Comportamento de cultivares de algodoeiro submetidos aos preparos de solo com grade pesada e com escarificador e avaliação de leguminosas e gramíneas visando à integração lavoura-pecuária no Vale do Iuiu, Região Sudoeste da Bahia

Abstract

n the context of a revitalization program of the cotton culture in Southwest Bahia, where the objective was to evaluate the behavior of four kinds of cotton tree (BRS 201, BRS Aroeira, BRS Cedro and Delta OPAL) in a HAPLIC CAMBSOIL submitted to two different kinds of soil tillage the conventional (disc harrow followed by disk plow ), and the summarized (chisel plow followed by de disk plow) in order to identify the most suitable management to the soil of Iuiu Valley. Simultaneously, was intended to evaluate the biotic circle of some species of beans and grass - sorgo forrageiro (Sorgum vulgare AG 250 1C), Sorgo silageiro (Sorgum vulgare volumax), capim pé-de galinha (Eleusine coracana), Guandu (Cajanus cajan), alfafa mineirão (Stylosanthes guyanensis) e feijão-de-porco (Canavalia ensiformes) - to identify those which would adapt better to the region providing the most efficient soil covering and the larger biomass production foreseeing the integration cow farming-agriculture. The experiments were installed in the district of Palmas de Monte Alto, Bahia, 448 m altitude, 14º 15’ 42” South latitude and 43º 21’ 26” West Greenwich, being the cotton one with randomization was made in randomized blocks, with 8 treatments (two soil management and four varieties of tree) and four repetitions. The beans and grass one, totally randomly lined, with six types of treatment and three repetitions. With the cotton experiment we got the following conclusions: in the conventionally tillaged area there was a significant difference in the yields of cotton with seed between the varieties BRS 201 and BRS Cedro (2 137 and 1 154 kg ha-1, respectively); there was no significant difference between the yield of cotton with seed and in fiber in the varieties Delta OPAL and BRS Cedro (895 and 675kg ha-1, respectively); there was no significant difference between the yield of cotton with seed and in fiber in the chiseling area; comparing the soil tillage one to anothers it was verified that the yield of cotton with seed and in fiber, the number of boll, the percentage of fibers and mass of a boll had no statistical difference by the Duncan test at 5% probability; Although there was no significant difference, the varieties which were more affected by the kinds of soil tillage were BRS Aroeira and BRS Cedro for, in relation to the conventionally till area, the yields of cotton with seed in the chiseling area was increased 12 % and 16%, respectively. The varieties appear in the following decreasing yield order (kg ha-1) of cotton with seed: In the conventional tillage area: BRS 201 (2 137), Delta OPAL (2 092), BRS Aroeira (1 773), BRS Cedro (1 547), and the chiseling one: BRS 201 (2 116), Delta OPAL (2 005), BRS Aroeira (1 990), BRS Cedro (1 789); the decreasing yield (kg ha-1) order of fiber was as follows: In the conventional tillage area: Delta OPAL (895), BRS 201 (826), BRS Aroeira (698), BRS Cedro (675), and the chiseling one: Delta OPAL (858), BRS 201 (816), BRS Cedro (815), BRS Aroeira (762). About the experiment of bean and grass, was verified that the sorgo silageiro and the feijão-de-porco and the guandu were the species that reached the full blooming earlier, on the other hand, the alfafa mineirão and the capim pé-de-galinha did later; the feijão-de-porco and the guandu were the species which propitiated the full soil covering in the shortest and longest period of time, in that order. The species assessed appear in the following decreasing order of initial growing time: sorgo silageiro, sorgo forrageiro, guandu, feijão-de-porco, capim pé-de-galinha, alfafa mineirão; the decreasing order of the value and height of the plants/length of stalk at the last evaluation was as follows: grass: sorgo silageiro (167,7 cm ), sorgo forrageiro (92,8 cm) and capim pé-de-galinha (54,8 cm); beans guandu (90,4 cm), feijão-de-porco (77,8 cm) and alfafa mineirão (55,4 cm); the decreasing order of dry mass production of the upper part ((kg ha-1) was as follows: sorgo forrageiro (16 140), sorgo silageiro (14 150) guandu (12 270), feijão-de-porco (6 300), alfafa mineirão (5 750), capim pé-de-galinha (5 220).