Status of your pomegranates: flowering yet?
Ariel has mentioned to me that pomegranates in Israel have been in full bloom for some time. Mine are quite a ways off from blooming but I thought it would be interesting to find out what stage of development pomegranates in different locations were.
I'd like to eventually have a calender to record flowering dates and fruit ripening dates (for different varieties) were in different areas.
Pesticide/Biological Control Common Name Pesticide/Biological Control Brand Comments* Application Rate bendiocarb Dycarb 76WP HV. One of the most effective pesticides for mealybug control 12-40 oz/100 gals. Turcam 76 WP HV. One of the most effective pesticides for mealybug control 11 oz/100 gals. bifenthrin Talstar T&O 10WP HV. Most effective when combined with products such as Orthene 6.4-32 oz/100 gals Talstar T&O Flowable HV. Most effective when combined with products such as Orthene. 8-40 oz/100 gals chlorpyrifos DuraGuard HV. Mealybug control has been very good. 25-50 oz/100 gals cyfluthrin Decathlon 20 WP HV., LV. When combined with products such as Orthene, control should be very good. 1 bag (50 grams)/9 gals. (high rate)-13 gals. (low rate). diazinon Knox Out GH HV. Do not with oil based adjuvants. 50-100 oz/gals. fenpropathrin Tame 2.4EC HV. Most effective when combined with products such as Orthene. 16 oz/100 gals. insecticidal soap M-Pede HV. May be used on greenhouse vegetables. 2.5 oz gals. Olympic Insecticidal Soap HV. May be used on greenhouse vegetables. 2.5-5 oz/gals kinoprene Enstar II HV., LV. Also registered as a pot submersion treatment for root mealybug control. Combinations with pyrethroid insecticides have been effective as foliar sprays. 5-10 oz/100 gals. as spray; For pot submersion, 0.5 oz/gal. lambda-cyhalothrin Topcide HV. Most effective when combined with products such as Orthene. 2.4-4.8 oz (2-4 bags)/100 gals. predatory ladybird beetle Cryptolaemus montrouzieri The mealybug destroyer. Most effective against mealybugs producing cottony egg masses (e.g. citrus mealybug). Make 3-4 releases at 2-3 week intervals. Predators do best in warm, humid conditions. 2-8/10 sq ft., or infested plant. citrus mealybug parasite Leptomastix dactylopii Tiny wasps that lay eggs in mealybugs. Make 2-4 releases at 2-4 week intervals. Parasites do best in warm, humid conditions. 2-5/10 sq. ft., or infested plant.
1. Parasitic wasp released
- The wasp, Coccophagus gurneyi, has now been released at 19 sites throughout the Riverland, 3 in Sunraysia and 1 in Hillston,
- A new strain of the previously-introduced citrophilous mealybug parasite, Tetracnemoidea brevicornis, has been introduced to the Riverland to add to its genetic base. These measures should enhance the biological control of citrophilous mealybug in these districts.
2. Life-history and ecology of citrophilous mealybug
Important aspects of citrophilous mealybug biology have been revealed.
The regional distribution of the mealybug species associated with inland citrus in NSW, VIC and SA has been defined, and this has aided negotiations to facilitate access of Australian citrus to markets in the USA and Korea.
Studies also revealed that in addition to the introduced parasites, two native parasites now commonly parasitise citrophilous mealybug.
Citrophilous and longtailed mealybugs usually have 3 generations per year, of which 2 occur on navel fruit during November–January and February–June. Although a partial synchronisation of the populations occurs on navel fruit when colonised by the young crawlers around November, there is considerable overlap between the generations, with all immature and adult stages present most of the time.
Citrophilous and longtailed mealybugs mainly infest leaves curled by citrus leafminer, under the calyx of fruit and less commonly in navel buttons. Most of the time the majority of mealybugs in the citrus canopy are found on curled leaves. Citrophilous mealybugs are also found on nightshade weeds in citrus orchards, but the presence of these weeds does not appear to contribute to the citrus infestations.
There is no consistent relationship between the abundance of the Nov–Jan and Feb–June generations. A relatively high density November population may, without any spraying, decline away to insignificance in the autumn, or vica-versa.
However, their honeydew which causes the sooty mould development in early winter, accumulates on fruit from November onwards, and hence mealybugs need to be managed for the entire period of fruit development.
3. Identify IPM-compatible spray treatments that control mealybugs
The third focus of the project which is to better integrate insecticidal and biological controls, has proved a challenge.
Insecticidal control of citrus mealybugs is inherently difficult, because of three main reasons:
- mealybugs are less sensitive to petroleum spray oils than are other citrus pests
- mealybugs feed in sheltered sites, and
- there is a supposed narrow timing-window for controlling mealybugs around calyx closure. This study has demonstrated that for at least a fortnight either side of calyx closure, the effectiveness of a mealybug spray is unaffected by spray timing. There is in fact a broad timing-window.
The impact of a large range of organophosphate (OP), carbamate, oil and oil-OP shandy mixes on CM and two important parasites (Coccophagus gurneyi and the red scale parasite Aphytis melinus) were evaluated and the findings of these evaluations were:
- Is as good as, or superior to, other insecticidal sprays registered for the control of mealybugs in citrus. However residues of the registered rate of chlorpyrifos remain toxic to the adult parasites for 10–14 days.
- Although further work is required, there is evidence that reduced rates of chlorpyrifos (½–¼ of the registered rate), either alone or in an oil shandy, can control moderate infestations of mealybugs.
- When applied at these reduced rates the toxicity of chlorpyrifos to the parasites diminished more rapidly than at the registered rate. Hence these reduced rates of chlorpyrifos are likely to have a lesser on beneficials compared to the registered rate.
- Oils, applied alone with standard oscillating-boom spray equipment, may produce a modest reduction in the abundance of mealybug infestations. The level of mealybug kill is less than that from OPs, but is achieved with less deleterious impact on beneficials.
3. Spray Coverage Essential
- What was evident throughout all the spray trials was the critical importance of good spray coverage to the achievement of effective mealybug control, particularly if 'softer' IPM-compatible treatments such as oil or reduced rate chlorpyrifos sprays are used.
- High volume spraying to fully wet the canopy is essential to access the mealybugs under the fruit calyxes and leaf curls. Unfortunately many growers' spray plants, including many oscillating boom sprayers, are inadequately set up to achieve good coverage.
- For effective control of mealybugs an oscillating boom spray must be operated at a pressure of at least 500 psi (3450 kPa) at the jets and at least 600–700 psi (4100–4800 kPa) at the pump, with an oscillation rate of 100–110 per min (if the oscillation rate is less than this then reduce the ground speed to less than 2.5 kph) and with the jets set to give pencilled spray cones that merge at about 1.5–1.75 metres.
The most important predator is the mealybug ladybird Cryptolaemus montrouzieri. The larvae are white and mealy with long waxy appendages and grow to 10 mm. The adults have black wing covers and other parts are reddish-brown. The ladybirds are about 4 mm long. Both adults and larvae feed on the mealybug and, once established, the predator is able to control heavy infestations in 2 to 3 months. It is, however, sometimes slow in locating an infestation. Lacewing larvae Oligochrysa lutea also help to control the pest. Parasitism by the introduced parasitic wasp, Leptomastix dactylopii is very effective. This parasitoid should be liberated at 5 to 10 000 per ha, once during October to January and is especially recommended for rollinia, soursop and casimiroa. Heavy ant infestations seriously affect natural enemies and should be controlled by a residual spray to the base of the tree. Serious infestations are often the result of suppression of natural enemies by insecticides. The ladybeetles and wasps can be obtained from 'Bugs for Bugs' at Mundubbera Queensland, phone (07) 41654663.
Spray soil around the base of the tree for ants.
Recommended chemicalsDimethoate is approved for durian, mangosteen and rambutan.
Chlorpyrifos is an approved treatment for ants on longan, lychee and pitaya