Agriculture Reference
In-Depth Information
ployed 2.5 L of organic compost (pH=6.4; C=29.6%; N=1.6%; P
2
O
5
=1.8;
K
2
O=0.17% and U=25.3%) plus 130 g of single superphosphate/pit; ad-
ditionally, 2.5 L of organic compost, 60 g of single superphosphate, and 60
g of dolomitic lime/pit were applied as sidedressing; plants were sprayed
twice a week with biofertilizer (Bettiol et al., 1997), at concentrations of 5
or 10%. In the conventional system, fertilization consisted of 200 g 4-14-8
(NPK)/pit and, after planting, a sidedressing application of 30 g N, 33 g K
and 10.5 g P/pit; 52 days after planting and beyond, plants were sprayed
once a week with foliar fertilizer [5-8-0,5 (NCaB)] at a rate of 3 mL L
-1
.
In the conventional system, 0.15g/pit of active ingredient of the in-
secticide carbofuram were applied before planting. According to the pro-
cedures utilized by conventional local growers, a blend of insecticides,
fungicides and miticides was sprayed twice a week, after planting. Active
ingredients of fungicides sprayed during the crop cycle were metalaxyl,
mancozeb, chlorothalonil, copper oxychloride, kasugamycine, cuprous
oxide, methyl thyophanate, iprodione, benomyl, cymoxamil, maneb and
monohydrate zinc sulphate, at the rates recommended by the manufactur-
ers. Insecticides used were deltamethrin, permethrin, methomyl, methami-
dophos, acephate, avermectin and cartap, also at the recommended rates.
Extracts of black pepper,
Eucalyptus
, garlic and fern; Bordeaux mix-
ture, and biofertilizer were applied twice a week (Bettiol et al., 1997;
Abreu Junior, 1998) to control diseases and pests in the organic system.
These applications were performed according to the program adopted by
organic producers in the region.
Weed control was carried out by mechanical weeding and with the her-
bicide glyphosate (directed spray) on post-planting in the conventional
system, and with mechanical weeding in the organic system.
After harvesting the tomato the area was planted with 'BR 201' corn;
sowing occurred 178 days after planting the tomatoes. The organic system
plots received an application of 4 m
3
of organic compost and single super-
phosphate at the rate of 20 g per meter; in addition, the biofertilizer was
sprayed at 10% as sidedressing. In the conventional system fertilization
consisted of 500 kg ha
-1
of the 4-14-8 NPK rate applied pre-planting and
15 g m
-1
urea as sidedressing. Weed control used the herbicide paraquat
(directed spray) in the conventional system, and mechanical weeding was
used in the organic.
