Difference in genotype of soybeans (Glycine max L.) Merr.) may result in variation of seed germination and vigor. The variation in seed quality and some physical characteristics of seed of 10 soybean genotypes and also the relationships among them were determined. Plants were grown in rainy season of 2000 and harvested when pods became yellow (physiological maturity). After the seed moisture had been dried to about 11 percent, seed quality, seed leachate and physical characteristics of seed were evaluated. The seed quality was obtained by standard germination test and vigor tests including field emergence and seedling length. Seed leachate was tested by electrical conductivity and imbibition. The physical characteristics of seed were measured by seed weight (seed size) seed shape (eccentricity value), wight and percent of seed coat and hard seed percentage. The results showed that seed germination of 10 soybean cultivars/lines had a wide variation from 50 to 100 percent. Lines with high germination (more than 80 percent) had a tendency to accompany with high seed vigor and low in seed leachate as well as water uptake. Observed correlation coefficients indicated a tendency for higher seed quality to be associated with higher percent of seed coat and slower rate of imbibition. Therefore, seeds with thicker seed coat would result in delayed moisture absorption. This may be the case of producing good quality of soybean seeds.

"The effects of various physical treatments and fruit incubation under ventilated ambient temperature for 5 or 7 days on the breaking of the seed dormancy of the local Thai cucumber varieties, 'Puang' and 'Jed-Bai' were investigated. The sun exposure and 9 day continuous hot air treatments (40degC) were effective in the breaking of the seed dormancy and improvement of seed germination rates and seed vigor in Puang', whereas the hot air and accelerated aging (45degC 100% RH. for 2 days) treatments increased the germination rates and seed vigor in 'Jed-Bai'. Before the physical treatments were applied, fruit incubation did not improve seed germination, although it increased the GAs contents in seeds. In general,, fruit incubation did not affect the influence of the treatments on dormancy. The analysis of GAs, ABA and cytokinins in seeds suggested that the sensitivity to ABA was different in the two varieties used and that some unknown germination inhibitory factors other than ABA played an important role in the dormancy of the local Thai cucumber varieties."

We investigated the relationship between physical characteristics of artificial surfaces, spore attachment, and spore germination in Colletotrichum graminicola. Surface hydrophobicity and surface rigidity were both signals for breaking dormancy and initiating spore germination, but spore attachment alone was not an important inducing signal. The presence of a carbon source overrode the necessity for a rigid, hydrophobic substrate for spore germination. Spore attachment was typically stronger to more hydrophobic surfaces, but certain hydrophilic surfaces also proved to be good substrates for spore attachment. In contrast to spore germination, appressorial induction was more dependent on attachment to a rigid substrate than it was on surface hydrophobicity. Appressoria were induced efficiently on hydrophilic surfaces, as long as there was significant conidial attachment to those surfaces.

Legumes are important crops and a major component of rice-based cropping systems (RBCS) in many Asian countries. Crop establishment following rice is an important constraint to production and is profoundly affected by soil physical, chemical, and biological factors, and by soil management. Considerable research has been done to understand the role of these factors on crop establishment. This review evaluates these studies and investigates future research needs, which include: classification of post-rice environments in terms of suitability for legumes; breeding programs specific to legume improvement for post-rice environments; seed characteristics allowing germination in still-saturated and compact soils; enriching germination and seedling vigor; and development of appropriate implements for tillage and sowing in post-rice soils.

Cryopreservation in liquid nitrogen (LN) is relatively routine for many small, desiccation-tolerant (orthodox) seeds. Seeds of Pyrus species are considered orthodox but have not been evaluated for LN storage. Seeds of freshly collected P. communis L. ('Bosc') were evaluated for germinability and by TZ staining after exposure to four LN treatments: 1) direct immersion and direct removal; 2) direct immersion and 1 minute in LN vapor phase before removal; 3) 2 minutes in vapor phase before immersion and direct removal; and 4) 2 minutes in vapor phase before immersion and 1 minute in vapor phase before removal. Fresh 'Bosc' seed viability evaluated by TZ and greenhouse germination tests remained high (83% to 100%) following four types of LN treatments, compared to the controls (77% to 87%). Differences in 'Bosc' seed viability were small and TZ results showed no significant differences among the LN treatments. Direct LN immersion and removal resulted in significantly more greenhouse-germinated 'Bosc' seeds than the other treatments and fewer control seeds germinated than any LN treated seeds. Fresh 'Bosc' seed cryopreserved at 7.9% moisture exhibited high germinability by both TZ and germination tests. LN exposure caused no physical damage to the seeds.

The change in physical traits of fungicide and insecticide sprays prepared in raw water decreased the tank life of sprays and restricted the choice of tank mix product partner. The pH has been increased, Mankogal-80 + Sucip 20-EC spray stability decreased, as well as the surface tension of all spray liquids except for the insecticide emulsion. The conductivity of everyone fungicide in raw water suspensions were increased, and the differences in between one fungicide and relevant admixture with insecticide suspension became bigger, especially during 24 h ageing. Mancozeb in Ridomil MZ 72 suspension at recommended and 50% diluted concentration in raw water decreased the germination of Alternaria alternata conidia less than the corresponding concentration in tap water. The decrease in mancozeb effect was obvious with Mankogal-80 spray suspension or its admixture with insecticide in raw water but with lower spray concentration (1/25, 1/10 of recommended). The phytotoxicity on tomato was induced by tank mix of Mankogal-80 + Sucip 20-EC in raw water.

"La presente investigación se llevó a cabo en dos etapas, la primera en el invernadero de Alta Tecnología del Departamento de Forestal de la Universidad Autónoma Agraria Antonio Narro (UAAAN), en donde se estableció el cultivo de melón de los genotipos Top Mark y Crusier con la evaluación de diez tratamientos en un diseño de bloques completos al azar con arreglo factorial. Los tratamientos consistieron en inocular plantas durante diferentes etapas fenológicas con los virus Mosaico del Pepino (VMP) y Virus Mancha Anular del Papayo Variante Sandía (VMAP-S). La segunda etapa se llevó a cabo en laboratorio y consistió en dos fases: la primera en la detección por el método ELISA de los Virus VMP y VMAP-S en tejido vegetativo, fruto (cáscara y pulpa) y semilla (testa y endospermo) en frutos cosechados a madurez fisiológica. En la segunda fase del trabajo de laboratorio se evaluó la calidad física y fisiológica de la semilla de acuerdo a las regulaciones establecidas por el ISTA (1996). Los resultados de la prueba ELISA indican presencia de ambos virus de ambos virus en semilla obtenida en invernadero. Se localizaron los dos virus en testa y endospermo y en fruto (cáscara y pulpa) solo se detectó el VMAP-S, con lo que se demuestra la transmisión de los virus mencionados por semilla. En relación a los genotipos evaluados es importante destacar que la variedad Top Mark presentó mejores valores en germinación estándar para las variables por ciento de germinación, longitud de plúmula y longitud de radícula y solo en primer conteo el híbrido presentó mejores promedios. Mientras en lo correspondiente a envejecimiento artificial se obtuvo un comportamiento similar entre genotipos, esto es, no se detectaron diferencias estadísticas significativas entre ellos. Las evaluaciones de calidad en la semilla obtenida en los diferentes tratamientos, indican que las características físicas mostraron una buena calidad dentro de los parámetros evaluados. Sin embargo, en lo correspondiente a calidad fisiológica, la germinación estándar estuvo por debajo del porcentaje establecido para esta especie. Así mismo con referencia al vigor mostró valores altos por lo que se muestra una diferencia amplia entre estos dos parámetros debido probablemente a una latencia inducida por manejo de la semilla." | "The treatments consisted in the innoculation of plants during different phenological stages with the Cucumeber Mosaic Virus (CMV) and the Papayo ring spot virus - Watermelon Variant (PRSV-W). The second step was carried out in laboratory and it consisted of two stages: The first one consisted in the detection by the ELISA method of the CMV and PRSV-W viruses in vegetative tissue, fruit (skin and flesh) and seed (seedcoat and endosperm) in fruits harvested at physiological maturity. In the second stage of the laboratory work the physical and physiological seed quality were evaluated according to the regulations (ISTA, 1996). The results of the ELISA tests showed the presence of both virus in greenhouse grown seed. Both virus were detected in seed coat and endosperm, while the PRSV-W was only detected on fruit, showing that the viruses were transmitted by seed. In relation to the evaluated genotypes, it is important to point out that the Top Mark variety showed the best results in the standard germination test for the following variables: germination porcentage, plumule length and radicle length, while the hybrid only excelled in the first count variable. The artificial agging test showed a similar performance between genotypes, this is, no significant statistical differences were detected between them. The evaluations of the seed quality from the different treatments showed good physical characteristics. However, for the physiological quality the standard germination variable was bellow the stablished percentage for this species. In relation to the vigor tests, the results showed higher values for all variables than in the germination test, probably due to induced dormancy related to seed handling."

Compost maturity is one of several issues that the composting industry must face as it attempts to provide a high quality product to the agricultural community. In this paper, we examine the potential for using immature compost prepared from a mixture of municipal solid waste (MSW) and biosolids as a mulch for control of weeds in vegetable crop row-alleys. Two field experiments were conducted with 4 and 8-week-old composts in the fall of 1995 and the spring of 1996. The 4-week-old compost was applied to mulching depths of 3.8 (68 t dry weight.ha-1), 7.5 (135 t dry weight.ha-1), 11.3 (203 t dry weight.ha-1), and 15 cm (270 t dry weight.ha-1) in the fall, and at 2.0 (35 t dry weight.ha-1), 3.8, 7.5, and 11.3 cm depths in the spring. Other treatments were paraquat applied at 0.6 kg.ha-1 and an untreated control. All treatments were applied in row-alleys between raised, polyethylene-covered soil beds. The 8-week-old compost was applied to depths of 3.8,7.5,11.3, and 15 cm in fall and to depths of 2.0,3.8,7.5 and 11.3 cm in the spring. Untreated alleys served as controls. In the fall 1995 experiment under low weed pressures, the 4-week-old compost applied to 7.5 cm or greater depths completely inhibited weed germination and growth for 240 days after treatment. In the spring 1996 experiment, 4-week-old compost completely inhibited weed germination and growth for only 65 days if applied to a depth of 7.5 cm or deeper due to higher prevailing weed pressures, particularly due to yellow nutsedge (Cyperus esculentus L.). In the same spring experiment, a 50 % reduction in percentage weed cover was obtained for 240 days with a 11.25 cm deep layer of mulch compared to the control. In the fall 1995 experiment, 8-week-old compost applied at 7.5 cm or depths completely inhibited weed germination and growth for 240 days. In the spring 1996 experiment, 8-week-old compost applied as a 11.25 cm mulch reduced percent weed cover as compared to the control up to 240 days. In general, weed cover and weed dry weight decreased linearly as the depth of the mulch increased.Under these immature composts, inhibition of germination or subsequent weed growth may have been due to both the physical effects of the mulch and the concentrations of phytotoxic fatty acids during the first few days after mulches were applied. At the time of mulching with the 4-week old compost, acetic acid was present at a concentration of 1221 mg.kg-1 in tthe fall mulch, and at 4128 mg.kg-1 in the spring mulch. The same concentrations in the 8-week-old compost for the fall and spring mulches were 1118 mg.kg-1 and 3113 mg.kg-1 , respectively. In conclusion, immature compost may provide an effective alternative weed control method for row-alleys in vegetable crop production systems. During these experiments, it was observed that man-made contaminants such as glass, hard and soft plastics in the composts were esthetically unacceptable and potentially posed hazards to field workers.

The ginning of cotton (Gossypium hirsutum L.) results in the accumulation of approximately 90 kg of gin trash per bale of cotton ginned. In the past, disposal of raw gin trash was by burning, land application and feeding to livestock, but problems with clean air standards, weed seeds and diseases, and chemical residues, respectively, make each of these methods unacceptable. Composting the gin trash would alleviate certain problems associated with land application on farm fields. Experiments were conducted to investigate windrow composting. A split plot experiment with five reps was initiated to evaluate turning times, nitrogen (N) fertilization and bacterial inoculation. Composite samples were collected and analyzed for nutrients and selected chemicals. Another experiment was established to compare timing and physical methods of turning windrows. The Lipsey-gin-trash-composting system was investigated by sampling three compost piles at three different cotton gins. The chemical composition and weed seed germination were investigated. Results indicate that windrow composting does not solve the weed seed or plant disease problem; otherwise, the product was satisfactory. The Lipsey-gin-trash-composting system resulted in a pile of material whose outside 0 to 15 cm depths contained viable weed seeds and disease organisms, but none survived below this exterior. This system resulted in an incomplete composting material with offensive odors.