Orginally published in the N.E.P.G.A. Newsletter - September, 1994
September is the final month before our weigh-off at Topsfield. By this time most of the huge weight gains are over and most pumpkins are creeping along and thickening up. September can also be a time of disappointment, when a large pumpkin may split or rot from a fungal disease. Just about every seasoned grower has a number of "fish that got away" stories concerning their best pumpkins of years gone by. Unfortunately, some pumpkins seem destined to go down and no matter what you do, the tide cannot be turned. Now let's look at the brighter side. There are things you can do to keep your pumpkin in good shape.
1. Chilling Injury Eight years ago, after losing a large pumpkin, I contacted Dr. Werner Lipton of the U.S.D.A. Dr. Lipton was the vegetable storage expert for the U.S. government. He described a phenomenon called "chilling injury." Chilling injury happens when pumpkins are subjected to temperatures below 50 degrees for extended periods of time. The cell walls of the pumpkin become weakened and therefore much more prone to disease. This is one of the reasons you see most of the pumpkin diseases appearing in September and October. Watch out for extremely high or low temperatures. After separating the pumpkin from the vine, I would try to keep the pumpkin somewhere in the 60 degree range. High 70's or 80's will cause seed sprouting inside the pumpkins so keep them cool but not cold or hot.
2. Skin Cracking Skin cracking is a common problem that happens during rapid mid to late season growth. You may see some sapping or jelly-like substance coming out of the cracks. If it is a small crack with a little droplet of sap which quickly hardens, you can leave it alone. If you have larger cracks with larger amounts of jelly-like sap coming out you can brush it away with a soft tooth brush, flush with clear water, let dry and treat the crack with a fungicide solution. Most growers treat cracks with Ridomil-Bravo, Captan or a combination of both to kill a wider spectrum of diseases. Cracks can appear anywhere but are most common on the stem and blossom ends. If a crack continues to grow you may have to take additional steps. Clean up a larger crack as mentioned above and then seal it with grafting wax or clear silicone rubber. If the crack continues to grow you may have to apply more grafting wax. If a crack breaks through to the interior of the pumpkin and air is allowed to get into the seed cavity your season will be over shortly. Grafting wax is probably the best agent, since it remains flexible. If your pumpkin has a large crack or hole that exposes the internal seed cavity you will be disqualified. If you are not sure if your pumpkin may be subject to disqualification call Hugh, Tom or myself for an opinion. We have suffered this disappointment and will give the grower the benefit of the doubt whenever possible. If you have a pumpkin on the verge of collapse or one with a large hole please leave it home and bring your number two specimen.
3. Handling Damage All pumpkins have one flat side. If you are gently rolling your pumpkin to put a lifting tarp underneath, make sure you let the pumpkin back down slowly. The pumpkin will crack if you thump it back down on its flat side. When rolling a pumpkin to put a tarp underneath make sure you warn the lifting team not to grab onto the pumpkin by the stem, or it will break off. If the official lifting team at the fair should damage a stem while putting your pumpkin on the scale, we will include the broken stem in the weight. If the pumpkin come into the fairgrounds with a missing stem it will be weighed as is so try to keep your stem intact. A one inch piece of vine is allowed on either side of the stem so leave a small bit on. An official from the NEPGA will trim all vines to one inch before weighoff.
Atlantic Giant pumpkins have a softer skin and flesh than regular field pumpkins. It is important not to scuff up the bottom of the pumpkin by sliding the pumpkin along the floor or sliding one into the back of a pickup truck. The injured bottom will rot out rapidly. Keep a blanket or a piece of cardboard under the pumpkin to avoid floor scuffing. Some growers will place their pumpkin on a large piece of foam rubber to cushion it during transport and unloading.
Most people lift their pumpkins with a reinforced canvas tarp. Gently roll the pumpkin up on its edge, place the tarp underneath, let the pumpkin gently back down and get 6 or 8 strong lifters. A plain piece of canvas will do O.K. for a 300 to 400 pounder. If you suspect your pumpkin is in the 500 plus category I would seriously consider getting a professionally made lifter from a canvas shop or call us for more details on proper tarp construction. Mine is made of rubber impregnated canvas with extra nylon webbing sewn into it. It has handled pumpkins over 700 pounds.
How do you know if you have a 300, 400 or a 700 pound pumpkin? Most seasoned veterans can just look at a pumpkin and give you a rough idea of its weight but there can be a large variance depending on the thickness of the pumpkin. A very general rule of thumb would be to measure the circumference of the pumpkin with a cloth or soft plastic tape measure. Measure from stem end around the side of the pumpkin to the blossom end and them back to the other side of the stem end. 105 inches equals approx. 300 lbs., 120 inches equals approx. 400 pounds, 130 inches equals approx. 500 pounds. 140 inches equals 600+ pounds. Pumpkins of low height (22-24 inches) weigh less. Pumpkins having a height of 30 to 34 inches weigh more. Pumpkins with heavy ribs and a "netting" like surface seem to weigh more for their size than the big smooth skinned ones. Sometimes even the veterans can be fooled by as much as 100 pounds on the weight of a pumpkin. I have had a high, ribbed pumpkin of 130 inch circumference weigh 614 pounds and then had a lower smooth one of 136 inch circumference weigh 418 pounds. If you have two big pumpkins and you're not sure which one is heavier, it would be wise to find a scale and weigh them before making your decision. Bigger is not always heavier. In 1991 I supplied some seeds to a west coast grower. He took his largest (by measurements) to the Fair. It weighed 580 pounds. He left the smaller pumpkin home which he later found out weighed in at 641 pounds and would have been enough to win the competition.
A more accurate way of measuring pumpkins would be to combine three different measurements. Measure from ground to ground, from the stem and to the blossom end, measure ground to ground width wise, and measure the circumference. Add the three numbers. Typical measurements on a big one might be 90" ground to ground lengthwise, 90" ground to ground widthwise, and 140 inches in circumference for a total of 320 inches. Any combined measurement total of 300 inches or more is a very large pumpkin with potential to be 600 pounds or more. A pumpkin of this size could be 48" or more in width, which may not fit into a standard pickup so plan ahead.
4. Stem Rot or Softening It is common to see soft spots develop on the stems of pumpkins. It could happen anywhere but seems to be more prevalent in southern growing areas. It could be gummy stem blight or other fungal diseases. If you see the start of this, brush the soft area away with a toothbrush, rinse with clear water and let dry. Next apply a fungicide solution to the stem and try to keep the stem as dry as possible. Reapply the fungicide solution every week to help prevent a reoccurrence.
5. Frost Protection Under no circumstances should frost every be allowed to get to your pumpkin. On nights when the temperature is going low, cover your pumpkin with heavy quilts and remove them the next morning. In interior valleys on clear nights with no wind the temperature will fall below freezing when the rest of the forecast area may be 40 degrees. Generally a light frost (30 degrees) will not kill your entire plant. You may experience a 50% leaf kill. If the temperature drops into the 20's you could suffer a total leaf kill. If your pumpkin has stopped growing a few weeks before a frost it may not matter that much if the leaves are killed - just protect the pumpkin. If the pumpkin is still growing and you want to try to save the foliage to keep the plant going, follow the steps below:
|A. If you have a light frost 30-32 degrees you may have success by running overhead watering on your entire plant right through the night.|
B. If you don't have access to high volume overhead watering the other method of plant protection would be to purchase a large piece of Remay or P-17 or P-30 Agryl Fabric. P-30 will protect a plant from mid to upper 20 degree temperatures. Overhead watering will not be effective when temperatures dip to the mid 20's. If you need more information on Remay or Agryl Fabric call us. It comes in widths up to 42 feet and is quite expensive but can be reused. It might take you a week to latch onto a piece of this material. Do not wait until the last minute if you have a large pumpkin still growing in September.