Xtremehorticulture

Xtremehorticulture of the Desert

Use of Oregano Essential Oils to Control Food Spoilage

Leave a Comment / food spoilage, oregano oil /

Essential oils (EO) have stood out for their potential application as antimicrobial agents, playing an important role in ensuring food quality and safety. In addition, the synergistic effect of EO blends can improve action spectrum for more effective applications.  The purpose of this research was to evaluate the in vitro antimicrobial activity of oregano, sweet fennel, and cinnamon EOs, and their blends, against the pathogenic bacteria Escherichia coli and Staphylococcus aureus, and the fungus Penicillium spp. The antimicrobial activity was determined by the diskdiffusion method, at both microbial optimal growth temperature and refrigeration temperature.  Different EO volumes were investigated, and an effective inhibition was observed for the concentration of 3 μL. Oregano EO has proven to be effective in all assays, when compared to the EO combinations. International Food Research Journal 25(2): 540-544 (April 2018) Go to the Journal Article

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Apricot and Apple Tree Growing Poorly

1 Comment / Apple, apricot, fertilizer, sparse growth /

Q. My apple and apricot trees have small leaves and not much new growth. The few dark green leaves are almost dead. I fertilized the plant in the prescribed periods and watered the plant as in previous years. The apple tree made flowers but few fruits. The apricot had lots of apricots and dropped some earlier but few green leaves. Apricot tree sparse and not filling in properly. Having a tree with the canopy this open can lead to borer problems if it doesn’t already have them. Apple tree is sparse. The same thing applies to Apple trees. They need enough water and a big enough basin to water the roots, nutrients which we supply through rich compost or fertilizers, and a surface mulch which decomposes to enrich the soil. A. Thanks for the pictures. I think the problems are a combination of water, fertilizer and soil. As you know, the trees should be thick and dense this time of year. They are not because, I think, they lack these three ingredients. Water Your trees are about 8 to 10 feet tall and would need about 20 to 30 gallons of water every other day during the hot summer months. As trees get older and larger, they need more water. That works out to about 75 to 100 gallons each week.             There is a basin at the bottom of the tree that is maybe 3 feet in diameter. Increase the size of that basin to about 6 feet in diameter or 3 feet from the trunk in all directions. That will accommodate more water and spread it about a foot beyond the basin. Compost or fertilizer             Spread about 1 cubic foot of good quality compost in the basin away from the trunk before you water it again. This compost should have a high nutrient content such as Viragrow’s. Many do not.             After rebuilding the basin in a six-foot diameter around the tree and applying compost, fill the basin with a hose or sprinkler on the end of a hose. Fill the basin twice. Mulch             Cover the soil in the basin with woodchips from local trees if you can find them. If you can’t find any, use straw 4 to 6 inches deep until you can find some woodchips.             Increase the amount of water to the tree by covering that soil with about one – two inches of water flooding the basin. Water the tree three – four times per week using this basin and flooding technique. You should see new growth starting in about 7 to 10 days.

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Design and Installing Lawn Irrigation Not As Easy As It Looks

Leave a Comment / brown spots, lawns, turfgrass /

Q. We installed a lawn 18 months ago, but it has a difficult time during summer months. I aerate it, fertilize it and I know the drainage is good because the landscaper installed the system to our HOA requirements. I water twice daily, six days a week around 5 AM and 9 PM. There is a decent amount of shade and the yard faces south. Even the heavily shaded areas have problems. What can I do differently? Brown patches in lawns during hot summers will quickly show irrigation weaknesses. Notice these patches are also close to the patio where people walk. This area should probably be core aerified annually due to traffic. A. I looked at your pictures and the lawn looks good in most places except for a few small brown areas. Brown spots during summer months frequently point out weaknesses in the irrigation system. In your case the brown spots are also in front of the patio where there is alot of human traffic. Areas like this should be core aerified annually. Hollow tine aerifier             My first suspicion is the irrigation system and was not installed or maintained properly. Let’s cover the basic “must dos” when installing and maintaining an irrigation system. Water pressure The operating water pressure MUST be within the operating range of the sprinkler nozzles. Frequently this is 15– 30 psi. Some expensive sprinkler heads have built in pressure regulators, but lesser expensive ones may not. If the water pressure is too high, fogging or misting will occur out of the nozzle. If the sprinkler head is “fogging”, then brown spots will occur in weak areas. If pressure is too high, reduce it with a pressure regulator. If water pressure is too low, remove any pressure regulator, change it for the proper one or install a booster pump to increase the water pressure. Head to head coverage Water must be thrown from the nozzle far enough to reach neighboring sprinkler heads. Sprinkler heads must be installed at distances specified by the nozzles. These distances are meaningless if you don’t have the right water pressure. Sprinkler nozzles Sprinkler nozzles specify the operating pressure range, allowable spacing between sprinkler heads and precipitation rate in inches per hour among other things. These nozzles must be matched to each other. If someone maintains the irrigation system and replaces a nozzle with the wrong kind, it will produce brown spots in underwatered, weak areas.             Curved areas and re-curved areas of the lawn are the most difficult to water. There are adjustable nozzles that can be used but it will always be a weak irrigation area subject to brown spots.             Never water early at night like at 9 PM. If your lawn is healthy and it has a good irrigation system, one irrigation per day during summer is all that most lawns need IF the sprinkler system was designed and installed correctly. Irrigation should finish just before dawn. If you must water late in the day, apply water so that the grass leaf blades dry before it gets dark.             Don’t rake or catch the grass clippings when mowing. Most mowers now are “mulching mowers” with a special blade and deck design. Returning the clippings to the lawn substitutes for one fertilizer application each season.

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Sap Is Oozing from My Kumquat Limbs

Leave a Comment / citrus, disease, kumquat, sap /

Q. Unfortunately it appears our kumquat trees may have bacterial blast fungus. Our tree appears very healthy and has given us a lot of fruit, but we recently noticed sap coming from the bottom of main branches. What treatment would you recommend? Sam is oozing from the limbs of this kumquat.It sounds crazy but disease stress from management issues can cause sap oozing like this to appear. The KISS rule tells me to look at the soil and watering issues first. A. I usually follow the KISS rules for diagnosing plant problems. Unless we are in a citrus production area, or there is a history of disease on these trees, I first conclude it’s a man-made problem. Regardless, we must rule out the simplest reasons first before we jump to more exotic disease problems.             Root death because soils are kept too wet cause these symptoms on citrus. For this reason, I assume the trees watered too often or there is a water drainage problem in the soil surrounding the roots. Simple test if watering too often issues After the first year of growth, all fruit trees, including citrus, should be rooted firmly in the soil. A simple diagnostic tool helps judge whether wet soils should be a concern or not. Move the tree by its trunk, back and forth, while looking at where the tree enters the soil. The tree should be firmly anchored in the soil and not move it. If tree roots move the soil easily, then the soil has probably been kept too wet and the roots began “drowning” or rotting.              There is a tendency during hot weather to water fruit trees more often, even daily. Most fruit trees, including citrus, prefer at least one day of no watering between watering days. Unless the tree is newly planted, or planted in sand, never water trees daily. Instead, increase the minutes on the clock when you do water. Mulch can add one extra day between irrigations             Anything that shades the surface of the soil during summer helps tree roots function better. Their primary functions regarding tree health are the uptake of minerals and water. They do this better, however, if the surface of the soil is mulched. Woodchips (or even shredded cardboard, shredded newspaper or straw) lying on the soil surface gives fruit trees one extra day between waterings during the summer.             If the soil is not mulched or covered, soils dry quickly and get hot in our summer sun and heat. When soils are wet, tree roots grow where there is a good mix of air and water. Unless the soil has been amended quite a distance from the tree at the time of planting, most of the tiny roots that feed on water and nutrients grow in the top 6 inches of soil.

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Yellow Bird of Paradise Growing Poorly

Leave a Comment / Mexican bird of paradise, planted, poor growth, yellow bird of paradise /

Q. I’ve planted a Mexican Bird of Paradise about three years ago. It has never flowered and has only grown a small amount in that period. Any ideas why? Could it be its location? It doesn’t get morning sun, only afternoon sun. Bird of paradise lack of growth probably because of water, soil amendments and fertilizer. A. Thanks for sending pictures. I must be a little careful because watering too often and not giving the plant enough water can create similar results. Afternoon sun should be enough for this plant. Make sure it’s not near a “hot” wall from the afternoon sun.             Notice how the plant has more foliage, or “leafy growth” because of the suckers, at the bottom? The stems growing above the suckers are nearly void of leaves. That is usually a sign the plant is not getting enough water at each irrigation. It can also indicate the plant doesn’t have much nitrogen fertilizer for growth.             I must be careful because we are considering two things; how much water the plant is getting and how often it gets it. I would recommend watering this plant with about five gallons or more at each watering. Water it three times a week during the summer. Use two drip emitters within six to 12 inches of the base on either side of the plant.             These are “desert plants” but they also can grow in wet landscapes if there is drainage. They grow best in improved and amended soils. If this was planted directly in your landscape soil without soil amendments like compost, or an inferior amendment was used at planting, then it could struggle as well. Apply a good compost within about 12 inches of the plant in a circle and water it in. Use about ¼ bag each plant.             Pull rock away from the base of the plant until it gets firmly established and you see plenty of new growth.

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Heavy Metal Content in Tomatoes Grown in Soils with Biosolids

2 Comments / biosolids, compost, Heavy metals, plant uptake /

HEAVY METAL NUTRIENTS IN TOMATO PLANTS CULTIVATED IN SOIL AMENDED WITH BIOSOLID COMPOSTS1 Authors:   W.J. Melo, A.A.D. Cintra, M.D. Revoredo, L.T. Braz Keywords:   Lycopersicon esculentum Mill., Cu, Mn, Zn, composting process, waste DOI:   10.17660/ActaHortic.2003.627.26 Abstract:The use of biosolids in horticulture could contribute to recycle residues produced by men. This study analyzed concentrations of Cu, Mn and Zn in the compost during fermentation, in the soil amended with the composts and in the tomato plant materials. Five composts were produced using sugar-cane bagasse, biosolid and cattle manure in the proportions: 75-0-25; 75-12.5-12.5; 75-25-0; 50-50-0 and 0-100-0 (composts with 0; 12.5; 25; 50 and 100% biosolid), respectively. These composts were used in an experiment with 6 treatments (the 5 composts and a control with mineral fertilization) in a design of randomized blocks with a split plot design. The control and the treatment of 0% biosolid received inorganic nitrogen. All the treatments received the same amount of N, P and K. Two tomato plants were cultivated in each 24 L pot, in a greenhouse at the Technology Department of the Faculdade de Ciências Agrárias e Veterinárias of the Universidade Estadual Paulista in Jaboticabal County, São Paulo State, Brazil. The concentrations of Cu, Mn and Zn were evaluated in the compost 7, 27, 57, 97 and 127 days after composting began, in the soil 0 and 164 days after the compost applied, and in the plants. Compost, soil and plant samples were subjected to digestion with HNO3, H2O2 and HCl and the metals were determined by AAS. There were positive and significant correlations between Mn in the compost and Mn uptake by the plant (0.46 p>0.05), and between Zn in the compost and Zn concentration in the plant (0.78 p>0.05). Cu, Mn and Zn concentrations increased during composting. The biosolid in the compost supplied Cu and Zn to tomato plants, and the cattle manure supplied Mn to the plants. Note:  There is much discussion in horticulture regarding heavy metals in soils and in plants. What are heavy metals? In the periodic table of elements, heavy metals are those elements identified as metals that have a high atomic weight.  Heavy metals include those that are considered toxic to us and other animals, as well as metals which are nutrients. In the research below, only heavy metals which are considered plant nutrients (at low concentrations) are taken into consideration. Copper = Cu, manganese = Mn, zinc = Zn are plant and animal nutrients at lower concentrations such as reported here. In this report, the heavy metals that were plant nutrients and use of biosolids was considered a “good” thing.

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Use of Tree Spikes to Climb Palms or Not?

Leave a Comment / climbing gaffs, Pruning palms, tree spikes /

Q. I have Mexican fan palm trees that were skinned a few years ago. I just had them trimmed.  The trimmer climbed the trees with spikes. The spikes left holes in the trees. Will this harm them? A. Most likely not but using tree spikes or “gaffs” is not a good idea. The holes created by climbing gaffs create places for diseases to enter the tree. One disease, a lethal disease for Canary island and Mexican fan palms called Fusarium Wilt, can enter the tree through these wounds. This can be particularly true if the gaffs were used first to climb a tree that was infected. Fusarium wilt of palms in Florida Fusarium wilt of plams in California             This disease and others can also be transmitted from tree to tree on pruning equipment if this equipment is not cleaned and sanitized properly between trees. Several methods can be used to sanitize pruning equipment including alcohol, Pine-Sol, TSP or trisodium phosphate, and even 30 seconds of direct heat from a butane lighter.             There isn’t a good reason to NOT clean and sanitize pruning equipment. It’s laziness. Would you go into surgery and let the doctor use a dirty scalpel? If climbing gaffs must be used, at least sharpen, clean and sanitize them before climbing.             I can understand why you might be upset having holes punched into “skinned” palms. Avoid putting holes in the trunk whether it’s pounding nails, pruning with a chainsaw or climbing with gaffs. Climbing gear that create holes are no longer recommended for pruning palms. Taking a gentler approach is preferred. Ladders, “cherry pickers” or scissor lifts are recommended.

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Favorable Growth of Trees in Soils Amended with Compost

Leave a Comment / compost, planting trees /

Effect of organic amendment for the construction of favourable urban soils for tree growth L. Vidal-Beaudet1,4, G. Galopin2 and C. Grosbellet3 1 Agrocampus Ouest, Centre d’Angers, Unité de Recherche EPHor, Angers, France 2 Agrocampus Ouest, Centre d’Angers, UMR IRHS, Angers, France 3 Florentaise, Le Grand Pâtis, Saint Mars du Désert, France 4 IRSTV-FR CNRS 2488, Ecole Centrale de Nantes, Nantes, France SUMMARY  Ornamental tree planting and establishment in cities is a great challenge because urban soil physical properties are unfavourable to the development of root systems. Our objectives were to measure (i) the effects of organic matter on soil physical properties and tree development, and (ii) the effects of ensuing root development on soil physical properties. Using twenty-four 600-L planted or bare soil containers, we monitored physical properties such as dry bulk density, aggregate stability and near-saturated hydraulic conductivity of our reconstituted soils over a 5.5-year period. A 28-cm thick top layer of sandy loam amended with 40% (v/v) sphagnumpeat or organic composts was laid on top of a 28-cm thick layer of sandy loam. Bare-root Ostrya carpinifolia trees were planted in half of the 24 containers, and we monitored shoot development and root biomass and distribution. After 5.5 years, trunk diameter had increased from 59 mm for the control soil to 66 mm for soil mixed with green waste compost, and 74 mm for soil mixed with co-compost of sewage sludge and wood chips. After 4.5 years, trunk diameter was strongly correlated with the total number of axes (r=0.94) and fine root length density (r=0.98), and was confirmed as a good indicator of tree development. Fine root development increased stable aggregate formation in all treatments as compared to bare soil. After 4.5 years after planting, the tree root system induced by a high organic matter input had significantly improved near-saturated hydraulic conductivity and was fit to support fertile urban soils. Keywords aggregation, artificial soil, compost, Ostrya carpinifolia, tree development, urban horticulture Significance of this study What is already known on this subject? The quality of the constructed soil used for backfilling the tree pit plays a major role in tree performance. Soil organic matter content also plays a key role in agronomic fertility, so the use of organic amendments and especially composts appears as an ideal solution to boost urban tree growth. What are the new findings? The addition of high levels of organic composts immediately improved the soil physical properties (e.g., dry bulk density, aggregate stability and hydraulic conductivity) and in return fine tree roots modified soil structure and decreased dry bulk density in the top layer. Correlation coefficients confirmed trunk diameter as a very good indicator of tree above and belowground architecture. What is the expected impact on horticulture? Sustainable tree planting and establishment in cities is a great challenge for managers of urban tree resources. In these cases of urban horticulture, to decrease tree replacement frequency and ensuing costs, it is necessary to improve the establishment and maintenance of trees in cities. To develop urban horticulture, it is essential to educate all the city makers (landscape architects, civil engineers, urban planners, municipal officials and urban farmers) about optimal soil specifications expected for fertile urban soils: choice of organic matter nature, sources of organic matter or mineral material, proportions of organic matter in term of soil structuring and soil profile design.

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