Agronomy

Description

As a cucurbit crop, cantaloupe are related to other warm-season crops like cucumbers, gourds, squashes, pumpkins and watermelons. In the U.S., true cantaloupes don’t grow commercially. Instead, these melons tend to be more prevalent in Europe. True cantaloupe fruits have hard, rough, warty rinds. Muskmelons, however, produce fruit with netted rinds, and they’re typically thought to be cantaloupes. As a result, the U.S. oftentimes interprets “muskmelons” and “cantaloupes” to be the same. This guide uses the term cantaloupe.

Site Selection

Cantaloupe planting sites should have good water-holding characteristics, and the soil pH level should range from 5.8 to 6.6. Well-drained sandy or sandy loam soils provide good growing conditions; however, if managed properly, then medium-textured soils may also represent possible cantaloupe planting areas. Good air and water infiltration are other site selection considerations. Raised beds that are 6 inches to 8 inches tall would enable the planting area to drain well.

Avoid choosing a planting site that has grown other melon, cucurbit or solanaceous crops within the past three years. Without the necessary rotation, cantaloupes may experience higher disease risk. To grow and mature well, cantaloupe plants require temperatures from 65 degrees F to 95 degrees F. Temperatures outside of this range, especially when cooler than 50 degrees F or warmer than 95 degrees F, would slow growth and maturation.

Producers can consider growing cantaloupe in high tunnels, which act as solar greenhouses and lack fossil fuel-based heating and ventilation. Raising cantaloupe in high tunnels would extend the growing season; offer protection from the environment, pests and diseases; and create desirable growing conditions. By growing cantaloupe in a high tunnel instead of a field, harvest may occur four weeks to five weeks earlier. Within a high tunnel, prepare the soil by tilling it, fertilizing it and forming raised beds that measure 4 inches to 6 inches tall and 20 inches to 32 inches wide. Laying black plastic mulch over the raised beds and installing drip irrigation are other possible production practices. After planting, use row covers to protect transplants from cool weather. Growers can keep row covers in place until flowering begins. Plants grown in high tunnels may require trellising made from plastic net and tensile wire or nylon twine and tensile wire. Pruning trellised cantaloupe plants would help to manage vine growth and produce high-quality fruit. For trellised plants that yield heavy fruit, the fruit may also require extra support such as slings that hold the fruit.

Fertility

Specific fertilizer requirements will depend on soil test results. As a general guide, producers would apply nitrogen and phosphorus at 40- to 50-pound rates at planting through side placement. Potassium needs at planting would range from 100 pounds to 120 pounds. Later, during the growing season, plants benefit from another 40 pounds to 50 pounds of nitrogen and possibly 40 pounds to 80 pounds of potash.

Variety Selection

Although producers should choose varieties based on whether they’re adapted to the intended planting area, they should also pick varieties that fit well with market needs.

Producers can choose cantaloupe varieties based on several defining characteristics, such as rind texture, flesh color, fruit size, fruit shape, flavor, earliness and disease resistance. Cantaloupe rinds may have fine or heavy netting. From a flesh color perspective, growers may choose from varieties with orange or salmon color, and fruit shape could be round or oblong. When evaluating cantaloupe varieties for their disease resistance, look for varieties that can tolerate Fusarium wilt, downy mildew and powdery mildew.

Planting

To grow cantaloupe, producers can choose to plant seeds or transplants, which tend to be most common. If planting seeds, then sow them at 0.5- to 1.5-inch depths. When seeding cantaloupe, establish single rows with 6- to 8-foot spacing or twin rows with 3-foot spacing on 9- to 15-foot centers. Seeds quickly germinate with 90 degree F temperatures. Thin seedlings to 12- to 15-inch spacing after seeds have sprouted and established themselves.

Commercial producers typically use transplants. By choosing transplants, producers can reduce their risk and produce cantaloupe fruit earlier. An earlier crop may command higher prices. About 18 days to 24 days before planting, producers sow cantaloupe seeds in a greenhouse setting. Desirable transplants will meet several characteristics: two to four true leaves, stalky stems and strong roots. Before planting, ensure that the transplants have been properly conditioned or hardened, meaning that they’ve had reduced fertilization and irrigation to prepare for growing conditions post-transplanting.

When soil temperatures 3 inches deep have warmed to 60 degrees F, producers can transplant cantaloupe seedlings. Any frost risk should also have passed. Cantaloupe plants could experience damage if exposed to mild frosts or cold temperatures. To protect seedlings, producers can use row covers, or they may plant rye strips to be one grain drill wide. Fall rye plantings placed every five rows to six rows can provide protection. The cover offered by row covers or rye strips may accelerate fruit harvest by one week to two weeks.

For operations that use cantaloupe transplants, space the single rows every 5 feet to 6 feet, and within these rows, space plants every 24 inches to 30 inches. Narrow in-row spacing may be possible for operations that have adopted plastic mulch, drip irrigation and fertilizer injection practices. Applying a starter solution to transplants may boost growth potential.

Cultural Management

Cantaloupe production can use plastic mulch. Lay the black plastic mulch to cover rows 10 days to 14 days before planting. This practice allows the soil to warm. Combined with a drip irrigation system, plastic mulch may boost cantaloupe yields and enable plants to mature earlier. Some research indicates that using plastic mulch will increase yields to 6,000 melons to 12,000 melons per acre relative to the 2,000 melons to 5,000 melons produced on average in bare ground growing environments.

To pollinate cantaloupe, pollen must be physically moved from flower to flower. Honeybees play an important role in supporting pollination and maximizing cantaloupe production. For producers concerned that their fields have too few pollinators, they may place an active honeybee hive for every acre planted to cantaloupe. According to some research, producing marketable fruit from one female flower requires visits from eight bees. A single flower has only a few hours on the day it opens to be pollinated. To limit harm to honeybees, avoid spraying insecticides on flowering plants. Another strategy involves applying insecticides when bees aren’t active. Target making those applications after sunset.

Water Management

If cantaloupe plants experience water stress, then they may fail to develop full leaves, mature on schedule, consistently produce fruit and yield well, depending on the growing season stage affected by dry conditions. Plants lacking adequate moisture during flowering and fruit development are most likely to experience marked yield declines. For operations that use drip irrigation, the irrigation system not only supplies water to plants, but it also offers a mechanism for cantaloupe producers to fertilize plants.

Although cantaloupe plants need reliable access to water, avoid applying too much. As cantaloupe fruits mature, too much water may trigger melons to crack. Additionally, providing excess water as the fruit ripens may reduce sugar levels. In production systems that use plastic mulch, overapplying water would present problems as the plastic discourages the soil from drying. To know whether soil moisture levels are adequate, consider using a soil moisture monitor, such as electric resistance blocks or tensiometers.

Weed Control

Weeds growing in cantaloupe fields require management for several reasons. They may reduce light, nutrients, water and physical space that would otherwise be available to cantaloupe plants. Insects, diseases and nematodes can exist in weed cover, so controlling the weeds may help with managing other pest challenges, too.

To manage weed populations, potential strategies include applying herbicides, laying plastic mulch and rotating crops. Cultivation represents another possible tool if cantaloupe growing areas have mild weed pressure and the cantaloupe plants haven’t started generating too many vines. Other possibilities include selecting weed-free sites and employing pre-plant weed control efforts. Cantaloupe growers should especially emphasize implementing weed control strategies during the first five weeks of cantaloupe plant growth. By actively managing weeds early, cantaloupe plants may grow to the extent that they can shade the ground and better compete with weeds.

Insects and Diseases

Several insects can challenge cantaloupe production. Those include cucumber beetles, aphids, squash vine borers, seed corn maggots, leafminers and rindworms. If striped or spotted cucumber beetles infest cantaloupe fields, then they may not only feed on young transplants, but they also may spread bacterial wilt in the field. Using traps and scouting cantaloupe fields will help producers to determine whether pesticide applications are necessary. Some experts recommend scouting for pests two times per week. Other pests that may cause damage throughout the cantaloupe production process include field mice and rats. They can damage seeds. Ripe fruit could be affected by pests such as crows, coyotes and raccoons.

From a disease perspective, diseases that afflict cantaloupe may target plant roots or foliage or the fruit itself. Specific diseases that can influence cantaloupe production include bacterial wilt, Fusarium wilt, cucumber mosaic virus, squash mosaic virus, watermelon mosaic virus, powdery mildew, downy mildew and gummy stem blight. Nematodes, such as the root-knot nematode, can also target cantaloupe plants. Disease control options include prioritizing disease resistance when choosing cantaloupe varieties, rotating crops appropriately, selecting planting sites that provide the necessary air and water drainage and applying fungicides.

Harvest and Storage

Cantaloupe fields are typically harvested several times given that the fruit typically has staggered pollination. Producers make harvest timing decisions based on the extent of the fruit’s “slip.” Factors other than slip that may influence harvest timing are the melon’s netted appearance and its background color. Based on the intended market, harvest may occur at various maturation stages.

Full slip refers to the condition when the stem and fruit easily separate, and the stem end has a scar left after harvest. After a slight tug, the melon would cleanly slip from the vine. When harvested during the full-slip phase, cantaloupe fruit would have the best taste and texture, and they would be ideal for local marketing. If producers don’t anticipate immediately shipping or marketing cantaloupe, then they may choose to harvest earlier.

To be accepted commercially, however, note that cantaloupe should generally be at three-quarters to full slip. With earlier harvest, cantaloupe may lack sweetness, and they may more easily bruise and scuff. A melon harvested at three-quarters slip would have about one-fourth of its stem still attached. Harvesting the melon would require breaking that stem.

With respect to netting and color, melons ready for harvest would have a full covering of raised, well-rounded netting. When the melon has uniformly developed a deep green color, it has reached maturity. However, not until the melon turns a light yellowish tan has it ripened fully. Melons that have developed brownish coloring may have poor quality. After harvest, cantaloupe will continue to ripen. Their sugar levels won’t further develop, however.

After harvesting cantaloupes, inspect the fruit, and cull melons that don’t meet size, maturity and quality standards. Field heat should also be removed. Hydrocooling or forced-air cooling could both serve as options to remove field heat. Cooling melons soon following harvest would help to preserve sugar content and flavor. Quickly remove cantaloupe fruit from sun exposure after harvest to address sun scald risk. When packing cantaloupe, avoid stacking the melons in layers too high because the stacking weight could cause bruising.

Food safety is another consideration for fruit quality. Establishing the right protocols that address potential hazards may help to ensure product safety. Addressing such hazards may involve limiting field exposure to animal or feedlot effluent, minimizing toxic pesticide exposure, testing the water supply for bacteria or other harmful residues and upholding sanitation standards for harvest labor and equipment.

Storing cantaloupe melons after harvest requires temperatures that range from 36 degrees F to 41 degrees F, and the relative humidity level should range from 90 percent to 95 percent. Given these storage conditions, anticipate that cantaloupe quality would be preserved for 12 days to 15 days. If stored at temperatures too cool, then cantaloupe fruit can develop a chilling injury, which is characterized by symptoms like pitting, poor ripening, off-flavor development and surface decay.

Sources

Coolong, Tim and George E. Boyhan. 2014. Cantaloupe and Specialty Melons . University of Georgia. Athens, GA 30602.

Harper, Jayson, Lynn Kime, Michael Orzolek and Steve Bogash. Cantaloupe Production. Penn State Extension. University Park, State College, PA 16801.

Jett, Lewis W. 2006. High Tunnel Melon and Watermelon Production. University of Missouri Extension. Columbia, MO 65201.

Kaiser, Cheryl, Matt Ernst and Tim Coolong. 2010. Muskmelon (Cantaloupe). University of Kentucky. Lexington, KY 40506.

Motes, Jim, Warren Roberts, Jonathan Edelson, John Damicone and Jim Duthie. Cantaloupe Production. Oklahoma State University. Stillwater, OK 74074.

Schultheis, Jonathan. 1998. Muskmelons (Cantaloupes). North Carolina Cooperative Extension. Raleigh, NC 27695-7602.

Suslow, Trevor V., Marita Cantwell and Jeffrey Mitchell. 2013. Cantaloupe: Recommendations for Maintaining Postharvest Quality. University of California. Davis, CA 95616.