Effects of SB Plant Invigorator on Bemisia tabaci Development in Tomato Plants

Whitefly control programmes are mostly based on the application of insecticides. However, Bemisia tabaci is able to develop resistance to many of these chemical substances, and high levels of resistance have been reported for many insecticides in different agricultural systems worldwide. Moreover, many of these chemical products are toxic to the environment if they are not used properly. These disadvantages make necessary to search for alternative strategies of pest control for its implementation in IPM programmes. Utilization of new products which fight physically but not chemically against pest is one of the alternative methods investigated nowadays. The Stan Brouard Group has developed an environmentally respectful stimulant of plant growth called SB Plant Invigorator (SBPI) which helps the plant to produce quality fruits. It presents a physical mode of action that makes the product respectful with the environment. Due to its formulation, SBPI is not a pesticide but a plant stimulant, and it is proved not to be a toxic but an environmentally safe product. No harvest interval is therefore required after use, special health and safety measures for users are not necessary, and the product does not cause problems with residuals in food. As its activity against insects is achieved by physical means, insects do not develop resistance to SBPI and it continues being useful after a long time application. The objective of the present study was to test whether SBPI is effective to control B. tabaci in commercial tomato plants (cv. Marmande) which lack the Mi-1 gene of resistance to whiteflies. Three days after the first foliar spraying (2ml/l solution), the product seemed to be ineffective against the adult insects, as the numbers of died females were practically equal for both, control and treated plants. No statistically significant differences were found for the oviposition values, although the mean number of eggs laid on SBPI-treated leaves was slightly greater than that observed on control plants. Treatment was repeated weekly during the next 4 weeks. At 31 days, new adult whiteflies started to emerge from pupae in control plants, with significant differences with the SBPI-treated plants where any L3, L4 or new adults were not found. Differences in the number of L1+L2 were not statistically significant, although the mean number of individuals in these larval stages on SBPI-treated plants was twice as much on control plants. In conclusion, SBPI is an effective alternative product to control B. tabaci in tomato as foliar application under these conditions inhibits or delays larval development avoiding the risk of a new whitefly generation.

Peer reviewed