Abstract:
During the 2005/2006 campaign, a trial was conducted at the Experimental station of Lipembe in the District of Morrumbala to assess the effect of intercropping in cotton band (Gossypium hirsutum L.) and pigeon pea (cajanos cajan.) On attack intensity pests and the yield of intercropped crops. For this purpose, a plot of plots subdivided into a strip (Strip Split Plot) was obeyed, with two factors (type of cultivation and method of application), in which the main plot (type of cultivation) presented 2 levels, being a combination in strip and pure cultivation and the sub-plot (application method) also with 2 levels namely treatment based on the Economic Threshold and based on the Calendar. A total of 5 treatments were tested, of which 2 pure cotton crops, one treated based on the economic threshold and the other based on the calendar, 2 intercropping cultures in cotton band and pigeon peas treated also one based on the economic threshold and the other with based on the calendar and finally the pure cultivation of pigeonpea without chemical application. The most prominent pests observed were aphids and American caterpillar in the case of cotton and jassids in the case of beans. Statistically the type of cultivation as well as the method of application had a significant effect on the percentage of aphid infestation, average density of eggs and American caterpillar and on the yield of seed cotton. The combined cultivation in the strip showed higher average yield of seed cotton (645.5 Kg / ha) compared to pure cultivation (494.5 Kg / ha) and the Land Equivalence Index (RSI) was also higher in the intercropping treated based on the economic threshold (1.67) in relation to pooling treated on the basis of the calendar (1.64). In terms of net returns, strip crops showed better returns (2,854.00 Mt and 2,732.00 Mt, LE and Cal, respectively) compared to pure crops (1,566.00 Mt and 1,008.00 Mt, LE and Cal, respectively) and treatments based on the economic threshold (1,566.00 Mt and 2,854.00 Mt, pure and strip, respectively) in relation to treatments based on the calendar (1,008.00 Mt and 2,732.00 Mt, pure and strip, respectively ). From the results of the study, it can be concluded that strip cultivation treated based on the economic threshold presents better advantages compared to pure traditional cultivation treated based on the calendar. These advantages are in terms of the incidence of pests, better yields and net returns coupled with the ecological advantages that associated cultivation offers. (TRADUÇÃO NOSSA)
