Double Cropping Options for a Fall Vegetable Crop

Double Cropping Options for a Fall Vegetable Crop

Fruit and vegetable production on plastic mulch is a substantial investment.  To help justify the high input cost, farmers oftentimes choose to double crop.  This practice can provide a significant amount of additional income for the farm if a good farm management plan is in place, there is a demand for the product, and the weather cooperates.

plastic mulch bed

Plastic mulch beds. Photo Credit: Blake Thaxton.

Field Prep

Spring fruit and vegetable crops are usually grown on black plastic mulch, but fall crops are usually grown on white plastic.  Black plastic mulch helps absorb heat to warm the soil in the late winter and spring.  White plastic mulch helps reflect light to cool the soil in the late summer and fall.  In order to reuse black plastic from the spring, painting the mulch is recommended.  White interior latex paint can be diluted with water and sprayed on the plastic.  At least one study has shown the ratio of paint to water can vary drastically without any significant difference in yield.

Crop residue leftover from the spring crop should be removed to reduce the risk of plant and human pathogens and deter harboring of insect and rodent pests.  If pests are an issue or a potential threat, then the soil can be fumigated before the second crop is planted.  Also, it is important to continue to irrigate the beds during the time between the two crops.  This will ensure a good water distribution throughout the bed when the second crop is planted.

Fertilization

When double cropping, it is important to consider each crop’s fertilizer needs independently.  Never assume that excess fertilizer from the spring crop will be taken up by the fall crop.  Take a soil sample before the second crop is planted to determine nutrient deficiencies.  If phosphorus is required for the second crop, then phosphoric acid can be injected through the drip.

Stringing tomatoes. Photo Credit: UF/IFAS Photo by Tyler Jones UF/IFAS Communication Services

Crop Selection

It is never a good idea to plant members of the same plant family sequentially, such as tomatoes after an eggplant crop, or zucchini after a watermelon crop.  The Vegetable Production Handbook of Florida lists production practices for various crops by plant family.  Recommended fall crops to follow tomatoes include: squash; broccoli; or cabbage.  Recommended fall crops to follow watermelons and other cucurbits include: peppers; tomatoes; or broccoli.  Consider plant spacing when selecting a second crop.  Added holes in the plastic mulch will reduce it’s integrity and promote weed growth.  No matter what crop you choose to plant this fall, make sure you have a good marketing plan in place, with your buyers already lined up.

 

Controlling Pocket Gophers in Hay Fields

Controlling Pocket Gophers in Hay Fields

Southeastern Pocket Gopher (Geomys pinetis). Credit: Joseph W. Jones Ecological Research Center

The Southeastern Pocket Gopher, Geomys pinetis, sometimes called “Sandy-Mounders,”  is a native rodent wildlife species in most of Florida, Southern Alabama, and Southern Georgia.  They are typically found in fields with sandy, well-drained soils that are fairly common in the coastal plains.  Sandy fields are not the best sites for cropping, but are commonly used for hay fields and pastures. Bahiagrass and Bermudagrass rhizomes and roots appear to be preferred food for these rodents.  They also enjoy eating peanuts, sweet potatoes, sugarcane, alfalfa, and peas.  Populations of southeastern pocket gophers have been documented to be as high as 6-8 per acre.  With an average lifespan of 2-7 years.¹

Pocket gophers tunnel underground feeding on plant roots, and seldom venture above ground except to push dirt out of their tunnels.  This is where the main problem arises.  While their root feeding can cause crop issues, the main problem is the mounds of sand they push up scattered over sizeable areas.  Those mounds of sand wreak havoc on hay harvesting equipment.

Control Options

Controlling these pesky rodents is not simple.   Pocket gophers are seldom above ground, so they have few natural predators to manage their populations.  Pocket Gophers have extensive burrows, with tunnel systems that average 145 feet in length.  Every so often they dig a lateral tunnel to the soil surface to push dirt out of their burrow, and then seal it up again to prevent predator entry.²

In the early spring or late fall, when grass growth is limited, pocket gopher mounds are highly visible, making it a good time to attempt control measures. You have to closely monitor for fresh mounds to know where pocket gophers are actively living and feeding to attempt control measures.

Poison Baits

Pocket gophers are a native wildlife species, so they are protected by Florida Law.  It is not legal in Florida to make above ground broadcast applications of poison baits to control nuisance wildlife species.  Since they spend very little time above ground, this would not work well anyway.  It is legal for private land owners to apply subsurface toxicant baits, that are labeled for controlling pocket gophers, and that have been approved for use by the Florida Department of Agriculture (FDACS).

The publication Pocket Gophers, from the University of Nebraska, states that, “Several rodenticides currently are federally registered and available for pocket gopher control. The most widely used and evaluated is strychnine alkaloid (0.25 to 0.5% active ingredient) on grain baits.”  In Florida, there is only one strychnine alkaloid bait that has been approved for use by FDACS for controlling Pocket Gophers.  The product is called Gopher Bait 50.  The label for this product outlines specific Use Restrictions:

This product may only be used to control pocket gophers (Geomys spp., Thomomys spp., and Pappogeomys spp.) in subterranean applications only in rangelands, pastures, croplands and non-crop areas. Do not apply this product by use of mechanical burrow builder. Do not apply this product above ground over agricultural crops or anywhere else.  Do not apply directly to food or feed crops. 4

The challenging part of using toxic baits, is that it is difficult to apply the bait where the gophers are actively living and feeding. It has to be applied directly in the main tunnels used for travel and feeding.  There is equipment available that is specifically made for field scale, subsurface application on larger acreage.  The publication Using Burrow Builders for Pocket Gopher Control provides some examples of equipment designed for area subsurface bait application.  This publication also has a chart to help calculate the rate to apply based on the bait product label specification.³  However, the strychnine product labeled for use in Florida does not allow for mechanical application with “burrow builders” for large area application.So to use this specific product, you have to place the bait in each tunnel manually, and then seal the tunnel back up for consumption.  If the bait gets wet, it loses its effectiveness, which can be challenging from time to time in Florida.  Strychnine is a fast acting chemical, once consumed by the pocket gopher, causing death within hours.²    But because they die underground,  there is no way to know how effective the treatment was, except for the reduction of new mounds.

Trapping

Trapping is the most effective control method for controlling pocket gophers on a smaller scale.  It does requires constant observation to recognize fresh mounds to know where to place the traps.  Sonny Fortunato, a hay farmer in Jackson County, has become skilled at trapping pocket gophers. During a recent farm visit, he agreed to assist with the production of the following video, that shows the techniques he uses to successfully trap pocket gophers in his hay field.  The trap was set and the gopher was captured in less than 30 minutes that day.  This was the tenth pocket gopher he has successfully trapped thus far in his 16 acre hay field this spring.

There are quite an assortment of traps made for catching pocket gophers.  The Victor Gopher Trap, demonstrated in the video, can be purchased at farm supply stores, or ordered online through Amazon for less than $10 each.  But, there are a number other brands and types that can be effective.

The trap demonstrated in the video does not  immediately kill the gopher, so the trap should be attached by a wire to a stake.  Don’t use string or ropes, as these can be chewed off by the gopher’s sharp teeth.  Using the staked wire, the trapped gophers can be pulled to the surface and quickly euthanized with a sharp blow to the head. Traps should also be checked on a regular basis to prevent extended suffering.  Choker-loop type traps actually kill the gopher when trapped, but may not be as effective on larger gophers.¹

A trapping permit or pest control license is not required for private land owners in Florida to trap and exterminate pocket gophers on their property, but is required of professionals who are hired for this service. As demonstrated in the video, this is something you can do yourself.  It does require time, patience, and careful observation for fresh mounds to place the traps in the best locations.

For more information on controlling pocket gophers, or other pests on your farm, contact your local County Extension Agent.

For more information, the sources used for this article are available through the following links:

  1. Southeastern Pocket Gopher (William H. Kern, Jr., University of Florida)

  2. Pocket Gophers (Ronald M. Case and Bruce A. Jasch, University of Nebraska)

  3. ATTRA Gophers: Vertebrate IPM Tip Sheet

  4. Using Burrow Builders for Pocket Gopher Control (Scott E. Hygnstrom, Stephen M. Vantassel, & Bruce E. Anderson,
    University of Nebraska)

  5. Martin’s Gopher Bait 50 label

  6. What are those “Sandy-Mounders” anyway?

 

Controlling Rats and Mice around the Farm

Controlling Rats and Mice around the Farm

The Norway rat, roof rat, and house mouse are destructive rodent pests in and around farm facilities. This can be especially true during the winter months, as they seek food and refuge indoors. Rats and mice consume and contaminate feed, gnaw on structural, mechanical, and electrical components, and weaken concrete slabs and walkways with their burrowing activities. They can also potentially carry diseases such as bubonic plague, leptospirosis, rabies, and bacterial food poisoning.

Usually the first signs of rodent infestation are droppings or urine stains in and around buildings, because rats and mice are most active at night. If rodents are seen repeatedly during the day, it is an indication of an established population. It is estimated that for every rodent seen during the day around barns and poultry houses, there are likely 20 to 50 that are unseen.

Effective rodent control involves a three step process. The first step is to “rodent-proof” the structure. This is very difficult because rats and mice can squeeze through holes just large enough to pass their heads through, as small as ¼ for mice and ½ inch for rats. They can climb through pipes, jump vertically three feet, horizontally four feet, and climb wires, cables, vines, and trees to enter a building.

To be effective, rodent-proofing must block all possible entry points. Openings must be sealed with mortar, concrete, sheet metal, or hardware cloth (19 gauge or heavier with no openings more than ¼ inch) around augers, pipes and wires where they enter structures. Also, corrugated metal siding should be sealed and corner seams made tight.

Good sanitation is step number two. Food, water, and nesting material must be eliminated. Recommended practices include:

  • Clean up debris and trash.
  • Store feed in metal cans with tight fitting lids.
  • Keep grass short and maintain at least a 3-foot space around the building that is free of brush, trash, and weeds.
  • Dry up water sources such as dripping faucets or leaking pipes.
Rattus rattus male

Janet Hurley~ Texas A&M Agrilife Extension Service~ Bugwood.org

The third step is population reduction with traps and baits. Since rodents have a small home range, rats travel no more than 100 feet and mice less than 30 feet from their nesting site, trapping is an effective, quick and economical method of control. Trapping is often underrated, especially where only a few rodents are present. Common snap traps, glue boards, and live traps can be used to supplement baiting programs, or in situations where baits may pose a hazard. Traps should be placed along walls, near holes, or at right angles along beams, rafters, or other travel ways. Traps may be baited with a variety of food items such as whole nuts, peanut butter, or small pieces of meat.

There are many different types of rodenticides (poison baits) on the market. They may be formulated as bar baits, pellets, concentrates, or tracking powders (Table 1). In most situations, ready-to-use commercial baits are preferred over mix-your-own baits, because they do not require the applicator to handle a concentrated toxicant. Bar baits are formulated with a high wax content for outdoor use and high humidity areas. Pellets are formulated with grain and a binder that holds the pellet together for indoor use. Concentrates and tracking powders are occasionally used by professional pest control operators.

Rodenticides are classified into two broad chemical groups: anticoagulants and non-anticoagulants. The older, or first generation, anticoagulants were first discovered in the 1940s. Warfarin was the first on the market and became the best known and most widely used. However, its use is limited today due to resistance and newer, more potent anticoagulants that are available. Most of the first generation anticoagulants are multiple-dose baits: that is they cause death only after they are eaten several days in a row. The newer second generation anticoagulants are effective after a single dose. These include brodifacoum, bromadiolone, and difethialone. The single-dose anticoagulants are generally effective against rodents resistant to the older multi-dose compounds.

The two most common non-anticoagulant baits are bromethalin and cholecalciferol or vitamin D³. Bromethalin kills rodents by shutting down their ability to produce energy within the cells of the body. A single-dose is usually lethal within 1 to 3 days. It is considered safe, and a minor threat of secondary poisoning, because it causes the rodent to stop feeding days before it dies, so most of the poison has been excreted prior to death and possible ingestion by a predator or pet. Cholecalciferol is a calcium releaser that causes too much calcium to be released into the blood, disrupting body functions. Cholecalciferol kills anticoagulant resistant rodents and there is no problem of secondary poisoning of pets or wildlife that eat poisoned rodents. Cholecalciferol will act as a single-dose poison, if a sufficient amount is consumed by a rodent in one feeding, but it will act as a multiple-dose poison if consumed in lesser amounts over several days.

Zinc phosphide is a single-dose bait which has been used for many years. This is a restricted-use product, which is mostly used for agricultural rodent control, because it offers little risk of secondary poisoning of beneficial predators. However, it has no antidote and is not appropriate for use around children, pets, or livestock.

When using rodenticides, safety must be the first consideration. Poison baits must be placed where they are inaccessible to children, pets, livestock, and wildlife. Tamper-proof bait stations should be used where rodent runs are exposed and in all outdoor situations.

 

Table 1. Common Rodenticide Baits

Active Ingredient Trade Names Type Formulation Dose Required

ANTICOAGULANTS

chlorophacinone Rozol, Ramucide, Microzul, other brands 1st generation Tracking powder, pellets, blocks, concentrate Multiple dose; death 5-7 days after feeding.
diphacinone Ramik Green, Contrax-D, Ditrac, Trap-N-Sak, other brands 1st generation Pellets, place packs, bait blocks Multiple dose; death 5-7 days after feeding.
pindone Pival, Pivalyn 1st generation Bait packs and blocks, bulk Multiple dose; death 5-10 days after feeding.
warfarin Ferret, Contrax, other brands 1st generation Place packs, bulk Multiple dose; death 5-10 days after feeding.
brodifacoum Attack, Havoc, Jaguar, D-Con, Talon, other brands 2nd generation Place packs, bulk, pellets, bait blocks Single dose; death 5-7 days after feeding.
bromadiolone Boot Hill, Contrac, Hawk, Just One Bite, Maki, Tomcat 2, other brands 2nd generation Place packs, bulk pellets, bait blocks Single dose; death 5-7 days after feeding.
difethialone Generation, Hombre 2nd generation Pellets, place packs, bait blocks Single dose; death 5-7 days after feeding.

NON-ANTICOAGULANTS

bromethalin Assualt, Fastrac, Vengeance, Tomcat, Trounce, other brands Neurotoxin Place packs, bulk, bait blocks Single dose; death 2-4 days after feeding.
cholecalciferol Rampage, Quintox, Terad3 Blox, other brands Vitamin D³ calcium releaser Place packs, bait blocks Single or multiple dose; death 3-5 days after feeding.
Zinc phosphide

“Restricted-Use Pesticide”

Many brands Stomach poisoning from phosphine gas formation. Pellets, mixed grains Single dose (acute); quick knock down.

 

For more information, refer to the following publications used as resources for this article: