Rice Research: Open Access
Open Access

Pathogen, Altrnariaria leaf spot

Introduction

Pathogen-caused leaf spot diseases, notably those of fruit trees and such vegetables as tomato, pepper and lettuce area unit of 2 sorts, those caused by bacterium and people caused by plant. Leaf recognizing of either kind is usually similar in look and result. Infected plants have brown or black water-soaked spots on the foliage, generally with a yellow halo, sometimes uniform. The spots enlarge and can run along beneath wet conditions. Beneath dry conditions the spots have a dotted look. As spots become additional varied, entire leaves might yellow, wither and drop. Members of the Prunes family (stone fruits, together with cherry, plum, almond, apricot and peach) area unit notably vulnerable to microorganism leaf spot. The fruit might seem noticed or have sunken brown areas. Microorganism leaf spot also will attack tomato and pepper crops in vegetable gardens. A leaf spot could be a restricted, stained, morbid space of a leaf that’s caused by plant, microorganism or infectious agent plant diseases, or by injuries from nematodes, insects, environmental factors, toxicity or herbicides. Symptoms These stained spots or lesions typically have a center of mortification or death [1]. Typical leaf spot symptoms embrace light-coloured, circular spots (0.5–1.0 cm) with a light-brown edge. The spots eventually flip death and black pycnidia will be seen with oculus. Serious infection results in leaf loss. The plant is seed borne and therefore the initial symptom is light-weight spots of indefinite space on the leaves. It’s apparently favored by warm temperature. Altrnariaria leaf spot is caused by the plant Alternaria brassicae, and therefore the malady will cause severe injury to cabbage if left uncontrolled. Initial symptom’s area unit little circular, dark spots on the surface of older leaves. Because the spots enlarge, homocentric rings develop among the lesions, that area unit typically encircled by a yellow halo, resulting in severe defoliation. The causative infectious agent of the malady is transmitted within the same means as that of the disease. Olive leaf spot, a plant malady, is one in every of the foremost common and damaging diseases of olives. This plant malady infects the leaves with the primary fall rains. The plant spots enlarge and become coloured, resembling the “eye spot” of a peacock’s tail; they’re thus typically named as “peacock spots.” In spring, infected leaves defoliate, reducing bloom and therefore the ensuant crop. In years of high winter rain, untreated trees will lose fifty % of their cover thanks to olive leaf spot infection. Dense trees and wet conditions encourage the best olive leaf spot infection. Pruning (to eliminate dense clumps of foliage) mitigates infection and enhances the coverage of protecting fungicides. Viral leaf spot diseases embody the Apple iron deficiency anaemia leaf-spot virus from the genus Trichovirus, Tospoviruses, and Coconut cadang-cadang virusoid [2].Certain chemicals square measure want to treat leaf spot malady, like the antimycotic agent, the primary antifungal agent to possess been developed, that treats several plant life and microorganism leaf spots.Prevention of leaf spot malady includes selection choice, crop rotations, plant hygiene and antifungal agent use for seeds and foliage. To prevent to unfold of pathogens smart sanitation is vital additionally because the rejection of handling plants once wet, planting pathogen-free and resistant cultivars and moving out infected plants. Reducing the wetness around plants and in greenhouses by smart plant spacing for air circulation, and watering early within the day also can facilitate forestall leaf spot malady [3]. medical aid of tools and laundry of hands is very important once handling infected plants. Leaf spot are often prevented by guaranteeing that you just don’t cut your grass too low. Long, thick-bladed grass is a lot of immune to harm to the grass blades. Adding atomic number 7 to soil throughout a leaf spot infection will entirely kill a section stricken by leaf spot. Avoid overwatering infected grass and aerate the soil to push water drain throughout rainy conditions. Fungicides square measure associate degree possibility for treating leaf spot; however they are slowly effective once applied to infected lawns throughout the disease’s initial stage. If an antifungal agent is applied throughout the “melting out” stage, it willhave very little to no impact. Optimally, fungicides ought to be applied once within the early spring and once more in late spring. Contact the specialists at Cardinal Lawns to debate your choices for preventing malady and creating your field look its best

References

1. Horst R. (2008) Westcott’s Plant Disease Handbook. Springer Netherlands.
2. Agrios G (2005). Plant Pathology (5th ed.). 
3. Dicklow M. (2019) Leaf Spot Diseases of Floricultural Crops Caused by Fungi and Bacteria.