Effects of N-fertilization and spacing on african rice gall midge <i> Orseolia oryzivora </i> harris and gagn&eacute i a sub-humid area of southeastern Nigeria

Abstract

Nitrogen fertilization and spacing hold a strong promise in the integrated management of rice insect pest problem. Therefore, three levels of urea: 0, 80 and 160 kg N ha-1 and three spacings: 10-cm x 10-cm, 20-cm x 20-cm and 30-cm x 30-cm were evaluated for two years in Abakaliki, Nigeria, for the control of rice gall midge. The experiment was set up using split-plot arrangement in a randomized complete block design (RCBD) with three replications. Results of the trial showed that nitrogen significantly increased incidence by gall midge (P<0.05) with 160 kg N ha-1 recording the highest incidence of 50.95% and 36.01% in 2002 and 2003 trials, respectively. Similarly, incremental doses of urea n-fertilizer increased the grain yield of rice but only up to 80 kg N ha-1. Beyond this level further n-fertilization had no effect. Generally, increasing plant population significantly increased the incidence by the midge (r = 0.93 and 0.99 in both years). Conversely, grain yield was significantly reduced with increasing population. Differences among treatment combinations between nitrogen and spacing however did not produce any significant effect.

Farmers’ Perceptions of Rice Production Constraints and Stem Borers Management Practices in Tanzania

“…The effect of fertilizer inputs has also described by Sarwar (2011) who reported how important is the plant nutrient in changing population dynamics of herbivores apart from being a good indicator in improving host plant quality. This was further supported by the study by Ogah et al (2005) who reported increased rice gall midge damages in Nitrogen applied plots as compared to the control.…”

Biology of the African rice gall midge Orseolia oryzivora (Diptera: Cecidomyiidae) and its incidence on wet-season rice in Nigeria

“…Ogah et al (2005) have suggested that delayed sowing may reduce the incidence of O. oryzivora in southeastern Nigeria, by reducing the period during which rice plants are available for infestation by the midge. This suggests that alteration of the planting period according to climatic factors could affect the incidence of O. oryzivora.…”

“…The African rice gall midge (AfRGM) Orseolia oryzivora Harris and Gagné (Diptera: Cecidomyiidae) is the most serious insect pest of lowland and irrigated rice (Williams et al, 1999;Ogah et al, 2005Ogah et al, , 2009Nwilene et al, 2006). Indigenous to Africa, the insect's status has changed during the last two decades from a minor to a major pest, and in several countries in Africa, it causes perennial economic damage to rice (Nacro et al, 1996;Singh et al, 2004).…”

Impact of Rice Stem Borers and Identification of &lt;i&gt;Orseolia oryzivora&lt;/i&gt; Harris &amp; Gagn&#233;, 1982 (Diptera: Cecidomyiidae) Biotypes in the Southern Cameroon

“…This enrichment could further reduce pesticide intake due to the negligible presence of pests, reduce yield losses and increase farmers' incomes for the sustainable development of rice. On the other hand, the incidence of midge increases with increasing levels of nitrogen fertilization [24]. The latter also showed that stem borers' attack was positively correlated with soil moisture and nitrogen content, hence the strong presence of white panicles and Yaoundé, compared to Ntui.…”