scholarly journals Mechanical Conditioning to Control Height

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.

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.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 545d-545
Author(s):  
D.I. Leskovar ◽  
J.C. Ward ◽  
R.W. Sprague ◽  
A. Meiri

Water pumping restrictions of high-quality irrigation water from underground aquifers is affecting vegetable production in Southwest Texas. There is a need to develop efficient deficit-irrigation strategies to minimize irrigation inputs and maintain crop profitability. Our objective was to determine how growth, yield, and quality of cantaloupe (Cucumis melo L. cv. `Caravelle') are affected by irrigation systems with varying input levels, including drip depth position and polyethylene mulch. Stand establishment systems used were containerized transplants and direct seeding. Field experiments were conducted on a Uvalde silty clay loam soil. Marketable yields increased in the order of pre-irrigation followed by: dry-land conditions, furrow/no-mulch, furrow/mulch, drip-surface (0 cm depth)/mulch, drip-subsurface (10-cm depth)/mulch, and drip-subsurface (30 cm depth)/mulch. Pooled across all drip depth treatments, plants on drip had higher water use efficiency than plants on furrow/no-mulch or furrow/mulch systems. Transplants with drip-surface produced 75% higher total and fruit size No. 9 yields than drip-subsurface (10- or 30-cm depth) during the first harvest, but total yields were unaffected by drip tape position. About similar trends were measured in a subsequent study except for a significant irrigation system (stand establishment interaction for yield. Total yields were highest for transplants on drip-subsurface (10-cm depth) and direct seeded plants on drip-subsurface (10 and 30 cm depth) with mulch.


2021 ◽  
Vol 22 (15) ◽  
pp. 7877
Author(s):  
Fahimeh Shahinnia ◽  
Néstor Carrillo ◽  
Mohammad-Reza Hajirezaei

Environmental adversities, particularly drought and nutrient limitation, are among the major causes of crop losses worldwide. Due to the rapid increase of the world’s population, there is an urgent need to combine knowledge of plant science with innovative applications in agriculture to protect plant growth and thus enhance crop yield. In recent decades, engineering strategies have been successfully developed with the aim to improve growth and stress tolerance in plants. Most strategies applied so far have relied on transgenic approaches and/or chemical treatments. However, to cope with rapid climate change and the need to secure sustainable agriculture and biomass production, innovative approaches need to be developed to effectively meet these challenges and demands. In this review, we summarize recent and advanced strategies that involve the use of plant-related cyanobacterial proteins, macro- and micronutrient management, nutrient-coated nanoparticles, and phytopathogenic organisms, all of which offer promise as protective resources to shield plants from climate challenges and to boost stress tolerance in crops.


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.


Author(s):  
Yu. K. Shashko ◽  
A. L. Dolgova ◽  
M. N. Shashko

Fungi p. Fusarium is one of the most harmful pathogens of wheat diseases. Their harmfulness is caused both by direct losses due to decrease in yield, and indirect as a result of infection of the obtained products with mycotoxins and decrease in process, baking and sowing parameters of grain. Due to high potential losses, analysis of quantitative parameters of harmfulness of fusarium pathogens of spike and grain is relevant. The paper presents data showing the harmfulness of Fusarium of spike and wheat grain. The causes of direct and indirect losses in case of damage to wheat spike by fungi of p. Fusarium. Direct losses of crop yield are shown in the natural conditions of Minsk region and with the epiphytotic development of the disease in case of artificial infection, which can reach over 50 %. The effect of Fusaria on baking properties of wheat is analyzed. It was determined that grain damage causes decrease in weight of 1000 grains and the flour yield when it is used in the milling industry, as well as deterioration in its quality due to decrease in protein and crude gluten level. The effect of pathogens on sowing parameters of grain is determined. It is concluded that for use as seeds in terms of laboratory germination capacity, batches of grain infected with Fusarium only up to 15 % can be accepted. The data obtained will allow us to adapt protective measures against Fusarium of spike and grain and reduce its negative impact on crop yield and quality of the products obtained.


2021 ◽  
Vol 12 ◽  
Author(s):  
Nathan P. Nordstedt ◽  
Michelle L. Jones

Water stress decreases the health and quality of horticulture crops by inhibiting photosynthesis, transpiration, and nutrient uptake. Application of plant growth promoting rhizobacteria (PGPR) can increase the growth, stress tolerance, and overall quality of field and greenhouse grown crops subjected to water stress. Here, we evaluated Serratia plymuthica MBSA-MJ1 for its ability to increase plant growth and quality of Petunia × hybrida (petunia), Impatiens walleriana (impatiens), and Viola × wittrockiana (pansy) plants recovering from severe water stress. Plants were treated weekly with inoculum of MBSA-MJ1, and plant growth and quality were evaluated 2 weeks after recovery from water stress. Application of S. plymuthica MBSA-MJ1 increased the visual quality and shoot biomass of petunia and impatiens and increased the flower number of petunia after recovery from water stress. In addition, in vitro characterizations showed that MBSA-MJ1 is a motile bacterium with moderate levels of antibiotic resistance that can withstand osmotic stress. Further, comprehensive genomic analyses identified genes putatively involved in bacterial osmotic and oxidative stress responses and the synthesis of osmoprotectants and vitamins that could potentially be involved in increasing plant water stress tolerance. This work provides a better understanding of potential mechanisms involved in beneficial plant-microbe interactions under abiotic stress using a novel S. plymuthica strain as a model.


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>


Sign in / Sign up

Export Citation Format

Share Document