2012 archive of Newsletters published by both The RACK and other publishers on various agricultural topics .
Proper Use of Phosphate Essential to Early Season Development
Adequate plant nutrition is essential for profitable canola production. Plants with high level of nutrients are able to withstand environmental stresses and pests. Early plant establishment and vigor also reduce plant vulnerability and contributes positively to high yields. After germination, nutrients for the young seedling are available in the soil either as applied by the grower or leftover from previous activities. Due to continuous cropping most agricultural lands in Canada depend heavily on application of fertilizers to obtain higher crop yields. Fertilizers that contain major nutrients for plant growth such nitrogen, phosphorus, potassium and sulphur have been used to achieve the desired results. Plants require other micro-elements including calcium, magnesium, zinc, iron, manganese and boron for healthy growth. Both the macro and micro minerals are applied either as bulk or staggered during the plant vegetative growth stage.
Inside this issue: Cutworms; Got Fertilizer?; Reduce your Nitrogen Loss; Variable Rate Technology. V4 Issue-3
After seeing some damage in the recent years it is increasingly important to keep an eye out for cutworms. Cutworms can affect most crops butare of the biggest concern in crops with low plantcounts such as peas, chickpeas, lentils and canola.There are various species of cutworms, which isimportant as different species have differentfeeding techniques and different lifecycles.
In the fall months, adultcutworms may lay upto 1000 eggs in thesoil with each specieshaving differing preferences on location. DuringApril and May the eggs hatch and the larvaebegin feeding on the plant seedlings. Dependingon the species, the larvae moult six or seventimes, during which time they do not feed.
When moulting they remain a few centimeters belowthe soil in an idle state. Studies in Alberta havefound that 20%-50% of the cutworms in a fieldcould be in the idle state. This is problematic whentrying to use insecticide to control cut worms, assome larvae are inactive in the soil at the time ofapplication. To determine the difference betweenthe moulting stage and non moulting stage; anon-moulting larvae will have green plant matterin its stomach whereas a moulting larvae will havean empty stomach. After the larvae have finishedfeeding they will burrow deeper in the soil andpupate. After pupation, adult moths emergeand will begin laying eggs within a week ofemergence. It is hard to predict the damage andlength of risk on cutworms as the larval stage canshorten or lengthen up to thirty days dependingon the species and temperature.
When scouting for cutworms, you should checkevery week from mid May until early June. Damage will appear as missing rows or patches inthe field where you will find bare spots or wiltedcut off plants. Plantsare generally cut offat ground level andlay wilted on top ofthe soil. The cutwormsfeed at night which makes it hard to see them, butafter finding damage, if you dig near a damagedplant you will likely find a cutworm. Estimatedeconomic thresholds in canola are reached whenmore than 3-4 cutworms/m2 are present.
Control methods for cutworms are difficult,especially if they are in a moulting stageProducts such as Permethrin or Chlorpyrifos canbe effective as they act through both contactand ingestion. Application in the very earlymorning or late evening will be more effectiveas the cutworms prefer to feed at night. Culturalcontrol methods, although not always practical intoday's direct seeding world, include tilling 10-14days prior to seeding, tilling prior to cold weatherand leaving a crust on the soil in the fall to deteradults from laying eggs. In some cases, treatmentthat is localized to the affected patches may bemore economical.
Are You Wasting Your Glyphosate? V4 Issue-2
Every year, Western Canadian Farmers spray glyphosate on their farms, and every year, they waste up to half of what they are applying. Glyphosate can be easily inactivated in the field in the spray solution and on the weed surface. Luckily, this inactivation can be easily prevented through the use of water conditioners.
It is not a secret that hard water is hard on glyphosate. But have you ever wondered why? Hard water contains high levels of Calcium and Magnesium, both of which are positively charged ions. These are the same ions that are responsible for the scale build up in your coffee pot or household taps. Because a glyphosate molecule carries a negative charge, the positive Calcium and Magnesium attract the glyphosate and hold onto the molecule. When the molecule is bound to the positive ions, it is unable to reach its final destination in the plant thus reducing the activity of the herbicide. In some cases the glyphosate molecule may still be capable of entering the leaf surface however the bound Calcium and Magnesium ions slow it down drastically. This lengthens the herbicide activity and decreases the efficacy.