| Title |
Investigators | Department | Objectives | Approach Keywords | Progress Reports | Impact Statements | Publications | |
Project * COL00633 | |
| Title | Organic Cropping Management Systems |
| Investigator(s) | Godin, RE; Larsen, HJ; Zimmerman, RJ; |
| Department | Soil and Crop Sciences |
| Objectives | Objective 1: Research and develop economically viable integrated crop management systems that address research and information needs for examining holistic organic cropping management systems for tree fruit, horticultural and agronomic crops. a. Research and develop integrated pest management systems to enhance beneficial insects, plants and soil biota to improve organic pest management. b. Research and develop cropping systems that maintain and increase the overall soil fertility in organic management systems. c. Research and develop disease and weed management practices for organic crop production systems. d. Investigate cover cropping sequences and/or cover crop rotations that maintain or increase soil organic matter and soil fertility. e. Investigate alternative cropping systems for horticultural and economic viability and sustainability, such as vegetables and small fruits for incorporation into diversified organic cropping systems. |
| Approach | The approach of the organic program in western Colorado will use a `holistic' or `systems' approach to studying cropping and cropping management. This `systems' approach acknowledges and/or assumes that all aspects of a cropping system are interrelated and interactive. These aspects or components include but are not limited to crops, water, soil, pests and environment. A `systems' approach attempts to identify and quantify the effect(s) that changing one or more components of the system has on other components of that system in order to maintain a balance between components and within the `system'. The goal of the organic systems approach requires that each component of the system be maintained and/or enhanced in order to ensure sustainability and viability over time while maintaining the environmental integrity of the system. This program will examine methods and processes that are aimed at understanding and enhancing organic agricultural production systems in order to benefit producers and consumers both economically and agriculturally over the long-term. |
| Keywords | Organic crop production, Organic systems research, Organic crops management |
| Progress Reports | |
| 1999 | One aspect of this project is to improve the sustainability of apple growers in Western Colorado by improving fruit thinning. Consistent annual cropping will be needed in the future for the apple industry to survive. One method of insuring annual crops is return bloom. Proper timing of thinning sprays is critical to achieving good return bloom. Many times, by the time the grower decides he needs to apply another thinning spray, the critical application time has past. The aim of this particular experiment was to use fruit diameter growth measurements to determine if there is a way to know ahead of time if a thinner is going to work or not. An experiment on 'Smoothee' Golden Delicious was done to test the method and its application. Nine trees were selected and 3 treatments were assigned to each of three replicates. One set of three trees were control trees with no thinner applied. A second set of three trees had the thinner carbaryl at 355 ml / 378 L (0.75 pint per 100 gal), NAA 200 at 21 ml / 378 L (0.7 oz. per 100 gal), and Regulaid at 473 ml / 378 L (1.0 pt per 100 gal) applied on 28 May, 4 days after beginning fruit measurements (normal first thinning spray timing). A third set of three trees had the prior thinning treatment plus carbaryl at 355 ml / 378 L (0.75 pint per 100 gal, Regulaid at 473 ml / 378 L (1.0 pt per 10 gal) applied 14 days later. Average fruit diameter was 19 mm (0.75 in). Five clusters per tree were selected and all of the fruit in the cluster were individually measured daily until 1 July. All of the data has not been thoroughly analyzed yet. The average percent of fruit left in a cluster on 11 June was 49, 47, and 32 percent for the control, one application, and two applications, respectfully. On 1 July, the percent of fruit left in a cluster was 43, 13, and 20 for the control, one application, and two applications, respectfully. There was some variability in the data (two applications of thinner had more fruit left than just one application). On 1 July 1999, more clusters in the control had 3 fruit per cluster, more clusters in both the one application and two applications of thinner had no fruit. Two preliminary conclusions can been drawn from this experiment. First, it would appear that the second application of thinner was not needed. That the clusters with two or three fruit in them, did not necessarily get reduced to singles by two applications. Also, by 1 July there was a greater reduction in percent fruit left on those with only one application than on those with the second application (47 to 13 versus 32 to 20) . Secondly, it does appear that once a fruit stops growing, it will eventually fall off (data not presented). The problem is determining what will cause that effect. |
| 2000 | Fruit sunburn is a major cause of fruit cullage for Golden Delicious apple in Colorado, with losses some years of up to 30% of harvested fruit (value of $1 million). An aluminum-coated polyethylene woven shade cloth structure utilizing two weave densities (50% shade weave and 70% shade weave) was used to provide shading for Golden Delicious apple during afternoons from July 20 to Aug. 22, 2000. Fruit harvested in mid-September was evaluated for severe sunburn (sufficient to cause cullage). Severe sunburn was 27% for non-protected fruit but only 4% for both weave densities (an 86% reduction). Crop losses for apple and peach to spring frost have ranged from $5 million to $14 million since 1991. Ways to delay bloom could reduce susceptibility to frost injury and enhance cropping reliability. Gels consisting of mixtures of sodium alginate (3% wt./vol), different sugars (sucrose,0.5 M, or molasses, 15% vol/vol), diluted white latex paint, and various adjuvants were applied to developing peach and apple buds 3-4 weeks prior to bloom. The alginate gels were cross-linked with calcium chloride to provide stability and durability. Such alginate applications delayed peach bloom by 4.4 - 6.6 days at one location and by 0.5 to 1.0 phenological stages (typically 5-7 days /stage) at two other locations. The applications had no measurable effect on bloom timing for apple at any of the three sites used. Soybean oil sprays (5% vol/vol) applied at 4 wks pre-bloom had no effect on bloom timing for either peach or apple. Hybrid Populus sp. are currently being considered as an agroforestry crop for area agricultural producers. A study comparing first year growth of trees under furrow versus trickle irrigation found no differences in growth for trees in the two irrigation programs (both had mean trunk circumferences of 6.86 cm and mean trunk diameters of 2.22 cm). However, the furrow irrigation system applied 17X more water through the season than did the trickle irrigation system (10,985,416 l/ha versus 637,766 l/ha, respectively). The excellent growth under both regimes demonstrates that such trees can be grown using trickle irrigation with high expectations of excellent first year growth. |
| 2001 | In cropping reliability studies, dormant applications on 2/2/2001 of kaolin clay (5.69 kg ai/l , repeated one time after drying) to `BerendaSun' and `Red Globe' peach delayed bloom by 6 days and 4 days, respectively. Applications of dilute white latex paint (10% vol/vol, applied 2/7/2001 and repeated one time after drying) delayed `BerendaSun' bloom 4 days and `Red Globe' peach 2 days. Jonathan cv. `Ruby Jon' and `Granny Smith' apple, `Bartlett' pear, and `Glohaven' peach were not delayed by either treatment nor by application of soybean oil (10% vol/vol, applied 2/6/2001) or application of a mixture of sucrose (0.5M) + sodium alginate (30 g/l) + glycerol (1% vol/vol) + white latex paint (5% vol/vol) immediately followed by application of CaCl2 (3% wt/vol) on 3/24 and 3/27/2001. Blossom clusters were reduced by 67% in pear treated with the soybean oil. Chardonnay grape treated with soybean oil (10% vol/vol) or with Stylet-Oil (5% vol/vol) on 3/9/2001 experienced severe damage with none of the 6 vines in each treatment surviving to bud burst. No such damage was observed on grape cvs. Vignoles, Cabernet Franc, or Cabernet Sauvignon. Further study is needed. Also see CRIS projects COL00157, COL00779, and COL00675. |
| 2002 | In the past decade there has been a significant increase in organic fruit production in Colorado with a corresponding increase in the number of organic fruit growers. Organic fruit currently accounts for approximately 20% of all fruit grown in Colorado. Organic fruit growers are eager for new information to aid in orchard and vineyard management. However, there has been little research to answer the multitude of basic unknowns presented by organic fruit production. There are several studies underway at the Western Colorado Research Center (WCRC) to address the needs of organic fruit growers for research based information. Scientifically based research on organic fruit IPM and fertility, along with crop variety trials have recently started and results are still inconclusive. This information will be beneficial to organic as well as conventional fruit growers if significant pest control can be achieved with reduced chemical application. Researchers are currently studying weed control using various mulches, codling moth control using pheromone traps, organic thinning using various oils, several powdery mildew control studies for grapes and manure/fertility studies on tree fruit. Fruit pest management programs are currently in transition. Insect pest management programs are transitioning from organophospate and carbamate insecticides to programs utilizing narrow-spectrum insecticides and/or organic and biological controls. In recent years, there have been many narrow-spectrum and organic insecticides introduced to the marketplace. However , product efficacy is often dependent on local conditions. In western Colorado, high UV light levels and low humidity have been observed to have significant impacts on pesticide efficacy levels when compared with trials conducted in other areas of the United States. This research is designed to determine whether new insecticides are efficacious under Colorado climatic conditions and local fruit pest management programs. An organic weed/mulch study in apples is in its second of three years with trends indicating that weed fabric barrier is not only the most effective treatment against weeds but also shows that tree grown with weed barrier had higher yields and better soil moisture retention this year when compared to bark mulch, paper mulch, flaming or mowing. These results are not yet conclusive, however, the research does show promising trends. Several IPM projects have also been started this year on sustainable wine grape production, they include a study on powdery mildew control using reduced fungicide treatments and mite control of powdery mildew. |
| 2003 | There are several studies underway at the Western Colorado Research Center (WCRC) to address the needs of organic growers for research based information. Research is being conducted on weed control, soil fertility and table grape varieties. These studies have made significant progress in the past year. A three year study on organic mulches for weed control, in cooperation with a local organic apple grower, is in the final stages of data collection and sample analysis. The trends of this study indicate that landscape fabric, or weed barrier, is not only the most effective treatment against weeds but also shows that trees grown with landscape fabric had higher yields and better soil moisture retention when compared to bark mulch, paper mulch, flaming or mowing. This information will be beneficial to organic as well as conventional fruit growers if significant weed control can be achieved without chemical herbicide applications. These results are not conclusive; however, the research does show promising trends. A second study, in its first year, is examining the use of corn gluten meal, an organic by-product with pre-emergent herbicidal properties, on weed control in organic vegetables. The corn gluten meal did not prove effective and split applications or higher rates will be examined next year. The third study, in its second year, is a cooperative project with a local organic peach grower that is looking at organic fruit tree fertility. The objective is to produce the required fruit fertility on-farm rather than purchase inputs. Preliminary findings show a definite yield benefit from applying alfalfa, grown on a neighboring field, to peach trees. The fourth organic study is a variety trial on organic table grapes. The objective is to determine if several of six cold hardy varieties can be economically viable in western Colorado. The vines were planted in the spring of 2003 and are growing well. The first small harvest should occur in late summer of 2005. |
| 2004 | There has been little replicated research done to provide information to organic growers in the areas of organic soil fertility, organic weed control, insect and disease management, or irrigation management in organic production systems. The purpose of this project to address the needs of organic growers in western Colorado for information on appropriate crop management practices that address pest management, soil fertility, manure management, cover crops and diversification in a holistic management scheme. For 2004, a weed management project on a mature apple orchard was completed; a final report has been submitted to the Organic Farming Research Foundation. We found that paper mulch and landscape fabric had the fewest weeds and the highest apple yields. Weed competition does have a significant negative effect on apple production in a mature orchard. A second study on organic fruit trees involves applying organic residues grown on-farm, such as alfalfa grown on a neighboring field and clovers grown in the alleyway, for tree fertility. Results to date shows alfalfa imported from a neighboring field to have significantly higher yields than any of the other four treatments. A third study examining organic weed control options in organic vegetables has completed the second of three years. Results indicate that corn gluten meal applications of one ton per acre can reduce weed competition in organic vegetables by 70% over the control. An organic table grape variety trial is in its second year with the first harvest expected next year. A new project started in 2004 is examining organic green bean seed production. The first year's results show two of the five varieties tested, Rattlesnake and Hystyle, had higher seed production than Kentucky Wonder, Climber or Provider. |
| 2005 | An organic weed management study was completed in 2005. The study examined four rates of corn gluten meal (CGM), and an organic pre-emergent herbicide, for efficacy in organic vegetable production. The lowest rate of CGM, 0.56 tons/ha, had the fewest weeds, highest yield and highest net returns of any of the CGM treatments. The lowest CGM treatment had comparable net returns to plastic mulch, the most used weed control method in organic vegetables. Other CGM rates used were 0.84 tons/ha, 1.12 tons/ha and 1.70 tons/ha (in a split application). The data from this study shows that CGM is an effective and cost effective weed suppressor in organic fields with lower rates performing as well as the higher rates. If weed pressure is moderate, CGM can be as cost effective as plastic mulch without the disposal problems inherent in using plastic mulch. We also found that in fields with high weed pressure, CGM was not as effective on fields with moderate to low weed pressure. Western Colorado is an ideal location for organic seed production because there is little or no disease and pest pressures effecting organic seed production. This was the second year of an organic green bean seed production project. The results to date show that organic green bean seed production can be a viable crop for organic growers in a diversified cropping system. Seed yields on three of the five varieties tested had significantly higher yields than the other two varieties. A third and final year of study will be done to verify current findings. Many area livestock producers want to produce organic meat but do not have a local source of organic feed to supplement winter pasture and hay. Organic livestock producers could benefit from growing their own organic soybeans for supplemental winter feed and greatly reduce transportation costs, thereby increasing their income potential. It was determined that at $0 .66/ltr for diesel fuel the break even point for soybean production was 2.2 Mg/ha. Therefore, an organic soybean variety trial was begun to determine the best soybean varieties regarding season length best suited to western Colorado growing condition and climate. A second objective was to determine if growing organic soybeans in western Colorado is economically feasible and sustainable in rotation with other crops used in rotations for livestock feed. In the first year the highest yielding of the three varieties tested was also the longest season variety tested; yield was 2.4 Mg/ha. |
| 2006 | Much research has been conducted on young fruit orchards in the area of weed control and ground cover management. However, little research has been conducted to address weed control and ground cover management on older fruit orchards. Therefore, organic fruit growers in the western Colorado region were in need of information on organic weed control, ground cover management and fertility options for their older, perennial pome and stone fruit orchards. This study examined six different weed control/ground cover treatments and the treatment effects on orchard fruit production, fruit quality and soil fertility. The results showed that paper mulch consistently produced significantly higher yields than all other treatments. However, when the cost of labor for treatment application and maintenance was factored into the total costs, a mowed grass ground cover showed the highest income potential. The lower maintenance cost of the mowed grass ground cover more than offset the lower fruit production. Organic fruit growers now have sound scientific data to base their weed control and ground cover management decisions on for their orchards. The use of propane flaming was a common organically approved weed control method practiced in the area prior to this study. Due to the increasing costs of propane, growers are phasing out propane flaming as a weed control/ground cover management method. This research has been timely by showing that organic fruit growers have a viable, less costly alternative to propane flaming that doesn't result in a yield reduction. The results of this research are therefore having a positive economic impact on organic fruit growers in the western Colorado region and western U.S. area as a whole. |
| Impact | |
| 1999 | This is the first year of this project and the impact is not known. The preliminary expectation of the impact of this project could be significant. With proper thinning, a grower could increase their returns by up to 100 percent. An environmental impact is that less chemical could be potentially placed in the environment if a second or even third application of thinner could be avoided. |
| 2000 | Fruit protection from sunburn between late July and late August could reduce severe sunburn on Golden Delicious apple by 86% and increase local fruit packout and returns by $1 million. Adaptation of methods to reduce fruit loss to spring frost could reduce local fruit losses by $3-8 million per year in freeze years. |
| 2001 | Colorado fruit growers suffer periodic crop loss due to spring frost. Methods to delay bloom could mean the difference between a full crop, a partial crop, or no crop. Crop valuations in 2000 were $5 million for apple, $8 million for peach, $1 million for pear. Also see CRIS projects COL0157, COL0779, and COL0675. |
| 2002 | The potential economic impact of these reduced pesticide use studies is very high. The resulting improved fruit quality and yield would produce higher income for growers due to significantly less input costs for pesticides. Should this research prove successful, the environmental impacts would be greatly reduced, again due to a reduction in pesticide use. The results of these studies will also contribute to the research based information available to organic growers. The social impact of this research should also be significant due to reduced pesticide exposure to workers, communities and consumers. |
| 2003 | The potential economic impact of these studies is reduced herbicide use from improved non-herbicidal weed control, reduced input costs from on-farm grown fertilizers, and more diversity in marketable crops for growers. These resulting improvements would produce higher income due to significantly less input costs and improved number of marketable crops. Should this research prove successful, the environmental impacts would be greatly reduced, again due to a reduction in herbicide use and fertilizer input costs. The results of these studies will also contribute to the research based information available to organic growers. The social impact of this research should be significant due to reduced herbicide exposure and better economic viability for growers and communities. |
| 2004 | The expected impacts of this project will be positive economic, environmental and social benefits. These studies should increase farm profits, partially from reduced herbicide and fertilizer costs, but also from improved crop production and higher prices paid for organic fruits and vegetables. Other economic impacts will result from reduced input costs for fertilizers grown on-farm rather than purchased commercial organic inputs. Our variety trials will help increase crop diversity, reduce risk and increase profitability by informing growers of possible new crops and their accompanying production systems. The resulting improvements from these projects will produce higher income due to significantly less input costs and improved number of marketable organic crops. Should this research prove successful, the potential environmental damage would also be reduced due to a reduction in herbicide use and fertilizer inputs. The results of these studies will also contribute to the research based information available to organic growers as a whole. The social impacts of this research should be significant, because of reduced herbicide exposure for growers and better economic viability for growers and their communities. |
| 2005 | The expected impacts of this project will be a positive economic, environmental, and social impact on the area farms and communities. The CGM study results should boost farm net returns by reducing input costs while reducing the environmental impact of the disposal of the plastic mulch. The organic green bean seed production study will enhance crop diversity thereby reducing economic risks. Organic seed is in high demand due to National Organic Standards requirements and few producers of organic seed. Consultations with several nation-wide seed sellers indicated they had low supplies with demand and prices rising quickly. The impacts of the organic soybean study potentially will be economical and environmental. If the first year results hold, farmers will be able to reduce their input costs by reducing feed hauling costs which will also reduce the environmental impact due to reduced fuel use. Increasing farm income will improve the economic viability of the farms that will in turn improve the economic viability and social stability of the area communities. |
| 2006 | The expected impacts of this project will be a positive economic, environmental, and social impact on the area farms and communities. This study should boost farm net returns by reducing labor input costs while reducing the environmental impact by reducing petrochemical use. The organic green bean seed production study will enhance crop diversity thereby reducing economic risks. The positive economic and environmental impacts of this study will have a further positive social impact on area farms. Increasing farm income will improve the economic viability of the farms that will in turn improve the economic viability and social stability of area rural communities. |
| Publications | |
| 1999 |
Gaus, A. G. 1999. Beginner's Branch. Fruit Growers Nwsl. 19(5):2. (Colo. St. Univ. Coop. Ext.) Gaus, A. G. 1999. Beginner's Branch. Fruit Growers Nwsl. 19(4):2. (Colo. St. Univ. Coop. Ext.) |
| 2000 |
Gaus, A.G., Larsen, H.J., and Rogoyski, M.K. 2000. Growing Peaches: A Guide for Western Colorado and the Rocky Mountain Region. Bull. 570A. Colo. St. Univ. Coop. Ext., Colo. St. Univ ., Ft. Collins. 40 pp. |
| 2001 |
Gaus, A.G. 2001. Sunburn Reduction in Apple Utilizing an Aluminet Canopy. Western Colorado Research Center Research Report 2000. Colo. Agric. Exp. Stn., Colo. St. Univ., Ft. Collins. (on the web at: www.colostate.edu/programs/wcrc/annrpt/00/Gaus_SunburnReductionApple.html) --- Also see CRIS projects COL00157, COL00779, and COL00675. Larsen, H.J., Stushnoff, C.E., and Rogoyski, M.K. 2001. Cropping reliability: Methods to enhance bud survival and cropping reliability in fruit crops. Western Colorado Research Center Research Report 2000. Colo. Agric. Exp. Stn., Colo. St. Univ., Ft. Collins. (on the web at: www.colostate.edu/programs/wcrc/annrpt/00/Larsen_BloomDelay.html) Zimmerman, R. 2001. Population and Control of the European Earwig, Forficula auricularia, in Western Colorado Peach Orchards. Western Colorado Research Center Research Report 2000. Colo. Agric. Exp. Stn., Colo. St. Univ., Ft. Collins. (on the web at: www.colostate .edu/programs/wcrc/annrpt/00/Zimmerman_Earwig.html) |
| 2006 |
Godin, R., Ela, S., Max, S., Schultz, K., and Rohde, J. 2006. Organic Alternatives for Weed Control and Ground Cover Management: Effects on Tree Growth, Development and Productivity. Agricultural Experiment Station, Technical Bulletin TB06-03. Colorado State University, Ft. Collins. http://www.colostate.edu/Depts/AES/Pubs/pdf/tb06-3.pdf |