As expected, the susceptible cultivar DLL, cultivated in naturally-infested plots, exhibited high infestation levels over the whole experiment (GI ranging from 9.2 to 9.4).
In this context, areas with high infestation levels could even more strongly favour the native species in the low mussel zone and perhaps create new balances in the mid zone.
The brown planthopper (BPH; Nilaparvata lugens (Stål) Family: Delphacidae) is a pest of rice in Asia that reduces rice yields at high infestation levels (15).
For example NERICA-14 and -16 were very susceptible to Sh-Mbita but showed intermediate resistance under high infestation levels of Sa-Kyela and NERICA-1 and -13 showed good resistance to Sh-Mbita but were susceptible to Sa-Kyela.
Only three NERICA cultivars (NERICA-2, -3 and -10) and the O. glaberrima parent CG14 showed very good field resistance to Sa-Kyela under high infestation levels (in the 2012-2 trialthoughough several others e.g. NERICA-4, -8, -12, -14 and -16, as well as NERICA-5, -9, -11, -15 -17 and -18 showed intermediate resistance.
The same trend was generally observed for the other modalities, the highest infestation level being observed in the case of the heterozygous F1 [DH330 × DLL] after the third year of cultivation (GI = 3.7).
Several studies have reported that dengue vector abundance is highly heterogeneous, with some neighborhoods showing significantly higher infestation levels.
Interestingly, in Kyela, CG14 showed very good resistance to S. asiatica under both low (2011 and 2012-1) and high (2012-2) infestation levels and achieved the highest yield (greater than 2 t ha−1) each year.
William G. Walter, the chief executive, said the company's agricultural products business has had strong sales "driven by high insect infestation levels in North America, growth in new labels for some of our proprietary chemistries and a shift in demand".
