The crimper/roller (C/R) system for killing rye was used to evaluate growing pumpkins organically and conventionally. Farmers throughout the Midwest desire new methods to keep pumpkins clean from soil. Clean pumpkins reduce the need for hand labor, which is expensive and becoming harder and harder to hire.
Fall seeded Wheeler rye produces very high plant biomass in the spring. Healthy vigorously growing rye will C/R better than stressed rye. Healthy rye will remain on the ground as a mulch and will not come back upright as long as it is C/R at the pollination stage. Conventional farmers can C/R earlier because they can treat the rolled rye with glyphosate to keep it from coming back up. The pollination growth stage of the rye at KBS usually occurs about the first week of June. This date can be late for soybean planting, but is very acceptable for pumpkin plantings.
Weed control in organic pumpkins is very difficult. We utilized several farmer advisory inputs to reduce weeds. We had good success growing pumpkins in 2009. Pumpkin yields from the treatments using rye and no-till were not as good as clean cultivation and the hand-hoed pumpkin treatment. We found that broadleaf weeds dominated when wheat straw was used in the zones where the pumpkins grew and grass weeds where we didn’t use straw. The rye mat did reduce soil on the pumpkins. Transplants matured earlier than planting by seed and had a higher percentage of orange pumpkins.
The C/R system worked very well in the conventional system. Our highest pumpkin yield resulted with clean tillage (no rye) or transplants with a zone burndown in 2009. Our cleanest pumpkins were seeded or transplanted directly into killed rye with no zones, however the yields were lower.
With an unseasonably cool summer in 2009, there was an advantage for growing pumpkins as transplants. Most farmers currently grow pumpkins from planting seeds.
The rye C/R system did provide excellent season-long weed control. Only two herbicide applications were used each year. We applied fungicide treatments every week from July 21 through September 15 in 2009. We never needed to use an insecticide treatment either year. This could be from the rye system, the cool season or our location.
In the Midwest and Northeast regions, pumpkin farmers use no-till planting following glyphosate burndown on cover crops like cereal rye (Secale cereal) and hairy vetch (Vicia villosa). This reduces herbicide applications (currently $22/A), decreases nitrogen fertilizer rates (currently about 140 lbs/A), limits the number of required tillage operations (about $16 to $29/A each) and provides mulch for pumpkins. The mulch also decreases pumpkin contact with the soil and mud, which reduces the incidence of soil-borne diseases and the need for fruit cleaning labor at harvest. Farmers and consumers—especially pick-your-own customers—have been satisfied with the new production system (Anonymous 2003), but the main challenge has remained the difficulty in managing the cover crops. In a previous SARE-funded project, Wyenandt et al. (2005) demonstrated the feasibility of no-till pumpkin production in Ohio and stressed the same limitations indicated above.
When rye is burned down too early, there is not enough full-season residue to accomplish the goals outlined above. When rye is too tall, burn-down herbicides are less effective and may require two applications for good control. In spring, hairy vetch is difficult to control with herbicides. The lack of complete control causes planter plug-ups and cover crop bunching in the field. This can result in competition from the hairy vetch and a poor crop stand. The C/R proposed for use in this study will improve the current no-till pumpkin production system by reducing the risk associated with poor cover crop management. Reduced reliance on burn-down herbicides and on environmental conditions favorable for their application could provide growers with more flexibility while enhancing their revenues.
- Determine appropriate cover crop management techniques to maximize biomass production.
Evaluate the C/R system for weed control, disease management and nitrogen availability.
Develop and implement an Extension and outreach program to disseminate results to Michigan and NCR growers.
Chicken manure at 80 lbs/N credit was applied in the fall of 2007 for pumpkin planting in the spring of 2008. K-mag potassium source was applied and tilled into the soil at the recommended rate. Wheeler rye was planted at 3 bu/A rate. An unplanted rye zone was established by blocking two seeding holes totaling 15 inches for a zone of bare soil to plant pumpkins in the spring of 2008.
One treatment was planted directly into the C/R rye and our control was a no rye (hand-weeded) control. All treatments received fungicide applications using Citrex™ on a scheduled basis. No insecticides were used and no additional weed control practices were used with exception of the control treatment where weeds were controlled by hand weeding.
The same experiment was replicated in Benton Harbor, Mich., for organic in 2007/2008. Sandy soils required only one rototilling, we used plastic for weed control and all treatments were drip irrigated (Table 1).
Potash 0-0-60 was broadcast at the recommended rate with 30 lbs/A of nitrogen, then incorporated in the fall of 2007. Following the fertilizer application, Wheeler rye was drilled at 3 bu/A using a conventional drill with spacing 7.5 inches apart.
In the spring of 2008, two treatments were sprayed with glyphosate creating 15-inch zones where the pumpkin seeds would be planted. Biomass samples of the rye were taken prior to C/R the rye. Fifteen-inch zones were established in the rolled rye with a rototiller.
A pumpkin planter was used to plant pumpkin seed in the established zones.
Dual II™ plus glyphosate was used as a broadcast application into the rolled rye. Fungicide applications were applied on a 14-day schedule from July 15 to September 15. A grass weed herbicide, Poast™ was used to control volunteer rye (Table 2).
On September 28, 2008, Wheeler rye was planted at 3 bu/A. On April 24, Treatment 5 had red clover broadcast at 15 lbs/A. On April 27, 155 lbs/A of K20 sulpher of potash (SOP and 30 lbs/A nitrogen (non-GMO soybean meal) were applied. On May 5, rye was removed from Treatments 2 and 3 and on May 8 all other treatments had rototilled 10-inch zones established. On June 3, Treatments 2 and 3 were field cultivated. Zoned treatments were rototilled again on June 10. On June 14, the rye was rolled and Treatments 2 and 3 field cultivated again. On June 15, pumpkin seeds and transplants (variety Magic Lantern, 115 day) were planted by hand. On June 23, 120 lbs/A in row of blood meal (13-0-0) was applied. On June 30, shredded straw was applied in row for Treatments 1 and 5. We applied 1.8 inches of irrigation to all treatments in two applications. Citrex™ fungicide was applied weekly from July 21 through September 15. The clean tilled treatments were hand-weeded two times. Pumpkins were harvested September 30, 2009. Plot size was 15 by 30 feet with row spacing of five feet and seed in row 3 feet (Table 3).
In fall 2008, plots were treated with 30 lbs/A of nitrogen. Wheeler rye was drilled at the 3 bu/A rate.
In spring 2009, 30 lbs/A of nitrogen was applied on March 24. On April 17, 190 lbs/A of K20 and 25 lbs/A of phosphorus were applied. Ten-inch zones were established for Treatments 1 and 4 using glyphosate on April 24. On May 4, Treatments 1 and 4 were 10-inch band sprayed with glyphosate again due to weed growth. Treatments 3 and 6 were broadcast sprayed with glyphosate on May 4. Treatments 3 and 6 were flail mowed and disked twice on May 8 and field cultivated on May 18 and June 3. Treatments 1 and 4, 10-inch zones were rototilled. On June 15 transplants and seeds were planted by hand. On June 16, Dual II Magnum™ was applied between the rows. On June 23, 120 lbs/A nitrogen was applied in the row. Three irrigation events occurred with 2.6 inches applied. Fungicides Bravo™ plus Champ™ were applied weekly from July 21 to September 15. Variety Magic Lantern with a plot size of 15 by 30 feet, row spacing 5 feet and seed in row spacing of 3 feet were used (Table 4).
The rye biomass for organic rye was 1,281 lbs/A in 2008 at KBS. The organic study at KBS became so weedy that we could only harvest the clean-hoed treatment. The hand-weeded treatment yielded 15,285 lbs/A of marketable pumpkins. These pumpkins were dirty and small. In the Benton Harbor, Mich. study, due to high weed pressure, no pumpkins were harvested.
The rye biomass for conventional rye was 1,204 lbs/A. Establishing zones with glyphosate resulted in our highest marketable pumpkin yield of 2,800 pumpkins/A or 31,000 lbs/A. The clean tilled treatment provided the next best results at 2,600 pumpkins/A or 28,000 lbs/A. The lowest yield resulted when pumpkin seeds were planted in solid rye at 1,400 pumpkins/A or 16,000 lbs/A.
The best yield of pumpkins at the Benton Harbor site was planted into solid rye, which yielded 2,800 pumpkins/A. Eighty-six percent were clean. This could be a result of using black plastic for weed control and drip irrigation on sandy soils. All other treatments were about the same, around 2,400 pumpkins/A and clean.
The organic experiment was changed in 2008/2009. Having had very little success in 2008, we brought in a group of farmers to re-evaluate the current treatments. The farmers suggested that we consider using pumpkin transplants to get a jump on the weeds. They also recommended that we plant red clover early as a companion crop, and use wheat straw in the pumpkin rows for weed control. All of the farmers’ suggestions were adopted for the 2009 season.
Our experiments were at KBS and in Charlotte, Mich., in 2008/2009.
The highest yielding organic pumpkin treatment resulted after transplants were used and weeds were hand-hoed. The yields were about 27 tons/A as compared to rototilled zones without straw and transplanted at 3 tons/A. The largest pumpkins by weight resulted when weeds were removed by hand-hoeing pumpkins that were planted by seed. The average pumpkin weight was 17 lbs. The C/R treatments were all significantly lower in weight than the clean tilled pumpkins. All those treatments were less than 7 lbs/pumpkin in weight. The clean tilled seed planted pumpkins resulted in the highest weight. The percent of orange color for these pumpkins though was 42 percent as compared to the tilled zone pumpkin transplants with straw, which were rated at 100 percent orange.
In conclusion, the C/R rye did reduce dirt from splashing on pumpkins. In the organic system we could not obtain season-long weed control in the rototilled zones or the zones with straw residues. Broadleaf weeds grew in the zones where straw was applied and grass weeds grew where we didn’t apply straw for weed control. The frost-seeded clover treatments interfered with the pumpkins and I wouldn’t recommend this as a favorable treatment.
Excellent yields and healthy pumpkins can be grown organically. It is very important to control the weeds. The C/R system did not provide adequate weed control in this study.
Pumpkins that were transplanted matured earlier and had a higher percentage of orange color as compared to the clean tilled seed planted treatment in 2009. This could be important when you have a cool and slow growing season like we had in 2009. Consumers do not want green pumpkins.
We also conducted an experiment in Charlotte, Mich., where a farmer wanted to grow canola and second crop pumpkins following canola harvest. The farmer chose a short-season pumpkin variety. We worked with him to design the experiment. A local organic greenhouse was used to grow organic transplants for this and all of our organic pumpkin trials. Again, we wanted the pumpkins to get a jump on the weeds. These pumpkins were being planted later than usual due to a delayed canola harvest.
Unfortunately, the summer of 2009 was terrible for this study. We had one of the coolest summers on record. We also had drought and the pumpkins were not irrigated. As a result, this on-farm trial failed to provide any data.
The farmer still wants to combine these two crops, but will need more cooperation from Mother Nature to make it happen.
In 2009, pumpkin transplants provided the highest yield as compared to planting them by seed. When zones were established using a rototiller or glyphosate and planted with pumpkin transplants the two highest yields each reaching 4,200 pumpkins/A resulted. Planting pumpkins from seed resulted in a 2,500 pumpkin/A yield. Pumpkins planted directly into the rye with either seed or transplant resulted in our cleanest pumpkins, but low yield at 2,400 and 2,300 pumpkins/A, respectively. The transplants planted in the burndown zones doubled the pumpkins/A yield as compared to the burndown seed pumpkin treatment at 4,200 to 2,100 pumpkins/A, respectively.
The results of these data may be unusual because the summer of 2009 was very unseasonably cool. Pumpkins like it hot, but we had very few hot days in 2009. What we have learned over the years working with the C/R system is that vigorously growing rye rolls and crimps much better than stressed thin stands of rye. The rye in this study had nitrogen applied in the fall and spring. This really enhanced the mulch thickness, which kept the pumpkins clean and provided season-long weed control. We had very few weeds in all of our treatments where we had planted rye as a cover crop.
The C/R system can work and save farmers money by keeping pumpkins cleaner and reducing herbicide treatments. We did have some plants die when we planted directly into rye without building zones. We checked these plants for disease, but nothing was found.
Soil Management in Organic Pumpkin Production slideshow
- Pounds of pumpkins per acre (Conventional 2009)
- Number of pumpkins per acre (Conventional 2009)
- Soil Management in Organic Pumpkin Production
- Average pounds/pumpkin (Conventional 2009)
Educational & Outreach Activities
- Organic pumpkin production using rye and the crimper/roller system. Great Lakes Fruit and Vegetable Expo. December 2009. 75 farmers.
Herbuck’s organic egg production winter meeting. February 2010. Guest lecturer to 75 farmers.
Michigan State University (MSU) Crop and Soil Sciences seminar. March 2009. 40 researchers.
General session No-till Conference, Des Moines, Iowa. January 2010. 850 farmers.
Break-out session No-till Conference, Des Moines, Iowa. January 2010. 75 farmers.
Branch County Farmer’s Day, Michigan. February 2010. 55 farmers.
Lecturer for MSU Agronomy Systems class. February 2010. 15 students.
- Farmer tour from North Carolina. August 2008. 55 farmers.
Youth group from Barry County, Mich. June 2009. 15 students.
New Ag Network Advisory Group. August 2009. 8 farmers.
International IPM group. June 2009. 22 professionals.
MSU Crop and Soil Sciences and Horticulture departments. September 2009. 5 faculty members.
The Ohio State University sustainable ag group. August 2009. 30 educators.
Multi-county and Extension educator tour. August. 25 educators.
Areas needing additional study
The conventional C/R system with zones had excellent results both years. The rye mulch kept pumpkins clean and provided season-long weed control. Using a burndown and pre-emergent herbicide was needed for this system. Excellent pumpkin yields resulted from these reduced input systems. Adding nitrogen to the rye to improve its vigor seemed to contribute to the effectiveness of the C/R system. The healthy rye remained flat on the ground after crimping it. Insects were not a pest problem on any treatments and no insecticides were used. Fungicide applications were needed and used for all plantings.
Weed control remains the most important limitation for organic pumpkin production. The C/R system did not provide adequate weed control.
Note: We are repeating the conventional pumpkin experiment this summer 2010. We expect to publish these data in combination with 2009 data after 2010 harvest. Support for this year’s experiment came from the Land & Water Unit Cover Crop Program at MSU/KBS.