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Pumpkins - High Light Intensity inhibits female flowers + questions

Firstly, I found this information in Annette McFarland, Succesful Gardening in Warm Climates on Pg 85 this morning.

'Cucumbers, melons, pumpkins, squash and zucchini...High light intensity can tend to make members of t his family produce large numbers of male flowers, but few females and therefore little fruit. one solution is to grow these plants beneath shade provided by trees and shrubs or just wait until the weather becomes more overcast. Pinching out the runners of plants will tend to make them more bushy and can also encourage production of more female flowers.'

I have a couple of self seeding pumpkins going crazy along my back fence with heaps of male flowers so will try the above advice and see how I go.

Can anyone tell me if they are affected by fruit fly - I noticed a couple of baby fruit last week with glee, but they have since fallen off. I know that insufficient pollination can cause fruit fall, but wonder whether I need to bag them for fruit fly.

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D, don't think fruit fly will be the culprit unless something else already damaged the fruit and the flies found the damaged fruit and moved in, generally it will require some fermentation/ sugar/sucrose level which new fruits don't often have.
If its pumpkins lack of pollination may be the answer............................................
Depending on what species the baby fruit are, the answer will vary or have they been affected by a biological symptom (bacterior/mildew, or lack of traces or phosphate/calcium etc.

I don’t think it’s a problem with fruit flies. I have fruit flies problem with my capsicum and tomatoes, but not the pumpkins. I’ve only got two pumpkins out of about 5 vines this year, I believe it’s due to the fact that when I had female flowers, there’s only one or two male flowers, and I thought I will do hand pollination over the Christmas break, but all the flowers were male during that time >__<” I’ve pinch out the tip of the vines the other day, I hope I will get a better balance soon ~
Thanks Florence, I have only male flowers as well and have pinched out the tips on the weekend. Anthony is probably onto something as I looked last night and there were a few (only about 1% though?) leaves with yellow splotches. I'll get out my books tonight and have a look. Probably chuck a handful of Antonys special fertiliser blend on and hope for the best.

Fruit fly has been a huge issue with almost everything this summer - I nearly cried when two individually bagged rockmelons that were almost ripe got bitten and had maggots in them. The bags were a bit small and were pressing on the fruit. I will be making some bags soon as all the ones I have left are too small and they cost too much to buy.
My daughter's butternut pumpkin have yellow splotches on the leaves too, so if you find out what it is, please let me know :) We have had a couple of little fruit develop but then they dropped off :( Got a couple more now, so I will see how they go.
hugs Lucie
Okay, yellow splotches could be:
*sun damage on a young plant or a calcium deficiency can cause yellow spots also.

Downy Mildew (fungus - Pseudoperonospora cubensis): Angular yellow spots appear on the upper surface of the leaf during periods of high humidity. The underside of leaves, opposite the yellow spots, becomes covered with grayish growth which is the spore producing structures of the fungus. This growth is more noticeable early in the morning when heavy dew is present. Spores are easily carried by wind from diseased plants. Cool temperatures along with free moisture are ideal for mildew infection and spread. Hot, dry weather may reduce or stop disease development. Resistant varieties should be used when possible.
Organic tips
• Avoid overhead irrigation.
• Select resistant varieties. Try to remove leaves as soon as they are affected. Grow plants on a trellis to improve the air circulation around them.
• Spray vulnerable plants regularly with a seaweed based product to build plant vigour.
• Mulching acts as a barrier and helps restrict the spread of fungal spores from the soil onto the plant.
• Dispose of fallen leaves and prunings.

Oh dear, think I have the latter, I will check tonight & remove all leaves affected & do a search through my books for organic remedy, might try my milk one first for powdery mildew & see how I go. This is probably causing the fruit fall too...
i wonder what sort they are. what were you eating from the shop?
if they are big ones like queensland blues they can take ages to start fruiting. jap pumpkins will generally fruit in a reasonable time. i'm not sure about butternuts - i have an idea they fruit late, but i've never had success with them
Scarlett, I will email a picture of one little baby fruit I found, looks like it has a pattern on it so maybe a qld blue - although I normally buy butternut so not sure.
Hi folks this is a great site for all things pumpkin check it out have fun.......................

Common Pumpkin Diseases:
One of the two major threats to your prize pumpkin is disease( the second is those Pesky Bugs). Of these two, there is more than a casual relationship as insects, especially, the cucumber beetle, are carriers of disease. Powdery mildew, a white powder-like bacteria is the most common culprit. Powdery mildew thrives in hot, humid weather--in the middle to late summer--- just as your pumpkin is really getting big. It spreads rapidly, and will quickly destroy the plant. This problem is common to many vining plants, from cucumbers to squash of all kinds.

A second disease is Bacterial Wilt. This disease is evident by a wilting and browning of the leaves. Sometimes the leaves will firm up at the end of the day, only to repeat itself the next morning, and get worse each time. This can sometimes be confused early on with wilting due to lack of water or high temperatures. Wilting from lack of water results from either a literal lack of water in the soil or the vine ends not getting enough water as the fruit is sucking up all the nutrients. The acid test for bacterial wilt is to take one leaf and cut it an inch or so from the vine. If the sap that drains out is yellow and stringy, you have confirmed the presence of the disease.

There is no known cure and the plant will certainly die. The best course of action is to remove the diseased plant.

Plant Viruses On-Line is a thorough and complete guide to information on viruses of all the cucurbita family.

Refer to the saying at the top of this page: "An ounce of prevention is worth a pound of cure". There is no cure for a pumpkin patch that has been overcome by Powdery Mildew or Bacterial Wilt. Therefore, the best defense is a good offense. Here are the best defensive measures to help avoid this and other disease problems.

Water only in the morning or during the day. Avoid late afternoon and evening. Powdery Mildew and other diseases thrive in humid weather. Watering at night adds fuel to the fire. When you water in the morning, the sun quickly dries the leaves. Watering at night leaves moisture on the leaves for the entire evening and early morning period. On warm nights, this is the ideal growing condition for Powdery Mildew. A friend of mine has a huge field where he grows pumpkins. His family has grown them and sold them in our town for generations. A few years ago, he told me how he had a disaster with his crop. The vines were shriveling and the leaves were turning white. He said he kept on watering them in hopes that they would grow back. The more he watered, the worse it became. I asked him about his watering technique. He said he waters with an overhead sprinkler at night. I then explained the impact of humidity on the disease, and that watering was only promoting it's growth. Even though there is less evaporation of the water at night, it is not worth the risk of disease.

Water only to the roots and vines. If you apply water with a soaker hose, the leaves do not receive the additional moisture that promotes growth of diseases. Place the soaker hose facing down. This also minimizes water on the leaves.

Apply sprays to control diseases before they get started. A fungicide disease spray may save your crop from this problem. Many of us want to avoid chemicals wherever possible, and that is obviously commendable. If you do not eat the pumpkins, you should have less concerns about applying fungicides. Start applying disease control sprays early and before disease occurs. If your pumpkin patch is already infested, apply it right away. If caught soon enough, the plants should recover.

Remove diseased plants from the garden. Do not turn diseased plants into the soil or compost them. Diseases can overwinter either in the soil or in your compost pile. It then re-infests this years' crop.Compost piles sometimes do not get hot enough to kill bacterias. Toss diseased plants out in the trash or send them to your local lawn waste re-cycling center.

More Information:
Cucurbit Disorders


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