G22 resulted in an increase in the number of nematodes and protozoa in the rhizosphere as compared to noninoculated controls. This trend was repeated using a model sand system into which the bacteriophagous nematode Caenorhabditis elegans was introduced. It was subsequently found that non-inoculated germinating pea seeds exerted a nematicidal effect on C. elegans, which was remedied by inoculation with either strain F113lacZY or F113G22. This suggests that nematicidal compounds released by the germinating pea seeds were metabolized by the microbial inoculants before they affected nematode populations in the spermosphere or rhizosphere of pea. In contrast, inoculation of wheat plants resulted in significantly lower nematode populations in the rhizosphere, whereas protozoan numbers were unaffected. No nematicidal effects of inoculated or noninoculated wheat seeds could be found, suggesting that microfaunal populations were affected at a later stage during plant growth. Because of their key roles in accelerating the turnover of microbially immobilized N and organic matter, plants that support a larger microfaunal population are likely to benefit from a higher availability of inorganic nitrogen. Therefore, an understanding of plant-microbe interactions and their effects on soil microfaunal populations is essential in order to assess the effects of microbial inocula on plant mineral nutrition. Received: 27 May 1999; Accepted: 15 July 1999; Online Publication: 17 December 1999     

香蕉园施用白花鬼针草的控草增效作用

[目的] 探索香蕉园施用白花鬼针草的可行性。[方法] 采用培养皿萌发试验生物测定法,以发芽率、发芽势、发芽指数、活力指数等化感效应指标评价白花鬼针草对蕉园4种优势杂草的化感作用,同时通过盆栽模拟试验探讨香蕉园施用白花鬼针草后杂草、香蕉和土壤三者的关系。[结果] 当白花鬼针草浸提液浓度为0.0125 g·mL^-1时,对马唐综合化感效应为促进作用,对短叶水蜈蚣、牛筋草、柔弱斑种草综合化感效应为抑制作用,白花鬼针草浸提液浓度为0.025~0.1 g·mL^-1,对4种受体杂草综合化感效应均为抑制作用;白花鬼针草处理具有降低种子发芽率,延缓种子发芽时间的作用,同时对杂草萌发后的鲜重有微弱促进作用,但这种促进作用较弱,综合化感效应表现为抑制作用。随着白花鬼针草茎、叶施用量的增加,控草增效作用不断提升,当施用量为400 g·株^-1时,控草增效作用最佳,对杂草综合株防效为78.99%,综合鲜重防效为70.60%,香蕉苗生物量增加19.79%,土壤有机碳、碱解氮、速效钾依次增加8.72%、10.36%、16.30%。[结论] 本研究初步探明了在香蕉园施用白花鬼针草具有防控蕉园优势杂草、提高土壤肥力和促进香蕉生长的效应。     

Effect of soil cultivation and anaerobiosis on cavity spot of carrots

Cultivating between rows and narrow beds of carrots reduced the severity of cavity spot in one year and reduced the incidence and severity in single rows in a second year on land where the disorder was endemic. Growing carrots on ridges initially reduced symptoms more than inter-row cultivation. Soluble carbohydrates leached from carrot roots in vitro and the quantities increased when anaerobic conditions were imposed. Untreated and cell-free extracts of soil suspensions amended with 1% glucose and incubated anaerobically applied to carrots in the laboratory caused the outer layers of the secondary phloem to collapse resembling a cavity spot lesion. Unamended and fresh soil solutions had no effect.     

The effect of vesicular arbuscular mycorrhizal associations on growth of cereals

The growth of wheat seedlings which were already mycorrhizal when transplanted to a field deficient in phosphorus was improved compared with non-mycorrhizal controls, and grain yield was increased three-fold by the fungus, indicating that Endogone stimulated growth and increased yield. Differences between mycorrhizal and non-mycorrhizal wheat were eliminated by the application of phosphate fertilizer, indicating that the fungus does not enhance wheat growth in soils containing enough available phosphate. It is probable that the mycorrhizal effect is primarily to improve the supply of phosphate. There were clear relationships between spore number in the soil and mycorrhizal development and between the extent of root infection and increased growth. The extent of root infection was greatest in mycorrhizal plants in soil not supplemented with phosphate and it decreased in inoculated plants in the plot supplemented with superphosphate. The non-centrospermous and non-zygophyllaceous weeds growing on the experimental field had typical vesicular arbuscular infection and indigenous Endogone spores in their rhizospheres. The centrospermous plants were non-mycorrhizal and had no Endogone spores in their rhizospheres.     

The effect of small doses of nematicides on migratory root-parasitic nematodes and on the growth of sugar beet and barley in sandy soils

Smaller amounts of D–D (6–12 gal/acre) (68–135 1/ha) or ethylene dibromide (9 gal/acre) (100 1/ha) than are customarily used to disinfest field soils killed many root-parasitic nematodes (Trichodorus, Pratylenchus, Tylenchorhynchus and Longidorus attenuatus) when injected 6–8 in (15–20 cm) deep during early autumn in rows 10 in (25 cm) apart in well-drained sandy soils. They also increased the yield of sugar beet grown in fields infested with Trichodorus or Longidorus attenuatus, without affecting sugar percentage or juice purity of the roots, and in some places increased the yield of barley grown after the beet. D–D was much less effective when injected 8–12 in deep during late autumn or winter. Increasing nitrogen dressings to the seedbed from 1·5 to 3 cwt/acre (188 to 376 kg/ha) increased sugar beet yield in one field, decreased it in another and decreased juice purity in both. In two other experiments extra nitrogen did not affect sugar beet yield. Even smaller amounts of the nematicides ‘placed’ in the rows, before or after sowing sugar beet in them, killed many of the nematodes and also increased sugar yield. Phytotoxic nematicides can be placed in the rows during autumn, winter or spring but placement is simpler during spring, when the treated rows are indicated by the position of the marks of the tractor wheels left when the nematicide was applied. When applied during autumn or winter, the rows need to be indicated by drilling wheat or grass.     

The influence of soil moisture on losses of buried seeds to fungi

Although soil fungi are likely to be a major cause of mortality for buried seeds, few ecological studies have examined the role these pathogens play in natural systems. In particular, few studies have investigated whether losses of seeds to soil fungi are habitat-dependent. We used fungicide treatments to investigate whether losses of buried seeds of four grasses (Bromus inermis, Danthonia spicata, Glyceria striata, and Poa pratensis) to soil fungi differed among meadows differing in soil moisture. We also applied water to some treatments, to determine whether this increased losses of seeds to fungi. For all four grasses, fungicide additions improved one or more measures of seed viability, though this effect was small. For Danthonia and Glyceria, fungicide was less likely to improve viability in dry meadows than in wet and/or mesic meadows. Adding water reduced some measures of viability of seeds of Danthonia and Poa in dry meadows, but fungicide partly counteracted these negative effects, suggesting that adding water reduced performance by increasing fungal attack. These results indicate that fungi represent a hazard for buried seeds of these species, particularly in wetter soils, and potentially may contribute to the reduction of populations of vulnerable species in wetter sites.     

Pre‐dispersal seed predators and fungi differ in their effect on Luehea seemannii capsule development,seed germination,and dormancy across two Panamanian forests

Pre‐dispersal seed predation can greatly reduce crop size affecting recruitment success. In addition, non‐fatal damage by seed predators may allow infection by fungi responsible for post‐dispersal seed losses. The objectives of this study were (1) to quantify pre‐dispersal seed predation and fungal infection in a Neotropical tree species, Luehea seemannii, that produces dehiscent fruits and wind‐dispersed seeds, and (2) to link pre‐dispersal effects on seed quality to seed survival in the soil. To examine how seed predators and fungi influence seed losses, mesh exclosures, fungicide, and the combination of both treatments were applied to separate branches in the canopy of trees in Gamboa and Parque Natural Metropolitano (PNM), Panama. To determine if treatments affect seed viability and survival in the soil, half of the seeds collected from each treatment were buried for 4 weeks in forest soils and subsequently allowed to germinate before and after the breaking of dormancy. Overall, 24 percent of developing fruit were lost to insect attack. In contrast, fungi infected only 3 percent of seeds at the pre‐dispersal stage. For seeds germinated directly after collection, fungicide significantly increased germination in the wetter site (Gamboa) but decreased germination in the drier site (PNM). The pre‐dispersal insect exclosure treatment increased the fraction of seeds that remained dormant after burial in the soil. This result suggests that exposure to insect predators may cause physical damage to seeds that results in the loss of physical dormancy but does not necessarily increase the susceptibility of seeds to pathogen attack in the soil.