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ations and Damage

Figure 1. Total Lygus bug population at SREC blackeye trial. Sloid line at 0.5 Lygus/sweep represent treatment threshold.

Figure 2. Average Lygus population composition from SREC blackeye bean trial.

played a role in making the plots less desirable for adult migration and residence. Averaged nymphal populations were greatest between 7/6 and 7/13/2009 but adults composed over 50% of the population during this trial (Figure 2). Irrigation and spacing had the greatest influence on Lygus population. There were significant differences (P<5%) in Lygus populations between irrigation treatments from 7/6/09 until 8/3/09. There were significant differences (P<5%) between spacing treatments in total Lygus/sweep from 7/6/09 until 7/20/09 (Table 1). The plots which had Every Irrigation treatment had greater Lygus population densities than other irrigation treatments with 70% of plots exceeding threshold on 7/13/09 (Figure 3). Yield was influenced by treatments with the most densely planted and irrigated producing the most beans (Sanden et al, 2010). Yield was greatest in treatments that were most closely planted (2â&#x20AC;? between plants) and most frequent irrigation (every 7 days, every furrow) with yield reduced as irrigation was restricted and spacing increased (Table 2). Between conventional irrigation and deficit irrigating (Reduced 14 day interval treatment), 8.2 inches of water was conserved (Sanden et al, 2010). Based on subsample assessments of beans, the quality of beans in this trial would be graded as U.S. No. 2. No significant differences in the amount of Lygus feeding on beans were noted in any treatments (Irrigation, Spacing or Variety) at the 5% significance level but differences in treatments were observed (Figure 4). For example Reduced Irrigation treatment had fewest stings per 100 gm subsam-

Total Lygus 29-Jun

6-Jul

13-Jul

20-Jul

27-Jul

3-Aug

10-Aug

Irrigation

NS

XXX

X

XXX

XX

X

NS

Spacing

NS

XXX

XXX

NS

NS

NS

X

Variety

NS

NS

NS

XX

NS

NS

NS

Significance Level X

5%

XX

1%

XXX

0.1%

NS Not Significant

Table 1. Weekly ANOVA results for total Lygus/sweep from blackeye trial, SREC 2009.

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