Francisco Ivaldo Oliveira Melo

Mutantes morfológicos de algodoeiro herbáceo como fonte de resistência ao bicudo

This work aimed to evaluate the effects of three morphological mutants of upland cotton lines (Gossypium hirsutm L. r. latifolium Hutch.), isolated or in combination in the same cotton genotype, as a source of resistance to boll weevil, Anthonomus grandis Boheman, 1843 (Coleoptera, Curculionidae). The experiment was carried out in the field, under natural infestation, with a completely randomized block design arranged in a factorial 2× 3 plus an additional treatment, with four replications. In a multiple choice test, the character mutant frego bract presented the higher reduction on boll weevil oviposition damage (34.71%), in relation to the normal equivalent. The okra leaf reduced the boll weevil damage only when associated with frego bract (40%). The combination of the three mutant characters in the same plant presented the least square percent with oviposition damage (23.13%).

Controle químico de plantas daninhas na cultura do arroz irrigado no estado do Ceará

A field experiment was conducted, during the dry season of 1995, on alluvial soil of the Vale do Curu Experimental Farm, State of Ceara, Brazil, in order to evaluate the effect of the herbicides: propanil (4.8 kg a.i.ha-1), fenoxapropethyl (0.14 kg a.i.ha-1), fenoxaprop-p-ethyl (0.11 kg a.i.ha-1), oxadiazon (0.62 kg a.i.ha-1) and the mixtures propanil + molinate (2.52+2.52 kg a.i.ha-1 ) and propanil + 2,4-D (2.72+0.22 kg a.i.ha-1) on the control of weeds in rice, cultivars METICA-1 and CICA-8, growing under flood irrigation. The best weed control and paddy rice yield were provided by propanil and the mixtures propanil + 2,4-D and propanil + molinate. Plant height, days to flowering, head size and the weight of 1000 seeds were not affected by the herbicides. The symptoms of toxicity caused by the herbicides on the rice plants of the two cultivars were slightly severe.

Preferência de Bemisia tabaci biótipo B em linhagens mutantes de algodoeiro

The effects of cotton lines (Gossypium hirsutum L. r. latifolium Hutch.) with mutants morphologic characteristics: okra leaf, frego bract and red plant in relation to host plant resistance to whitefly (Bemisia tabaci bioyipe B Hemiptera: Aleyrodidae), were evaluated in choice or no choice assays. The assays were carried out in the greenhouse conditions, according to a completely randomized block design, in a 23 + 1 in a factorial arrangement with four replications. The mutant with red plant characteristic was less attractive and less preferred for oviposition than the normal green plant does, in both, whit or without choice tests. It did not have preference in relation to the form of the leaf and bract type.