96 research outputs found
Sprinkler Fertilization and Plant Damage
APPLYING fertilizer through sprinkler irrigation systems
is fast and simple — and the nutrients in solution
are quickly available to plants. However there's
the possibility of plant damage when high fertilizer concentrations
are applied without rinsing the fertilizer from the
plants
Applying Nitrogen Through Continuously Moving Sprinkler Systems
Sprinkler irrigation is an excellent way of
fertilizing agricultural crops. With fixed sprinkler
systems, high concentrations of fertilizer can
be applied in a short time and washed off the
leaves so that no leaf burn results. However,
when self-propelled irrigation systems such as
the center-pivot, self-propelled laterals, or other
single or multiple sprinkler systems are used,
fertilizer must be fed into the sprinkler system
continuously to obtain maximum uniformity of
fertilization. There is no opportunity to wash the
fertilizer from the plant leaves. Therefore, a study
was conducted to determine the nitrogen-fertilizer
concentrations that can be applied without
damage to plants
Natural Distribution of Parasitoids of Larvae of the Fall Armyworm, Spodoptera frugiperda, in Argentina
To develop a better understanding of the natural distribution of the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), and to update the knowledge of the incidence of its complex of parasitoids. S. frugiperda, samplings in whorl-stage corn were carried out in provinces of Argentina from 1999 to 2003. S. frugiperda larvae were collected from corn in localities of the provinces of Tucumán, Salta, Jujuy, Santiago del Estero, La Rioja, Córdoba, San Luis, Chaco and Misiones. In each locality 30 corn plants were sampled and only larvae located in those plants were collected. The parasitoids that emerged from S. frugiperda larvae were identified and counted. The abundance of the parasitoids and the parasitism rate were estimated. The S. frugiperda parasitoids collected were Campoletis grioti (Blanchard) (Hymenoptera: Ichneumonidae), Chelonus insularis (Cresson) (Hymenoptera: Braconidae), Archytas marmoratus (Townsend) (Diptera Tachinidae) and/or A. incertus (Macquart), Ophion sp. (Hymenoptera: Ichneumonidae), Euplectrus platyhypenae Howard (Hymenoptera: Eulophidae), and Incamyia chilensis (Aldrich) (Diptera Tachinidae). C. grioti was the most abundant and frequent during the five-year survey. Similar diversity of parasitoids was obtained in all the provinces, with the exception of I. chilensis and E. platyhypenae that were recovered only in the province of Salta. In the Northwestern region, in Tucumán, C. grioti and species of Archytas were the most abundant and frequent parasitoids. On the contrary, in Salta and Jujuy Ch. insularis was the parasitoid most abundant and frequently recovered. The parasitism rate obtained in Tucumán, Salta and Jujuy provinces were 21.96%, 17.87% and 6.63% respectively with an average of 18.93%. These results demonstrate that hymenopteran and dipteran parasitoids of S. frugiperda occurred differentially throughout the Argentinian provinces and played an important role on the natural control of the S. frugiperda larval population
Sprinkler Fertilization and Plant Damage
APPLYING fertilizer through sprinkler irrigation systems
is fast and simple — and the nutrients in solution
are quickly available to plants. However there's
the possibility of plant damage when high fertilizer concentrations
are applied without rinsing the fertilizer from the
plants
Les Equoidea (Perissodactyla) de l\u27\uc9oc\ue8ne pr\ue9axial pyr\ue9n\ue9en espagnol
Volume: 42Start Page: 428End Page: 43
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