23 articles tagged "Cantaloupe".

Watermelon harvest is in full swing in southern Indiana. At this time, we frequently see many types of leaf symptoms. Some of them are caused by foliar diseases, such as anthracnose, Alternaria leaf blight and gummy stem blight. These diseases require special attention, normally in the form of fungicide sprays, to slow spread of the disease. However, the appearance of a moderate amount of foliar disease in mid-season doesn’t necessarily need an immediate fungicide application. Other leaf symptoms may not be caused by diseases or insects. Here are some examples of leaf symptoms that are not associated with a pathogen. It is important to correctly identify the source of the symptom to prevent unnecessarily pesticide spray. In the article When a yellow leaf is just a yellow leaf, Dr. Dan Egel discussed general rules for determining if the symptom is a disease or not. If you are not certain whether the symptom[Read More…]


The Purdue MELCAST system allows growers to apply foliar fungicides according to weather conditions instead of using a calendar-based system.

MELCAST is a weather-based disease-forecasting program that helps growers schedule foliar fungicides. MELCAST stands for MELon disease forCASTer. This program, designed by Dr. Rick Latin, Professor of Plant Pathology at Purdue University, keeps track of weather conditions so that cantaloupe and watermelon growers can apply foliar fungicides to their crops when they are most needed. The foliar diseases that MELCAST was designed for are Alternaria leaf blight, anthracnose and gummy stem blight. In a typical year, MELCAST will save growers 2 to 3 foliar applications of fungicides without sacrificing yield. MELCAST works by having growers apply fungicides at specific Environmental Favorability Index (EFI) values instead of using a calendar-based schedule. The extension bulletin “Foliar Disease Control using MELCAST” BP-67 describes this program in more detail. To use MELCAST, follow these steps: Apply your first foliar fungicide application when vines first touch within a row or earlier. Find a MELCAST site[Read More…]


This article provides more detailed information about this herbicide. How does Chateau® herbicide work Chateau® is a group 14 mode-of-action herbicide. Compounds in this group are most active on broadleaf weeds. Before Chateau® became available,  no other preemergence herbicide with the same mode of action was labeled for use in watermelons and cantaloupes. The active ingredient of Chateau® herbicide, flumioxazin, controls susceptible weeds by inhibiting propoporphyrinogen oxidase (PPO), an enzyme that controls chlorophyll synthesis. Because of chlorophyll production inhibition, a chain reaction occurs within the plant that causes cell membrane disruption. Chateau® herbicide can assist in the postemergence control of emerged weeds. It is taken up by roots, stems, or leaves of young plants. It kills weeds through direct contact. There is usually little or no translocation of the herbicide within plants. Foliage necrosis can be observed after 4 to 6 hours of sunlight following the herbicide application. Susceptible plants[Read More…]


Chateau SW® herbicide now has a 24(c) special local needs label for cucurbits. This product is produced by Valent, but the label is held by the Indiana Vegetable Growers Association (IVGA).  To obtain a label, one must be a member of the IVGA, pay an annual $100 processing fee, read and understand the ‘conditions for use’ and have the appropriate forms signed and notarized. One cannot use Chateau SW® without completing these forms and obtaining a label. This process must be repeated every year. Chateau® can only be used in row middles between raised plastic mulch beds that are 4 inches higher than the treated row middle. The mulched bed must be at least 24 inches wide. The application must be directed between rows with a shielded sprayer. Chateau® cannot be applied post-transplant. Do not apply more than 4 oz. of Chateau® per acre at a broadcast rate during a single application.[Read More…]


After harvest, storing vegetables in optimal conditions is important to ensure the whole season’s hard work has paid off. This article discusses the optimum storage conditions for tomato, pepper, cucumber, watermelon, cantaloupe and sweet corn. Tomato Ideal storage conditions for tomatoes depend on the maturity stage of picking. If tomatoes are picked at mature green, store them in 66 to 70°F with 90 to 95% RH would encourage uniform ripening. Temperatures above 81°F reduce intensity of red color and reduce fruit shelf-life. Green tomatoes are chilling sensitive. If the temperature is below 55°F, fruit may develop chilling injury. Red tomatoes are safe to store at 50°F, however, flavor and aroma may be negatively affected compared to storing them at 55°F. Pepper Optimum storage condition for peppers is 45 to 55°F with 90 to 95% RH. Temperatures lower than 45°F may cause chilling injury. Colored peppers are in general less chilling[Read More…]


Figure 5. Breakdown and death of older cantaloupe leaves caused by manganese toxicity.

Manganese toxicity is a common problem for cantaloupes growing in sandy soils across southwestern Indiana. Because symptom of manganese toxicity can easily be confused with foliar diseases, growers may misdiagnose the problem and waste fungicides by spraying for nonexistent diseases. As we now know that manganese toxicity is a nutrient related disorder caused by low soil pH, it is important for growers to learn the symptom and address the problem in right directions. Manganese toxicity can develop on both cantaloupes and watermelons. But the symptom is more often observed on cantaloupes as they are more sensitive to acid soil conditions than are watermelons. The symptom on cantaloupes is first noticed when light green to yellow color shows between the veins on older leaves (Figure 1). Look at the leaves toward the sun and you will notice the chlorosis is formed by numerous tiny light green to yellow pin-hole type spots growing[Read More…]


Many cantaloupe and watermelon growers have transplanted seedlings to the field. Soon, these growers will have questions about what and when to apply fungicides. The article below in this issue of the Vegetable Crops Hotline will address what fungicides to apply (Fungicides schedules for cucurbits). This article discusses when to apply fungicides with the MELCAST system. MELCAST (MELon disease foreCASTer) is a weather-based disease-forecasting program for cantaloupe and watermelon growers developed By Dr. Rick Latin at Purdue University. Instead of using a calendar based fungicide application program where one applies fungicides every 7 to 14 days, the MELCAST program lets growers apply fungicides when the weather is most conducive to disease. The diseases for which MELCAST may be used for are: Alternaria leaf blight, anthracnose and gummy stem blight. Details are listed below or in the extension bulletin, Foliar Disease Control Using MELCAST, BP-67-W. Download the bulletin at http://www.extension.purdue. edu/extmedia/BP/BP-67-W.pdf or[Read More…]


Figure 1. Seedcorn maggot in a melon stem

I received my first report of seedcorn maggot damage on cantaloupes last week (Figure 1 and 2). A grower in northern Indiana reported losing 90-95% of his plants. Given the cool, wet growing conditions, it wouldn’t be surprising to see more reports of this type for a number of crops, including melons, beans, corn, onions, and crucifers. Some of these crops have insecticide alternatives that can be used at planting but other, like melons, have no such option. The best approach for melon growers is to either wait for warmer weather or cover the young plants with row covers to physically exclude the flies from laying eggs. If you have had plants killed by maggots, wait at least 3 days before replanting in the same holes to give the maggots time to complete their development. See the article from Issue 625 (published on April 13, 2017) for more details.


Many cantaloupe and watermelon growers are either growing transplants in a greenhouse or are expecting delivery of transplants in the next few weeks. Either way, growers should inspect transplants for disease before planting in the field. Below I will describe several common transplant diseases of cantaloupe and watermelon as well as management options. Gummy stem blight on transplant seedlings may be recognized by the water soaked area of the stem near the seed leaves (Figure 1). (A water soaked area near the soil line is more likely to be damping-off.) The water soaked area may eventually turn brown and woody. A closer look at the woody area may reveal the small, dark fungal structures of the gummy stem blight fungus. Medium brown, irregular lesions may also be observed on true leaves. The fungus that causes gummy stem blight (Didymella bryoniae) may survive in crop debris, thus overwintering in the field[Read More…]


In issue 619 and 620 of the Vegetable Crops Hotline newsletter I gave you a brief background of the materials used and methods followed during the variety evaluation. I also discussed some of the challenges we encountered while doing the trial work. The varieties evaluated included: Entry # Variety 1 Sephia (Galia type) 2 Tirreno (Italian netted cantaloupe) 3 Rawan (Ananas type) 4 Rowena (Ananas type) 5 Migdal (Galia type) 6 Magnificenza (Italian netted cantaloupe) 7 Kenza (Charentais) 8 Karameza (fully netted cantaloupe) Preliminary data will be discussed in this article. Statistical analysis of all the data has not been concluded and therefore only treatment averages are reported. Yield: One of the criteria that was set for the variety trial was that the fruit size needed to be between 2 – 4 lbs. At Meig’s Farm Magnificenza, Sephia and Kenza produced fruit that varied in weight between 3.28 and 3.96[Read More…]


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