Week+5+-+BBTV+recommendations

__**Week 5**__ //BBTV recommendations//

Banana Bunchy Top Virus is one of the worst banana diseases, it is spread by Aphids and has no known cure. Due to its extreme nature, often such drastic measures as burning crops are utilized, as many believe it is the only way to be sure the entire disease and disease spreading bugs are terminated. Many others believe however that there are other options, such as those listed below that are worth trying before killing off entire years worth of income, food and bartering goods. Greener options are also available. The greatest fight against BBTV is perhaps regulated and heavily scrutinised trade and trade practices, in co-operation with the many prevention methods listed below.

**Commercial-grower Methods for Aphid Control and.**For control of aphids on banana plants, Prentox Diazinon AG500 has been approved for use in Hawaii on plants that are not fruiting (SLN no. HI-900007, EPA reg. no. 655-459). Diazinon kills aphids on contact but has no residual effect on aphids. Aphids on heliconia and flowering ginger in the vicinity of banana plants can be controlled with insecticides approved for such use. No systemic insecticide is approved for use on banana against aphids. Infected banana plants can be killed with the systemic herbicide glyphosate. Roundup Ultra™ (SLN no.HI-960005, EPA reg. no. 524-475) is approved for use in Hawaii on banana; follow label directions. Even if only a single sucker in a mat is infected, the entire mat must be destroyed. If regrowth occurs from the rogued plants or mat, both aphid control and rogueing must be repeated until the plants are completely killed. Anyone using diazinon or glyphosate in a BBTV control program in banana must have a copy of the Special Local Need pesticide label covering the use in their possession at the time of application. These labels can be obtained from the pesticide retailer or the Hawaii Department of Agriculture, Pesticides Branch. Caution: Pesticide use is governed by state and federal regulations. Read the pesticide label to ensure that the intended use is included on it, and follow all label directions.

**Establishing New Plantings**Banana growers establishing new commercial plantings should use extreme care in selecting or obtaining suckers and corms to establish new fields. “Seed” materials should be obtained from BBTV-free areas. Tissue-cultured plantlets should be derived from mother plants that have been “indexed” for BBTV and grown in insect proof screen-houses. Homeowners wishing to plant bananas should seek reasonable assurance that the keikis are virus-free. There is no certification program in Hawaii to ensure that banana plants being sold are free of BBTV. After planting bananas, examine them frequently for signs of virus infection.

**Plant Quarantine**Hawaii law prohibits importation of banana planting materials into the state without permit and a one-year quarantine period. A local quarantine has also been imposed by the Hawaii Department of Agriculture prohibiting movement of banana plants and plant parts (except fruits) from Oahu and Kona to any other islands, and this quarantine may be extended to include Kauai. To reduce the risk of introducing BBTV to new areas, shipping banana planting materials between any of the Hawaiian Islands is not recommended. Also, when heliconia or flowering ginger plants, cut flowers, or propagules are shipped between islands, precautions should be taken to ensure that they are free of the banana aphid. Controlling banana bunchy top virus where it is established and keeping it out of virus-free areas is everybody’s business. If your plants are infected, your neighbours likely will soon be too, and vice versa.

**For further advice on BBTV identification and control**contact your local Cooperative Extension Service office, or the CTAHR Plant Disease Clinic (Oahu: 956-8053, Hilo: 959-9155), or the Hawaii Department of Agriculture, Pest Control Branch (Oahu: 973-9538, Hilo:974-4143, Kona: 323-4565, Wailuku: 873-3555, Lihue:274-3069).

**//Revised by//**//Stephen A. Ferreira1, Eduardo E. Trujillo1, and Desmond Y. Ogata2 from an earlier version titled “Bunchy Top Disease of Bananas,” Commodity Fact Sheet BAN-4(A), 1989. Nilton Matayoshi and Myron Isherwood, Hawaii// //Department of Agriculture provided comment.1CTAHR Department of Plant Pathology, 2CTAHR Agricultural Diagnostic Service Center.//

**** **CONSIDERATIONS/RECOMMENDATIONS**

> > > Monitor pest populations for early control. Use yellow cards to alert you of new infestations and scout plants by turning leaves to work out were they are. Control is simpler and less expensive when plants are young and spray coverage is not an issue > >
 * Use a fallow period, if possible, when no crop is grown to clear pest populations
 * Do not plant new crops near or close to neighbouring infested weeds or old crops (greenhouse and open field)
 * Use seedlings that have been grown away from infested areas, i.e. start with a clean crop.
 * Avoid moving aphids around the crop on staff moving from infested to clean areas. Do not work in old crops on windy days, especially when prevailing winds are blowing towards new plantings
 * Mesh screening has been shown to effectively exclude aphids in covered/protected crops and use of reflective plastic soil mulch can be beneficial in reducing aphid numbers. Rolls of yellow sticky tape may be useful in some greenhouse designs if placed near entry points and hot spots.

__**Crop monitoring**__
 MAKE INSPECTIONS ROUTINE AND KEEP GOOD RECORDS!
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;">Get into the habit of walking right through your crops in a set pattern (a M or Z)
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;">Check about (about 1%) of your plants very carefully
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;">Hunt for aphids and symptoms of virus disease where this is an issue
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;">Check underside of new leaves for feeding nymphs and adults
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;">Keep good records of pest levels and treatments used

<span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;"> **Monitoring with sticky traps (only adults with wings are caught on traps):** <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;"> For insecticide-based control programs economic thresholds need to be worked out from monitoring and spray records using sticky trap and plant leaf checks. Decide on a threshold level for aphids in your crop, above which you must spray and below which you can safely withhold spraying.
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;">Plan the layout of traps to identify hot spots and estimate overall aphid levels together with plant scouting
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;">Place traps just above the plant tops
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;">Do a weekly count of aphids on each trap and look for infected plants. Mark infected plants with tape for removal and replace sticky traps.
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;">Note any aphid hot spot and check aphid numbers on nearby plants to find the size of hot spots. Check for biological control activity.
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;">Record trap, scouting details
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;">If aphid numbers are above the threshold you must spray. Think about using chemicals compatible with bio control
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;">Check numbers on marked plants 1-2 days after spraying to check results

**<span style="background-color: #ffffff; color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 120%;">Note: **
> > > >
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;">If you can spot isolated hot spots early you may only need to spray a small area!
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;">Plan to introduce biological control agents as soon as thrips are found

<span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 130%; text-align: left;">__**Chemical control**__
<span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;"> Chemical control of aphids is not as difficult as some of the other pests, though some aphid species are resistant to some chemicals. All stages are susceptible but small droplet size is much more effective and will make better contact. Only spray for aphids when you need to, but don't wait till you've got large numbers, spray early and always look for 'hot spots" in your monitoring.

<span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;"> Because of the aphids habit of colonising the growing points, they can be easy targets, but are more difficult to control when large populations move to the underside of leaves. For this reason the systemic type of insecticides are more effective. When using the contact products you need to make sure you spray the entire plant to achieve control. Remember that only a few females will recolonise a plant in a week in summer.

<span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;"> //Include a resistance management strategy into your spray program to reduce the chance of aphids becoming resistant. If monitoring indicates the need to spray earlier, then insecticide resistance, inappropriate spray application or inadequate farm hygiene should be suspected and expert advice sought.//

<span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 130%; text-align: left;">**__Relevant beneficial insects__**
<span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;"> Natural enemies have been investigated and biological control programs using a number of naturally occurring insects is possible. There is a parasitic wasp, hoverfly larvae, several ladybird beetles and lacewings that will attack aphids, but they are all very easily killed by insecticides and their residues. Naturally occurring beneficial insects usually lag behind the build up of aphids and some damage can occur before effective control is achieved.

<span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;"> As with WFT you can also boost the numbers of these wild beneficial insects in your crop naturally by holding back on broad spectrum insecticides, providing safe plant species as habitat near the crop and maintaining higher levels of organic soil carbon.

<span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;"> Only a parasitic wasp and the green lacewing are commercially available for aphid control. The brown lacewing and a ladybird beetle are currently under development.

<span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 120%; text-align: left;"> The female adult wasp is about 0.6mm long and black in colour, with a thin slender body. A female wasps lays its egg into the aphid, the wasp egg then hatches and feeds on the insides of the aphid. The aphid dies and the larvae of the wasp pupates inside the aphid body swelling it and turning it into an "aphid mummy" usually a golden or silvery appearance depending on the aphid species. An adult wasp then emerges from a small circular hole it cuts in the shell. At 25oC a wasp lifecycle takes 10 days.

<span style="background-color: #ffffff; color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 120%;">Green lacewings are generalist predators and the larval stage will eat most small insects and eggs it encounters. It particularly likes aphids and can consume 60 aphids in an hour. Adults feed on nectar and pollen.

<span style="background-color: #9dec9d; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 250%; text-align: center;"> __**A little more green and in view of future control:**__

__<span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 130%; text-align: justify;">**Cultural controls:** __<span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 130%; text-align: justify;">There are 400 known species of Ladybirds in near by Australia. Many are voracious aphid predators at all stages of their lives. Juvenile ladybirds of some species superficially resemble mealybug and woolly aphid, but are more active and less numerous. You can learn to identify them by observing them feeding. **They take time to locate and control aphid numbers.**

__<span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 110%; text-align: justify;">**Supporting strategies include:** __


 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 110%; text-align: justify;">feeding plants with a low nitrogen ‘flower and fruit’ fertiliser or reducing the frequency and amount of fertiliser to prevent the production of soft, sappy growth;
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 110%; text-align: justify;">regular hand weeding. Weeds, especially milk thistle (sow thistle), are favourite aphid food plants;

__<span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 110%; text-align: justify;">**Other controls:** __


 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 110%; text-align: justify;">rubbing aphids off plants, using fingers and thumb
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 110%; text-align: justify;">using the jet of a hose to wash aphids off plants;
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 110%; text-align: justify;">spraying plants with soapy water. Use horticultural soap or soap made from vegetable oils;
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 110%; text-align: justify;">control over-wintering eggs on deciduous fruit trees, roses and other deciduous shrubs by spraying when they are leafless during mid-winter. Spray once only with lime sulphur. Ensure the spray saturates stems and any bark fissures;

__<span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 110%; text-align: justify;">**Lime sulphur:** __
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 110%; text-align: justify;">was the first artificial pesticide and is a permitted input for organic gardens;
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 110%; text-align: justify;">is used for spraying deciduous trees to control fungal spores, bacteria and pests and their eggs on the surface of plants. Lime sulphur will burn foliage;
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 110%; text-align: justify;">Bonsai enthusiasts use undiluted lime sulphur to bleach tree bark to accelerate their aged look;

__<span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 110%; text-align: justify;">**Caution:** __


 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 110%; text-align: justify;">Lime sulphur is strongly alkaline. With a pH of 11 it is corrosive and reacts with acids producing toxic hydrogen sulphide. Solutions should be agitated to prevent settling and blocking spray nozzles during use. Wash spraying equipment throughly afterwards;
 * <span style="background-color: #ffffff; color: #000000; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 110%; text-align: justify;">Safety goggles and gloves should be worn while handling lime sulphur;