Yield response of two tomato cultivars to microirrigation and antitranspirant rates on a sandy soil

Two tomato (Lycopersicon esculentum Mill.) cultivars, 'Agriset 761' and 'Equinox', were grown in spring (Feb-Jun) and fall (Sep-Dec) 1996 with two microirrigation rates [0.8x (HI) and 0.5x (LO) of the daily open pan evaporation (PE)I and sprayed either weekly or bi-weekly with Anti-Stress 200 (acrylic polymer) antitranspirant at 4.68 L ha(-1) per application during the first 10 wk of the season. As the season progressed, tomato plants were taller (P less than or equal to 0.05) with LO than with HI irrigation. Early (first harvest) yields of extra-large and total marketable fruits were higher with the HI than with the LO irrigation rate in the spring. However, in both spring and fall, seasonal total yields tended to be higher with the LO than with the HI irrigation rate. Fruit yields were similar with antitranspirant sprays or with a water control. In both seasons 'Equinox' yields were higher in the early harvests man 'Agriset 761' yields, but seasonal total yields of 'Agriset 761' were higher than seasonal total yields of 'Equinox'. Residual soil concentrations of N0(3)-N and K were higher (P less than or equal to 0.05) with the LO than with the HI irrigation rate.