Resumen

RUIZ, C; RUSSIAN, T  y  TUA, D. Irrigation moment and calcium nitrate effect on tomato (Lycopersicom esculentum L.) plants. Rev. Fac. Agron. [online]. 2008, vol.25, n.3, pp.421-439. ISSN 0378-7818.

The effect of irrigation moment and calcium applying on growing and the first harvest of tomato cv. Rio Grande plants was studied. Irrigation by furrows was used and nitrate of calcium (240 kg.ha^-1) was used as a calcium source. Treatments were morning irrigation + Ca (MICa); afternoon irrigation + Ca (AICa); irrigation in the morning without Ca (MIWCa) and afternoon irrigation without Ca (AIWCa). A plot design divided with two factors, two levels and three replicates was used. The variables were evaluated to the 40 and 60 days after the treatment applied (DATA). Plant eight (PH), primary branches number (PBN), of floral clusters (FCN), of flowers (FN), of blossom-end rot fruits (BERF) and healthy (HF), fresh weight (FW) and dry weight (DW) of leaf were evaluated. N except for the treatment MICa, to the 40 DATA were found in enough levels and it was deficient to the 60 DATA; P and Mg were enough, K was low, Ca was found high and the microelements were found in enough levels. The larger PH, to the 40 DATA, corresponded to the IA and the Ca, in the same way to the 60 DATA to WCa. In the variable PBN, FCN and FN, statistical differences were not found. The larger number of FN corresponded to the treatments IMCa and IAWCa and the higher average of BERF to the AIWCa and AIWCa. Differences were not found for the variables FW and DW.

Palabras clave : Blossom-end rot; tomato; calcium; irrigation.