Sweet pepper: releasing swirskii earlier with Nutrimite boosts control

The commercial availability of Amblyseius swirskii heralded a revolution in biocontrol in the Almeria sweet pepper industry. “Employed by growers in this region for many years, swirskii is now routinely used in sweet pepper crops,” says Ivan Cano, technical advisor at Biobest Sistemas. “However, installations are pollen dependent and until now have been reliant on 20-30% of the flowers appearing in the crop - usually approximately four weeks after planting. 

“This strategy is not without its challenges due to large pest pressures early in the crop, unreliability of the flowering period making scheduling of swirskii orders difficult and often the need for chemical corrections.”

2015 proved to be a difficult year with high whitefly pressure just before flowering delaying releases of swirskii and, in many cases, the whole biocontrol programme (Orius, A. colemani).

New Bio revolution for sweet pepper growers

While polyphagus in character and showing great adaptability to high temperatures, swirskii needs a satisfactory food source for fast population growth.

“In the absence of suitable pest, the mites feed on the crop pollen to build up numbers,” explains Ivan. “However, it would be advantageous for swirskii to establish earlier.”  

Developed by Biobest, Nutrimite™ is a highly nutritional food supplement based on specially selected pollen. It accelerates and enhances the population development of pollen feeding phytoseid predatory mites, such as swirskii.

By employing Nutrimite™, swirskii can now be released before flowering improving control of target pests – thrips, whitefly and spidermite - in sweet pepper crops. Established sooner, the predator provides greater protection earlier on.

Supported by scientific data

Several commercial trials in Almeria in 2015, carried out by Biobest’s R&D team based in Spain, have shown several tangible benefits of earlier swirskii establishment.   

“Our trials demonstrate that by using Nutrimite™ swirskii establishment is improved and can be at least ten days earlier, boosting overall control of target pests,” explains Antonio Robledo from Biobest Sistemas’ R&D department. “Technically, it is possible to release even earlier, however, most growers prefer to use compatible chemicals early in the crop to keep it as clean as possible before releases.

“Nutrimite™ has a higher nutritional value than sweet pepper pollen,” he says. “With a single application of Nutrimite™ (500g/ha) our trials have shown the swirksii population can remain 2 - 3 times higher for at least a month, compared to the standard strategy.”

In addition, following good distribution of Nutrimite™ pollen grains over the plants and crop, swirskii distribution improves providing greater protection after just a few days.

New improved strategy

Biobest’s new strategy for sweet pepper crops relies on the addition of a general application of Nutrimite™ together with the usual introduction of Swirskii- Breeding-System sachets, three weeks after planting. In addition, sensitive parts of the crop are reinforced with the Swirskii-System containing loose material. 

“The loose mites should be sprinkled in to previous pest hotspots – such as near to windows,” explains Ivan. “Using this new strategy population build up is earlier, quicker and leads to improvements in overall predatory mite distribution throughout the greenhouse. All three contribute to promoting a larger and more effective overall population in the crop helping to boost overall control of these key pests.”

Biobest’s new strategy offers several tangible benefits.

* Faster and stronger protection/control of key pests - the predatory mites are established earlier.

* Better overall control - the Swirskii predatory mite population is larger and better distributed through the greenhouse.

* Improved easy of management - timing of installation is not reliant on crop flowering.