8/9/2011 9:15:29 PM
Authors: Natalie Hummel and Michael Stout
Rice farmers in Louisiana who use seed treatments to manage insect pests in their fields have a choice of seed treatments in 2011: Dermacor™ X-100 (DuPont Crop Protection) and CruiserMaxx® (Syngenta). In addition, Valent has requested an experimental use permit (EUP) for NipsIt INSIDE seed treatment, an insecticidal seed treatment alternative similar to thiamethoxam. If approved, NipsIt INSIDE will be used on a limited number of acres in Louisiana in 2011 and will potentially be available on a wider scale in 2012. Although these three insecticidal seed treatments are similar in many respects, they also differ in key ways. Understanding the similarities and differences between the two seed treatments is crucial to making the right insecticide choice for each rice field.
The key pest targeted by CruiserMaxx, Dermacor X-100, and NipsIt INSIDE is the rice water weevil, the most important early season insect pest of rice in Louisiana. Dermacor X-100 has been evaluated against the rice water weevil in multiple small-plot tests over many years at the LSU AgCenter Rice Research Station in Crowley, and in addition has been used commercially in Louisiana the past three growing seasons. Dermacor X-100 provides excellent control of rice water weevil larvae; in commercial fields, weevil populations were typically reduced by 90-95% compared to fields not treated for weevils. CruiserMaxx has also been evaluated in multiple small-plot trials over the past several years at the Rice Research Station, and it too provides good control of rice water weevil larvae, although, in side-by-side comparisons of Dermacor X-100 and CruiserMaxx conducted in small plot trials at the Rice Research Station, control of weevil larvae given by CruiserMaxx is generally not as good as control given by Dermacor X-100. In rice water weevil demonstration tests in commercial fields in 2010, we found that Dermacor X-100 provided the best level of weevil control, followed by pyrethroid (Karate pre, Karate pre + mustangMax on fertilizer post, or Karate post) and CruiserMaxx. Dermacor X-100 provided significantly better control than the other two treatments. There was no significant difference in weevil control between the pyrethroid and the CruiserMaxx seed treatment. Unfortunately, the results from hybrid test plots (25 pound seeding rate) in 2010 did not provide any more clarity about the ability of CruiserMaxx to provide effective weevil control at the low seeding rates. We plan to repeat the demonstration test again next season, particularly focusing on the low seeding rate question. Small plot replicated research that may also clarify the question of effectiveness of CruiserMaxx at low seeding rates will also be conducted.
Probably the most important difference between the three seed treatments is their activity against secondary pests. Because these chemicals belong to different chemical classes (the active ingredient in Dermacor X-100 is a type of anthranilic diamide, whereas CruiserMaxx and NipsIt INSIDE are neonicotinoids), they are effective against different pests. CruiserMaxx and NipsIt INSIDE will probably provide better control of colaspis larvae (present in a few fields in southwest Louisiana in 2009 and 2010) than will Dermacor X-100, and will also provide good early-season control of sucking insects such as aphids, thrips and chinch bugs. Dermacor X-100, on the other hand, should provide excellent control of early-season Lepidopteran pests such as fall armwyorms. Recent evidence from both Louisiana and Texas indicate that Dermacor X-100 provides protection against stem-boring insects. Evidence from Texas also indicates that Dermacor X-100 may help control South American Rice Miner in rice. The spectrum of pests controlled by each of these seed treatments is probably the most important consideration in choosing between the three. As a related consideration, CruiserMaxx is marketed as part of a seed treatment “package” (CruiserMaxx® Rice) that includes fungicides that may help control seedling diseases and rice blast.
There are also similarities and differences in the agronomic practices that are used with each of these seed treatments. Importantly, the use of both seed treatments is restricted to dry-seeded (drill-seeded or dry broadcast) rice; neither product can be used in water-seeded rice. Also, the per-seed application rate of CruiserMaxx will not change with rice seeding rate, unlike Dermacor X-100, for which application rate is adjusted for seeding rate. This may make CruiserMaxx easier to use, but it should be noted that the use of CruiserMaxx at very low seeding rates (for example, seeding rates typically used for hybrid rice varieties) has not always provided acceptable control in tests conducted by LSU AgCenter. Details on the use patterns for NipsIt INSIDE are not known yet.
The expected availability of three seed treatments for insect control in rice, along with other available products for insect control (Karate, Mustang Max, and the other pyrethroids), gives Louisiana farmers a wide range of options for managing their insect pests in drill-seeded rice. Unfortunately, there are not as many choices in water-seeded rice, and expanding the range of options for insect management in water-seeded rice is a continuing focus of research for the Entomology program.