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Effectiveness of methiocarb and netting for bird control in a highbush blueberry plantation in Quebec, Canada Charles Vincent* and Michel d. Lareau Station de recherches, Agriculture Canada, 430 boulevard Gouin, Saint-Jean-sur-Richelieu, Quebec, Canada J3B 3E6

For threc consecutive years (1984-1986), percentage fruit losses caused by frugivorous birds were estimated in a 10-year-old highbush blueberry (Vaccinium corymbosum L.) planting located at Frelighsburg, Quebec, Canada. Four treatments were evaluated: these were (1) one application of methiocarb (Mesurol 75 WP) at the first ripe fruit stage, (2) as for (1) but with a second application about 10 days later, (3) bird netting and (4) a control sprayed with water. The average percentage fruit losses from the untreated plots were 37.4% in 1984, 24.1% in 1985 and 64.3% in 1986. In plots covered with bird netting, the average losses were 9.1, 6.1 and 7.1%, in 1984, 1985 and 1986, respectively. These damage levels differed significantly (p < 0.05) from those observed in the untreated plots. Except for treatment 2 in 1984, no significant differences were observed between the methiocarb-treated plots and the untreated plots.

Keywords: Bird damage; highbush blueberry; Vaccinium; methiocarb; bird netting

The extent of bird damage to blueberries is variable 1990) and Ontario (Anonymous, 1992). However , both in time and space, as shown by conflicting netting adds up to 12-13% of the annual production published reports. As a result of a mail survey, Mott costs of blueberries in Quebec conditions (Lareau, and Stone (1973) estimated blueberry losses through 1990). bird damage to be 5% in the USA, but with large One of the oldest cultivated highbush blueberry variations from state to state: 5% in New Jersey, (Vaccinium corymbosum L.) plantings in Quebec is 6-20% in Michigan, and 4(P60% in Oregon. In located at Agriculture Canada's Frelighsburg Experi- Florida, bird damage varied from 17 to 75% (Nelms, mental Farm. Lareau and Vincent (1985) observed Avery and Decker, 1990). In a study conducted in several frugivorous birds, such as the American robin Massachussetts, Southwick (1981) estimated highbush (Turdus migratorius L.), northern oriole (lcterusgalbula blueberry losses to be 50% by weight. In Maine, Ismail, L.), cedar waxwing (Bombycilla cedrorum Vieillot), Schemnitz and Gramlich (1974) concluded that losses and red-winged blackbird (Agelaiusphoeniceus L.). The of lowbush blueberries (Vaccinium angustifolium Aft.) most numerous and damaging species to the blueberries to birds was insignificant. In Quebec, the importance of was by far the American robin. yield reduction by frugivorous birds is unknown. The study reported here was conducted to estimate

Several bird-control methods exist in agriculture, the importance of bird damage to highbush blueberry Some pesticides such as methiocarb have repellent plantings in Southwestern Quebec. The efficacy of effects when sprayed on grapes (Hothem et al., 1981) netting was compared with that of two methiocarb- and blueberries (Southwick, 1981). A study conducted treatment programmes in order to determine their in Illinois found that methiocarb would reduce bird economic feasibility. damage to highbush blueberries (Courter , Larson and Randell, 1981). In Maine, Schemnitz Ismail and

Gramlich (1976) did not find a significant difference Materials and methods between methiocarb-treated and untreated lowbush

blueberry plots. The experiments were conducted in 1984, 1985 and Netting is an effective non-selective bird-control 1986 in a 10-year-old highbush blueberry planting

method with the added advantage of being environment- (0.1 ha, cv. Blueray) located at Agriculture Canada's ally sound. Although few results are published on its Frelighsburg Experimental Farm (45 degrees 03 minutes use, netting is recommended in several fruit-growing N, 75 degrees 50 minutes W). Bushes were 1 m in regions of North America such as Quebec (Lareau, height and spaced 1.5 m in rows 3 m apart. The field

layout was in a randomized complete block. The *To whom correspondence should be addressed experimental unit, replicated four times, consisted of

0261-2194/93/05/0397-433 © 1993 Butterworth-Heinemann Ltd

Crop Protection 1993 Volume 12 Number 5 397'

Bird cont ro l in h ighbush blueberr ies: C. Vincent and M.J. Lareau

three bushes. Treatments were as follows: (1) one 64.3% in 1986. Visual observation showed that the application of methiocarb (ICiesurol 75 WP, Mobay American robin, Turdus migratorius, consistently Chemical Corporation, Kansas City, Missouri, USA) at caused most damage over the 3 years of this study. The the first ripe fruit stage, i.e. 17 July 1984, 16 July 1985 netting treatment had significantly (p < 0.05) less and 7 July 1986; (2) the same as (1) but with a second missing fruit than the other treatments. Except for methiocarb application on 23 July 1984, 26 July 1985 treatment 3 in 1984, the two methiocarb treatments and 21 July 1986; (3) installation of a Conwed bird did not differ significantly from the untreated plots. netting before the first ripe fruit stage; (4) untreated For the 3 years, about half of the total percentage of plots, sprayed with water only. The methiocarb treat- missing fruit in the untreated plots was consistently lost ments consisted of 150 g active ingredient in 1001 water before the first pick (Figure 1). In contrast, the applied to the whole plants to the dripping point, using percentage of fruit missing in the netted plots was a hand spray gun at 1380 kPa pressure, consistently low (< 4%) throughout harvest.

Before the first treatment, 20 fruit clusters were Precipitation occurring following methiocarb applic- tagged from the middle plant in each experimental unit ations could explain the poor results obtained with these and the number of berries was counted on each. All the treatments. There were 9.1, 39.5 and 51.2 mm of rain ripe fruit was picked at each harvest (see Figure 1 for between the first treatment and the first harvest for harvest dates) and the number of missing (i.e. eaten, 1984, 1985 and 1986, respectively. It is possible, pecked or fa l len)frui t was determined. Missing fruit therefore, that the methiocarb applied in the first could be either fallen (i.e. naturally or by bird treatment w a s w a s h e d o f f i n 1985 and 1986. A solution pecking), eaten, or pecked by birds. After a few days to such a problem would be to increase the number of lying on the soil under hot temperatures, the fruit applications. For instance, inMassachussetts,Southwick decomposed rapidly, and naturally fallen fruit could (1981) made three applications during the picking not be distinguished from fruit removed by birds, season, whereas Holland et el. (1985) recommended

Data were first converted to percentages, transformed seven applications in New Zealand. (arcsin), then analysed by ANOVA with treatment means separated by a Duncan's multiple range test (SAS Institute Inc., 1985). Results are reported as T mean percentage of missing fruit with the significant 1 4 - ( 9 . 1 ) - - (2.9) (15.9) (35) (77.6) a

levels based °n the transf°rmed data" The precipitati°n 12 i L data were from a meteorological station situated 500 m 10

8 away. 6

~2 2 R e s u l t s a n d d i s c u s s i o n ~ o - 1~1. , . , ,

o ~ 23 Jul 30 Ju ly 6 A u g u s t 13 Augus t 20 Augus t u

A three-way ANOVA (year X treatment X date) ~ 14 V revealed that differences between year (F = 116.1, i~ 12 39 (__119.1) (2.7) (4.8) b d.f. = 2), treatments (F = 15.3, d.f. = 3) and date of o 10

o harvest (F = 12.58, d.f. = 8) were significant at ~ a , ~_. p = 0.001. An ANOVA was therefore done for each .~ 6 |L year (Table 1). The cumulative mean percentage of ~ 4 missing fruit from the untreated plots varied greatly ~ 2 from year to year: 37.4% in 1984, 24.1% in 1985 and e o , m ~ . . . . 29 July 2 August 9 August 15 August

o3 ._c 7o 5TI ~ .2) (46.3) (13.7) (43.9) C

60 Table 1. Mean cumulative percentage of fruit losses (eaten, 5o pecked or fallen) in a highbush blueberry plantation at 4o Frelighsburg, Quebec 30

Year 201o Treatment 1984 1985 1986 i L ~ ~ - - J

23 Ju l y 30 Ju l y 6 Augus t 11 Augus t 1. Methiocarb at first ripe fruit 24.3ab" 23.6a 79.5a 2. Same as 1 plus methiocarb 10-16 14.4b 20.6a 80.5a Harvest (date)

days later 3. Netting 9.1b 6.1b 7.1b Figure 1. Mean percentage of missing (eaten, pecked or fallen) 4. Control (water only) 37.4a 24.1a 64.3a fruit in (a) 1984, (b) 1985 and (c) 1986 in a highbush blueberry

plantation at Frelighsburg, Quebec. Dates of first and second r 2 of the model 0.673 0.603 0.833 treatments (arrowheads) were (a) 17 and 23 July 1984, (b) 16 and Fvalue (between treatments = 3 d.f.) 5.79 2.69 13.73 26 July 1985, and (c) 7 and 21 July 1986. Numbers in parentheses P > F value 0.017 0.10 0.001 represent precipitation (mm) between either the first methiocarb

treatment and the first harvest or two harvest dates. "Within columns, means followed by same letters do not differ significantly I I , Treatment 1 (one methiocarb application); ~, t reatment 2 Lo = 0.05), according to Duncan's multiple range test (two methiocarb applications); [~, untreated; '~, netting

3 9 8 Crop Protect ion 1993 Vo lume 12 Number 5

Bird control in highbush blueberries: C. Vincent and M.J. Lareau

Birds are mob i l e and the i r a t tacks a re t h e r e f o r e very Courter, J. W., Larson, G.E. and Randell, R. (1981) Reducing s p o r a d i c and u n p r e d i c t a b l e ( R o g e r s , 1980). The supply songbird damage to blueberries with a carbamate repellent. Trans.

IlL State Hort. Soc. 107, 79-83 of food could exp la in the large va r ia t ions in d a m a g e

Eck, P. (1988) Blueberry Science, Rutgers University Press, New dur ing the course of this t r ial . F o r e x a m p l e , at Brunswick, NJ, 284pp F re l i ghsbu rg , frosts in M a y and June 1986 c o n t r i b u t e d

Holland, P. T., Koller, M. S., Lawn, G. D. and Robinson, M. D. to a 50% dec rease in yield ( L a r e a u and R a n c o u r t , (1985) Beating the birds: control of bird damage in blueberries. In: 1986) and losses of 64 .3 -80 .5% of frui t were r e c o r d e d Blueberries: Proc. Ruakura Hort. Conf, Hamilton. NZ, pp. 16-18, in the u n n e t t e d plots ( T a b l e 1). A s imi lar s i tua t ion was Ministry of Agriculture and Fisheries, New Zealand

also o b s e r v e d in Michigan ( M o t t and S tone , 1973). Hothem, R. L., Mott, D. F., DeHaven, R. W. and Guarino, J. L. (1981) Mesurol as a bird repellent on wine grapes in Oregon and

Wi th an ave rage p r o d u c t i o n o f 3.5 kg pe r p lan t , a California. Am. J. Enol. Vitic. 32, 150-154 dens i ty o f 2150 p lan t s ha ~ and a sel l ing pr ice of Can.

Ismail, A. A., Schemnitz, S. D. and Gramlieh, F .J . 11974) Bird $2.40 kg t frui t ( L a r e a u , 19901, gross income e x p e c t e d damage to blueberry fields in Maine. Res. Lifo Sci. Univ. Maine at for a n o r m a l yea r wou ld be - $ 1 8 000 ha t. T h e annual Orono 21(12), 1-13

cost of ne t t ing is e s t i m a t e d at $1500 ha -I o r 8 .3% of Lareau, M. J. (199(I) La Culture du Bleuet au Qudbec. Bull. Tech. gross income ( L a r e a u , 1990); u n d e r such cond i t ions , No. 14, Station de recherches, Saint-Jean-sur-Richelieu, Qu6bec, 27

t he r e f o r e , ne t t ing wou ld have been p ro f i t ab l e for each PP yea r of the tr ial . It is r e p o r t e d tha t b i rd d a m a g e is Lareau, M. J. andRaneourt, B.(1986) Essaisdccultivarsets61ection

de bleuetiers. Rdsumd de recherches, Saint-Jean-sur-Richelieu, Agri- g r e a t e r in p lan t ings that a re a d j a c e n t to fores ts l E e k , culture Canada 15, 2 1988). Because the p lo t s in this tr ial were at leas t 500 m Lareau, M. J. and Vincent, C. (19851 Effect of methiocarb-treated f rom w o o d e d a reas , the to ta l d a m a g e r e c o r d e d m a y not blueberries on the field behaviour of frugivorous birds. Acta Hort.

be r e p r e s e n t a t i v e of many p lan t ings in Sou thwes t e rn 165, 177-183 Q u e b e c . Ne t t i ng t he r e fo re a p p e a r s to be the bes t tact ic Mott, D. F. and Stone, C. P. (1973) Bird damage to blueberries in the to con t ro l b i rd d a m a g e , pa r t i cu l a r ly in p lan t ings nea r United States. Spec. Sci. Rep. Wildl. U.S. Bur. Sport Fish Wildl. No.

forests. 172, 15 pp Nelms, C. O., Avery, M. L. and Decker, D. G. (1990) Assessment of bird damage to early-ripening blueberries in Florida. Proc. 14th Vert. Pest Conf. lEd. by L. R. Davis and R. E. Marsh) pp. 302-306,

Acknowledgements University of California, Davis, California

Rogers, J .G. , Jr (1980) Bird problems in agriculture In: Bird T h e au tho r s a re gra tefu l to L . - G . S i m a r d for f ie ld Problems in Agriculture (Ed. by E. N. Wright, I. R. lnglis and C. J. ass is tance . This is con t r i bu t i on no. 335/92.12.02R of Feare) pp. 173-179, BCPC Publications, Croydon A g r i c u l t u r e C a n a d a R e s e a r c h S ta t ion at Sa in t - Jean - SAS Institute Inc. (1985) Statistics. Version,5 Edn. SAS Institute Inc,

su r -R iche l i eu . Cary, NC Schemnitz, S. D., lsmail, A. A and Gramlich, F. J. (1976) Effective- ness of methiocarb for repelling birds in Central Maine Lowbush Blueberry Fields. Res. Life Sci. Univ. Maine at Orono 23(12), 1-6

References Southwick, F. W. (1981) A chemical bird repellant for highbush blueberries. Mass. Fruit Notes 46(2), 10-12

Anonymous (1992) Bird damage and its prevention in orchards and Received 8 September 1992 vineyards. In: Fruit Production Recommendations, Publ. 360, Ontario Revised 17 December 1992 Ministry of Agriculture and Food, Toronto, Ontario Accepted 17 December 1992

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