EVALUATION OF HANDLING PRACTICES OF WEEDS IN MELON CULTIVATION. LOS SANTOS, PANAMA, 1999-2000.

Abstract

The invasion of weeds constitutes one of the most important problems in melon cultivation. In the region of Azuero, Panama, there is not counted with efficient technologies for is handling. The trial had the objective to evaluate and to select the most efficient practices of handling of melon weeds. It was established in the Experimental Station of the River Villa, Los Santos, Panama, located between 7°57' North latitude and 80°25' West longitude. Five treatments were evaluated disposed in a design of Completely Randomized Block. The experimental unit consisted of two ruts of 9.2 m of length by 2.0 m of wide. The following treatments were evaluated: naptalan-sodium + manual weeding; halosulfuron-metil + propaquizafop; clomazone + manual weeding; plastic cover and an absolute witness. Naptalan-sodium was applied in incorporated presowing, the halosulfuron-metil and propaquizafop in postemergency to the cultivation and the weeds; clomazone in preemergency to the cultivation and the weeds. The predominant weeds were: Rottboellia cochinchinensis, Echinochloa colonum, Cyperus rotundus, Kallstroemia maxima and Amaranthus spinosus. In order to determine the efficacy of the treatments were samplings in visual form to the 14 and 40 days. The best treatment was the plastic cover. The control of weeds was almost total, except in the opening, by where seedling emerged. The greater infection of weeds occurred in the treatment with clomazone (90%), which exerted very good control on weeds of wide leaf, but not on pimentilla; in addition, was toxic to the cultivation. The naptalan-sodium had positive effects on the weeds of wide leaf, but not on the ciperaceas not gramineas. The halosulfuron-metil exerted very good control on pimentilla; nevertheless, it caused toxic effects to the cultivation. Propaquizafop controlled the gramineas efficiently. The plastic cover almost controlled the weeds in its totality. In this treatment, it was obtained the greater yield in fruits and kilograms by hectare and the economic analysis indicated a RMT of 231%.