Common name:Powdery mildew Latin binomial:Golovinomyces cichoracearum (formerly Erysiphe cichoracearum) andPodosphaera fuliginea (formerly Sphaerotheca fuliginea) Host crops: All cucurbit vegetables (e.g. cucumber, cantaloupe, melon, pumpkin, andsquash). There are different races of the pathogens.
Common disease name: Various viruses of cucurbits Pathogen names: A complex of viruses is able to infect cucurbits. The most important viruses tend to be Cucumber mosaic virus (CMV), Squash mosaic virus (SqMV), Watermelon mosaic virus I (WMV-1), Watermelon mosaic virus 2 (WMV-2), and Zucchini yellow mosaic virus(ZYMV). With the exception of SqMV, which is seedborne in melon and transmitted by beetles, the other major viruses are transmitted by several aphid species in a non-persistent manner.Minor cucurbit viruses include Tobacco ringspot virus (TRSV), which is mainly transmitted by nematodes (Xiphinema americanun), Tomato ringspot virus (TmRSV), which is nematode transmitted and can overwinter on many weed species without expressing symptoms, andClover yellow vein virus (CYVV) which is aphid- transmitted. Host crops: Most cucurbit crops. However, the different cucurbit viruses can differ in host range, including within the Cucurbitaceae. Some of these viruses also infect plants in other families, which is important to know for disease management practices.
Problem: Blossom end rot
Cause: Calcium deficiency resulting from various environmental conditions and management practices, e.g., inadequate Ca in the soil, inconsistent water as a result of alternating wet and dry periods that decrease Ca uptake by plants, and even excellent growing conditions such as a period of very bright sunshine and warm temperatures mid-season.
Crops affected: Tomato, pepper, eggplant, and various cucurbits.
A physiological problem: prominent when air is cooler than the soil, soil moisture is high, and relative humidity is high. The low plant transpiration rates combined with an increase in water absorption by roots from the soil leads to increased cell turgor pressure, resulting in eruption of epidermal cells as the inner cells enlarge. Protrusion of the inner cells causes epidermal cells to die and discolor, resulting in a ’warty’ appearance that can be misidentified as a disease. In addition to foliar symptoms on some hosts, many cucurbit crops develop wart-like protruberances on the fruit.
Photo Source: Lindsey du Toit,
Washington State University.
Phil Hamm, Oregon State University.
Photo Source: Lindsey du Toit, Washington State University.
What are these bumps on my vegetables? Edema or oedema: It doesn’t matter how you spell it, it still doesn’t look good. What is it, what causes it and how can I prevent it? Michigan State University Extension