SILVA, S. M. S.; http://lattes.cnpq.br/0654495217313534; SILVA, S. M. S.; SILVA, Sérvulo Mercier Siqueira e.
Résumé:
The cultivation of castor plants in the Northeast of Brazil stands as alternative for
creatin of employment and income in the family agriculture. The objective of the
present study was to verify the effects of different water depths and populations of
castor plants (Ricinus communis L.) cv. BRS ENERGIA, from germination to
production. Two experiments were carried out in Experimental Farm Embrapa Algodao,
located in the district o f Barbalha-CE, in randomized block design with plots in strips.
In Experiment I sixteen treatments resulting from the factorial combination of four
water depths (294.22; 382.50; 479.75 and 679.75 mm) and four populations of plants
35,460 plants ha"1 (0.60 m x 0.47 m), 39,682 plants ha"1 (0.60 m x 0.42 m), 45,045
plants ha"1 (0.60 m x 0.37 m) and 52,083 plants ha"1 (0.60 m x 0.32 m) in four
repetitions. Were used the Experiment I I conducted is same design as of Experiment I
and the same number of treatments and the factorial combination of four irrigation
depths (311.74; 460.40; 668.53 and 850.54 mm), and four population of plants 27,777
plants ha"1 (0.60 m x 0.60 m), 33,333 plants ha"1 (0.60 m x 0.50 m), 41,666 plants ha"1
(0.60 m x 0.40 m) and 55,555 plants ha"1 (0.60 m x 0.30 m) with four repetitions. The
irrigation method used was by aspersion, where the water depths were in accordance
with line source sprinkler irrigation in relation to the irrigated strips. Oh the base of
results of the study, it was verified that irrigating with a water depths of 668,53 mm the
maximum response to plant height (111,43 cm); leaf area (8.111,78 cm2); rate of
absolute growth of plant height (1,94 cm day"1); leaf area index (3,25 m2 m"2) and
productivity (2.678,38 kg plant"1) was obtained. The values for these variables were on
average 8% superior in comparison to those obtained with of the irrigation water depths
460.40 mm, which is recommended, considering the edaphclimatics characteristics of
Microregion of Cariri in the State of Ceara/Brazil, due the economy of the 208,00 mm
of the water depths in the crop cycle. In relation to the population o f plants the best
results for the growth variables and development were obtained with the population of
27,777 plants ha"1 (0.60m x 0.60m), with 2,282.74 kg ha"1 productivity.