Case Study 34 Pollination Aware Tomatoes

This case study is the primary source of information on potential pollination services for the industry. It is based on data provided by industry, the ABS and other relevant sources. Therefore, information in this case study on potential hive requirements may differ to the tables in the Pollination Aware report (RIRDC Pub. No. 10/081) which are based on ABS (2008) Agricultural Commodities Small Area Data, 2005-06.

Introduction The (Lycopersicon esculentum) originated in South America outside in orchards and can be consumed fresh, canned or used and it has been grown in Europe for hundreds of years and to produce sauces, juices, pastes or powder. The seed also yields is now extensively grown around the world. The tomato is a her- 24% oil which is used in salad oil, margarines and soap. Tomato baceous, usually sprawling plant in the Solanceae, or nightshade plants typically reach 1–3m in height and have a weak, woody family, that is typically cultivated for the purpose of its fruit for stem that often vines over other plants. The leaves are 10–25cm human consumption. The tomato is recognised worldwide for its long, with 5–9 leaflets which can each get up to 8cm long with savoury flavour and distinctive red colour. Thousands of varie- a serrated margin. The plant is also covered with short coarse ties of tomatoes exist; however, the most commonly cultivated hairs and has a glandular secretion with a characteristic unpleas- varieties may include classic, cherry and cocktail, plum and baby ant odour, particularly when bruised (McGregor 1976). plum, beef and vine or truss. Tomatoes can be cultivated under cover in greenhouses or Tomato production in Australia The tomato industry in Australia can be separated into two counting for 55% while Victoria, New South Wales and Western distinct sectors, those grown for use in processed foods and those Australia produced 20%, 12% and 5% respectively (Table 2). grown for the fresh market. Victoria is the major producer for Tomato producing regions of Australia are shown in Figure 1. the processed market accounting for 86% of total production followed by New South Wales at 12% and small amounts in the other states (Table 1). Table 1 Production of tomatoes for processing per state (ABS 2008) Queensland NSW SA QLD WA VIC on the other Production per state 126,946 hand produces (‘000 tonnes) 17,935 93 2297 273 the majority of tomatoes for the Percentage production 12.15 0.06 1.55 0.18 86.05 fresh market ac- per state (%) Case Study 34 Pollination Aware

Table 2 Production of tomatoes for the fresh market per state (ABS 2008) NSW SA QLD WA VIC TAS NT

Production per state 28,912 14,715Table 2 130,147Production of12,043 tomatoes for 47,433the fresh market per997 state (ABS 2008)30 (‘000 tonnes) NSW SA QLD WA VIC TAS NT Percentage production 12.34 6.28Production per 55.55state (‘000 tonnes)5.14 28,912 20.2414,715 130,1470.42 12,043 47,4330.01 997 30 per state (%) Percentage production per state (%) 12.34 6.28 55.55 5.14 20.24 0.42 0.01

Figure 1 Tomato production regions within Australia (ABS 2008)

Pollination in tomato The flower of the tomato is hermaphrodite (having bothF igure male 1 Tomatopollinating), production various regions tests within have Australiashown that (ABS -facilitated 2008) and female reproductive organs) with the style elongating at pollination results in higher fruit set and fruit size (Higo et about the time the anthers begin to release their pollen into the al. 2004; Sabara et al. 2004). In the field, wind movement is styler tube (McGregor 1976). The stigma is receptivePollination to its own in tomatoinstrumental in bringing about self-pollination in tomato crops; pollen or other pollen one or two days before anther Thedehiscence, flower of thehowever, tomato is in hermaphrodite commercial greenhouses(having both maleinsufficient and female wind reproductive may result organs) with which favours cross-pollination. The anthers are also theconstructed style elongating in diminished at about the pollination time the anthers and lowbegin fruit to release set. Before their poll theen mid- into the styler tube in such a way that the slightest vibration will send a rain(McGrego of pollenr 1976) 1990s,. The stigmasupplemental is receptive pollination to its own of pollen tomatoes or other in greenhouses pollen one or was two days before anther dehiscence, which favours cross-pollination. The anthers are also constructed in such a way down around the stigma. Nectar secretion from tomatothat plantsthe slightest accomplishedvibration will sendusing a hand-heldrain of pollen vibrating down a roundwands, the but stigma currently,. Nectar secretion from seems of little, if any, value in attracting honey ; andtomato bumble plants seemscommercially of little, if any,reared value bumble in attracting bees are honey used bees; almost and exclusively bumble bees have been bees have been reported to gather chiefly pollen fromreported tomato to gatherin chiefly other countriespollen from because tomato theyflowers are (McGregor significantly 1976) less. expensive Each seed requires one flowers (McGregor 1976). Each seed requires one pollenpollen grain, grain, andand thus more many effective pollen grains than aremanual needed vibration on each (Sabarastigma to et avoid al. 2004). misshapen fruit being and thus many pollen grains are needed on each stigmaproduced. to avoid In Australia, most tomatoes are grown outdoors, but there is an misshapen fruit being produced. In the past tomatoesincreasing have been preference shown to for be thenon -useself -ofpollinating, closed greenhouses, and although which modern cultivars can be autogamous (selfresults-pollinating), in improved various quality tests while have shownallowing that large insect reductions-facilitated in pollination the results in In the past tomatoes have been shown to be non-self-pollinating,higher fruit set anduse fruit of water size (Higo and pesticides.et al. 2004; SabaraGreenhouse et al. 2004) tomatoes. In the are field, currently wind movement is and although modern cultivars can be autogamous (self-instrumental in bringing about self-pollination in tomato crops; however, in commercial greenhouses insufficient windhand-pollinated may result in diminished with industrial pollination electric and lowvibrating fruit set. wands. Before This the mid-1990s, supplemental pollination of tomatoes in greenhouses was accomplished using hand-held vibrating wands, but currently, commercially reared bumble bees are used almost exclusively in other countries because they are significantly less expensive and more effective than manual vibration (Sabara et al. 2004). In Australia, most tomatoes are grown outdoors, but there is an increasing preference for the use of closed greenhouses, which results in improved quality while allowing large reductions in the

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incurs high labour costs (Hogendoorn et al. 2006). . Both of these studies however indicated that there were Table 2 Production of tomatoes for the fresh market per state (ABS 2008) significant limitations in experimental design. Banda and Paxton NSW SA QLD WA VIC TAS NT Earlier research by Bailey and Lodeman (1895, as cited in (1991, as cited in Higo et al. 2004) conducted their study in McGregor 1976) concluded that bees in the greenhouse were August, a time when there is a wealth of competing vegetation Production per state 28,912 14,715 130,147 12,043 47,433 997 30 of no value as pollinators of tomatoes; however, Neiswander (‘000 tonnes) outside, and additionally their honey bees were allowed only (1966, as cited in McGregor 1976) found that visits from honey five days in the greenhouse, possibly insufficient time in which Percentage production 12.34 6.28 55.55 5.14 20.24 0.42 0.01 bees increased fruit production even though the flowers had also to both acclimatise and learn to forage on tomato. Cribb et al. per state (%) received shaking treatments. (1993, as cited in Higo et al. 2004) used small experimental More recent research investigating the use of honey bees as houses and noted some harmful effects on colonies, possibly due pollinators of tomatoes has been done using small experimental to the small size of compartments in which they were allowed greenhouses; however, results have been largely inconsistent. to forage, and potential pollen deprivation. Sabara et al. (2004) Banda and Paxton (1991, as cited in Higo et al. 2004) tested used honey bees for three week periods in small experimental honey bees in small experimental houses, but they found that tomato greenhouses and found that these fruits produced honey bees were “erratic” and not effective; however Cribb significantly more seeds than bagged flowers restricted from et al. (1993, cited in Higo et al. 2004) concluded that tomato facilitated pollination. yield was improved with treatments that included the honey

Pollination management for tomatoes in Australia There are a number of factors within the tomato crop which as to the density of hives required was research conducted have a direct bearing on the pollination efficiency of honey bees: in Canada by Higo et al. (2004). Honey bees were used as a supplement to bumble bees for the pollination of tomatoes. The study recommended honey bees should be stocked at a density Crop layout of two to four hives per hectare, with higher numbers used if • Row spacing and blossom density: Tomato plants are usually bumble bees are reduced. Given that Australia does not have cultivated in rows, 1 to 2m apart in the field, but usually bumble bees, one may need to assume that higher numbers may tied up on strings when grown in greenhouses. Under com- always be required for Australian tomato crops if honey bees are mercial harvesting methods, cultivars are desired that set a the sole pollinators. maximum amount of fruit in a relatively short time, and the fruit retains its keeping qualities for several days both on the Higo et al. (2004) suggests that colonies should be placed evenly vine and after it is harvested. The stigma of the flowers will throughout the greenhouse and out of the way of greenhouse usually remain receptive to its own pollen for 1–2 days and workers and equipment (sturdy stands above the crop canopy). to pollen from other plants for 4–8 days (McGregor 1976). Installation and removal of colonies should also be done late in the day and timed to overlap and prevent gaps in pollination, because foragers may need an acclimation period Density of bees/arrangement of hives before they begin working the tomato flowers (Higo et al. 2004). Very little information exists on the density of honey bees required for adequate pollination of tomatoes, especially in an Australian context. One study which may give an indication

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Timing while hives remain on the property. Most poisoning occurs Honey bees should be allowed time to acclimatise and learn when pesticides are applied to flowering crops, pastures and to orient and forage on the tomato crop. Higo et al. (2004) weeds. found that honey bees took about a week to acclimatise before It is strongly recommended that growers take the following steps recording high levels of activity. If honey bees are to be used in to prevent or reduce bee losses: commercial greenhouses, growers should schedule installation and removal of colonies so that their crops are not left without • follow the warnings on pesticide container labels adequate pollination while honey bees acclimatise (Higo et al. • select the least harmful insecticide for bees and spray late in 2004). the afternoon or at night • do not spray in conditions where spray might drift onto Preparation of bees adjacent fields supporting foraging bees For a hive to be able to adequately pollinate a crop it must be • dispose of waste chemical or used containers correctly above certain strength in bee numbers. To achieve this, beekeep- • always warn nearby beekeepers of your intention to spray in ers may need to provide some form of stimulation before hives time for steps to be taken to protect the bees; give at least are placed into greenhouses or orchards. This may require either two days’ notice artificial stimulation by feeding pollen supplements and substi- • always advise nearby farmers. tutes or by placing an apiary among another nutritious flowering crop before moving it onto tomatoes. Because the tomato flower does not produce nectar and its pollen is unattractive, bee Weather Temperature and rainfall have a marked effect on honey bee colonies health may quickly deteriorate. Therefore in addition activity. Bee activity is very limited below temperatures of 13oC, to supplements before pollination, hives should be supplied with with activity increasing up to around 19oC, above which activity sufficient sugar water for the total time expectancy of pollination tends to remain at a relatively high level. Decreases in both (KBS 2009). numbers of bees visiting blossoms and the distance from the hive at which bees forage occur with a decrease in temperature. Availability of bees for pollination Tomatoes are a significant vegetable crop in Australia with some form of industry in every state (see Figure 1); however, tomato Alternatives Opportunities for improvement: Research at the University of West- blossom is not seen by an apiarist as a primary resource given its ern Sydney conducted in April 2006 (Bell et al. 2006) found that poor nutritional value to honey bees. Supplementary feeding native blue-banded bees ( cingulata) pollinated green- may be needed in order to maintain strong working colonies. house tomatoes just as efficiently as the vibrating wand method. This increased cost is worn by the apiarist and then passed Significantly more, heavier, larger and rounder tomatoes were onto the grower who wants to bring in hives for pollination. It produced by the plants in both the ‘Bee Pollination’ and ‘Vibrat- is therefore obvious to see that a purely crop-pollinating bee ing Wand Pollination’ groups compared to the control. No industry would need to be developed separate to the honey significant difference was seen between the ‘Bee Pollination’ and producing industry. ‘Vibrating Wand Pollination’ groups. These results are similar to those seen overseas in studies of greenhouse tomato pollination Risks by European bumble bees (Higo et al. 2004). This indicates that Pesticides: One of the biggest drawbacks of placing bees near any the native blue-banded bee could be a very good pollinator for agricultural crop is the possibility of colonies or field bees being Australian greenhouse tomato crops and would also reduce costs affected by pesticides. Pesticides should be kept to a minimum for those growers using the vibrating wand method.

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Potential pollination service requirement for tomatoes in Australia Optimal use of managed pollination services in all tomato grow- ing areas in Australia would require an estimated service capacity as indicated in Table 3 below. Prior to committing resources to commercial pollination of tomato crops it would seem necessary and appropriate to undertake further work to conclusively establish the effectiveness of the application of such a service and the most efficient management arrangements for using it.

Table 3 Potential pollination service requirement for tomatoes in Australia State Peak month Area (ha) Average hive Estimated number total density (h/ha)* of hives required VIC December 2,996 4 11,984 NSW January 903 4 3,612 QLD February 2,543 4 10,172 WA December 259 4 1,036 NT January 1 4 4 SA February 85 4 340 TAS December 8 4 32 Total 6,795 27,180 Note: *Area sourced from ABS (2008), flowering times from Mann (2009) and average hive density sourced from the upper recommendation by Higo et al (2004)

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References AUSTRALIAN BUREAU OF STATISTICS (ABS) 2008. Agri- MANN, L. 2009. RE: Australian Processing Tomato Industry. Type to cultural Commodities: Small Area Data, Australia, 2005–06 STRATEGEN. (Reissue), ABS No 7125.0. MCGREGOR, S.E. 1976. Insect pollination of cultivated crop plants. BELL, M. C., SPOONER-HART, R. N. & HAIGH, A. M. 2006. USDA, Tucson, Arizona. Pollination of Greenhouse Tomatoes by the Australian Bluebanded Bee Amegilla (Zonamegilla) holmesi (Hyme- SABARA, H. A., GILLESPIE, D. R., ELLE, E. & WINSTON, noptera: ). Economic Entomology, 99, 437-442. M. L. 2004. Influence of Brood. Vent Screening, and Time of Year on Honey Bee (: Apidae) HIGO, H. A., RICE, N. D., WINSTON, M. L. & LEWIS, B. Pollination and Fruit Quality of Greenhouse Tomatoes. 2004. Honey Bee (Hymenoptera: Apidae) Distribution Economic Entomology, 97, 727-734. and Potential for Supplementary Pollination in Com- mercial Tomato Greenhouses During Winter. Economic Entomology, 97, 163-170. HOGENDOORN, K., GROSS, C. L., SEDGLEY, M. & KELLER, M. A. 2006. Increased Tomato Yield Through Pollination by Native Australian Amegilla chlorocyanea (Hymenoptera: Anthophoridae). Economic Entomology, 99, 828-833. KBS. 2009. Tomato Pollination [Online]. Koppert Biological Systems. Available: . [Accessed 2009].

This case study was prepared as part of Pollination Aware – The Real Value of Pollination in Australia, by RC Keogh, APW Robinson and IJ Mullins, which consolidates the available information on pollination in Australia at a number of differ- ent levels: commodity/industry; regional/state; and national. Pollination Aware and the accompanying case studies provide a base for more detailed decision making on the management of pollination across a broad range of commodities. The full report and 35 individual case studies are available at www.rirdc.gov.au.

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Notes

Page 7 This project is part of the Pollination Program – a jointly RIRDC funds for the program are provided by the funded partnership with the Rural Industries Research Honeybee Research and Development Program, with and Development Corporation (RIRDC), Horticulture industry levies matched by funds provided by the Australia Limited (HAL) and the Australian Government Australian Government. Funding from HAL for the Department of Agriculture, Fisheries and Forestry. The program is from the apple and pear, almond, avocado, Pollination Program is managed by RIRDC and aims to cherry, vegetable and summerfruit levies and voluntary secure the pollination of Australia’s horticultural and contributions from the dried prune and melon agricultural crops into the future on a sustainable and industries, with matched funds from the Australian profitable basis. Research and development in this Government. program is conducted to raise awareness that will help protect pollination in Australia. RIRDC Publication No 10/141 ISBN 978-1-74254-111-2