Upland rice yield as affected by previous summer crop rotation (soybean or upland rice) and glyphosate management on cover crops

The appropriate chemical management of cover crops in no-tillage aims to obtain greater benefits with its employment in agricultural systems. The objective of this study was to assess upland rice yield as affected by the previous summer crop, species and desiccation timing of cover crops by glyphosate. Sown cover crops were sown (November 2007), followed by rice in half of the experimental area and soybean in the other half (November 2008). After the harvesting of these crops, the same cover crops were sown again (March 2009) and followed by upland rice in the total area (November 2009). The experiment consisted of the combination of five cover crops (fallow, Panicum maximum, Brachiaria ruziziensis, B. brizantha and Pennisetum glaucum), four desiccation timings (30, 20, 10 and 0 days before rice sowing), and two antecedents of the summer crop (rice or soybean) under no-tillage system (NTS), plus two control treatments at conventional tillage system (CTS). Cover crops significantly affect rice grain yield and its components. There is a significant tendency to highest yield when cover crop desiccation is conducted farther from the rice sowing date (from 2,577.1 kg ha-1 - desiccation at rice sowing to 3,115.30 kg ha-1 - desiccation 30 days before rice sowing). Soybean as an antecedent of summer crop allows better upland rice yield (3,754 kg ha-1) than rice as an antecedent of summer crop (2,635 kg ha-1); fallow/soybean/fallow (4,507 kg ha-1) and millet/soybean/millet (4,765 kg ha-1) rotation at no-tillage system, and incorporated fallow /soybean/ incorporated fallow (4,427 kg ha-1) at conventional tillage system allow the highest rice yield; upland rice yield is similar at no-till (3,194 kg ha-1) and till system (2,878 kg ha-1).

Implications of weeds of genus euphorbia for crop production: a review

The genus Euphorbia comprises about 2000 species ranging from annuals to trees, including C3, C4, and CAM species. Euphorbia species widely studied in agriculture includes E. antiquorum, E. carollata, E. dentata, E. dracunculoides, E. esula, E. geniculata, E. granulata, E. helioscopia, E. heterophylla, E. hierosolymitana, E. hirta, E. maculata, E. microphylla, E. nerifolia, E. piluifera, E. pulcherrima, E. royleana, E. supine, and E. thiamifolia. These species have been reported mainly in field crops/vegetables, orchards, pastures, and rangelands. Euphorbia plants may present allelopathic effect over desirable cereals, pulses, oilseeds, vegetables, forage plants, and nitrifying bacteria, posing a serious threat to livestock production on open range lands through the release of allelochemicals from roots, stems, leaves, and inflorescence in the rhizosphere. Leaves are reported to be more toxic than other plant parts. Competition of Euphorbia spp. against crop plants is the most important crop yield-limiting factor. The critical period for Euphorbia competition with crops is reported to take place between 17 to 70 days after emergence for most crops, depending on root development during the initial crop growth stage, crop height, tillering or branching capacity, whether weeds emerge at the same time as the crop or later after crop emergence; how quickly crop canopy develops and also on Euphorbia species. A yield reduction of 4-85% has been reported in field crops with different Euphorbia species and distinct occurrence densities. Euphorbia species decrease herbage production by 10 to 100% in pasture and rangelands, with many acting as natural insecticide, fungicide, nematidicide, immunopotentiator, or immunosuppressor.

Germination ecology of wild onion: a rainfed crop weed

Asphodelus tenuifolius is becoming a more common weed in rain-fed area in Pakistan. Laboratory and greenhouse experiments were conducted to determine the effect of different environmental factors on germination and emergence of A.tenuifolius. Results showed that A.tenuifolius can tolerate a wide range of varying environmental factors. Greatest percentage of germination (80%) was recorded at 15 ºC constant temperature; however, considerable germination occurred at 20 and 25 ºC. Light for 10 h photoperiod stimulate germination of Asphodelus tenuifolius compared with complete darkness. Germination was totally inhibited at osmotic stress higher than -0.8 MPa. There was no significant difference in germination at pH 6 to 8; however, there was a slightly decrease at pH 9, compared with distilled water. Asphodelus tenuifolius was very sensitive to salinity; however, a few seeds of A.tenuifolius were able to germinate even at 150 mM NaCl concentration. Greatest emergence occurred with seed placed at soil surface and emergence decreased with increase in burial depth. No emergence occurred from 4 cm or greater. This information may aid in developing tools and strategies for management.

Soil Persistence of Chlorimuron-Ethyl and Metsulfuron-Methyl and Phytotoxicity to Corn Seeded as a Succeeding Crop

Two experiments were carried out to evaluate soil persistence of chlorimuron-ethyl and metsulfuron-methyl and phytotoxicity to corn seeded as a succeeding crop. One experiment was conducted with chlorimuron-ethyl applied at 20 g ha-1, and one with metsulfuron-methyl applied at 3.96 g ha-1. Treatments were arranged in a factorial design with two types of soil (sandy and clay), three irrigation regimes (daily, weekly and no irrigation) and four application timings (90, 60 and 30 days before corn seeding, as well as untreated plots). Soil persistence of the herbicides was influenced by water availability, molecule water solubility (leaching potential) and application timings prior to corn seeding. In sandy soil, with adequate water availability, leaching probably had the greatest influence, reducing the persistence of the products, and consequently allowing less time between product application and corn seeding. In clay soil, microbial degradation was probably more important, because it was assumed that the lesser time available for microorganism activity, the lesser the damage was observed for corn, as long as the crop had enough water availability. Metsulfuron-methyl was the least phytotoxic herbicide, possibly as a result of the properties of its molecule and its higher leaching potential.

EFFECT OF POST-EMERGENCE HERBICIDE APPLICATIONS ON RICE CROP WEED COMMUNITIES IN TOLIMA, COLOMBIA

ABSTRACTThe weed communities of agricultural systems are dynamic and respond to changes in agronomic practices. This study aimed to evaluate the effect of post-emergence herbicide control programs made by farmers on weed communities and commercial lots of rice. The evaluations were carried out in 96 commercial lots located in the Centro, Meseta and Norte zones of the department of Tolima. In each lot, 1 ha was marked off, in which the evaluations were carried out by randomly throwing a 0.2 x 0.2 m sampling-square 5 times. Samples were taken before the first post-emergence application, after the first post-emergence application, after the second post-emergence application, and once the post-emergence applications were finished. The evaluated variables included density and cover of the weeds and the crops. The IVI of each species was calculated and the control program was analyzed in terms of decreases in the number of individuals for the 15 more encountered species. Before the applications, higher density values were found. The first and second post-emergence applications reduced the average density by 41% and 12%, respectively, throughout the department. Between the first and fourth evaluations, the density of the weeds and crops decreased throughout the department by 51.7% and 39%, respectively. The weed density variable proved to be the most influential in the populations after the herbicide programs were carried out.

SELECTION OF HERBICIDES TARGETING THE USE IN CROP SYSTEMS CULTIVATED WITH SHOWY CROTALARIA

ABSTRACT The increase in the area planted with Crotalaria spectabilishas occurred by several factors, highlighting the potential to reduce the nematodes, nitrogen fixation and the high production of biomass. By becoming a species sown as a crop, it is necessary to control the weeds that coexist with showy crotalaria. This change in the use of this crop creates the possibility of this specie becoming a weed. The aim of this study was to assess the potential use of herbicides applied in preemergence and postemergence of C.spectabilisfor different purposes (control of volunteer and selectivity plants). Three experiments were installed in a greenhouse (two with herbicides applied in preemergence - in soils with distinct textural categories; and one experiment with herbicides applied in postemergence). The results of the experiments with herbicides applied in preemergence showed that: amicarbazone, atrazine, diuron, metribuzin, prometryn, fomesafen and sulfentrazone showed effectiveness for control of C.spectabilis in clayey soil. Besides these, flumioxazin and isoxaflutole also showed potential to be used in the control of showy crotalaria in soils with loam texture. In relation to the postemergence herbicides, atrazine, diuron, prometryn, flumioxazin, fomesafen, lactofen, saflufenacil, amonio-glufosinate and glyphosate can be used aiming the chemical control of C.spectabilis. Herbicides chlorimuron-ethyl, diclosulan, imazethapyr, pyrithiobac-sodium, trifloxysulfuron-sodium, clomazone, pendimethalin, S-metolachlor and trifluralin applied in preemergence, and imazethapyr, pyrithiobac-sodium, flumiclorac, bentazon and clethodim applied in postemergence caused low levels of injury to C.spectabilis plants, making necessary the development of new searches to ensure the selectivity of these products.

WEED MANAGEMENT WITH HERBICIDES APPLIED IN PRE AND POSTEMERGENCE ON CASTOR CROP

ABSTRACT The aim of this work was to evaluate the weed management with herbicides applied in pre and postemergence on castor crop. The treatments were constituted by management systems using herbicides in pre (PRE) and postemergence (POS): 1) S-metolachlor at 576 g ha-1 (PRE 1) and chlorimuron-methyl at 15 g ha-1 (POS 1); 2) PRE 1 + clomazone at 650 g ha-1(PRE 2) and POS 1; 3) PRE 1, POS 1 and halosulfuron-methyl at 112.5 g ha-1(POS 2); 4) PRE 1, POS 1 and ethoxysulfuron at 60 g ha-1 (POS 3); 5) PRE 1, POS 1 and ethoxysulfuron at 120 g ha-1 (POS 4); 6) PRE 1 + PRE 2, POS 1 and POS 2; 7) PRE 1 + PRE 2, POS 1 and POS 3; 8) PRE 1 + PRE 2, POS 1 and POS 4; 9) hand-hoeing control and 10) non-weeded control. The experimental design was randomized blocks with four replications. The association of the herbicides in PRE combined to sequence applications of chlorimuron-ethyl and halosulfuron-methyl or ethoxysulfuron in POS resulted in the highest control levels of Richardia scabraand Cyperus ferax. Mild phytointoxication symptoms to the crop were more persistent with ethoxysulfuron at 120 g ha-1. The acceptable control of the weed species and similar yield to the hand-hoeing control permitted to conclude that S-metolachlor + clomazone PRE, followed by chlorimuron-ethyl and halosulfuron-methyl POS proved to be more adequate as a weed management strategy on castor crop.

RR soybean seed quality after application of glyphosate in different stages of crop development

In consequence of several studies and speculations concerning the issue of RR transgenic soybean after the application of glyphosate, additional scientific investigations became necessary to clarify the actual viability of the product use when applied in different developmental stages of the soybean crop. Therefore, this study was aimed to evaluate the physiological quality as well as seed health quality of RR soybean subjected to application of the herbicide glyphosate in different phonological stages of the transgenic soybean, cultivar CD 219RR. For this, an experiment with a complete block experimental design with treatments randomly distributed within the block, with four replications, was carried out. The assessed treatments were foliar sprayings of glyphosate in three increasing dosages [0 (control); 1,440 g ha-1; and 2,880 g ha-1] of acid equivalent, applied in two crop developmental stages: vegetative (V6) and reproductive (R2). The variables assessed were: germination; first count of germination; fresh and dry mass of seedlings, lengths of seedling and root; vigor and viability by the tetrazolium test; and seed health quality. Glyphosate application may adversely affect physiological quality of RR soybean seeds, when applied in dosages varying from 1,440 to 2,880 g acid equivalent per hectare at the stages V6 and R2.

Irrigation scheduling for Sovereign Coronation grapevine based upon evapotranspiration calculations and crop coefficients /

Several irrigation treatments were evaluated on Sovereign Coronation table grapes at two sites over a 3-year period in the cool humid Niagara Peninsula of Ontario. Trials were conducted in the Hippie (Beamsville, ON) and the Lambert Vineyards (Niagara-on-the-Lake, ON) in 2003 to 2005 with the objective of assessing the usefulness of the modified Penman-Monteith equation to accurately schedule vine irrigation needs. Data (relative humidity, windspeed, solar radiation, and temperature) required to precisely calculate evapotranspiration (ETq) were downloaded from the Ontario Weather Network. One of two ETq values (either 100 or 150%) were used in combination with one of two crop coefficients (Kc; either fixed at 0.75 or 0.2 to 0.8 based upon increasing canopy volume) to calculate the amount of irrigation water required. Five irrigation treatments were: un irrigated control; (lOOET) X Kc =0.75; 150ET X Kc =0.75; lOOET X Kc =0.2-0.8; 150ET X Kc =0.2-0.8. Transpiration, water potential (v|/), and soil moisture data were collected each growing seasons. Yield component data was collected and berries from each treatment were analyzed for soluble solids (Brix), pH, titratable acidity (TA), anthocyanins, methyl anthranilate (MA), and total volatile esters (TVE). Irrigation showed a substantial positive effect on transpiration rate and soil moisture; the control treatment showed consistently lower transpiration and soil moisture over the 3 seasons. Transpiration appeared accurately reflect Sovereign Coronation grapevines water status. Soil moisture also accurately reflected level of irrigation. Moreover, irrigation showed impact of leaf \|/, which was more negative throughout the 3 seasons for vines that were not irrigated. Irrigation had a substantial positive effect on yield (kg/vine) and its various components (clusters/vine, cluster weight, and berries/cluster) in 2003 and 2005. Berry weights were higher under the irrigated treatments at both sites. Berry weight consistently appeared to be the main factor leading to these increased yields, as inconsistent responses were noted for some yield variables. Soluble solids was highest under the ET150 and ET100 treatments both with Kc at 0.75. Both pH and TA were highest under control treatments in 2003 and 2004, but highest under irrigated treatments in 2005. Anthocyanins and phenols were highest under the control treatments in 2003 and 2004, but highest under irrigated treatments in 2005. MA and TVE were highest under the ET150 treatments. Vine and soil water status measurements (soil moisture, leaf \|/, and transpiration) confirmed that irrigation was required for the summers of 2003 and 2005 due to dry weather in those years. They also partially supported the hypothesis that the Penman-Monteith equation is useful for calculating vineyard water needs. Both ET treatments gave clear evidence that irrigation could be effective in reducing water stress and for improving vine performance, yield and fruit composition. Use of properly scheduled irrigation was beneficial for Sovereign Coronation table grapes in the Niagara region. Findings herein should give growers some strong guidehnes on when, how and how much to irrigate their vineyards.

Elucidation of odour-potent compounds and sensory profiles of Vidal blanc and Riesling icewines from the Niagara Peninsula : effect of harvest date and crop level

I t was hypothesized that the freeze/thaw cycles endured by icewine grapes would change their chemical composition, resulting in unique chemical fingerprint and sensory properties, and would be affected by harvest date (HD) and crop level (CL). The objectives were: 1) to identify odour-active compounds using gas chromatographic and sensory analysis; 2) to determine the effect of CL and HD on these compounds; 3) to determine the icewine sensory profiles; 4) to correlate analytical and sensory results for an overall icewine profile. CharmAnalysis™ determined the Top 15 odour-potent compounds in Vidal and Riesling icewine and table wines; 24 and 23 compounds, respectively. The majority of the compounds had the highest concentrations in the icewines compared to table wines. These compounds were used as the foundation for assessing differences in icewine chemical profiles from different HD and CL. Vidal and Riesling icewine were made from grapes picked at different HD; HI : 19 December; H2: 29 December; H3: 18 January; H4: 11 February (Vidal only). HI wines differed from H3 and H4 wines in both Vidal and Riesling for aroma compounds and sensory profiles. - Three·CL [control (fully cropped), cluster thin at fruit set to one basal cluster/shoot (TFS), and cluster thin at veraison to one basal cluster/shoot (TV)] were evaluated for Riesling and Vidal cultivars over two seasons. Vidal icewines had the highest concentration of aroma compounds in the control and TV icewines in 2003 and in TFS icewines in 2004. In Riesling, most aroma compounds had the highest concentration in the TV icewines and the lowest concentration in the TFS wine for both years. The thinned treatments were associated with almost all of the sensory attributes in both cultivars, both years. HD and CL affected the chemical variables, aroma compounds and sensory properties of Vidal and Riesling icewines and freeze/thaw events changed their sensory profile. The most odour-potent compounds were p-damascenone, cis-rose oxide, 1- octen-3-ol, 4-vinylguaiacol, ethyl octanoate, and ethyl hexanoate. The role of Pdamascenone as a marker compound for icewine requires further investigation. This research provides a strong foundation for the understanding the odour-active volatiles and sensory profiles important to icewine.

IMPACT OF CROP LEVEL AND HANG TIME ON THE COMPOSITION OF FOUR WINE GRAPE CULTIVARS FROM THE NIAGARA REGION

This study analyzed the use of two viticultural practices: “crop level” (half crop; HC, and full crop; FC) and “hang times”, and their impact on the composition of four grape cultivars; Pinot gris, Riesling, Cabernet Franc and Cabernet Sauvignon from the Niagara Region and wine volatile composition by GC-MS. It was hypothesized that keeping a full crop with a longer hang time would have a greater impact on wine quality than reducing the crop level. In all cultivars, a reduction of crop level induced reductions in yield, clusters per vine and crop load, with increases in Brix. Extended hang time also increased Brix related to desiccation. The climatic conditions at harvest had an impact on hang time effects. The GC-MS analysis detected the presence of 30 volatile components in the wine, with different odour activity values. Harvest time had a positive impact than crop reduction in almost all compounds.

Statement of John O'Connor Damaged Wheat Crop

Statement (handwritten, 3 pages) in which John O’Connor states that his wheat crop of 1834 was damaged. A fence was also down which resulted in his wheat crop being destroyed by cattle and pigs. The defendants had to pay the plaintiff for damages. S. D. Woodruff was the arbitrator in this case, Aug. 1835.

Chart of station 2, crop sections of the old back ditch on the south side of the feeder, station 45, station 118 and the total length from the culvert to lot no. 5

Chart of station 2, crop sections of the old back ditch on the south side of the feeder, station 45, station 118 and the total length from the culvert to lot no. 5. This is signed by Fred Holmes, April 13, 1857.

Morphophysiological traits in crop improvement case study-sorghum [by] Ratikanta Maiti; ed. [by] Pedro A. Wesche-Ebeling, Manuel Rojas Garcidueñas [and] Paul R. Earl

UANL

Effet de l’irrigation par l’eau usée sur la biomasse aérienne et souterraine d’une culture intensive de saules en courtes rotations

Le but de cette étude est de comprendre l’effet d’une irrigation par les eaux usées et /ou de la fertilisation par les engrais chimiques sur la productivité aérienne et souterraine d’une plantation de saule Salix miyabeana SX67 en CICR dans un contexte de filtre végétal. Nous avons d’une part évalué l’impact de diverses doses d’eau usées et/ou de la fertilisation minérale sur les rendements en biomasse ligneuse d’une culture de saules au cours d’un cycle de croissance de deux ans. D’autre part et pour la même période nous avons comparé le développement racinaire (biomasse, morphologie et distribution dans le sol) suite aux divers traitements. Les résultats ont montré qu’au terme de deux ans de croissance, les traitements par les eaux usées aussi bien que celle par les engrais a permis l’augmentation des rendements de la biomasse aérienne de notre culture de saules avec un effet plus prononcé suite au traitements des eaux usées qu’à celui du fertilisant chimique. Nous avons mesuré des productivités en biomasse aussi élevées que 39,4 Mg ha-1 et 54,7 Mg ha-1 et ce pour les parcelles qui ont reçu la plus grande quantité d'eaux usées, respectivement pour les saules non fertilisé et fertilisé (D3-NF et D3-F). La majeure partie du système racinaire était en superficie avec 92-96% des racines (racine fine et racine grosse) concentrées dans les premiers 40 cm de sol et nous avons trouvé que la biomasse des racines fines était comprise entre 1,01 et 1,99 Mg ha-1. Généralement la fertilisation chimique n’a pas eu d’effet sur les rendements en biomasse des racines totales et/ou fines. Bien que l’irrigation par les eaux usées ait entraîné une réduction statistiquement significative de la biomasse racinaire, néanmoins cette réduction n'était pas linéaire (avec une réduction de la biomasse de D0 à D1, une augmentation de D1 à D2 pour réduire de nouveau de D2 à D3). Cette tendance porte à penser qu'au-delà d'une certaine quantité d'eau et de nutriments (suite à l’irrigation par les eaux usées), le développement du système racinaire des saules est affecté négativement, et bien que la biomasse aérienne soit restée élevée sous le traitement D3, nous pensons que le développement de la plante a été quelque peu déséquilibré. Aucun changement significatif n'a été constaté dans les traits morphologiques liés à l'irrigation par les eaux usées.