- Author: Surendra K. Dara
There has been a growing interest in the recent years in exploring the potential of biostimulants in crop production. Biostimulants are mineral, botanical, or microbial materials that stimulate natural processes in plants, help them tolerate biotic and abiotic stressors, and improve crop growth and health. Several recent studies demonstrated the potential of the biostimulant or soil amendments in improving crop yields and health. For example, in a 2017 field study, silicon, microbial, botanical and nutrient materials improved processing tomato yields by 27 to 32% compared to the standard fertility program (Dara and Lewis, 2018). In a 2017-2018 strawberry field study, some biostimulant and soil amendment products resulted in a 13-16% increase in marketable fruit yield compared to the grower standard (Dara and Peck, 2018). He et al. (2019) evaluated three species of Bacillus and Pseudomonas putida alone and in different combinations in tomatoes grown in laboratory and greenhouse. The combination of Bacillus amyloliquefaciens, B. pumilus, and P. putida increased the plant biomass and the root/shoot ratio. Significant increase in fruit yield, between 18 and 39%, was also achieved from individual or co-inoculations of these bacteria. A field study was conducted in processing tomato to evaluate the impact of nutrient products containing beneficial microbes and botanical extracts on tomato yields and fruit quality.
The study was conducted from late spring to fall of 2018 to evaluate three treatment programs compared to the grower standard. Tomato cultivar Quali T27 was seeded on 25 April and transplanted on 19 June using a mechanical transplanter. Due to high temperatures at the time of planting, some transplants died and they were re-planted on 28 June. Herbicide Matrix was applied on 5 July and Poast was applied on 13 July followed by hand weeding on 27 July. Crop was irrigated, fertigated, and treatements were applied through a drip system. Overhead sprinkler irrigation was additionally used immediately after transplanting. The following treatments were included in the study:
1. Grower standard: 10-34-0 Ammonium Polyphosphate Solution was applied at 10 gal/ac at the time of transplanting followed by the application of UAN-32 Urea Ammonium Nitrate Solution 32-0-0 at the rate of 15 units of N at 3, 6, and 13 weeks after planting and 25 units of N at 7 weeks after planting.
2. Grower standard + BiOWiSH Crop 16-40-0: BiOWiSH Crop 16-40-0 contains 16% nitrogen and 40% phosphate along with B. amyloliquefaciens, B. licheniformis, B. pumilus, and B. subtilis at 1X108 cfu/gram. Crop 16-40-0 was applied at 1 lb/ac at the time of planting followed by the application 0.5 lb/ac at 3, 6, and 9 weeks after planting.
3. Grower standard 85% + BiOWiSH Crop 16-40-0: Crop 16-40-0 was applied at the same rate and frequency as in treatment 2, but the grower standard was reduced to 85%.
4. RootRx: RootRx contains 5% soluble potash and proprietary botanical extracts and is supposed to stimulate a broad range of antioxidant compounds in the plant. It was applied at 0.25 gal/ac at the time of planting followed by the application of 0.5 gal/ac at 3, about 7, and 13 weeks after planting.
Each treatment contained 30' long bed with a single row of tomato plants and replicated five times in a randomized complete block design. Along with the fruit yield, the sugar content of the fruit and leaves [using a refractometer from three fruits (two measurements from each) and four leaves per plot], chlorophyll content (using a digital chlorophyll meter from four leaves per plot), and frost damage levels (using a visual rating on a 0 to 5 scale where 0 = no frost damage and 5 = extreme frost damage with a complete plant death) were also monitored. Due to an unknown reason, some plants in the fifth replication were stunted halfway through the study. Data from the fifth replication were excluded from the analysis. Data were subjected to the analysis of variance using Statistix software and significant means were separated using the Tukey's HSD test.
Fruit yield: Marketable and unmarketable fruit yield was monitored from 27 August to 13 November. Seasonal total for marketable fruit was significantly (P = 0.04) different among the treatments where RootRx resulted in a 26.5% increase over the grower standard while Crop 16-4-0 with the full rate of the grower standard had an 8%, and with 85% of the grower standard had a 13.2% increase. It appeared that a similar improved yield response was also seen when Crop 16-40-0 was used at a reduced rate of the grower standard in other studies conducted by the manufacturer.
Sugar content: Sugar content of the fruit and leaves was measured once after the last harvest and there were no significant (P > 0.05) difference among the treatments.
Chlorophyll content: Chlorophyll content was measured once after the last harvest and there was no significant (P > 0.05) difference among the treatments.
Frost damage: Study was concluded after frosty conditions in November 2018 damaged the crop. Although there were no statistically significant (P > 0.05) differences, plants treated with RootRx had the lowest rating of 2.
Acknowledgements: Thanks to Jenita Thinakaran and the field staff at the Shafter Research Station for their technical assistance, Plantel Nurseries for providing transplants, and BiOWiSH Technologies and Redox Chemicals for their financial support.
Dara, S. K. and D. Peck. 2018. Microbial and bioactive soil amendments for improving strawberry crop growth, health, and fruit yields: a 2017-2018 study. UCANR eJournal of Entomology and Biologicals (https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=27891)
Dara, S. K. and E. Lewis. 2018. Impact of nutrient and biostimulant materials on tomato crop health and yield. UCANR eJournal of Entomology and Biologicals (https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=26054)
He. Y., H. A. Pantigoso, Z. Wu, and J. M. Vivanco. 2019. Co-inoculation of Bacillus sp. and Pseudomonas putida at different development stages acts as a biostimulant to promote growth, yield and nutrient uptake of tomato. J. Appl. Microbiol. https://doi.org/10.1111/jam.14273
- Author: Surendra K. Dara
Tomato bug on a tomato plant. Photo by Surendra Dara
The bug that is commonly referred to as the tomato bug might have been around for a while, but it was in the spring of 2014 that a homeowner in Goleta (Santa Barbara County) reported infestations and damage to tomatoes in their home garden for the first time. In August, 2015, an organic vegetable grower in the Lompoc area had severe tomato bug infestations in tomatoes and zucchini. In a tomato field intercropped with zucchini bugs were found on both hosts, but more on the younger zucchini plants which have developing flowers and fruits compared to mature tomato plants. This incidence suggests the potential of tomato becoming an important pest of vegetables in commercial fields and home gardens. In September, 2015, tomatoes and yellow squash plants at the University of California Davis vegetable garden also had moderate tomato bug infestations. Younger tomato plants in the Davis garden had more tomato bugs than the squash plants next to them.
More tomato bugs were seen on younger zucchini than on older tomato plants (above) while more bugs were seen on younger tomato than on older yellow squash plants (below) Photos by Surendra Dara
It appears that tomato bugs can infest multiple hosts other than tomatoes and probably have a preference for plants with actively growing flowers and fruits.
Tomato bugs on zucchini flowers. Feeding damage appears as depressed spots on the fruit.
A field study planned for managing tomato bugs on organic tomatoes and zucchini with several botanical and microbial pesticides could not be executed, but the grower reported effective control with Pyganic+OroBoost and Pyganic+DebugTurbo+OroBosst when they tried some products on their new zucchini plantings under hoop houses. Other treatments that included Entrust, Trilogy, Pyganic, and DebugTurbo did not appear to suppress tomato bug populations. This input from the grower can be useful until scientifically conducted field study results are available in the future.
It is not clear if tomato bug is emerging as a new vegetable pest in California or the warm and dry conditions in recent years are contributing to the secondary pest outbreaks. Considering significant yield losses caused due to organic zucchini in the Lompoc area, it is important for growers and PCAs to know about the pest so that tomato bug can be added to their monitoring program.
Information on tomato bug origin, biology, and damage can be found at: http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=14833.
There is some discrepancy about the identity of what is commonly referred to as the tomato bug. Entomological Society of America listed Engytatus modestus (Distant) as the tomato bug and it is referred to as such and considered as a biocontrol agent in some literature (Parrella et al., 1982). However, Nesidiocoris tenuis (Reuter) is referred to as the tomato bugn in other reports where it is considered as a pest (El-Dessouki et al., 1976, Santa Ana, 2015).
N. tenuis is generally considered a beneficial insect and Arnó et al. (2006) characterized the damage to tomato plants. This insect is considered as a potential predator for controlling the tomato borer, Tuta absoluta (Meyrick), which has emerged as a serious pest in Spain and other European countries (Urbaneja et al., 2008). Another study in Spain reported N. tenuis both as a predator and a pest (Calvo et al., 2009). As a predator, tomato bug caused a significant reduction in sweetpotato whitefly, Bemisia tabaci Gennadius, populations under greenhouse conditions, but also caused necrotic rings on the petioles of leaves.
Regardless of the taxonomic status, tomato bug can both be a predator of several arthropod pests and a pest of tomatoes, yellow squash, and zucchini. Since it can feed on insects and plants, it is considered zoophytophagous.
Arno´ J, C. Castañé, J. Riudavets, J. Roig, and R. Gabarra. 2006. Characterization of damage to tomato plants produced by the zoophytophagous predator Nesidiocoris tenuis. IOBC/ WPRS Bull 29:249–254
El-Dessouki, S. A., A. H. El-Kifl, and H. A. Helal. 1976. Life cycle, host plants and symptoms of damage of the tomato bug, Nesidiocoris tenuis Reut. (Hemiptera: Miridae), in Egypt. Zeitschrift fur Pflanzenkrankheiten und Pflanzenschutz 83: 204-220.
Parrella, M. P., K. L. Robb, G. D. Christie, and J. A. Bethke. 1982. Control of Liriomyza trifolii with biological agents and insect growth regulators. California Ag. 36: 17-19.
Santa Ana, R. 2015. Humans may be culprit in latest South Texas invasive insect problems. AgriLife Today, 14 September, 2015. (http://today.agrilife.org/2015/09/14/tomato-bug-invades-south-texas/)
Urbaneja, A., H. Montón, and O. Mollá. 2008. Suitability of the tomato borer Tuta absoluta as prey for Macrolophus pygmaeus and Nesidiocoris tenuis. J. Appl. Entomol. 4: 292-296.