Bacterias: invisible diseases of the cucumber crop
Tutoring cucumbers is a way to reduce diseases and provides conditions that reduce the incidence and development of bacteria.It is very important to recognize cucumber diseases as soon as symptoms appear, and know their possible treatments to avoid further propagation, increasing the effects of losses or affections they may provoke.A lot of research went into knowing more about these diseases, and has turned into treatments that allow crops to develop without being attacked by pathogens. These treatments are more efficient if they are used in preventive ways, and it has been observed that their efficiency decreases once the crop is affected by the condition.Better results are achieved when preventive measures are used along with sound cultural practices. Tutoring is an essential horticultural practice for growing cucumber. A crop with a tutoring net like suggested by HORTOMALLAS, besides becoming more efficient when applying preventive chemical treatments, it will allows the plant to expand its sun light exposition and capture, while at the same time favoring aeration in between plants, avoiding excessive humidity accumulation that will encourage the development of diseases.
Angular leaf stain (pseudomonas syringae, P. Lachymans)The pathogens responsible for this infection are the cucumber bacterias Pseudomonas lachrymans and P. Syringae. Damages caused by these bacterias are observed on the leaf: on the top it shows points of humidity and on the lower part of the leaf we may see gray colored stains with a watery semblance sometimes delimited with a yellow halo. Sometimes depending on conditions drops of exudate are present. The leaf´s rib limits the stains which makes them have an angular shape. This pathogen may dry and fall from the rest of the leaf causing perforations. Damages that may appear on the fruit are superficial and only skin deep, causing the fruit to have a poor aspect and affecting its marketable opportunity. Bacteria is disseminated by rain or workers´ contact.It is also transmitted by infected seeds. injuries caused by cucumber bacteria stain Symptoms for this disease are similar to the angular stain, but bacterial stain does not show exudate drops, like angular stain this may infect stem, petiole and fruit. It presents humid stains that evolve to dry stains.
Bacteria rot or soft rot (erwinia carotovora)This bacteria is found in the soil. In order to infect the plant it will use any vegetable matter wounds at the neck level, causing soft rot on the stem, tissues will assume a brown color and possible further stains will present depending on conditions. When the bacterial infection is initiated, the fruit will appear as damp in certain areas that will rot later.
Bacterial diseases Agro-Chemical treatmentsUsually all bacterial contagions are caused by: using infected seeds, bacteria use seeds as a way to disseminate, or direct mechanical contact with a sick plant, usually workers come in contact with plants during pruning and tutoring. Also insects may be the cause of mechanical transmission of bacteria in cucumbers. If a plant is infected a diagnosis has to be done to know the type of infection we are dealing with. Knowing exactly the type of pathogens we are facing with will increase the chances of a cure, by aiming specific targets.Once we have the right diagnosis for cucumber disease we must apply the right treatment, but in most cases is recommended to erradicate the infected plants since most existing treatments are more useful in disease prevention. The following agrochemicals can be used to prevent bacteria incidence in cucumbers: copper sulfate, copper hydroxide, copper oxychloryde, kasugamicina, streptomycin sulfate and oxytetracycline.
Bacterial withering, bacterial wilt (Erwinia tracheiphila)This bacteria is transmitted by vectors like the beetles Acalymma vittata and Diabrotica undecimpunctata. The first symptom observed in the plant affected by bacterial wilt is the sudden leaf withering that will later lead to plant´s death. Since the infection of the crop is due to mechanical vectors, one of the preventive treatment is to avoid this vectors from entering the cultivated area or using insecticide to avoid beetles contact with the plant. (or better yet biological controls with the predator that feeds on these beetles. Preventive measures to minimize bacterial infections: recommendations to avoid bacteria incidence on crops are:
- get the ground, tools and workers perfectly disinfected
- using healthy seeds
- monitoring the crop regularly
- take away identified sick plant remains
- eliminate possible reservoirs of possible vectors
- crop rotation
- eliminate undergrowth weeds
- using bacteria resistant varieties
- using trellises to avoid humidity accumulation
Cucumber plants with trellis netThe tutoring net by HORTOMALLAS is recommended as preventive measure since it helps avoiding large periods of humidity, and allows the crops better aeration; it reduces possible contagion by workers´s coming in contact with the plant as the netting requires a lot less labor than tutoring with raffia twine. This informative material may be of help to identify bacterial diseases, but it is recommended to consult with your local trained agronomist for a better diagnosis and tests before deciding what course of action to take in order to save your diseased cucumber crop. Biol. Diana Jiménez. Reference.Alonzo-Torres M. 2007. Producción de Hortalizas todo el año. Mozambique. Recuperado el 12 de octubre de 2015 de http://www.entwicklung.at/uploads/media/5_Manual_f%C3%BCr_Gemuesebau.pdfZamudio González, B. Felix Reyes, A. 2014. Producción de pepino bajo invernadero en Valles Altos del Estado de México. Recuperado el 12 de octubre de 2015 de http://siproduce.sifupro.org.mx/seguimiento/archivero/15/2013/anuales/anu_2033-25-2014-05-1.pdfProductores de Hortalizas. 2005. Plagas y enfermedades de cucurbitáceas. Guía de identificación y manejo. Recuperado el 12 de octubre de 2015 de http://vegetablemdonline.ppath.cornell.edu/NewsArticles/CucurbitsSpanish.pdfArias S. 2007. Proyecto de diversificación económica rural. Manual de producción. Producción de pepino. Recuperado el 12 de octubre de 2015 de http://www.innovacion.gob.sv/inventa/attachments/article/3574/Manual%20para%20Producci%C3%B3n%20de%20Pepino.pdf
HORTOMALLAS manufactures and markets crop support nettings (trellising and tutoring as alternatives to the raffia twine labor intensive traditional system) that increase crop quality. Our Mission is to: INCREASE VEGETABLE CROP YIELD AND PROFITABILITY TO ALL THOSE VEGETABLES THAT NEED TUTORING AND SUPPORT USING NETTING INSTEAD OF RAFFIA. Since 1994 we help professional growers and farmers improve their cucumber, tomatoes, melon, zucchini, bean, chile, peppers crops where trellises and supports are needed. HORTOMALLAS is the ideal system for cucurbitacea and solonacea to improve their phytosanitary conditions, while increasing the solar exposure and the brix degrees. Besides the obvious labor costs savings, the use of HORTOMALLAS increases the life span of the plant, allowing longer periods of harvests and of a greater quality. Call us, our crop specialists will help you with specialized attention in the Americas and the Iberian Peninsula!