Crescimento e produção de genótipos de bananeira sob diferentes lâminas de irrigação

Abstract

Banana crop in the North of Minas Gerais is based almost that exclusively on two cultivars, 'Grande Naine' and 'Prata-Ana' of which more than 60% of the area is cultivated under irrigation. With the entrance of the black Sigatoka in the country and the imminent arrival of the pathogen in this region, besides the economical damages caused by Yellow Sigatoka and Fusarium wilt, studies on the release of genotypes resistant to pathogens of large impact on the banana crop it has been intensified. This work was carried out in order to study behavior of 'Prata-Ana', 'Grande Naine', 'Princesa', BRS Platina and FHIA-18 genotypes under five irrigation levels (25%, 50%, 75%, 100% and 125% of the reference evapotranspirationET.), in their first cycle in the North of Minas Gerais. The used design was in randomized blocks in split-plot scheme with three repetitions. In the parcels they were at random the irrigation depths, and in the sub parcels, the genotypes, totaling 75 sub parcels. In each sub parcel there were 20 plants, of which only the six central plants were useful. The trickle irrigation was used by means of micro sprinklers, with application intensity of 2.10 mm h 1. The vegetative characteristics of the plants, productive aspects (qualitative and quantitative), cycles (vegetative, productive and total) and use efficient of commercial water (Commercial UEA) were evaluated. In the evaluation of the vegetative characteristics of the genotypes it was used other variation factor, the time (149, 171, 192, 220, 240, 260, 290, 310 e 338 days after the transplanting - DAT). There was no significant effect of the triple interaction for any studied variable (plant height, pseudostem perimeter, number of leaves and leaf area). The irrigation depth of 125% of ET, provides greater values for all the studied variables, being the maximum growth observed in the last biometric evaluation accomplished, with 338 DAT. 'Princesa' and 'FHIA-18' present the highest plant heights, while 'Prata-Ana' and 'Grande Naine', the lowest ones. The production is larger in all the genotypes for the irrigation depth corresponding to 125% of ET, however the commercial UEA presents inverse behavior, with greater results in the irrigation depth of 25% of ET°. 'Grande Naine' shows the greatest production and commercial UEA, and 'FHIA-18', amongst the genotypes type Prata, presents the greatest production and commercial UEA.