This time of year, I obtain many complaints of pumpkin plants with yellow leaves. Tright here can be many kind of factors why pumpkin plants have actually yellow leaves. The most common reason for yellow pumpkin leaves doesn’t have actually anypoint to carry out with a disease that deserve to spreview from plant to plant. Typically, the reason for the yellow pumpkin leaves hregarding do through lack of water, weather that has been as well hot, nutrient deficiency or various other stresses. The photos and also discussion below will certainly, I hope, show my point.

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Let’s say you have a pumpkin field wright here you have pumpkin leaves that are yellow and you are wondering about the reason. You might want to ask yourself, which leaves are yellow and also wbelow are they yellow.

In Figure 1, yellow pumpkin leaves might be oboffered. When one looks a little bit closer to uncover out where the yellow leaves are, one have the right to watch that the yellowing runs down the row. In truth, it is the older leaves that are yellow (Among plant biologists, we choose the term chlorosis to yellow. But I will certainly proceed to usage the word yellow right here.) When older leaves are yellow and also the younger leaves show up green and healthy and balanced, the factor for the yellowing is generally stress-related, as suggested over. I am not as well worried around this type of yellowed pumpkin leaves.

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Figure 1. The yellowing of these pumpkin leaves seems to run dvery own the row.

Look aget at figure 1 to attempt out which component of the leaves are yellow. For the most part, the percent of the leaves that are yellow are the edges (or margins) of the leaves (Figure 2). One doesn’t watch entire leaves that are yellow. The yellowing doesn’t appear in the interior of the leaves. Yellowing on the outside of the leaf typically indicates that the factor is anxiety related as questioned over.

Older leaves tfinish to come to be yellow via time bereason nutrients favor nitrogen are mobile in the plant and will certainly relocate to the younger leaves where they are needed. In enhancement, the edges of leaves might become yellow because the edges of leaves have pores wbelow sap (known as the water of guttation by botanists) is secreted at night. This sap may have actually a mildly toxic impact on the leaves over time—this is the reason that the edge of older leaves may end up being yellow.

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Figure 2. The edges of this pumpkin leaf are yellow, a lot of most likely as a result of eco-friendly anxiety.

In figure 3, the yellowing of the pumpkin leaves is even more primarily over a bigger area in contrast to number 1 where the yellowing could be watched to run dvery own a row. Most of the yellowing appears in the foreground of the photo in figure 3. If one looks dvery own the hill, the leaves show up green and healthy. Now, let’s look at the soil beside the symptomatic pumpkin leaves. The soil appears sandy.

Next, we will walk down the hill wright here the pumpkin leaves are green and look earlier up towards the yellowed pumpkin leaves (Figure 4).

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Figure 3. This check out is from the height of the hill looking dvery own. The pumpkin plants in the foreground of this photos have yellow leaves. The soil is sandy at the top of the hill.

Aobtain, we alert that the location on top of the hill is in a basic area—they don’t seem to run down a row. That is, it isn’t just the older leaves that are yellow. Now, take a look at the soil beside the green pumpkin leaves at the bottom of the hill. The soil is much heavier through even more of a clay content than the soil at the optimal of the hill.

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Figure 4. This check out is from the bottom of the hill looking up. The pumpkin leaves at the bottom of the hill are mostly green and healthy. The soil at the bottom of the hill is reasonably heavy.

The leskid right here is that the pumpkins at the peak of the hill had actually much less access to water than the bottom of the hill. This is true both because hills tfinish to be better drained and also because sandier soils hold much less water. The grower had actually drip watering in place, but was not able to pump a lot water as a result of lack of water in a surconfront pond. Thus, the yellowing leaves at the top of the hill are due to drought stress and anxiety.

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Both of the areas of pumpkins pictured below developed good crops. The yellow on the pumpkin leaves does not necessarily suggest a disaster or an illness is in the future.

I hope the photos and conversation presented right here will assist one to figure out what is wrong in one’s pumpkin patch. However, if one still has actually inquiries about symptoms, it is ideal to sfinish off a sample to a diagnostic laboratory. Purdue University’s Plant and Pest Diagnostic Laboratory is a great resource


 — Purdue University Clinical Engagement Associate Professor Dan Egel

This column was initially published in the August edition of Purdue Unversity’s Vegetable Crops Hotline newsletter.