Traditional fertilization and its effect on corn insect populations in the Guatemalan highlands

Abstract

Cakchiquel farmers in Patzún, Guatemala stated that pest populations have increased in corn crops since they abandoned organic fertilization and adopted synthetic fertilizers. Given the dearth of scientific information about the effects of fertilization practices on pests, a controlled experiment was performed to elucidate these interactions. Pests, their natural enemies, and nutritional status were compared among corn plots with synthetic and organic fertilizers, and a control without fertilizer. Corn in fields treated with organic fertilizer applied for at least 2 years hosted fewer aphids (Rhopalosiphum maidis) than corn treated with synthetic fertilizer. This difference seems attributable to high concentration and total content of foliar nitrogen in corn in the synthetic fertilizer plots, although numbers of Spodoptera frugiperda showed a weak negative correlation with increased nitrogen levels. Coccinellidae populations were higher in plots with high aphid populations, but only where organic fertilizer was applied. There were no significant yield differences among treatments.

Nitrogen fertilization sources and insecticidal activity of aqueous seeds extract of Carica papaya against Spodoptera frugiperda in maize

“…Farmers in Patzun, Guatemala changed from organic fertilizers ("postura" of combining any available materials: ashes, lime, crop residues, weeds, and manure from goats, cows, horses, rabbits, and chickens in a mulch pile or well cow manure) by urea but observed the negative consequences of this change, with an increase in insect pests in the maize crops (Morales et al, 2001). …”

Effect of Application of Granular Organic Fertilizer Enriched with Boiler Ash and Neem Leaves Powder on Plant Resistance Against Insect Pests

“…In comparison to organic fertilizer, inorganic fertilizer contains more nitrogen that make plant cell contains more water favored by sucking insects. Previous study showed that infestation of aphids (Rhopalosiphummaidis) on corn in fields treated with organic fertilizer for at least 2 years was lower than corn treated with synthetic fertilizer [19]. It is suggested that nitrogen stimulates insect reproduction.…”

Mayan imaginaries of democracy: Interactive sovereignties and political affect in postrevolutionary Guatemala

“…They also fault individual farmers for not diversifying their crops, or not using organic methods, or using wrongheaded "traditional" practices, like burning their fields before planting, which removes more nutrients. Studies show, for example, that new pests result from adaptive resistance to pesticides or from the depletion of soil nutrients (Morales et al 2000). If they mention it at all, agronomists attribute input cost inflation to impersonal market forces of supply and demand.…”