Physiological Effect of New FA Antitranspirant Application on Maize

The field trial was conducted to study physiological effect of new FA antitranspirant on maize. The new FA antitranspirant was sprayed at 10 d pre-tasseling, ear filling stage and 10 d pre-tasseling + ear filling stage, with the concentrations of 0, 0.5, 1.0, 1.5 and 2.0 ml L-1. The results indicated that the application of new FA antitranspirant increased nitrate reductase activity(NRA), free proline content, chlorophyll content and water content of leaf, thus drought stress can be mitigated. The new FA antitranspirant increased photosynthesis rate and reduced transpiration rate, stimulated growth and reduced water loss. 10 d pre-tasseling + ear filling stage application had a cumulative effect on the indices compared with 10 d pre-tasseling and ear filling stage, except for NRA. The new FA antitranspirant caused an increase of grain yield by 5.37 to 29. 58% with different treatments. The optimal concentration is 1. 5 ml L-1, i. e. 75 g new FA antitranspirant dissolved in 50 kg water, and the optimal apply period is 10 d pre-tasseling + ear filling stage.

Physiological Effect of New FA Antitranspirant Application on Winter Wheat at Ear Filling Stage

The physiological effect of new FA antitranspirant on winter wheat was studied by field trial. The new FA antitranspirant was sprayed at ear filling stage, using the following concentrations： 0.5, 1.0, 1.5 and 2.0 mL L^-1. The results indicated that new FA antitranspirant increased nitrate reductase activity （NRA）, free proline content, chlorophyll content and water content of leaf, thus drought stress can be mitigated. The new FA antitranspirant increased photosynthesis, enlarged stomatal conductance and reduced transpiration rate, thus led to growth stimulation and water loss reduction. New FA antitranspirant caused an increase of grain yield by 7.2%, under the optimal concentration 1.5 mL L^-1.

Effect of a new antitranspirant on the physiology and water use efficiency of soybean under different irrigation rates in an arid region

Antitranspirants are exogenous substances applied to leaves to reduce luxury transpiration by regulating stomatal conductance to increase water use efficiency(WUE). A cheap and environmentally-friendly antitranspirant, FZ, was newly developed, extracted mainly from Alhagi sparsifolia. Its effects on soybean water use were investigated in a field experiment using the locally-used irrigation rate and a low irrigation rate(The lower and upper limit of irrigation is 40%–70% of field capacity). Foliar application of FZ and measurement of leaf physiological characteristics, final biomass, seed yield and water use efficiency were carried out during the pod bearing and pod filling stages of drip-irrigated soybean with film-mulching. Under the low irrigation rate, leaf stomatal conductance(gs) and transpiration rate(Tr)decreased significantly by 7 d after spraying, but photosynthesis(Pn) and instantaneous water use efficiency(WUE_(in)) were not significantly affec ted. The stomatal frequency, stomatal aperture, gs, Tr and Pn decreased by 1 d after spraying, without significantly increasing WUE_(in).However, applying FZ during the pod bearing and pod filling stages did not significantly affect the final biomass,water consumption, seed yield and WUE of soybean.Under the locally-used irrigation rate, applying FZ increased the activities of superoxide dismutase and peroxidase in the leaves by 38% and 33%, respectively,but did not significantly affect gs, Tr, Pn, stomatal aperture and stomatal frequency. Applying FZ three times during pod bearing and pod filling stages enhanced seed yield and WUE by 24% and 21%, respectively, but did not significantly affect the final biomass and water consumption. Therefore, seed yield and WUE of soybean were significantly increased by foliar application of FZ during the pod bearing and pod filling stages under the locally-used irrigation rate in arid region, but applying FZ did not have a positive effect on water use efficiency of soybean under a low irrigation rate.