greenhouses I shade net I hydroponics I aquaponics
How Powdery Mildew affect Peppers and how to
Prevent Stress on Plants With temperatures soaring during the high intensity of abnormal rainfall patterns and subsequent high humidity, Powdery Mildew can take its toll – if not early detected.
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Healthy n the production of sweet peppers peppers, Powdery Mildew is the most common with healthydisease and it is of vast economical looking foliage importance. The only effective way around them. to control Powdery Mildew is to have a holistic approach on the production of sweet peppers. Example of Powdery Mildew on a leaf. Powdery Mildew in peppers grows within the leaf and can be latent in the plant for 21 days before it becomes evident as having already infected the crop. It can result in defoliation of the plants, from which recovery is exceptionally slow. Hence, it is essential to monitor a crop carefully and react quickly. During its infection of the plant, Powdery Mildew utilizes nutrients from within the plant, interferes with photosynthetic processes, increases transpiration, impairs growth and increases leaf drop and flower loss. Generally, a 10% infection/infestation will result in a 10% yield loss. Conditions that encourage the growth leaf surface. of Powdery Mildew include 15.5 to The reaction of nutrient and 27°C, although powdery mildew can environmental conditions is also survive at temperatures as low as 4O°C, important as under low light conditions, low light intensity magnesium and Powdery Mildew During its infection of the concentrations in the has the ability to plant are reduced. plant, Powdery Mildew even germinate Under conditions utilizes nutrients from in the absence of of high disease within the plant, interferes water. On the other pressure, this low hand, suppressive with photosynthetic level of magnesium conditions include processes, increases could make the plants water on the plant transpiration, impairs more vulnerable as surface for extended they are unable to growth and increases leaf periods of time, build the papillae. drop and flower loss. day temperatures Also, under low light above 32°C and conditions, there is night temperatures above 18°C, direct also a reduced production of sugars sunlight or high pH conditions on the by the plant which will also affect the
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January/February 2021
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Volume 18 No 1
production of papillae. During winter, there are less uptake problems with magnesium and calcium; thereby also a reduced Powdery Mildew problem can be expected at this time. Understandably, the management of the irrigation and fertigation system is essential in controlling the infection. Pulsing has been found to be a highly effective irrigation technique that results in creating a low water tension in the soil medium and consequently increasing yields. Frequency of application is more important than the amount of fertilizer being applied, and this can be directly related to the increased availability of phosphorous and manganese. The importance of light in pepper production is little considered, particularly with regards to field pepper production. Plant density and the trellising of sweet peppers are all about sufficient light. A lack of light will not
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