The scouting report for our day-neutral organic strawberry project at the West Madison Agricultural Research Station (WMARS) was done Friday September 16^th in the afternoon. Field conditions during collections were windy and warm.

Methods of sampling include randomly sampling 60 plants by tapping flower clusters and foliage over a wide funnel into plastic bags so that insects can be counted and identified. Each plant is inspected for disease symptoms and flower clusters are counted.

This past week, we continue to see social wasps, soldier beetles, spotted cucumber beetles, Japanese beetles, leafhoppers, tarnished plant bugs (Fig. 1), common leaf spot (Fig. 3), and Phomopsis leaf blight (Fig. 4).

Minute Pirate Bugs (Orius spp.) (Fig. 1) continue to be present during our scouting and hopefully are feeding on some of the insect pests we observe in the strawberry patch, including thrips, spider mites, and insect eggs. At this time of the season, we do not anticipate spraying for any insect pest and will continue to rely on biological control agents to keep pests in check.

Spider mites, a common horticultural pest, remain present in our sampling with numbers showing a gradual decline as we enter the later part of the season (Table 1).

Spotted-wing drosophila (SWD; Fig 2) numbers increased to 0.41 larva per berry this week (Table 1). There is no formal action threshold for SWD and once larvae are detected in fruit, it is recommended to spray an insecticide to prevent further infestation. Recommended insecticides for organic production include products such as Spinosad (Entrust), Pyganic (pyrethrin), and Grandevo (chromobacterium). As we are nearing the end of the season and adult numbers in a nearby monitoring trap have declined in recent weeks, we do not anticipate spraying for SWD this season.

Tarnished plant bugs (Fig. 3) numbers are consistent with last week’s observations at 0.31 ± 0.07 tarnished plant bugs per flower cluster (Table 1) and remain a little over the economic threshold of one nymph per 4 flower clusters. As the season is reaching an end, we will not be applying any insecticide to control tarnished plant bugs.

Thrips numbers continue to decline this past week and are below the action threshold of 2-10 per flower or small berry (Table 1). Overall this season, thrips were present but did not seem to cause any significant fruit injury in the planting, thus no insecticide was applied to manage thrips.

Common Leaf Spot (Fig. 4)saw a decline this week (Table 2). As of the latest field observations, leaf spots remain mild with only a few spots per plant.

Phomopsis Leaf Blight (Fig. 5) numbers are consistent with the previous week (Table 2). This blight can lead to defoliation and fruit rot in later stages. Management strategies include removing infected leaves, weeding, and fungicide application.

Verticillium Wilt (Fig. 6) saw an increase in frequency this week (Table 2). We have also observed slight discoloration in the crown tissues of some collapsed plants. Management practices are limited once plants are presenting symptoms and mortality. Avoid planting in contaminated soils and prevent any root damage to the remaining healthy plants to minimize its spread.

Anthracnose (Fig. 7)showed a dramatic increase this week concentrated among plant rows with very dense foliage (Table 2). It’s possible a combination of rainy days, overripe berries, weeds, and dense foliage are responsible for the increase. This disease presents as sunken areas on the fruit appearing tan to dark brown. Available organic fungicides for managing anthracnose are most effective when the infestations are limited. Additional management includes removing ripe and infected fruits regularly to slow its spread. To read more about Anthracnose and other fruit rots of strawberry check out the article “Fruit Rots of Strawberry”.

Table 1. The average number of insects observed per plant in day-neutral strawberries during weekly sampling.

Dates of Weekly Scouting	Mites (Average per plant)	Thrips (Average per flower cluster)	Thrips (Average per plant)	Tarnished plant bug (Average per flower cluster)	Tarnished plant bug (Average per plant)	Spotted-wing drosophila (Average per berry)	Minute Pirate Bugs (Average per plant)
6/15/2022	0.22 ± 0.11	n/a	0.16 ± 0.09	n/a	0	n/a	n/a
6/22/2022	0.01 ± 0.01	n/a	0.03 ± 0.03	n/a	0	n/a	n/a
6/28/2022	0.08 ± 0.04	n/a	0.05± 0.03	n/a	0	n/a	n/a
7/05/2022	0.13 ± 0.06	n/a	0.12 ± 0.05	n/a	0.03 ± 0.02	n/a	n/a
7/13/2022	1.28 ± 0.35	n/a	0.25 ± 0.07	n/a	0.08 ± 0.49	n/a	n/a
7/19/2022	4.30 ± 0.51	n/a	0.20 ± 0.06	n/a	0.33 ± 0.08	n/a	n/a
07/28/2022	3.37 ± 0.38	n/a	0.27 ± 0.07	n/a	1.32 ± 0.24	n/a	n/a
08/02/2022	3.62 ± 0.35	n/a	0.23 ± 0.06	n/a	1.87± 0.29	n/a	n/a
08/09/2022	2.27± 0.27	0.30 ± 0.04	0.35 ± 0.09	0.69± 0.12	2.48± 0.34	0	n/a
08/16/2022	0.68 ± 0.12	0.10 ± 0.03	0.25 ± 0.06	0.71 ± 0.11	1.55 ± 0.17	0	n/a
08/23/2022	0.63 ± 0.1	0.12 ± 0.04	0.18 ± 0.05	0.64 ± 0.14	1.03 ± 0.17	0	1.80 ± 0.23
08/27/2022	0.80 ± 0.15	0.13 ± 0.04	0.23 ± 0.06	0.56 ± 0.09	0.85 ± 0.11	0.04 ± 0.06	1.33 ± 0.2
09/02/2022	0.83 ± 0.12	0.21 ± 0.05	0.48 ± 0.10	0.41 ± 0.07	0.82 ± 0.13	0.10 ± 0.11	1.12 ± 0.15
09/09/2022	0.57± 0.11	0.06 ± 0.02	0.12 ± 0.04	0.30 ± 0.05	0.67 ± 0.1	0.23 ± 0.3	0.62 ± 0.12
09/16/2022	0.50± 0.1	0.03± 0.02	0.08± 0.04	0.31± 0.07	0.6 ± 0.09	0.41± 0.8	0.63± 0.1

Table 2. The average number of disease symptoms observed per plant in day-neutral strawberries during weekly sampling.

Dates of Weekly Scouting	Common Leaf Spot (Average per plant)	Phomopsis Leaf Blight (Average per plant)	Verticillium Wilt (Average per plant)	Anthracnose (Average per plant)
6/15/2022	0	0	0	0
6/22/2022	0	0	0	0
6/28/2022	0	0	0	0
7/05/2022	0	0	0	0
7/13/2022	0.35 ± 0.06	0	0	0
7/19/2022	0.57 ± 0.06	0.25 ± 0.06	0	0
07/28/2022	0.55± 0.06	0	0	0
08/02/2022	0.8 ± 0.05	0.22 ± 0.05	0	0
08/09/2022	0.87 ± 0.04	0.17 ± 0.05	0	0
08/16/2022	0.77 ± 0.06	0.38 ± 0.06	0	0
08/23/2022	0.82 ± 0.05	0.23 ± 0.06	0.03 ± 0.02	0
08/27/2022	0.88 ± 0.04	0.33 ± 0.06	0.02 ± 0.02	0
09/02/2022	0.68 ± 0.06	0.27 ± 0.06	0.07 ± 0.03	0
09/09/2022	0.72 ± 0.06	0.28 ± 0.06	0.02 ± 0.02	0.02 ± 0.02
09/16/2022	0.62± 0.06	0.27± 0.06	0.12± 0.04	0.85± 0.17

This article was posted in Berries and tagged berry, Christelle Guédot, day-neutral strawberry, disease, DNS, DNS Organic, insects, Leslie Holland, organic, Organic Day-Neutral Strawberry Production, Organic production, organic strawberries, Rachel O’Neill Lewis, Strawberries, strawberry.