Creeping bentgrass summer decline as influenced by climatic conditions and cultural practices

2020 ◽  
Vol 112 (5) ◽  
pp. 3500-3512 ◽  
Author(s):  
Grady L. Miller ◽  
Mark A. Brotherton
Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 550
Author(s):  
Panagiotis Kanatas ◽  
Ioannis Gazoulis ◽  
Ilias Travlos

Irrigation is an agronomic practice of major importance in alfalfa (Medicago sativa L), especially in the semiarid environments of Southern Europe. Field experimentation was conducted in Western Greece (2016–2018) to evaluate the effects of irrigation timing on weed presence, alfalfa yield performance, and forage quality. In a randomized complete block design (four replications), two cultivars (“Ypati 84” and “Hyliki”) were the main plots, while three irrigation timings were the subplots (split-plot). The irrigation timings were IT-1, IT-2, and IT-3, denoting irrigation 1 week before harvest, 1 week after harvest, and 2 weeks after harvest, respectively. IT-1 reduced Solanum nigrum L. density by 54% and 79% as compared to IT-3 and IT-2, respectively. Chenopodium album L. density was the highest under IT-2. IT-3 resulted in 41% lower Amaranthus retroflexus L. density in comparison to IT-2, while the lowest values were observed under IT-1. Stand density and stems·plant−1 varied between years (p ≤ 0.05). Mass·stem−1 and alfalfa forage yield were affected by the irrigation timings (p ≤ 0.001). Total weed density and forage yield were negatively correlated in both the second (R2 = 87.013%) and the fourth (R2 = 82.691%) harvests. IT-1 and IT-3 increased forage yield, leaf per stem ratio, and crude protein as compared to IT-2. Further research is required to utilize the use of cultural practices for weed management in perennial forages under different soil and climatic conditions.


2021 ◽  
Vol 8 (1) ◽  
pp. 4
Author(s):  
María D. Ortolá ◽  
María Luisa Castelló ◽  
Maria C. Etchevers ◽  
Francisco José García-Mares ◽  
María D. Soriano

Moringa oleifera is a foliated tree widely cultivated in tropical latitudes, which is highly adaptable to climatic conditions and dry soils. Every part of the plant has nutritional, therapeutic or industrial benefits. This is due to its phytochemicals such as glucosinolates, phenolic compounds, alkaloids, terpenoids and tannins, high values of crude protein, carbohydrates, starch and lipids. In addition, the use of the leaves has increased considerably by the agro-food and biochemical industries since they are a valuable source of dietary proteins and essential amino acids. This work aimed to characterize three types of leaf from Moringa oleifera seeds with different origins (Thai (C1), Ghana (C2) and India (C3)), grown in the same plot, but with different cultural practices (intended for leaf production (C1 and C2) or sheath production (C3). For this, water content and optical properties were determined in the fresh leaves. Later the leaves were dried (50 °C for 8 h) and pulverized, analyzing their water content, antioxidant capacity, color and amino acid content. No significant differences were observed in fresh leaves in terms of humidity and color. In dry powder, a higher antioxidant capacity was registered in moringa type C2, with a% DPPH inhibition of 83.7%, although in all cases, it exceeded 60%, showing the high persistence of the antioxidants after drying. Serine, glutamic acid and alanine were the major amino acids with values of 373 ± 78, 301 ± 51 and 248 ± 9 mg/100 g of powder, respectively, without influencing the applied field treatment or origin.


2021 ◽  
pp. 1-10
Author(s):  
Laban K. Rutto ◽  
Yixiang Xu ◽  
Shuxin Ren ◽  
Holly Scoggins ◽  
Jeanine Davis

‘Hop’ (Humulus lupulus) cultivar trials were conducted at sites in three Virginia counties (Northampton, Chesterfield, and Madison) in response to demand by the craft beer industry for local ingredients. In 2016, a replicated study involving five cultivars (Cascade, Chinook, Newport, Nugget, and Zeus) was established on an 18-ft-tall trellis system at each site. Weather data influencing infectivity of downy mildew (Pseudoperonospora humuli) and powdery mildew (Podosphaera macularis), two economically important hop diseases, was collected, and to the extent possible, similar cultural practices were applied at each site. Climatic conditions favorable to P. humuli and P. macularis were present throughout the experimental period, and P. humuli infection was widespread at all sites starting from 2017. Among common pests, Japanese beetle (Popillia japonica) was the only one observed to cause significant damage. Unseasonably high rainfall in 2018 led to crop failure at all but the Northampton site, and harvesting was done at all sites only in 2017 and 2019. Yields (kilograms per hectare by weight) in 2017 were found to be ≥45% lower than second-year estimates for yards in the north and northwestern United States. Quality attributes (α and β acids; essential oil) for cones harvested from the Chesterfield site were comparable to published ranges for ‘Cascade’ in 2019, but lower for the other cultivars. More work is needed to identify or develop cultivars better suited to conditions in the southeastern United States. The influence of terroir on quality of commercial cultivars produced in the region should also be examined.


2019 ◽  
Vol 40 (03) ◽  
Author(s):  
U Barua ◽  
R P Das ◽  
B Gogoi ◽  
S R Baruah

India is endowed with a rich genetic diversity of fruits. The Hindustani centre represents 344 species of fruits. Northeast India, meeting ground of Indo-Malayan and Indo-Chinese bio-geographical areas is one of the 18 mega-biodiversity centers of the World, has contributed the fruit genera like Citrus, Musa, Mangifera, Docynia, Elaeocarpus, Myrica, Morus, Artocarpus, etc. There are a quite large number of indigenous and underutilized fruit crops, which are being used by the local inhabitants in rural areas. These underutilized fruits are fairly rich in vitamins, minerals, antioxidant properties and are serving as protective food. Because of their curative properties, different parts of these fruit and plants have been used in ethno-medicines. Apart from their nutritive and medicinal values quite a few of these underutilized fruits have good flavor, colour and juice content and can be used for value additions. Several underutilized fruit species which have potential for commercial exploitation are yet to be utilized to their potential. These fruit crops have not undergone any conscious phase of domestication and selection. Their cultivation is very restricted and they grow in wild and semi wild condition and adapted to local climatic conditions. Hence they can thrive even under most adverse situation. Their adoption on a commercial scale, with crop improvement, standardization of cultural practices and popularization in diverse farming systems and value additions are warranted to achieve stability in farm production and food security. Many underutilized species, well adapted to marginal lands and with low cost inputs, may thus be of great benefit for the survival of poor communities, employment generation and sustainability of agricultural ecosystems.


HortScience ◽  
1997 ◽  
Vol 32 (5) ◽  
pp. 878-879 ◽  
Author(s):  
A.M. Rist ◽  
R.E. Gaussoin ◽  
R.C. Shearman ◽  
J.D. Fry ◽  
W.W. Stroup

Golfers are demanding increased ball roll distances on a daily basis, but cultural practices to achieve this often are detrimental to the green. One option for increasing ball roll distance without altering cultural practices may be to select creeping bentgrass genotypes that provide less resistance to ball roll. Studies were conducted at the John Seaton Anderson Turfgrass and Ornamental Research Facility near Ithaca, Neb., and at the Rocky Ford Turfgrass Research Facility in Manhattan, Kans., to determine genotype and seasonal influences on golf ball roll distance. Eighteen creeping bentgrass (Agrostis palustris Huds.) genotypes were evaluated. Genotype was not a significant source of variability, but the location × season interaction was. Significant seasonal differences in ball roll occurred at both locations. Ball roll distances for spring, summer, and fall were 98, 15, and 31 cm greater at the Nebraska test location than at the Kansas site. Correlations between turfgrass visual quality and ball roll distance were not significant. Therefore, the use of genotypes exhibiting high turfgrass visual quality will not necessarily result in longer ball rolls. Since there were no season × genotype or genotype × location interactions, ball roll distance on genotypes at each location changed similarly with season. Genotype selection appears to have little influence on ball roll distance under the conditions tested at these two locations.


1992 ◽  
Vol 25 (11) ◽  
pp. 69-76 ◽  
Author(s):  
S. Li ◽  
J. Migita

A mathematical model is developed to predict the runoff of pesticides from paddy field to a river. The model describes the long term runoff as a function of physical-chemical properties of pesticides, cultural practices and climatic conditions. It is assumed that the adsorption and desorption of pesticides between soil and water phases are in equilibrium state, while the degradation in water and soil and the evaporation from water to atmosphere are of first-order reaction. The model is used to examine the relationships between the seasonal amounts of pesticide runoff and their environmental dynamic factors. A four-stage evaluation system is proposed to assess the impact of the runoff on drinking water by taking into account the amount of application, runoff ratio, toxicity and the possibility of being removed from raw water by water purification processes. The model simulates the daily variation of contaminant level in river water, thereby providing a basis for making recommendations for pesticide usage and water management for rice cultivation.


Biologia ◽  
2009 ◽  
Vol 64 (3) ◽  
Author(s):  
Valérie Hauchart

AbstractCotton cropping has been developing for more than 40 years in the western part of Burkina Faso. It has made a definite modernization of the traditional farming system. Modernization is illustrated by adoption of specific agricultural practices like monoculture, tillage, straight sowing and slope ridge planting. Misuse and non-adaptable local pedologic and climatic context of these new practices perturb soil hydrological processes. Outcomes are water loss by runoff, erosion and changes in the soils physical and physiochemical properties.Besides, we can notice in this area for more than 30 years climatic changes which require us to ask ourselves what are the resulting consequences. In fact, these climatic changes generate an extension of the rainy season, an increase in the frequency of high intensity spells but also recurrence of dry spells during the rainy season. Do these new climatic conditions exacerbate the consequences of cotton practices on hydrological processes and induce an aggravation of flow and erosion processes?These evolutions have direct consequences on crop production whereas needs are highly increasing. The improvement of the prevailing agricultural practices and innovative practices might provide improved pluvial resources in critical moments such as rainfall excess at the beginning and the end of the rainy season and short drought conditions after sowing or germination and during flowering. However two questions arise. In the rainfed agriculture, which cultural practices (to reduce runoff and to favour infiltration) are, in regard to pedologic, climatic or socio-economic context, able to allow improved water efficiency and, as a result, an increase of the food grains production? Might selected practices and production addition satisfy requirements of the coming population?


1992 ◽  
Vol 119 (1) ◽  
pp. 1-12 ◽  
Author(s):  
G. S. McMaster ◽  
W. W. Wilhelm ◽  
J. A. Morgan

SummarySimulation models are heuristic tools for integrating diverse processes and help to increase our understanding of complex processes and systems. Models that predict crop development can serve as decision-support tools in crop management. This paper describes a phenology simulation model for the winter wheat shoot apex and reports validation and sensitivity analysis results.The complete developmental sequence of the winter wheat shoot apex is quantitatively outlined and correlated with commonly recognised phenological growth stages. The phyllochron is used to measure the thermal time between most phenological growth stages, thereby increasing the flexibility over the growing degree-day (GDD) and photothermal approaches. Nineteen site-years covering a range of climatic conditions, cultural practices and cultivars across the Central Great Plains, USA, are used to validate the model.Validation results show that the predicted phyllochron (108 GDD) agrees well with the observed phyllochron (107 GDD) for ten cultivars. Mean seedling emergence is predicted to within 2 days in almost all of the 19 site-years. The ability of the model to predict growth stages accurately increased successively from jointing to heading to maturity. Maturity is generally predicted to within 5 days of the observed day.After validation, recalibration of the phyllochron estimates between growth stages are provided, and corrections for mesic and xeric conditions are suggested. Further validation of the entire developmental sequence of the shoot apex is recommended.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 750F-750
Author(s):  
Leslie A. Weston ◽  
M.M. Barth

Vegetables provide a major source of essential vitamins such as ascorbic acid and beta carotene and other quality components in the human diet. Postharvest yield and quality of vegetables depend upon genetic, biotic, edaphic, chemic and other factors, as well as combinations of these factors. Successful production, quality and nutritional value of vegetables are related to both primary and secondary metabolic processes occurring during vegetable growth and development. Related research has focused upon cultivar selection, cultural practices used during production, interaction of light and temperature, and use of chemicals for growth regulation, and pest control. We will discuss the effects of genetic, pest, and soil management; crop maturity at harvest; environmental modification; and climatic conditions. Postharvest vegetable quality will be characterized in terms of vitamin content, appearance, yield, and flavor.


1974 ◽  
Vol 8 (2) ◽  
pp. 81-88 ◽  
Author(s):  
William L Sims ◽  
Vincent E Rubatzky

Climatic conditions in California are so favourable that intensive outdoor horticultural production is economically feasible despite the inconvenience and expense of long-distance transport to high population centres in NE and N Central USA. Processing tomatoes typify the warm season, machine-harvested, outdoor crops, and crisp-headed lettuce the cool season, fresh market, hand-harvested crops. Cultural practices, including control of weeds, pests and diseases, are outlined.


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