TEXAS CITRUS

The subtropical climate of the Lower Rio Grande Valley of Texas, just north of the Mexico border, makes it a premier citrus-growing region. At one time, the Rio Grande Valley of Texas was the largest grapefruit-producing region in the country. In the 1950s, a series of freezes hit the area and citrus production declined precipitously. Texas citrus is making a comeback, and even though it ranks fourth in citrus production behind Florida, California, and Arizona, Texas citrus is still prized for its sweet taste and the ruby red color of its grapefruit.

Data on pesticide use in Texas citrus are not available. According to Dr. Juan Anciso, an IPM specialist with the Texas Agricultural Extension Service, most Texas citrus growers today rely predominantly on pesticides to control insects, weeds, and diseases, but also utilize basic IPM techniques. Two to three insecticide applications per season are typical, most of which are used to control citrus rust mite, a pest that causes superficial scarring to the outside of the fruit but does not effect taste or nutritional content. Regardless of the fact that the damage is cosmetic in nature, fresh market citrus growers cannot afford to let rust mite populations go unchecked because they will receive significantly less for their fruit from buyers if it is scarred.^[30]

"Growers that monitor their fields and use economic thresholds to determine when to spray are usually able to cut their insecticide applications in half," says Dr. Anciso. While almost all citrus growers in this region monitor their fields, approximately two-thirds do so on a regular basis and the rest do so infrequently."

At least one citrus pest in this region is controlled biologically. During the 1970s, the citrus blackfly was a serious pest and was difficult to control with insecticides. For several years, the Texas Department of Agriculture implemented, "Operation Squeeze," an attempt to eradicate the fly using aerial insecticide applications. Within three years, it was clear that chemical controls were not only ineffective but actually made the problem worse. Researchers at the University of Texas A & I at Weslaco (which has since merged with A & M) introduced two parasites that had been successfully used to control blackfly problems in Mexico and other citrus-producing regions. Within one year these parasites significantly reduced blackfly populations and now blackfly is rarely, if ever, a problem in citrus.^[31]

Texas citrus grower Dennis Holbrook, profiled in the following section, has been successfully utilizing biological mechanisms of insect control in his organic citrus groves.

The Importance of Organic Matter

Like his father, Dennis started out farming conventionally but began to think about changing his approach when he noticed that the productivity of his soils had declined precipitously. Recalls Dennis, "When my father used to farm, if we had to irrigate the orchard as much as five times a season, that meant it was a drought year. By the time I took over the business twenty years later, I was irrigating twice that much and applying nitrogen fertilizer at 50 percent higher rates. I knew something had to be wrong with our soil." Dennis decided to take some soil samples to George Schultz, a local agronomist who had worked in the area for forty years. George compared the soil on Dennis's farm to historical analyses of soil samples taken from the same area in the 1950s. The organic matter content in the area's soil ranged between 2.5 to 3.5 percent in the 1950s. In the 1980s, Dennis's farm showed an organic matter content of 0.225 to 0.4 percent.

Why might his soil organic matter be so low? "Back in the 1950s, it was common practice to allow native vegetation to grow on the orchard floor and incorporate it in the soil as a means of providing organic matter. By the time I started farming, herbicides were a regular part of our farming operation and most farmers tried to meet a standard of maintaining a weed-free orchard floor. Herbicides enabled us to create a sterile medium in which the citrus tree would grow. But in the mean time, we were not adding any organic matter to our soils." says Dennis. Although organic matter is usually a small percentage of the overall content of soils, it is extremely important for improving soil quality. For example, organic matter helps to improve the physical condition of soils, or tilth, which in turn helps with the transport of water and nutrients in soils.

Transition to Organic

In his search for ways to improve the quality of his soils, Dennis began to read about organic farming techniques. He was particularly intrigued by the principles of organic farming because of their emphasis on building soil fertility and productivity to support healthy plants. And he began to wonder if it wasn't possible to produce citrus and eliminate synthetic pesticides and nitrogen fertilizers. In 1983, the Texas citrus industry experienced its worst freeze in 200 years. "I lost my entire crop that year and decided that since I had to replant so many of my trees anyway that I might as well try some of it organically," says Dennis. His first attempts to find out about organic production practices and marketing channels were challenging. "Back then, organic farming was an underground community and it was really difficult to get information, particularly about how to market organically grown foods," says Dennis. Fortunately he was able to get some help from the Texas Department of Agriculture which was, at that time, developing organic standards and certification procedures under the leadership of Jim Hightower, the then Commissioner of Agriculture.

In order to be certified as an organic producer in Texas, no synthetic pesticides or fertilizers can be applied for three years prior to the sale of the crop. After the freeze, Dennis started farming 70 acres organically but because he was still in a transition period from conventional to organic, he sold most of the fruit on the conventional market. He was able to sell some fruit as organic because it had been grown on a ten-acre plot that had never been sprayed. "I packed the first fruit I sold as organic myself and even enlisted the services of my seven-year-old son to paste our logos on the boxes," says Dennis.

In 1989, another terrible freeze hit Texas and Dennis lost most of his crop again. "I would have completely gone under if we hadn't heard such a storm might hit and had the wherewithal to harvest as much as we could the ten days before the freeze hit. We harvested at least a month's worth of fruit in ten days and since the overall citrus supply plummeted, prices went up and we ended up surviving." After the 1989 freeze, Dennis stopped all conventional production and went 100 percent organic. By 1990, Dennis had converted all of his own acreage to organic and convinced a few of his clients to do the same. While it took him two years to get back into full production, Dennis's organic operation is now running smoothly. In 1997, he expected to sell close to 40,000 cartons of organic grapefruit and oranges.

Getting the Fruit to Market

Before he started farming organically, Dennis, like most citrus growers, sold his fruit to companies called "packers" who wash, polish, wax, and box the fruit and then coordinate shipping. When Dennis started growing his fruit organically, no one was packing organic fruit in his area and it became imperative that Dennis start his own packing and shipping company. While this seemed like a daunting task, Dennis started small and did not purchase any new equipment. "The only way I could afford to set up my own packing facility was to buy used, sometimes antiquated machinery. Now I always look for used parts to make my packing house functional. If I had to buy new machinery today, I'd go out of business," says Dennis.

"Figuring out how to farm organically and even building my own packing facility wasn't nearly as difficult as figuring out who to sell my fruit to. Once I could figure out who to contact, I trusted the fruit would sell itself," says Dennis. It took a lot of investigating but Dennis was fortunate enough to meet Texas Health Distributors, a division of Whole Foods Company, who bought his fruit the first year and is still one of his major distributors. To break into the California organic market, Dennis sent a sample carton of his fruit to several organic distributors in the state. Even though California is a major organic citrus producer, his fruit was picked up immediately because of its sweet taste.

Like many organic growers, Dennis has had a hard time transporting his product. "Once I developed a clientele, I could literally sell a week's worth of harvested fruit in an hour over the phone but figuring out how to ship it would sometimes take me a month," says Dennis. Several years ago, Dennis realized that his best strategy was simply to require distributors to arrange for their own pick-up and transportation from his packing shed.

Managing Weeds Organically

When Dennis farmed conventionally, he applied at least one or two herbicide applications each year to control weed growth along the orchard floor. Most citrus growers in the Rio Grande Valley value a weed-free orchard floor. As an organic grower, Dennis takes the opposite approach by eliminating herbicide use and encouraging the growth of weeds, which he calls native vegetation, along the middle between tree rows. Growth of native vegetation is controlled by mowing and cultivating, both of which provide the soil with a source of organic matter. To control weed growth in the tree rows and prevent competition for water and nutrients, Dennis uses a machine called a "tree hoe" that mulches vegetation under the tree and directs the cuttings out into the middle of the rows. Hand hoeing is only necessary when particularly tough perennial weeds take hold.

Citrus trees generally have shallow root systems. Dennis has noticed that his trees have developed deeper root systems in order to avoid surface level disturbances created by mechanical tilling and mulching. Dennis believes his trees are less stressed for water because with deeper roots they have a better access to a consistent water supply.

Dennis is starting to experiment with planting different legumes species such as vetch or clover along with his native vegetation. Leguminous plants have the ability to fix atmospheric nitrogen in nodules on their roots and when incorporated into soil can improve soil nutrient levels. This in turn decreases the amount of nitrogen he needs to add to the soil from purchased manure or compost.

One disadvantage of allowing ground cover in an orchard is that it may lower temperatures in orchards enough to increase the risk of frost damage. Depending on the time of year, frost can be quite damaging to citrus yields. Dennis has found that the use of ground cover in his operation has not increased the amount of frost damage he experiences. This is primarily because Dennis makes sure to keep the vegetation mowed during times when the risk of frost is extreme.

Insect Management

The three worst insect pests of citrus grown in Dennis' region are citrus rust mites, armored scale, and mealy bugs. Citrus rust mites cause cosmetic damage. Early season damage can make orange and grapefruit skins rough, and late season damage causes a bronzing of the skin. This damage does not affect the size, taste, or nutritional value of the fruit but because it is considered a defect, his fruit can be downgraded and receive a lower price. Scale and mealy bugs produce a honeydew that encourages mold growth on tree leaves that can disrupt photosynthesis and reduce yields.

When Dennis farmed conventionally, he applied synthetic insecticides on a calendar basis approximately three to five times a season. Under his organic production system, he has eliminated his use of synthetic insecticides and reduced his overall use of insecticides between 33 and 100 percent (see table, below). He now hires an entomologist during the growing season to visit his orchard every ten days to two weeks to determine pest and beneficial insect population levels. When rust mite populations reach damaging levels, Dennis relies on sulfur, a naturally occurring pest management material, commonly used for treating rust mites when his father first started farming. In fact, one of the jobs Dennis hated when he worked for his father was applying sulfur to the orchards. This was because it is most often applied in a dust form to citrus trees and Dennis found that it was always getting in his eyes and was caustic enough to singe off hairs if he wasn't careful. When he decided to farm organically, Dennis didn't relish the thought of going back to using dusting sulfur so he made some inquiries and found a water-soluble form of sulfur manufactured in West Germany that comes in pellets. He sprays the sulfur at night when the temperature is lower and there is more moisture on the tree. The sulfur pellets stick to the tree leaves when they come in contact with moisture and then as the temperature rises in the morning, the sulfur melts and eventually vaporizes, killing rust mites.

The ground cover in his orchards also attracts beneficial insects such as lacewings, lady bug beetles, and trichogramma wasps that help control rust mite and other insect problems. Dennis is particularly fond of lacewings, insects that during their nymph stage can eat substantial quantities of aphids. According to Dennis, the sulfur spray doesn't seem to bother the beneficials because they are more mobile than the rust mite and leave the orchard during the spraying.

Leaf cutter ants can sometimes be a problem in Dennis' orchards. The ants establish nests outside the orchard and have been known to march a considerable distance and defoliate a tree in one night. When Dennis finds a nest, he treats it directly with diatomaceous earth (an inorganic substance that is abrasive to insects and causes them to dessicate) and the botanical insecticide, pyrethrum—both considered acceptable materials under current organic agriculture regulations.

Disease Management

The worst disease in citrus is the fungal disease greasy spot, which causes premature leaf drop and can reduce foliage density. When greasy spot occurs, usually in wet weather, Dennis has always treated it with copper. Dennis still uses copper but has reduced his application frequency by 50 percent (see table, below).

Soil Fertility

One of the biggest challenges Dennis has faced farming organically is providing his citrus trees with adequate nutrients, particularly nitrogen. Under conventional management, Dennis applied up to 500 pounds of synthetic nitrogen fertilizer per acre. Now he applies two tons of manure and one ton of compost per acre. He buys the manure from a horse farm and livestock operation and has it hauled approximately 70 miles to his farm, which adds significantly to the cost. Dennis makes his own compost on site from culled fruit and tree trimmings. Making the switch to organic sources of nitrogen inputs was particularly difficult in the beginning because the nitrogen in manure and compost can be released to the soil slowly, which makes it difficult to rapidly supply enough nitrogen during periods of peak demand. Another difficulty with these nutrient sources is that nitrogen contents vary depending on which starting materials are used and the way they are handled. This makes it difficult to determine how much nitrogen is actually being applied unless each truckload is tested.

The advantage of adding compost and manure to his groves is that Dennis has increased the organic matter content of his soils. Twelve years ago, before Dennis started farming organically, his soil organic content was less than 0.5 percent and today it is up to 1.75 percent.

Economic Considerations

Yields and Quality

Dennis's organic grapefruit yields average 15 tons per acre, which represents 85 to 90 percent of the yields he got when he farmed conventionally. Although his yields have gone down, Dennis is not sure whether this is due to the two devastating freezes or his switch to organic production practices. Dennis, like most farmers in the area, had to replant trees after the two freezes so he has a higher than normal number of young trees, which produce fewer fruit than older trees. Early on in the transition period to organic, Dennis experienced a yield reduction that he attributes to inadequate soil nitrogen levels that resulted because he was unsure how much manure and compost to apply to his trees. He hopes to increase his yields in the future by spraying foliar nutrients on trees during critical periods of development to provide a quick source of nutrients and growth stimulants.

Dennis has found that the quality of his fruit has improved since he started farming organically. "My organic fruit is sweeter than anything I ever grew conventionally. I believe that because my soils are more balanced, my trees are healthier and they produce sweeter fruit. Hands down, I always win taste tests." says Dennis. Dennis compares the sugar content in his organic fruit on a regular basis to reports of the average sugar content of conventional grapefruits taken to juicing plants. Compared to their 9.5 to 10 percent figures, Dennis regularly achieves upwards of 12 percent.

Texas citrus farmers have established a marketing order for citrus that regulates the supply by using among other criteria, fruit appearance. (A marketing order is a mechanism that allows agricultural producers and distributors of specific commodities to join together to make collective decisions to ensure orderly markets, while remaining exempt from anti-monopoly laws.) As an organic farmer, Dennis must comply with these same marketing orders, so he makes sure his fruit meets the cosmetic standards.

Production Costs and Prices

Dennis's production costs increased between 40 and 50 percent when he first started farming organically. Although he irrigated only about half as much and applied fewer chemicals, his labor costs for weed control went up substantially. "I found there was a real learning curve with organic production practices. Now that I have figured out how to more effectively use mechanical cultivations, we've cut down on our labor costs," says Dennis. Dennis also found that his labor costs came down as his trees grew. The bigger the tree, the larger the shaded area in an orchard, which helps prevent weed growth and reduce the need for weed control. "I'd say my overall production costs are now 20 to 25 percent higher than when I farmed conventionally," says Dennis.

Dennis receives a premium for his organic fruit that makes up for the increased costs of production and lower yield. Although citrus prices fluctuate dramatically depending on the supply, Dennis's organic citrus often bring in as much as $16.00 a box, which is approximately double that of conventional citrus.

Concerns and Recommendations

Dennis is the only commercial scale organic citrus producer in Texas. "To hear my neighbors talk, you'd think it was impossible to grow citrus organically. They practically accuse me of getting up in the middle of the night and spraying. Well, I know it can be done and I think there are probably a few organic practices, such as building up soil organic matter with manure and compost, that conventional growers could employ to their benefit, even if they didn't want to go totally organic," says Dennis.

Many of the people who grow citrus in Texas do not own or lease their land and instead manage it for absentee landlords. This presents a significant barrier to implementing organic production practices in part because of some of the challenges facing farmers during the three-year transition period from conventional to organic practices. For example, once chemical controls are eliminated, yields may decline and costs increase until the system is better understood. This can prove too much for landlords who want to ensure steady profits year to year. When Dennis decided to farm 100 percent organic, he stopped managing citrus production for all but a few landlords who were willing to work with him. "I lost a few clients when I went organic but the majority were convinced by my arguments about building soil fertility. I basically told them that unless we take matters into our own hands, we would go under. They seemed to understand that constantly increasing our inputs was the wrong way to go. What I have learned since then has really convinced them that we are on the right track, and they are really pleased that our fruit is now of such high quality," says Dennis.

For Dennis, making the switch to organic farming has been more than a business success. "Ten years ago, I was sick and tired of farming. But going organic challenged me, made me have to think and re-learn farming all over again. All in all, it's been energizing," says Dennis.

Notes

30. Personal communication with Dr. Juan Anciso, Texas Agricultural Extension Service, University of Texas, Edinburg, Texas, March 13, 1997.

31. Personal communication with Dr. J. Victor French, Texas A & I, Westlaco, Texas, March 12, 1997 and Rod Summy, Research Entomologist, Rio Grand Valley Southern Tropical Plant Laboratory, Westlaco, Texas, March 8, 1997.