scholarly journals Evaluating Biorational Pesticides for Controlling Arthropod Pests and their Phytotoxic Effects on Greenhouse Crops

1998 ◽  
Vol 8 (2) ◽  
pp. 185-192 ◽  
Author(s):  
Fredric Miller ◽  
Susan Uetz

Horticultural oil and insecticidal soap were as effective as conventional insecticides and miticides in controlling a variety of sap-feeding insects and mites on common greenhouse crops. Neem extract (Margosan-O or Azatin) was less consistent and provided intermediate to good control of a variety of sap-feeding insects and mites on common greenhouse crops. Except for purple heart (Setcreasea purpurea K. Schum. & Sydow) and wax ivy (Hoya carnosa R. Br.), repetitive sprays of horticultural oil, insecticidal soap, and neem extract (Azatin) did not seem to cause any noticeable phytotoxicity or effect the growth of 52 species or cultivars of bedding plants and 13 species of foliage plants examined in this study. Repetitive sprays of horticultural oil and insecticidal soap significantly affected plant height and final quality of some poinsettia cultivars evaluated in this study.

1998 ◽  
Vol 8 (4) ◽  
pp. 529-534 ◽  
Author(s):  
Joyce G. Latimer

Mechanical conditioning is an excellent means of regulating the growth of vegetable transplants and some ornamental bedding plants. It improves the stature, appearance, handling characteristics, and overall quality of treated plants. The application procedures reported for transplants have included wind, shaking, brushing, and more recently impedance; all of which result in physical displacement of the growing points. Brushing has been most commonly studied for mechanical conditioning in high density transplant production. Brushing reduces plant height, increases stem and petiole strength, improves insect resistance in the greenhouse, tends to improve stress tolerance and enhance stand establishment in the field, and has no effect on crop yield. Although growers using the technique have been very pleased with the quality of brushed vegetable transplants, widespread commercial application of brushing is limited by a lack of automation.


2013 ◽  
Vol 23 (6) ◽  
pp. 823-829 ◽  
Author(s):  
David Llewellyn ◽  
Youbin Zheng ◽  
Mike Dixon

Hanging basket (HB) production alters the light environment in the lower canopy of ornamental greenhouses by intercepting and altering the spectral quality of incoming light. If shading is sufficiently high, the quality of the lower crops can be reduced. This work investigated changes in light quantity and quality at the lower crop level caused by HB production in Ontario, Canada. Light sampling occurred at three commercial greenhouse facilities throughout the Spring 2012 HB season. The greenhouses represented a range of HB densities (1.8, 2.4, and 3.0 baskets/m2) and different HB canopy architectures (one, two, and three tiers of HBs). Light samples were taken at three fixed locations within each greenhouse facility: outside, HB level, and lower crop level. Photosynthetically active radiation (PAR) was logged continuously at each location within each greenhouse environment. Spectral scans were made at each sampling location, within each greenhouse facility, at various times throughout the season to assess how HB production altered the red to far red ratio (R:FR) at lower crop level. As the season progressed, outdoor daily light integrals (DLIs) more than doubled from <20 to >40 mol·m−2·d−1. Light reduction caused by polyethylene films and structural components varied among locations, but remained steady throughout the season, averaging 48.3% for the three locations. As the HB crops matured, the rate of decrease in PAR at lower crop level varied according to facility and HB density with mean reductions of 42.5%, 32.6%, and 37.7% for the one-, two-, and three-tiered facilities, respectively. Mean lower crop level DLIs were all very similar, between 9.4 and 9.9 mol·m−2·d−1. Accordingly, there may be insufficient light below HB canopies to produce high-quality crops of many varieties of bedding plants that are commonly grown in Ontario. The one- and two-tiered systems reduced the R:FR at lower crop level by 14% and 10%, respectively, whereas the three-tiered system caused no reduction. More work is required to determine if the observed far red shift is sufficient to alter crop quality. These case studies provide a backdrop against which to help determine and interpret horticultural management strategies for a variety of greenhouse crops.


Agrociencia ◽  
2021 ◽  
Vol 55 (7) ◽  
pp. 597-610
Author(s):  
Odón Castañeda Castro ◽  
Miriam Cristina Pastelín Solano ◽  
Libia Iris Trejo Téllez ◽  
Eduardo Ariel Solano Pastelín ◽  
Fernando Carlos Gómez Merino

Sugarcane (Saccharum spp. hybrids) is moderately sensitive to salinity and the effects on plant performance vary according to stress level and genotype. This study aimed to evaluate the effect of salt stress induced by application of different NaCl levels in the irrigation solution on plant height, indirect index of chlorophylls (SPAD), and macronutrients concentration (N, P, K, Ca, Mg and S) and Na in leaves of two sugarcane varieties: CP 72-2086 and Mex 69-290. The experiment was set in a completely randomized design with a 2×5 factorial arrangement. The study factors were sugarcane variety (CP 72-2086 and Mex 69-290) and NaCl concentration (0.0, 71.8, 143.6, 215.4 and  282.7 mM NaCl). Salinity as a single factor negatively affected plant height, SPAD units and N and P concentration in leaves; Ca concentrations increased, while K, Mg and S remained unaffected by the tested NaCl levels. Mex 69-290 grew higher and concentrated greater levels of N and K. Interactions of factors showed that salinity reduced growth in both varieties, but this reduction was more pronounced in CP 72-2086. SPAD units were also significantly reduced by salinity in both varieties. Concentrations of N and P in leaves decreased in both varieties in response to NaCl, while those of K and Ca increased in Mex 69-290. Concentration of Na was higher in Mex 69-290 which exhibited better performance than CP 72-2086. Sodium concentrations in leaves increased in direct relation to the tested NaCl concentrations. Mex 69-290 reached higher concentrations of Na in leave tissues but displayed better health than CP 72-2086. Thus, the variety Mex 69-290 showed more efficient Na-tolerance mechanisms related to Ca and K concentrations, and an indirect chlorophyll index better than CP 72-2086.


2017 ◽  
Vol 38 (4Supl1) ◽  
pp. 2399 ◽  
Author(s):  
Diogo Brito de Almeida ◽  
José Geraldo Barbosa ◽  
José Antônio Saraiva Grossi ◽  
Fernando Luiz Finger ◽  
Joice Crescencio Heidemann

Exposure of bulbs to cold, a physiological phenomenon called vernalization, and bulb size are important factors in the production of lily bulbs and flowers. This study aimed to verify the influence of vernalization of bulbs on flowering cut lily plants, as well as the impact of size and shape of harvest on the production and quality of flowers and bulbs. In turn, the way the stems of the plants used for cut-flower production are cropped is of higher importance for the production of new flower bulbs. In this sense, the experiment was conducted in Viçosa, MG, in a greenhouse in a randomized block design, in split splot scheme with three replications, in which the vernalization periods (25, 35 and 45 days at 4 ± 1 C) constituted the plots; bulb sizes (diameters of 3.2-3.8 cm; 2.5-3.2 cm 1.9- and 2.5 cm), subplots and ways to harvest (full harvest of the stem at the required length for the commercial harvest of the flower, commercial stem harvest at the commercial length, maintaining 10cm of stem in the soil; removal of the floral buds as soon as their appearance is observed and harvest at the end of the season), the sub subplots. The bulbs were planted in beds, with 15 x 20 cm spacing. It was evaluated the number of plants that flowered and the number of flowers, the length and the diameter of the floral buds, fresh and dry weights, diameter and plant height as well as number, perimeter and amount of fresh and dry bulbs. There was a decrease in the plant height with the increase of the vernalization period and a reduction of the diameter of the planted bulbs, as well as of the number and the fresh and dry weights of the produced buds. The production of flowers and buds in number, size and weight was directly proportional to the size of the planted bulbs, while the form of harvest with removal of flower buds increased the number, the perimeter and the fresh and dry weights of the buds. Bulbs with diameter between 3.2 - 3.8 cm, stored for 25 days in cold chamber enable greater production of flowers and the highest stem height, factors that favor the increase in market value.


1994 ◽  
Vol 8 (1) ◽  
pp. 119-123 ◽  
Author(s):  
Alan C. York ◽  
Stewart M. Turner ◽  
Ronald E. Jarrett

The response of ‘Florico,’ ‘Victoria,’ and 'Stan II’ triticale to 2,4-D, dicamba, 2,4-D plus dicamba, diclofop, and thifensulfuron plus tribenuron applied POST during the tillering stage was examined. At rates twice those recommended for application to wheat, Victoria and Stan II were not injured, and injury to Florico was less than 10%. None of the herbicides or combinations adversely affected plant height at maturity, tiller or spike production, grain weight/spike, kernel weight, kernels/spike, yield, or test weight of any cultivar. Cultivars varied in tiller production, height, yield, test weight, kernel weight, and kernels/spike.


2020 ◽  
Vol 24 ◽  
Author(s):  
Ismael Leonardo Vera-Puerto ◽  
Jorge Leonardo Olave-Vera ◽  
Sussy Tapia ◽  
Wladimir Antonio Chávez ◽  
Carlos Arias

The aim of this work is to evaluate the reuse of municipal wastewaters treated through subsurface constructed wetlands (SS-CWs) as irrigation water in cut flower aeroponic cultivation under arid conditions. For this purpose, two experimental aeroponic cultivation systems were installed with the cut flower Lilium ‘Tresor’ planted and irrigated with SS-CWs treated water. The results showed that the quality of the SS-CWs wastewater has to be improved to be used in irrigation. Despite that, Lilium ‘Tresor’ grew under arid conditions with normal stem diameters and number of flowers but with heights under 0.65 m, which would restrict their commercialization to local markets. Water electrical conductivity (> 2300 µs/cm) and luminosity (> 120 klux) were factors that affected plant height. When compared to other cultivation systems, the aeroponic cultivation system used between 10 % and 20 % of the amount of water needed to produce Lilium ‘Tresor.’ Thus, this work showed the feasibility to produce cut flowers using an aeroponic cultivation system under arid conditions and irrigated with SS-CWs effluents. Likewise, it was detected that improvements to water quality and luminosity must be made for industrial scaling.


Author(s):  
Irpan Gunawan ◽  
Atak Tauhid ◽  
Isna Tustiyani

<p><em>Cauliflower is one of the vegetables for consumers. The demand for cauliflower was rising so it must be scaled up with fertilizer. The purpose of this study was to study the effect of chicken manure and NPK fertilizer on the growth and yield of cauliflower. The study was conducted in Sukasenang Village, Banyuresmi Sub-district, Garut Regency from July to August 2019. The study used a Randomized Block Design (RBD) in two factors each of the 3 rates with 2 replications. The first factor was the rates of chicken manure which consisted of 0, 10 and 20 tons ha<sup>-1</sup>; the second factor was NPK fertilizer which consists of 0, 100 and 200 kg ha<sup>-1</sup>. The parameter of this research was plant height, number of leaves, leaf area, weight and diameter crud. The results showed that there was no interaction between the chicken manure and NPK fertilizer. The treatment of 20 tons ha<sup>-1</sup> chicken manure affected the variable plant height, the number of leaves and leaf area. The rates of 200 kg ha<sup>-1</sup> NPK fertilizer had affected plant height, number of leaves, weight and diameter crud.</em></p>


Genetika ◽  
2018 ◽  
Vol 50 (1) ◽  
pp. 1-10
Author(s):  
Vesna Jankovic ◽  
Savo Vuckovic ◽  
Vojislav Mihailovic ◽  
Vera Popovic ◽  
Ljubisa Zivanovic ◽  
...  

Phleum pratense (L.) is the important forage grass species in Serbia. The study was conducted on 20 autochthonous population of Phleum pratense (L.), originating from Western Serbia. Plant height, protein content and crude cellulose content had a high direct impact on yield. Populations of PP16, PP20, PP2 and PP9 had the significantly higher yield of the raw matter compared to all the tested population and the highest values for the other evaluated parameters, also. The average yield of crude biomass was positive statistically highly significantly correlated with plant height (r=0.87**), and positively significantly correlated with a content of crude proteins and positive non significant correlated with crude cellulose (r=0.42 ns). Based on obtained values and by the appropriate choice of selection methods, we conclude that we have excellent genotypes, PP16, PP20, PP2 and PP9 for a successful selection process in order to obtain new high yielding varieties of Phleum pratense.


2016 ◽  
Vol 17 (1) ◽  
pp. 12 ◽  
Author(s):  
Tintin Suhartini ◽  
NFN Hadiatmi

<p>Morphological Characteristics Variability of Arrowroot (Marantha arundinaceae L.). The arrowroot has been recognized by most society member of Indonesia as a source of potential foodstuf. The arrowroot has low glicemic index, and high carbohydrate content, high quality of flour and can replace position of wheat flour as food material and industry. Evaluation and characterization are needed to get informations of superior characteristic of arrowroot as source of genetic variability to develop promising new arrowroot varieties. The result showed that the morphological characteristic of 20 arrowroot accecions were not different on the qualitative characteristics. The characteristics of leaf colour, stem and stalk leaf colour, and white colour of tuber were not different among arrowroot accecions. The quantitative characteristics of tuber or rhizomes type (tuber length and tuber circle), plant height, number of tiller/hill, total leaf/main stem, leaf length and leaf width among accecions had low variability. The tuber weight per hill had positive correlation with plant height, number of leaf, tuber length and tuber circle and negative correlation with leaf length, leaf width and stalk length leaf.</p><p> </p><p><strong>Abstrak</strong></p><p>Garut (Marantha arundinaceae L.) merupakan sumber pangan yang potensial bagi sebagian masyarakat di Indonesia. Garut memiliki indeks glikemik rendah dan kandungan karbohidrat tinggi. Tepung garut dapat menggantikan terigu sebagai bahan makanan dan industri. Evaluasi dan karakterisasi garut perlu dilakukan untuk memperoleh informasi sifat-sifat unggul untuk dapat digunakan dalam perakitan varietas unggul. Hasil evaluasi 20 aksesi garut yang dikarakterisasi menunjukan tidak ada perbedaan morfologis sifat kualitatif. Warna daun, pelepah dan tangkai daun, bentuk daun, bentuk dan warna umbi memiliki kesamaan antaraksesi. Karakter kuantitatif pada bentuk umbi (panjang dan lingkar umbi), tinggi tanaman, jumlah anakan/rumpun, jumlah daun pada batang utama, panjang dan lebar daun antar aksesi plasma nutfah garut memiliki keragaman yang sempit. Hasil analisis menunjukkan bahwa bobot umbi per rumpun berkorelasi positif dengan tinggi tanaman, jumlah daun, panjang, lingkar umbi, dan berkorelasi negatif dengan panjang daun, lebar daun, dan panjang tangkai daun.</p>


Author(s):  
Luis Osmar Braga Schuch ◽  
Igor Kohls ◽  
Andreia da Silva Almeida ◽  
Cristiane Deuner ◽  
Jerffeson Araujo Cavalcante

<p>La calidad fisiológica de la semilla podría afectar el rendimiento de granos de arroz. Las diferencias en la calidad fisiológica de las semillas pueden causar la reducción y desuniformidad de la emergencia en el campo, acarreando una diferencia en el crecimiento inicial de las plantas, y consecuentemente afectando el cultivo y su rendimiento. Se realizo un experimento con el objetivo de evaluar la distribución espacial y la variabilidad en la población entre las plantas de arroz, en función de la calidad fisiológica de las semillas. Fueron utilizados nueve lotes de semillas de la cultivar BR-IRGA 410, siendo tres de alta, tres de media y tres de baja calidad fisiológica. Cada bloque consistió de nueve líneas de 5,5 metros de longitud, separadas por 0,12 metros. Se evaluó el número de fallas consecutivas y la variabilidad entre las plantas a través del coeficiente de variación de la altura de plantas y de la materia seca. El uso de las semillas con baja calidad fisiológica proporcionó mayor desuniformidad en la distribución espacial de la planta en el campo, y una mayor variabilidad entre las plantas que componen la población, lo que puede proporcionar un aumento en la competencia intra-especifica.</p><p align="center"><strong><em>Seeds physiological quality and variability among plants in populations of rice</em></strong><strong><em> </em></strong></p><p><strong>Abstract: </strong>Several authors try to relate the physiological quality of seeds with grain yield of rice. Differences in the physiological quality of seeds can cause reduction and uniformity of emergence in the field, leading to differential on early seedling growth, and consequently affecting the culture and your yield. An experiment was conducted to evaluate the spatial distribution and variability in populations of rice plants, depending on the physiological quality of seeds. Were used nine seed lots of cultivar BR-IRGA 410, three lots of high, three lots of medium and three lots of low physiological quality. Each block was composed of nine lines of 5.5 meters in length, spaced 0.12 meters. We evaluated the number of consecutive failures in emergence, and plant variability through the coefficient of variation of plant height and dry matter. The use of seed with low physiological quality provides increased uniformity in the spatial distribution of plants in the field, and greater variability from plants comprising the population, which can provide an increase in intra-specific competition.</p><p> </p>


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